The Web of Life

Root Partners, Mycorrhizae

2012-01-09T13:52:00.000-08:00

The remarkable partnership between plant roots and fungi called mycorrhizae is worht studying. A mushroom is a lot more than a mere addition to the forest floor. Learn more about mycorrhizae

Land of the Jaguar

2011-11-06T09:07:00.000-08:00

Enter a Google search at your own risk. You may emerge from it hours later, bleary eyed and stiff jointed, when your body demands food and a bathroom break.
I had this experience recently while doing a translation from Spanish to English about the jaguar in Argentina. There are between 200 and 300 of these magnificent animals left in this country and the numbers keep dwindling. A few very dedicated lovers of the jaguar are doing their best to save it from extinction in Argentina. They call themselves "Red Yaguarete" (Jaguar Network). As part of their efforts they raise public awareness through publications so I help them periodically with translations to English.
Recently, they focused their interest on a large ranch in northern Argentina and the possibility of turning it into a national park. The group is trying to convince the government and the public of the benefits of such action. The ranch "Estancia La Fidelidad" is a large property. At 618,000 acres it is similar in size to The Great Smoky Mountains National Park (521,000 acres) and the Petrified Forest National Park (93,500 acres) combined. Located in the Dry Chaco in northern Argentina, it is crossed through the middle by the Bermejo River, one of the larger rivers of the area. Dry Chaco is a harsh land, hot and dry, with low human population and still relatively rich wildlife. A few rivers carrying water from the eternal snows of the Andes Mountains cross the region. The land is so flat that they spread widely in some areas creating wetlands rich in wildlife. It is in these places that the jaguar finds abundant prey and prospers.
Recently, as part of their efforts, "Red Yaguarete" surveyed the native flora and fauna of the ranch by jeep and by canoe, subsidized by their own funds. This is the report I am translating.
Google proved extremely useful. Through searches I learned that the "carpintero de los cardones" is called "White-fronted Woodpecker" and that the "oso hormiguero bandera" is the "giant anteater". But then, I wanted to know more about the reasons why this large ranch had become available. What had happened to the owners? Google obliged by giving me more than 62,000 entries, practically all of them in Spanish, for "Estancia La Fidelidad" including maps and videos.
A recent newspaper article caught my attention. The owner of the property and his widowed sister-in-law, who lived with him, were brutally assassinated last January by unknown people. Manuel Roseo was an older Italian immigrant, who lived in a very modest residence, although his huge property was valued at 200 million dollars. In the months preceding his death he discovered that somebody was using false papers and selling some of his land. He started investigating this matter and it is possible that this led to his murder. The story has all the makings of a mystery novel. It would be incomplete without some illegitimate children who could claim the inheritance. Not surprisingly there is a woman who says that her teenage daughter and eight year old son are Roseo's children.
So many questions! How did a poor Italian immigrant come to own this valuable land? Why did he continue to live like a day laborer? What was his relationship with his sister-in-law? What about the other woman and the possible heirs? And, who was selling his property behind his back? By adding the word "asesinato" (assassination) I could locate more than a thousand entries about the subject; not that they provided any clear answers to the mystery. I had to stop.
The next day I resumed my translation. Soon I needed to search another word in Google. This time my quest led me to a book published in the 1850s, an early survey of the Argentinean and Paraguayan Chaco, including descriptions of the land, flora and fauna and the peoples of that time. Thomas Jefferson Page, grandson of the American president was a ship captain commissioned by the United States to do a survey of the land north of La Plata River. He traveled the main rivers up north, all the way to Paraguay in his ship the "Water Witch" during the years 1853 to 1856 making maps and taking detailed notes, including some diplomatic activities along the way. The entire text of his book is available as an e-book and quite enjoyable and easy to read.
Thomas J. Page described some of the plants and animals and the lay of the land of a large part of the Dry Chaco. All this was useful for my purposes. It also covered many other matters, which I couldn't stop reading. He befriended the Argentinean president, general Urquiza, and gave him a ride up the La Plata River in his ship.
He attended a dance of the little angel ("Fiesta del angelito"). This is a peculiar tradition of several South American countries. When a child dies, the little body is dressed in the finest clothing and sat on a small chair, high in an altar decorated with candles and flowers. The parents and guests dance merrily all night and may even lend the little angel to other friends and relatives for subsequent celebrations until decay puts an end to this. The thinking is that heaven rejoices at the arrival of such a pure soul and that the family should be grateful that the baby went straight to heaven without enduring the trials and tribulations that the rest of us cannot escape. Needless to say, Google provided abundant entries to the search "Fiesta del angelito" that could take hours to read.
Thomas J. Page went so far north that his ship entered a region where the national borders had not been settled yet and Paraguay considered as part of their country. He was taken prisoner and released few days later; his maps were confiscated.
It was time to put this reading aside and to get back to my translation. One final tidbit, though: Thomas Jefferson Page went back home to Virginia; soon the Civil War broke up and he joined the Confederate navy. I had so many questions: Did he own slaves? Did he pass his genes to some of them the way his grandfather did? What did he think of Argentina, where slavery had been abolished the year of his arrival and where mixed race marriages were not uncommon?
More Google searches were in order. But, I really had to go now.

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Utilities right of way. Native plants

2011-08-14T09:41:00.001-07:00

Horsham Trail. Utilities right of way. Too much lawn, perhaps

Why don’t we turn all the utilities right of ways into oases for wildlife? Am I a dreamer? I hope not. Near my home there is a several miles long trail that runs under high voltage wires. When I walk there I see joggers and bikers, mothers pushing baby carriages and I see walkers, just like me. The surroundings are pleasant, just a tad artificial, not quite a nature area; although closer to a nature area than busy noisy streets.

A corn field next to the utilities right of way Horsham Trail

How much work and investment would it take to turn such areas into natural or semi natural ecosystems? Perhaps, with careful planning, they would be easier and cheaper to maintain if they were allowed to become more natural.

Restored native grasses at Pennypack Restoration Trust. An example of what could be done in other places

For instance, most of the lawns near the trail could be turned into wildflower meadows. The lawn closer to the trails could be allowed to support many broad leaved plants; accepting them as grass companions rather than seeing them as weeds. It would be helpful to replace the non-native trees already planted with native ones, which are considerably better at supporting wildlife.

"Unkempt" lawn with wildflowers which attract butterflies. Horsham trail

Some of these measures may be expensive at first but, ultimately, they would save money and upkeep time because native vegetation has evolved in that particular kind of soil and climate and is best suited for it. It also has co-evolved with the other members of the community. It supports more wildlife, including butterflies and birds, which add beauty in addition to contributing to the balance of nature. All and all it is a win-win situation.

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Invasive species

2011-08-14T09:40:00.001-07:00

I do not hate invasive species

This is my opinion about introduced species that become invasive. The species themselves are fine; what is problematic is our intentional and unintentional carrying plants and other organisms to other lands. This has given rise to an incredible large number of transplanted species that continue to alter ecosystems beyond anything that we could have imagined.

Wildlife food and non-native plants

2011-07-24T15:09:00.000-07:00

Queen Anne's lace and many visitors. What is it replacing?

I worry sometimes when people insist on seeing the merits of some introduced plant and claim that it is good for wildlife. We are all familiar with butterfly bush attracting butterflies and with the berries and rose hips of several alien plants which feed the birds. I have also seen Queen Anne’s lace blossoms covered with flower visitors. Another example is this blog article about English ivy and pollinators: Pollinators aplenty: English Ivy mixed blessings. The author tells us that the English ivy in his property is attracting numerous pollinators at a time when there aren’t any native flowers. He suggests that we “should step back and view non-natives with less disdain until we understand better what roles they now play in their adopted habitats.”

I think that this philosophy shows a lack of understanding of ecosystems and of what is missing in those that have been altered by humans. We tend to think that habitat loss is something far away, clear-cutting in the Amazon, for instance. We seem to forget that the urbanization and suburbanization of the areas where most of us live are representatives of a huge amount of habitat loss.

When pollinators and birds resort to non-native flowers and berries, it is because the habitat has been severely disturbed and the native plants that were supposed to sustain them are lacking. A healthy habitat is an assemblage of co-evolved and synchronized plants and the wildlife that feed on them. The absence of such plants is a very sad indication that the ecosystem has been dramatically disrupted.

Calling non-native plants beneficial to wildlife is ludicrous. They are merely acting as prosthesis. If I had a leg amputated, I too would sing the praises of a high quality prosthesis, no matter how alien to my body it was. But, I would prefer my own, native and co-evolved with my body, original leg.

Butterfly bush. It provides nectar to butterflies but very little else, unlike many native plants

Let us not be seduced by the fact that some introduced plants are used by wildlife. Normally, the natives do that job a lot better, plus they provide countless other services to the ecosystem. We are barely beginning to understand the very complex interactions between all the members of a living community. It is becoming apparent that most of them are missing when we mix organisms from all sorts of places.

More on the subject: I do not hate invasive species

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Viburnum leaf beetle, an introduced pest

2011-07-19T18:49:00.000-07:00

The viburnum leaf beetle was introduced accidentally along with non-native ornamental viburnums from Europe and Asia. It took perhaps a hundred years for it to become settled and to start multiplying in noticeable numbers. By then it had found out that native viburnums, such as arrowwood, were good to eat and lacked defenses against them. The consequences were, perhaps, unavoidable; the beetle is spreading across North America ravaging native viburnums.

Adult viburnum leaf beetles

Read the whole article:
Viburnum under siege
Viburnum under siege. Part 2

Leaf damage caused by the larvae on arrowwood viburnum

Larva and leaf damage

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Ladybugs, good and not so good

2011-07-12T15:05:00.000-07:00

Polished ladybug, a native one

We all love ladybugs. Some children’s books tell charming little stories about them. Even schoolchildren know that ladybugs eat bad insects. Five states, Delaware, Massachusetts, New Hampshire, Ohio and Tennessee, have chosen these handsome little beetles as their official state insects. Most ladybugs or ladybeetles deserve our esteem. They eat countless numbers of insects that damage our plants, so we are grateful.

Beetles, just like butterflies, go through a complicated life cycle. When they are growing up they look completely different from the cute little round buttons we are most familiar with. They start as larvae or, if you prefer, as grubs. Ladybug larvae are so ugly that you would want to squash them in disgust if you found them on your plants. Please, don’t! Remember that they clean up your garden from pests.

How can I describe them? They look like tiny alligators, longish, usually dark and with six stumpy little legs. They grow bigger and eventually, they curl up, become rounder, go to sleep and emerge from this stage as shiny new ladybugs. Both adults and larvae devour aphids or other little bugs with gusto.

What could be bad about ladybugs, or about some of them? It turns out that not all are worthy of our unconditional applause. Some have been brought to this country or to Europe, with the best of intentions, to fight unwanted pests. While they are quite good at this job, sometimes they wear out their welcome.

The first ladybug introduced in North America was the “vedalia” beetle. It was brought from Australia to combat the cottony cushion scale, a nasty insect that was decimating orange groves in California by sucking the plants vital juices. It was a stunning success; the beetle brought the pest under control to the great relief of citrus growers. This species of ladybeetle specializes on cottony cushion scale, which in turn specializes only on plants of the citrus family. So it never became a problem by not going beyond its boundaries. This is not the case with many other introduced insects.

Asian ladybeetle

After such success several other imported ladybugs joined the ranks of pest fighters. The most common and better know is the Asian ladybeetle or multicolored ladybug. It has spread so widely throughout North America that it is the ladybug you are most likely to see nowadays. It is not a picky eater, so its diet includes many kinds of aphids as well as other small soft bodied insects.

Infestation of Asian ladybugs in winter

And this is part of the problem; it is quite capable of eating other ladybugs or to out-compete them by its proficiency. As a result it may be driving some native ladybugs toward extinction. It also can become a nuisance to us because of its inclination to search for warm, comfortable places to spend the winter.

Convergent ladybeetle, a native one

It often finds them in garages, outbuildings or even our homes. Entire hordes of shelter seeking multicolored ladybeetles may invade our residences much to our annoyance. It seems that the crowds keep getting bigger each year.

Spotted ladybug, a native one

We still can’t appreciate the impact of this ladybug on some of the native species and on the ecosystems. But it doesn’t sound good. We continue to observe the development of events rather helplessly. In Europe the multicolored Asian ladybug has been declared a pest. It is too late for that here.

See:
Ladybugs
Asian ladybeetle
Good bugs gone bad

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“Locavore” birds. Grow your own birdseed

2011-05-22T19:02:00.001-07:00

Are we being a bit unrealistic about this business of buying bird seed? I don’t quite understand all this farmland devoted to growing bird seed. I assume that the farmer has to prevent birds from ruining his crop. So, all and all, I don’t think that we are truly helping the birds this way. Instead, we are bringing them to our yard for our own selfish pleasure and depriving them of habitat somewhere else.
If we really wanted to feed birds in our backyards we should grow our own birdseed, rather than buying it from other sources.
I know that bird seed has become a big business in recent years. It was a very good idea at the beginning and feeding the birds continues to be an educational tool that helps people appreciate wildlife. But perhaps it has gone too far. What we really need right now is to start growing plants beneficial to birds in our own backyards: the ultimate in “eating locally”.

I began to ask myself these questions and soon realized that I am not the first one. I simply googled “grow bird seed” and found out people who grow gardens from bird seed. I also found those who despair because spilled seed keeps growing where it isn’t wanted. They seem to miss the irony on feeding the birds and fighting against growing bird seed. “Buy only shelled seed”, “nuke it in the microwave oven” they say.
Fortunately the ones that choose to grow bird seed have a lot of good advice, from discussing the benefits of growing only native seeds to the money saving aspects of such gardening. I am sure that a little planning would be very helpful. Not all the bird seed that you buy will grow in your area and not all would look pretty in your garden, but there are some that can really enhance the beauty of your garden, plus being beneficial to pollinators as well as birds.

Yes, let us grow our own bird seed! Let our visiting birds become locavores!

Feed the birds with native plants

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A river of birds

2011-05-22T17:34:00.000-07:00

I keep an old National Geographic map posted on my wall. It is a map of the Americas with the flyways of migratory birds, long undulating arrows, some stretching from Canada and Alaska all the way to the southern tip of South America.

I was stunned the first time I saw that map and became instantly a bird watcher. I wanted to know more about this amazing phenomenon. Every autumn, these tiny feathered creatures develop the urge to move south. Some are veterans that have done the journey several times before; others are novices, with no knowledge of where they are going.

They know nothing beyond the nest where they were born just a couple of months before and the piece of land surrounding that nest. Now they are taken by this uncontrollable need to move. Are they following their parents or some ancestral instinct imprinted in their genetic material? In either case, they are inexorably pushed forward grueling hour after grueling hour, day after day. Most fly by night and choose higher altitudes to avoid being cooked alive by the heat of exertion and, perhaps, to escape predators.

So, they fly over meadows and forests, valleys and mountains and, most remarkably, over open ocean. An early Spanish explorer sailing through the Caribbean described a river of birds passing overhead.

Many know that they have arrived when they see the verdant forests of the Amazon and settle there for a few months, until the urge to move again brings them back to northern latitudes. Others keep going, on and on, five thousand miles and more, all the way to the Argentinean Pampas and to Patagonia. Only then they rest.

The roster of these long distance travelers is impressive. Starting with the most famous one, the peregrine falcon, the list goes on to smaller fliers: plovers, sandpipers, gulls, swallows, even a nighthawk and the tiny red eyed vireo. They all leave Canada and the United States in the late summer or fall, cross the equator and reach the Pampas at the start of the southern summer. There, they rest and wait until it is time again to start moving north in their quest to raise a family.

What captured my imagination the first time I saw that National Geographic map was the realization that the same bird I saw here in Pennsylvania in the summer may be arriving a couple of months later at my home town in Cordoba, Argentina. I told my family: If you see a bobolink, a swallow or a sandpiper, say hello to them. They are carrying my greetings from here.

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In praise of bare spots in the garden

2011-05-06T17:20:00.000-07:00

Eastern tailed blue butterfly on clover

Some gardeners consider any exposed earth as a blemish in need of a cure, be it mulching or reseeding the lawn and watering. But in a well balanced ecosystem even bare spots have a place, and a very important one at that.
How so? Because they provide habitat and housing for an array of unappreciated garden helpers. We should know more about them. The list is long, so I will not try to cover them all, just illustrate a few interesting ones.

Butterflies. We all love butterflies and associate them with flowers and nectar drinking, but the fact is that after they fill up their tummies with nectar; they still need other nutrients, salts. One way of getting the needed salts is to take them from moist soil. It is not uncommon to see a group of butterflies, either all of the same species or several species amiable mixed together, basking in the sun while sticking their long tongues on the wet soil to extract some minerals or drinking some water. Many gardeners attract butterflies by providing flowers for nectaring and plants for feeding their young. It helps to go a step further and leave some bare ground.

Clustering of bee nests next to a parking lot

Bees. Bees are the most important pollinators, not just honey bees but the countless species of solitary bees. Most species of bees don’t make hives like honey bees. Instead they lead solitary lives, each one tending her own brood. Some nest in hollow twigs or similar holes, but the great majority nest in tunnels underground. Sometimes they cluster their nests near each other creating veritable towns; other times they take advantage of any small patch of bare soil and build their nests there. In general they prefer sunny and well drained spots.

Square headed wasp at her nest

Solitary wasps. Just like bees there are numerous species of solitary wasps that nest in the ground. Many wasps visit flowers for nectar and perform some pollination. But, perhaps more importantly, they hunt for insects to feed their young. A healthy population of solitary wasps would cut down the need for pesticides significantly. Solitary wasps, as well as solitary bees, are not likely to sting and even if they do so when molested their sting is very mild.

Tiger beetle stalking its prey

Tiger beetles. Another form of pest control is the very colorful metallic green tiger beetle. Tiger beetles belong to a group called ground beetles for obvious reasons. They spend most of the time on or in the ground. Tiger beetles are ferocious hunters of insects. If you provide them with some bare soil you can count on them for keeping pest populations down.

In summary, bare spots contribute to the balance of the garden ecosystem. They provide food or habitat for a number of garden helpers, namely pollinators and pest controls. When you consider all their benefits you wonder why we are so unwilling to tolerate them. Shouldn’t we look at them as an integral part of the garden? There are some gardeners that intentionally make some sand piles and make sure that no pesticides get to them.

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How much is a bat worth?

2011-04-22T17:47:00.000-07:00

Who would think of putting a dollar value on a bat? Well, it turns out that some researchers have done just that. I am not talking about a baseball bat but about that creature of the night so loathed by some. We tend to associate bats with witches and demons rather than with crops.

Is there a reason for putting an economic value on a bat? The answer is: Yes. Bats feed on flying insects at night. Many of those insects are pests that damage our valuable crops. So it turns out that bats are valuable to farmers.

A group of scientists have been trying to estimate the numbers of insects bats eat and the possible impact on agriculture and forestry if bats stopped supplying this pest control. They published their conclusions in the scientific journal, Science. Through a number of complex calculations of pesticide application and crop losses they came up with a range between $3.7 billion and $53 billion a year in the United States alone. It is not possible to be more precise when considering so many variables. Anyway the numbers are impressive.

It is worth mentioning that these maligned creatures have other functions in addition to the pest control discussed in this study. They are pollinators of many night blooming flowers. Cacti, in particular, are dependent on bats for pollination. Many cacti of the West synchronize their blooming time with the migration of some species of bats. Try to imagine what the West would be like without cacti. Another service, especially in the tropics is seed dispersal. Bats eat the fruits of many trees, such as fig trees and pass the seeds far from the mother trees.

Unfortunately, in recent times, bats are encountering serious problems. There is one disease in particular that is decimating the populations of bats in the United States. This fungal disease, called "white nose syndrome", weakens and kills large number of bats, especially during the winter. Not much is known about this illness, nor there is a cure in sight yet. It is for this reason that the researchers decided to investigate how the loss of bats would affect agriculture. Even lacking more accurate numbers the results are alarming; the losses to crops and forestry could be very serious.

The web of life is very intricate and often we don’t know enough about all the threads that make this tapestry. This is another example of a creature whose value we fail to recognize. It took a threat to the welfare of bats, such as the white nose syndrome for the world to stand up and take notice. We are only now beginning to appreciate the value of the free services provided by these creatures: pollination, seed dispersal and pest control. We have to look at bats with renewed respect. Let us develop a kinder attitude towards our friends, the bats.

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The sounds of nature

2011-03-14T06:01:00.000-07:00

I remember starry nights at our summer house in Argentina. We would lie on reclining chairs or directly on the grass, contemplate the stars and enjoy the sound-filled air, a harmony of tiny voices, not at all like the man-made cacophony of cities. Chirps and tweets and peeps and murmurs and trills and purrs and an occasional distant bark or snort created a richly embroidered tapestry of sounds. We spoke softly or not at all to better savor the views and sounds.

Many years later, my memory of those long gone peaceful nights was jogged by a lecture with the title: “The Great Animal Symphony”. The speaker, Dr. Bernie Krause, has been collecting recordings of the so called nature soundscapes; not just the voices of specific animals, but the intricately complex combination of sounds that characterizes each locale on Earth.

He explained that the members of an animal community talk to each other in distinctive voices to avoid confusion with the many other voices nearby. Thus, each one has been refining its special signature of pitch, spacing of sounds and timing.

The result is rich and full of subtlety, in sharp contrast with the jarring dissonances of cars, planes, lawnmowers and similar noise makers found near any human habitation nowadays. Dr. Krause, urged by the rapid loss of nature soundscapes, keeps traveling to remote areas to record the remaining sounds of nature before they are gone.

I wish I had paid more attention to the magical night music at our country house. I could have tried to identify some of the members of that finely tuned orchestra. It is possible that some are already lost because of planes flying overhead and trees being cut down.

I realize now that the members of that orchestra had been polishing and rehearsing their symphony for many thousands of years. Can they cope with the intrusion of alien sounds? Are we destroying in a matter of decades what took eons to develop?

Dr. Bernie Krause: The Great Animal Orchestra

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Squirrels, managers of the forest

2011-01-16T11:17:00.000-08:00

A squirrel approaches a mushroom growing under a pine tree. It sniffs it and breaks off a piece. It scrambles up the tree carrying its treasure, finds a comfortable branch to sit on and proceeds to eat the snack to the last crumb. Then it wipes its whiskers daintily, shakes its fur and scurries away to go wherever it is that squirrels go when they feel full and contented.

This vignette is more than a trivial episode; it is forest management at its best. It is a fine example of the intricate web of life of the forest. How so?

Let us unravel the links of this chain. The chunk of mushroom that the squirrel just snacked on contains numerous spores which will travel intact through the entire digestive system of the little fellow. The spores will come out at the other end, fall to the ground, some of them will germinate and eventually produce new mushrooms.

There is a fungus under that very same tree where the squirrel enjoyed its meal. You don’t see it because it is underground. It is made of a myriad thin threads spreading in all directions in the darkness of the moist soil. It intertwines again and again making tangles and becoming one big network. It seeks the rootlets of the tree; when it senses one it approaches it, penetrates it and proceeds to grow inside the rootlet. The tree fights this invasion at first, producing little knobs at the entry point, but it soon surrenders. The fungus hungrily absorbs nutrients from the root. And then a miraculous thing happens: this fungus gives as much as it receives. It is more efficient than the tree at collecting water and salts and it passes some of these much needed commodities to the plant. The fungus becomes an extension of the tree, reaching hidden pockets of soil that rootlets cannot access. Thus it is called a mycorrhiza, which means fungus-root.

Periodically, the mycorrhiza produces “fruits”, although the more appropriate word is “fruiting bodies” since they don’t carry seeds but spores. These fruiting bodies are mushrooms that sprout from the ground almost overnight and almost magically. A mushroom is like an apple and the whole “apple tree” is the fungus buried underground. This is the mushroom that the squirrel ate and whose spores the little animal will spread unwittingly and not very elegantly somewhere else.

So the green foliage above takes the sunshine and turns it into molecules of life, sugars and other nutrients, and sends them down to the roots. There they also nourish the fungus which, in return, supplies the tree with water and minerals taken from the soil. The squirrel, blissfully ignorant of its job as keeper of the forest, scampers away with a belly full of spores that will keep the fungus-tree partnership going for many years to come thus ensuring the survival of its own home, the entire forest.

Trees, truffles, and beasts: how forests function By Chris Maser, Andrew W. Claridge, James M. Trappe

The living constellations beneath our feet
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Feed the Birds

2010-12-15T06:19:00.000-08:00

Goldfinches at feeder

You think that you love birds. Every week you pick up your binoculars and go birdwatching with others who share your interest. You have one or two birdhouses in your properties and, of course, bird feeders that you can see from your window while you drink your morning coffee. Yes, you are very much a bird lover.

But what would you think if I told you that you are probably dooming some birds to death and starvation through your gardening practices? Let us say that you decide to buy a new tree for your yard, you love the color and shape of Japanese maples and that is what you choose. Later on, you take a look at azaleas and rhododendrons and find out that there are some Chinese cultivars which you find extremely attractive. You bypass the native varieties and choose one of those.

These innocent actions have deplorable consequences for the birds that visit your yard. Birds have no use for those foreign plants. Well, you say, “I have seen them use those branches for nests, what could be wrong with such plants?”

Until just a year ago I would have thought exactly the same. I didn’t know the bad consequences of using non-native plants as long as they weren’t invasive. But reading a book by Doug Tallamy (Bringing Nature Home) opened my eyes to a whole new perspective and a new appreciation of how food chains work, not just in nature preserves and remote parks but in our own backyards.

A nutritious caterpillar feeding on native wild ginger

Numerous insects are adapted to native plants and find your Japanese maple and alien azalea totally inedible. So what? Who needs insects, anyway? You say. –Birds need insects; that is who! Ask yourself: what do birds eat? Particularly, baby birds with their voracious appetites and fast growing bodies? They need lots of proteins; that is why their parents spend several hours a day hunting for insects, because insects are little packages of protein. If your plants are non-native there isn’t much insect protein to be found on them and the birds have to search somewhere else.

So to put it in a nutshell, each time that you plant an exotic tree or shrub you are dooming some baby bird to hunger and death. Or, if it makes you feel better, each time that you plant native plants you are helping the birds you love, perhaps even more than you do with your bird feeders.

A handsome looking native shrub, mountain laurel

Nature centers and wildflower preserves as well as some arboretums sell native plants and can provide information on them. You can also find these regional native plant lists useful: Pollinator Friendly Planting Guide. They are intended for pollinator gardens but they can apply to all wildlife.

For the area I am familiar with, the Atlantic seaboard:
Delaware Native Plants for Native Bees

And of course, the book mentioned above: Tallamy, Doug: Bringing Nature Home and the website: Bringing Nature Home

Caterpillars are for the birds

2010-08-07T13:37:00.000-07:00

Have you ever seen a caterpillar hanging from a thread when you were walking through the woods? You probably have, more than once; it happens often enough that, although caterpillars are very small and not easy to see, everybody sooner or later gets a chance to see this peculiar scene.
Did you ever wonder where it was going? Certainly not up, most likely down. But, down where and for what reason?
Many caterpillars feed high on the canopy, devouring tender leaves and growing very fast. After they are done growing they start getting ready for the big transformation, called metamorphosis, which will turn the rather shapeless, wormy thing into a winged marvel, a moth.

Where you find a caterpillar there may be hundreds or thousands, all of them gleefully feeding on the same tree. Look up at the tree’s foliage above your head; there doesn’t seem to be much damage and this is very fortunate. Part of the reason is that there are many hungry creatures who regard the caterpillars as very tasty and very nutritious morsels of food. Among them you can count some of your most beloved birds, warblers, wrens, sparrows. You see them fleeting about and they may be picking up some of your caterpillar’s brothers and sisters. They will be taking them to their growing brood and ramming them down their hungry throats.
Let us get back to our question: where is the caterpillar going? It may be looking for a secluded place in the leaf litter, safe from winged predators (although not entirely safe for there are other hungry creatures in the soil too). Once on the ground it probably won’t go very far. In most cases it tries to find some leaf litter and it proceeds to bury itself in it. There it will begin spinning a cocoon using a special kind of saliva that changes into silk, strong and supple, as soon as it gets in touch with air.

It may proceed to undergo a big transformation in just one or two weeks to become an adult moth, or if it is the end of the season, it will wait until next year; hunkering down through a long and cold winter and will emerge only when the trees are already leafing out.

During that time it grows wings and legs and antennae and becomes a pretty moth ready to find a mate and to start the cycle all over again. If it is a female it will lay eggs after searching very diligently for the same kind of trees where it fed as a caterpillar.
Most caterpillars are very particular about their food; they can feed only on one kind of tree or perhaps a handful of related trees, for instance, only sugar maples or only several varieties of maples, but not oaks or ash trees. Others will choose only oaks or ash trees. They are so particular that many of the ornamental trees brought from overseas for their beautiful foliage or interesting shape are useless to them. The indirect consequence of a landscape with only imported plants is: no caterpillars - no food for the birds. If you love birds you may want to plant native trees to ensure that birds can find food hidden in their foliage.

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The living constellations beneath our feet

2010-04-06T13:47:00.000-07:00

“. . . There is some kind of electrochemical communication between the roots of the trees. Like the synapses between neurons. Each tree has ten to the fourth connections to the trees around it, and there are ten to the twelfth trees on Pandora”.

So, says Grace the scientist (Sigourney Weaver) in an effort to explain the near mystical interconnectedness of that fictional planet in the movie Avatar. Being a scientist she wouldn’t use the word “gazillion”, but that is how you can interpret those numbers, quantities so huge that they are hard to grasp.

Pandora isn’t the only planet where trees are interconnected; you need go no further than your own backyard. I am not just talking about those intangible connections between plants and their animal pollinators, and plants and their animal seed dispersers. And I am not speaking of the soil enriching organisms that fix nitrogen to the benefit of many plants. These and others are important links in the web of life; but, in addition to those, there are physical, intimate, direct connections between plants and certain kinds of fungi. Moreover these fungi can establish connections between the roots of different plants. These extraordinary organisms are called mycorrhizae (or if you prefer mycorrhizas). The word mycorrhiza comes from two Greek words, myco, meaning fungus (fungi in plural), and rhiza, meaning root.

Take a look at mushrooms, those delicious morels or boletus or the deadly Amanita; you see them scattered through the forest. They look like a very small component of the plant community compared to the trees that tower over your head. Each of those mushrooms is a “fruiting body”, similar to a fruit, except that it produces spores rather than seeds. The mushrooms are the visible parts of a very large organism buried underground and called a fungus. Imagine an apple tree where only the apples are visible sprouting above the ground while the whole tree is spreading its branches underground. Such an “apple tree”, the main part of the fungus, is a very peculiar kind of organism, not as solid as a regular tree; instead it is made of a very intricate web of thin threads spreading out and connecting with themselves again and again when they meet, like a huge tridimensional spider web. They also link with the roots of trees, wrapping around them and penetrating their bark.

Fortunately, mycorrhizae are beneficial fungi which do no harm to plants; instead they establish a partnership with them. With their numerous threadlike tendrils they absorb water and mineral nutrients from the soil more efficiently than roots; so they can transfer these to the plants. In return, they get the sugars and vitamins that the plants synthesize thanks to their chlorophyll and with the help of the sun. It is a cooperative venture that benefits both partners.

Other mycorrhizae never see the light of day; they produce their spores underground and don’t form mushrooms; as a consequence, most of us are totally unaware of their existence. They are perhaps more abundant and more important to the life of the plant communities than the ones that produce mushrooms. Some of them penetrate the very cells of roots establishing an even more intimate connection with their partners.

Some members of the vegetable kingdom don’t require this kind of help. But it is estimated that at least eighty per cent of all plants are dependent on or benefit in some degree from mycorrhizal associations. It is a very ancient contract between plants and fungi, at least 400 million year old existing long before there were dinosaurs roaming the planet. It is possible that the partnership is even older and that it was established when the first pioneer plants left the water and climbed on land, around 425 million years ago.

You may think at this point: “very interesting, but how does it compare with the planetary network in Pandora?” This is what I am getting to. All these hair-like tendrils are capable of recognizing the members of their own clone and also those of closely related clones when they come in contact. They fuse when they meet, to the point that they become like one. Thus they connect among themselves and they reach out to the roots of trees, not just one tree but several. They do it again and again, forming countless links. This is the “Wood Wide Web”, so called by those who study these relationships. The bridges they form are capable of carrying water and minerals and even other nutrients not just from fungus to plant and vice versa, but also from tree to tree. Thus a fir tree connects to another fir tree and also links to the birch tree beyond them. When you walk in your vegetable garden, little do you know that the leek is talking to the carrot using the unseen web right under your feet!

A field that gets plowed over every year and is cultivated with annual crops has to start from scratch building this network every year, but a forest possesses a network perhaps as old as its oldest tree. Thus, the majestic old tree, surrounded by younger ones becomes a hub, from which the fungal network radiates in all directions like the spokes of a wheel maintaining continuous communication among all its parts. It makes you think of “Home tree” in planet Pandora or of a wise old elephant matriarch ensuring the safety of its herd.

But it is really the mycorrhizae that are the stewards of the forest. They seem to sense where the pressing needs of a plant are and from where they can borrow. In the spring, when the birches are leafless, the mycorrhizae take nourishment from the firs and carry it to them. Later on, when the leaves of birches cast shadow over the fir trees and these need some food the web reverses its flow, providing nutrients to firs taken from the birch.

“That is more connections than the human brain” explains Grace “It is a network, a global network”. And so it is with these obscure fungi; each mycorrhizal community nurtures one patch of plants and it contacts loosely with surrounding communities throughout large tracts of land. They confer resilience and stability to the forest far beyond what the trees could do by themselves.

When I ask people I meet what the word fungus means to them, the most frequent answers are “disease”, “plant damage”. The answer should be “connectivity”, “cooperation” or “healthy plant communities”.

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List of articles

2010-02-05T14:49:00.000-08:00

Pollinators
Bees in the garden
The pure magnificent green bee
Bumblebees and Turtleheads
A Busy Pollinator and a Relaxed One
The Midge and the Chocolate Lover
My bees and climate change
Our friend the elephant mosquito
Partners and robbers
OF BEES AND HONEY. What is honey for?
Symmetry
Syrphus fly, a pollinator and aphid eater
Pollinators in Winter
Pollinatoars of the Pine Barrens, NJ

Moths as Pollinators
Pollinators, the Night Shift
Black-and-yellow lichen moth, a little known pollinator
Metalmark moths. More little known pollinators
More little known moth pollinators: seed casebearers and flower moths
Inch worms: more little known pollinators

Bee Houses
Bees in the garden
Pollinators in Winter

Gardening
Lawns for pollinators, grass companions
Lawn for pollinators. Part II
Lawn for pollinators. Part III
In praise of bare spots in the garden
Pollinator gardens and more
Utilities Right of Way, Native Plants

Pollinators in Winter
POLLINATORS IN WINTER. Fritillaries
HUMMINGBIRD MOTHS. Where do they go in Winter?

Flowers, their strategies
The Life of a Flower
Bumblebees and Turtleheads
DECEITFUL FLOWERS. Lady slipper
Only friends welcome here
Maple flowers
Flowers schedule
Inkberry pollination
Nectar: Breakfast of champions
Nectar: drink with a zing?
Where have all the spring beauties gone?

Biological Interactions
Alien invasions
Viburnum leaf beetle, an introduced pest
Wildlife food and non-native plants
The year the bears went hungry
BUGS IN THE GARDEN. Hornworm: Friend or Foe? Friend and Foe
GOLDENROD GALLS FABULOUS FAUNA
Goldenrod Galls and their Fauna
Goldenrod galls, The Long Stemmed Ones
THE BIRDS AND THE BEES. The True Story
The living constellations beneath our feet
Squirrels, managers of the forest
How much is a bat worth?

Birds
Caterpillars are for the birds
Feed the birds
A river of birds
“Locavore” birds. Grow your own birdseed

Nature
The sounds of nature
Utilities right of way. Native plants

Biocontrols
The prolific aphids
The Hornet's Nest
BUGS IN THE GARDEN. Hornworm: Friend or Foe? Friend and Foe
Syrphus fly, a pollinator and aphid eater
How much is a bat worth?

Little stories
A Night in the Life of a Working Mother
Floral Emissaries
For the Love of Flowers
Dancing in the Valley of the Lilies
The Poop Bug and the Golden Beetle
The year the bears went hungry
Ladybeetles, the good ones and the not so good

Dancing in the Valley of the Lilies

2010-02-02T12:25:00.001-08:00

The air was crystal clear in the meadow under the warm May sun, blue sky above and blue camas lilies below. That was the Mountain Dawn Farm Prairie, surrounded by trees and by more blue in the distance, the Cascade Mountains.

Many flower visitors buzzed along coming and going busily, most of them bees and bumblebees, but there were others; one in particular caught our attention. It had emerged from the ground after long winter sleep, along with numerous brothers and sisters. We called him SBF, a silly name but we all knew what we were talking about. SBF was a handsome dance fly with bright eyes, a hunch on his back, a slender abdomen and a thin, long tongue that had earned him the other name by which it is known, dagger fly. He delved deeply into flowers with his tongue and drank the nectar. He could also use his dagger for other purposes as we'll see later.

The nectar fueled his flight and he was doing a lot of flying that day. In his short life as an adult he had only one purpose, to find the girl of his dreams, seduce her with a well chosen present and make love to her. If time allowed he would find another girl of his dreams the next day. But for now he was busy searching for a wedding present that could satisfy the most demanding damsel. Midges were perhaps the best choice. He wanted one big enough to be appealing to his intended but not too heavy that he could not carry it for a certain stretch of time. He knew that at some point he would end up carrying both the prey and his beloved, so he had to make a careful choice.
When he saw a suitable one, he quickly pounced on it and stabbed it repeatedly with his dagger to subdue it and also to start preparing the delicious meal that he knew ladies willing to mate would favor.

After that he wrapped his gift with silk of his own making. Then he flew through the meadow in search of a meeting place, the equivalent of a singles bar. How do dance flies know where to congregate? I wouldn't know. But he did find a gathering with several suitors holding nuptial presents, just like the one he was carrying. He noticed with satisfaction that his gift compared favorably to most of the others. He joined the group suspended on the air, flying up and down, back and forth, holding his precious cargo on front of him, just as all the other bachelors. If you come into a cloud of them, you would think that they are dancing. That is how they got their name. More and more bachelor flies joined the ranks of dancers, all of them holding a present and all of them quivering with expectations and desire.

Meanwhile, somewhere in the same meadow a young female had emerged from the ground, the same as her brothers and had started her search. She looked very similar to the boys with one big difference, instead of a slender belly; hers was like an oval, loaded with eggs. Let us call her FBF. For those of you who are wondering about the names, SBF is a nickname, the full name being: Skinny Black Fly, so it is only appropriate that his plumper female relative be called Fat Black Fly. FBF needed protein to nourish the eggs that were her future children but she wasn't about to waste her precious energy on the search for food. She would let her lover take care of that. So she tried to make herself more seductive in order to attract the best suitor, one strong enough to provide a worthy and nutritious gift. Knowing that the males love well endowed ladies she plumped her stomach as much as she could. A little deception doesn't hurt, besides the boys were not beneath adding extra wrapping to their presents making them look bigger than they really were, so they were even. A fat belly in a female is a sign that she has a full load of mature eggs; neither he nor she knows that but they behave as if they knew it.
Off she went searching for the nearest gathering, wondering if she would find her knight in shining armor. Arriving at a meeting place, one handsome fellow caught her eye immediately, it was SBF. The gift that he was holding looked quite satisfactory so she approached him avoiding one or two overly eager fellows with their puny offerings. SBF was overjoyed when he saw her and gave her his package. She took it without ceremony and proceeded to devour the delicacy folding her wings and letting him carry her. For a few seconds the extra weight caught SBF by surprise but he quickly adjusted to it and flew some distance seeking privacy. There was no time to wait. He wanted to make love to her for as long as the meal permitted and so he did.

There isn't very much else to tell about this brief romance, other than soon FBF found the right place on the ground. It had some rich decomposing organic matter that would supply nourishment to her future babies and also warmth and shelter through the long months of winter. She laid her eggs there starting the new generation that would repeat the flower visits and the sun dance the next May.

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The prolific aphids

2010-01-29T05:49:00.000-08:00

So, your rose bushes look lovely, loaded with blossoms and you glory on their beauty. Then, disaster strikes, almost out of nowhere an invasion of vicious sap suckers starts draining the life out of the bushes: Aphids! You engage in a losing battle, hosing them, spraying soapy water, squashing them between your fingers; you refuse to use pesticides because you see yourself as ecologically responsible, besides pesticides wouldn't do much good anyway. The trouble is that when the infestation reaches a certain point it is already too late.

This is the rose aphid (Macrosiphum), a member of the very large and very odious family Aphididae and here we have an extremely heavy infestation. There are adults and youngsters, called nymphs, struggling for a free spot where to pierce the skin of the stem and feed on the plant juices. Notice that there are two kinds of adults, wingless and winged ones. Most aphids are wingless; they are little machines devoted to feeding, growing and reproducing, nothing else; they dispense with any other activities, even sex. But when conditions get too crowded some of them grow to be winged adults and fly off in search of better feeding areas.

So, what can you do to protect your roses? Prevention and foresight are the most effective tools against this stealthy enemy. It helps to know a little about their complex life cycle. In the fall or early winter rose aphids give birth to both males and females; they mate and they lay eggs which can overwinter safely. All the adults die with the onset of cold weather and the absence of juicy fluids in the plant stems; but the eggs can survive until next spring.

The eggs are pretty tiny, dark, shiny buttons scattered along the bush stems. You will have to try really hard to see them because of their minuscule size, less than 1/16"! Ah! But, if you could eliminate them or at least reduce their numbers considerably your worries would be almost over. In the spring each egg produces one female, but what a female! It is a supermom (professionals call her a foundress). It doesn't need to mate with a male, and it produces only live born females, which in turn do nothing but produce more and more babies. Since it doesn't spend any energy searching for food and since it doesn't need males to reproduce, the numbers can grow at an accelerated rate.
The colony shown above consists of descendants of one of those supermoms, a huge clone of identical twins, all of them feeding on your prized rose bush. That is why eliminating those nearly invisible eggs would protect your bush better than any later action.

The other line of defense is the wide array of aphid enemies, which under the right circumstances can keep the aphid populations from getting out of hand. Their enemies are our friends; who are they? Ladybugs are the first to come to mind; we all know that they are the gardener's helpers. There are a few others, just as helpful or perhaps even more so. Tiny parasitic wasps that lay their eggs inside the aphids; their larvae eats the growing aphid from the inside; gruesome, but an effective pest control. Syrphid fly larvae are gluttonous aphid eaters; each one can eat a few dozen aphids in the couple of weeks that it takes to reach maturity. Lacewing larvae, with formidable jaws, can attack aphids easily. All these are considerably smaller and less conspicuous than ladybugs, perhaps this is why they usually go unnoticed but they all play important roles in the control of aphid populations.
The trouble with pesticides is that they also kill all these aphid enemies; unfortunately the restoration of their populations takes considerably longer than the build up of aphid populations. So the immediate consequences of using pesticides are good but the long term consequences are counterproductive because the enemies of aphids aren't there when needed.

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ALIEN INVASIONS. Our native butterflies and the intruders that threaten them

2009-10-14T16:18:00.000-07:00

The invasive cabbage white Pieris rapae, a pest of cabbage and related plants.

When we see a white butterfly it is most likely an invasive European species, called a cabbage white. Its beauty often blinds us to the fact that it is an unwelcome intruder which behaves as a pest. Growers of cabbages, radishes and other plants in the mustard family hate the damage that its caterpillars do to plants. You may have seen that same damage if you grow ornamental cabbages in your garden. The cabbage white or Pieris rapae, is a sturdy fellow that does well in many habitats and keeps spreading throughout the continent.

West Virginia White (Pieris virginiensis), beleaguered by non-native plants and butterflies.

The North American native species of white butterflies are well behaved, feeding in a number of native plants, such as toothwort, watercress and other members of the mustard family. They are no threat to native nor cultivated plants as their numbers are not overwhelming and a good balance has been reached between butterflies and food plants.

There are four native species; they all look very similar but you can tell them apart by subtle differences. The lovely green veined butterfly or mustard white butterfly (Pieris oleracea) lives in woodlands across northern North America and in the Rockies and Appalachian mountains. The West Virginia white (Pieris virginiensis) is found in the Appalachian and Great Lakes regions. These butterflies face several threats to their survival; in addition to the more familiar one, loss of habitat, there is a more serious and insidious one due to the presence of an invasive plant, garlic mustard.

Garlic mustard (Alliaria petiolata)

Garlic mustard (Alliaria petiolata) is very familiar to most of us; an introduced invasive species originally from Europe and Asia; it was brought to America as food, although nowadays nobody uses it for this purpose. It promptly escaped cultivation and now is most commonly found in areas disturbed by humans. It can be found almost anywhere in the eastern United States, especially in the spring, growing vigorously in sun or shade, blooming and spreading its seeds. It belongs to the mustard family and this is the undoing of our native white butterflies. Females can't tell the difference between this plant and others of the same family and so they lay their eggs on this plant. Little do they know that garlic mustard is toxic to their babies; their larvae don't do well and die as a result.

One of the reasons for the successful spread of garlic mustard is that when brought to North America, it left behind most of its enemies, about 63 species of insects, including several species of butterflies. It is ironic that the one that tries to take advantage of it is being poisoned and killed by it.

You can learn more about the West Virginia White butterfly and conservation efforts in
Conservation Assessment for the West Virginia White (Pieris virginiensis Edwards) and garlic mustard and methods of control in Missouri Department of Conservation website.

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Bugs in winter

2009-10-09T15:04:00.000-07:00

If you live in latitudes where winters are cold enough for snow and ice, you see most insects disappear without hardly any traces. And yet, they come again in full force next spring. Where do they go? Aside for just a small handful that migrates to warmer climates, the rest are left with no choice but to find a hidden place to spend the winter. Unfortunately for us, some of them have figured out that human surroundings are nice and cozy and find shelter inside our homes. Such is the case of a striped black and bright red bug which sometimes becomes a nuisance in the fall in its search for warm places. It is the boxelder bug, so called because it feeds in the juices of boxelders and some other maples. Fortunately it doesn't cause serious damage.

Most ladybugs are well behaved and don't give you any trouble; however there are a few species that seek the comfort of each other company and together invade human residences. One of them is the Asiatic ladybeetle also called the multicolored lady beetle for reasons that are obvious in the picture below. Not two are alike in color and pattern. This lady beetle was introduced intentionally in the United States from Asia to combat aphids so years ago there weren't such invasions of these beetles. It is interesting that the same thing is taking place in some South American countries where this lady bug was unknown just a few years ago.

Another insect that may show up inside your home in winter, although for entirely different reasons is a long horned beetle of a very respectable size, the banded ash borer. If you have a fireplace and bring logs into the house you may find several of them crawling around and heading for the light of the window. This one has not been looking for the warmth of your house, instead you brought it in unwittingly with the logs where it was spending the winter. It feeds on the wood of ash and oak trees and remains out of sight for most of its life.

Goldenrod galls, The Long Stemmed Ones

2009-10-06T14:30:00.000-07:00

In addition to the more familiar goldenrod galls that we all notice, there a number of smaller galls of a variety of shapes. A very interesting one goes by the name of pedicellate gall. What this means is that it has a foot. I prefer to describe it like a long stemmed wine goblet. This curious small gall, less than an inch in length can grow on different places in the plant. The glass part is ribbed and it may have a purplish color.

You may have never noticed it before but you should have no trouble finding some of them now that goldenrods have reached their full size and are starting to bloom. So, look for them on leaves, stems or flowers. You may find them in isolation or in groups.

If you open them, you will find the small midge's larva or pupa inside. I have yet to take some home and keep them in a container with water and covered by mesh. I want to see the adult midge. So I will do this soon.

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Goldenrod Galls and their Fauna

2009-10-06T14:11:00.000-07:00

There are so many different types of goldenrod galls! They are made by insects that induce abnormal growth of the tissues of the plant, providing protection and food to the gall maker and no benefit to the plant. Not only that but there are many parasitoids and inquilines, a whole series of ecosystems with very complex faunas.

Here are some of my photos, comments and links to information on goldenrod gall fauna.

This type of gall is caused by a small fly, a gall midge. Each small gall is like a blister in between two leaves of goldenrod. Inside the gall the midge larva grows surrounded by food and seemingly in safety.

The safety is only an illusion. Quite often the galls are parasitized by tiny wasps that end up killing the larvae of the gall maker.

This is one of the parasitic larvae.

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The Midge and the Chocolate Lover

2009-10-05T16:42:00.000-07:00

What does a midge have to do with chocolate? More than you think. Chocolate comes from cocoa trees that grow in the tropics. These trees look quite different from most other plants. Instead of having flowers in the most conspicuous places, they have them on the trunk and lowest branches. These flowers are small and white and face down, the reason for all this is that they attract tiny flies, known as midges rather than bees or other better known pollinators. The midges are ordinarily attracted to fungus and cocoa flowers smell somewhat mushroomy, too. In essence, for the cocoa tree to bear fruit, first it has to be pollinated by midges.
Think about it next time that you eat a bite of that marvelous thing known as chocolate.

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GOLDENROD GALLS FABULOUS FAUNA

2009-10-01T08:59:00.000-07:00

Goldenrods can be quite abundant in fields along roads and in forest clearings. They are rather non-descript, weedy looking plants through the spring and early summer, but before the onset of fall, they explode in vibrant, luminous yellows that give them their name. Each flower is tiny but they are abundant and massed together at the tip of branches creating an impressive display.

Another season in which this plant may arouse the curiosity of passers bye is winter; quite often their tall, dry canes sport some odd looking round thickenings, half way along the stems. These balls are about an inch in diameter and they are very tough. You may puzzle about them; evidently they are not fruits, their placement is quite strange but they are most definitely part of the plant and not something that has been glued to it.

They are tumors called galls and they are provoked by some creatures, the gall makers. In addition to the highly visible round galls there are other types. Galls come in a wide array of shapes and sizes and location in the plant. Many different plants present galls of one sort or another; goldenrods and oaks seem to be more prone to this sort of attacks than most other plants.

How are these tumors produced? Do they serve any purpose? What causes them? Only recently have scientist began to crack some of these mysteries. There are many different agents that can cause these tumors; most of them are insects, but also mites, nematode worms, fungi and bacteria can produce them. Fortunately, in most cases, they don’t seem to have serious effects on the plants they use as hosts; other than being somewhat unsightly in some cases. The ones that affect your rose bushes are not going to make you very happy.

Galls are very specific kinds of tumors; unlike cancer they don’t grow in an uncontrolled way, instead they have a very definite structure. This structure serves the purposes of the gall maker not those of the plant. So, galls will be different depending on the organism that produces them. In fact one species of plants may carry several different types of galls, each one caused by a different organism and each one with a very characteristic shape, size and location in the plant.

The remarkable thing about gall makers is that they are capable of hijacking, taking control of, the genetic machinery of the plant and forcing it to grow tissues and an entire organ unlike anything else on that plant. This highly organized structure or organ, called a gall, provides shelter and food for the gall maker or its progeny.

Goldenrod round gall, early summer

Getting back to goldenrod’s round gall; it is caused by a small fly known by some as the peacock fly, although this name is confusing because it also applies to an unrelated kind of fly. Therefore, the best name for it is goldenrod gall fly. Early in the spring, when goldenrods are growing, female flies pick their target, the stems of growing goldenrods.
The fly pricks the stem of the growing plant with the egg laying organ, also called an ovipositor, depositing an egg inside the tender stem. Soon a tiny larva hatches and starts feeding on the tender tissues of the inside of the stem. When doing so a chemical in its saliva starts acting on the plant’s tissues altering the way they grow and forcing them to develop an unusual structure.

Goldenrod fly freshly emerged from a gall in early spring

In this manner the growing larva, or maggot, builds a home for itself and a source of food. The thick, tough walls of the gall provide an excellent shelter and the juicy tissues provide nourishment. The center of the gall is a round chamber where the insect fits snuggly. It can remain there feeling safe and contented; all its needs are taken care of until the next spring. It will grow through the summer, sleep through the winter and then emerge fully grown and transformed into a winged adult. The fully grown maggot is no bigger than a grain of rice; the adult is just like a winged grain of rice. Before going through metamorphosis the larva has one final task; it chews a tunnel all the way to the surface of the gall and stops just before breaking the skin. It has to do that because the adult fly does not have teeth and would be trapped inside otherwise.

Fly larva inside its gall in the middle of winter

Mysterious as this process is, it is not the whole story of goldenrods galls and their flies. A gall can be a universe within itself. Despite the protection provided by the sturdy walls of the gall, the larva isn’t as safe as it would seem. Several enemies have found the way to penetrate the defenses and make a meal out of them. Some raging battles take place inside the seemingly peaceful round balls. There are at least three kinds of parasites that can invade the sanctuary and take possession of the helpless maggot. Two of them are called parasitic wasps, black in color and even smaller than the fly. Another parasite is a beetle belonging to a kind called tumbling flower beetles which also attacks the galls. There are probably others, but with so much to learn, scientists are still studying the universe of the goldenrod round galls.

Often more than half of the galls that you see in a field of goldenrods contains, not a fly, but one of its parasites. Is this all? Oh, no! In winter black-capped chickadees and downy woodpeckers, knowing that goldenrod galls contain a small morsel of food, go after them when sufficiently hungry. Next time that you walk through a field of goldenrods in winter look for galls and you will notice the ones that have been cracked open by these birds. With a good eye you could even figure out which have been visited by one or the other of these two birds. Woodpeckers use their strong and sharp chiseled bills with precision, making a clean hole while chickadees, with their smaller bills, need to keep picking at the gall, chipping away here and there, until they finally reach the core; thus their holes are very sloppy by comparison. Both birds show a preference for larger galls; they seem to know that the smaller ones are likely to contain one of the smaller parasites rather than the fat and larger fly maggot.

Gall opened by a chickadee next to whole galls, collected in winter

This is the story of just one type of goldenrod galls, the one you are most likely to notice when seeing a goldenrod field. But as I said there is a fantastic gall fauna in goldenrods. There are at least fifty different kinds of gall makers, each one with its whole intricate story of chemical manipulation, delicate timing, enemies and intrigue. Several types of flies and midges and some small moths are responsible for these galls. Each builds a unique type of gall and has its unique life style, rhythm of life, assortment of enemies and location of the gall. In summary if you count all the types of gall makers and all the parasites or predators you realize that it is a real zoo, with a great variety of species.

One wonders how the goldenrod thrives despite the attacks from such a wide range of gall makers. Fortunately for the plant these gall makers have many enemies which don’t allow the populations to build up to dangerous levels. It is also fortunate for the downy woodpeckers and black-capped chickadees that these gall flies exist and provide them with much needed food in the dead of winter. And we are lucky too because we get to enjoy the beauty of blooming goldenrods in the fall and those of us who are bird watchers get to see the chickadees and woodpeckers year after year.

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Syrphus fly, a pollinator and aphid eater

2009-10-01T08:36:00.000-07:00

Among the many flower flies there are some that are beneficial to the garden in more ways than one. Flies of the genus Syrphus and also some of their relatives are moderately good pollinators when compared to bees. They visit flowers frequently because they need nectar to fuel their flight; the females also need protein rich pollen for their eggs to grow and mature. The reason why they are not as good as bees is that their bodies have very little hair so pollen doesn’t adhere very well to them. However what they lack in efficiency they make up in sheer numbers. In some instances flies are more abundant than bees and may end up providing a better service to some flowers.
The genus Syrphus counts with several species in North America. They are very hard to tell apart; as a matter of fact they are also hard to differentiate from their close relatives: Eupeodes. Entomologists need to examine them under the microscope and look for minute details of wings and other body parts to identify each species.
Beginners have an even harder time and frequently confuse them with bees, although their single pair of wings should be a clue that they are flies not bees. They are considerably smaller than honey bees but there are many species of native bees about the same size as Syrphus. There are other ways of telling these flies apart from bees; their antennae are very short and with a funny shape with a little appendage called an arista; their eyes are enormous and their legs skinnier than those of bees. As I mentioned before they are nearly hairless. Although they may look like bees you don’t need to fear their sting because they have none.

What is interesting about these flies is that in addition to being pollinators they are very helpful to your garden as larvae because they eat aphids. The female lays her eggs near an aphid colony. The tiny maggots that emerge from the eggs are blind and legless but they don’t seem to need those organs to find their food, so they promptly go to work helping themselves from the colony. It is odd to see some completely unconcerned aphids near a maggot devouring one of its sisters; they may even come close to inspect it. Each maggot needs a large numbers of aphids and no more than a couple of weeks to complete its growth. It finds a place to pupate, under a leaf or on the ground and emerges in a few days ready to start raising another family of pollinators-aphid eaters. Gardeners familiar with these qualities of Syrphus flies strive to grow the plants that will provide pollen and nectar to them to ensure that they do their duty as aphid patrol.

The year the bears went hungry

2009-09-07T17:38:00.000-07:00

Do you remember the children's book: Blueberries for Sal? Sally, a little girl, went blueberry picking with her mother every year. One day the two humans had a close encounter with a mother bear and her cub who were feeding on berries in the same blueberry hill. Both bears and humans decided to leave each other alone and continued their activities in opposite sides of the same hill. The thrill of this encounter remained firmly embedded in the minds of Sal and her mother.

What the book didn't tell you is that a few years later Sal and her mother went blueberry picking as it was their habit and suffered a big disappointment when they found no blueberries. The plants looked very healthy but almost totally lacking in fruit. So they went to the store where they bought berries for their traditional annual jam.

The mother bear and her new cub went also blueberry picking as they did every year and their disappointment was bigger than that of the humans. To them the juicy fruits were vital and they could not resort to a grocery store. That winter they went to sleep very hungry and it is not known whether they survived that tough season after such deprivation.

What Sal and her mother didn't know and what the bears had no way to know was that there had been a severe infestation of the nearby spruce forest. The caterpillars of a moth had reached enormous numbers and were defoliating the forest. To combat such a pest the foresters had sprayed a powerful insecticide, not realizing the further consequences of this action.

Blueberries need to be pollinated by very diligent bees, not necessarily honey bees, but a wide array of native bees, in particular the so called blueberry bee. Many of these bees nest near the trees that had been sprayed to combat the spruce worm. This brought tragedy to the little bees. They were poisoned just as effectively as the spruce worm and died by the millions. As a consequence nobody pollinated the blueberry flowers and the shrubs produced no fruits.

When blueberry growers in the area realized what had happened, they rose up in arms. They finally succeeded in putting an end to the pesticide use. However, it took several years for the bee populations to recover and as a consequence blueberry bushes, as well as a number of other plants in the area, produced very limited amounts of fruits and seeds. Not only bears suffered the scarcity of berries, but also a number of wild creatures of the forest that also depend on such food, such as birds. It is quite possible that many of them died of hunger.

Let us hope that the health of the forests and surrounding fields was eventually restored, so that Sal, her children and grandchildren can go on enjoying this marvelous web of nature made of blueberries and bees and of birds and bears.

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The Poop Bug and the Golden Beetle

2009-08-25T16:01:00.000-07:00

Somewhere out there, there is an ugly little bug with a sweet tooth for sweet potato leaves. It goes about munching leaves day after day and growing very fast. It starts life the size of the period at the end of this sentence or smaller and when it is fully grown it is still no bigger than a shirt button. Moreover if you saw one you would think that you were watching a bit of dark poop on a leaf. You would be very surprised when this black you know what started walking around and, if you watched very closely you would realize that there is something alive underneath.

The bug under that nasty dark pile has a funny looking tail with branches and hooks. It looks like a coat rack and the bug uses it precisely for that purpose. When he keeps growing, his skin becomes too tight for him so he grows a new, thin, elastic skin under it and peels off the old one; the new skin has room for growth because it can stretch before it gets harder and it allows room for growth. Each time that the poop bug sheds its old skin, it hangs it on the coat rack. Then the bug adds its own wastes on top of the wrinkled old skin. To do this it sticks out a long and flexible hose coming out from its back end and skillfully spreads the material on top of the existing messy thing. When it dries up it turns dark and rather disgusting. You can see it doing this in this video.

This ill mannered creature carries the whole thing over its body like an umbrella; that is why you can hardly see the bug. Why would it have such a filthy habit? Didn’t its mother teach it any better? Well, it turns out that it has a very clever reason for doing such a singular thing. The poop bug is a tasty morsel that any passing bird would gobble up with relish. But birds don’t feel tempted by this ugly sight, so they fail to see the snack underneath. That is how the little bug can go on munching away unmolested hiding from its enemies in plain sight.

Sweet potato plants look similar to morning glories with climbing vines, light green leaves and pretty trumpet shaped flowers. They look alike for a good reason; they are related. The poop bug likes morning glories just as well as it likes sweet potatoes; so if there are some morning glories in your neighborhood you may be lucky enough to find a poop bug if you look for them. Look at the leaves and if you see holes here and there you may be on the right track for finding a poop bug. Remember that they are very little, no bigger than a shirt button. Also, it may have already left the plant and moved on somewhere else. However, if you see one it is possible that it will wave its umbrella once or twice if startled, hoping to scare away the observer.

After it has been eating almost non-stop for a couple of weeks it will reach its full size and now it will be ready to turn into its adult shape as a beetle, that looks vaguely like a tiny ladybug. This is not an easy transformation; a lot has to take place to make all the changes, grow legs, antennae, wings. So it needs peace and quiet while doing all this remodeling. It may move to another plant nearby, not necessarily a morning glory, sweet potato or related plant, but something altogether different such as goldenrod.

It prefers to anchor itself on the underside of a leaf and once there it sheds its skin one more time and may or may not drop the umbrella along with it. Now it looks like an armored little tank called a pupa. The pupa goes to sleep for just about a week, after which time it wakes up ready to start a new life. During this time not much happens on the outside, but huge changes are taking place inside.

When it is time to come out of this shell the poop grub has one final trick up its sleeve. The front part of the pupal case opens up on two hinges; all what it takes is a little push and the front opens like a double door and the brand new beetle emerges like a car getting out of a garage, a very tight parking space if I may say so.

The gorgeous little creature that emerges bears no resemblance to the larva or the pupa. It is like a tiny turtle; its shell is glossy pink with a hint of gold. And then, depending on how the light hits it, it looks gold with a hint of pink; it may remind you of nail polish. It is pale at first, becoming a little richer and darker in a few hours. It usually sports six black dots; its edge is flared and transparent. The freshly emerged new beetle waves two delicate antennae exploring the new world. It may take a while before it tries its new wings and take to the air. Now it can proudly bear the name for which it is best known, the golden tortoise beetle. You can learn more about the golden tortoise beetle in Bugguide.

One wonders how this little piece of gold and pink emerged from such ugly, dirty grub. Keep checking those morning glories, you may be rewarded by its sight, just remember, it is no bigger than a tiny gob of pink nail polish.

The Hornet's Nest

2009-08-25T15:48:00.000-07:00

The fallen 12" wide hornet's nest showing some of its internal structure

A friend gave me a large hornet's paper nest the other day. She had found it last summer when she got stung while mowing her lawn. The nest was up on a tree, hanging from a high branch. After that she was weary of approaching the general area but did nothing to remove the nest and didn't suffer any further attacks. When Fall came, a strong wind broke the branch and brought down the paper nest already abandoned by its inhabitants.

When she gave me the nest, she asked me a few questions while we both marveled at its craftsmanship. There are several species of wasps referred to as hornets. They build paper nests up on trees using chewed pieces of vegetable material that hardens and becomes the consistency of paper.

The nest's envelope and cells are paper made of wood fibers mixed with wasp's saliva and applied in layers. The different colors show the variety of sources used in the construction

This is what Bugguide has to say about the life cycle of this particular kind of hornets: "A fertilized queen overwinters and starts a paper enclosed nest in the Spring. As the colony grows, multiple tiers are added, consisting of hexagonal cells. Males appear in the Fall." The Texas Agricultural Extension adds this information. And you can find a few more facts in the Fairfax County Public Schools website.

Hornet's stings can be very painful and they are more likely to attack when you happen to be close to their nests; that is where the expressions "mad as a hornet" and "hornet's nest" come from. Also, they can make nuisances of themselves, especially in the fall when they boldly approach any food available at picnics. Most people don't want to know anything beyond that; hornets are to be feared and avoided. An exterminator is the first thing that they think of when finding a nest in their properties.

But, there is another side to the story, worth examining. Hornets are omnivorous eaters whose diet seems to know no limits, but it can be grouped in two types: food for the adults, mostly sugary materials to fuel their flight and food for the growing babies, rich in proteins needed for building new tissues. They obtain the sweet materials from a variety of sources, from flower nectar to spilled soda on a picnic table; but mostly from the first. Thus, in their frequent visits to flowers they carry pollen from flower to flower and accomplish pollination. Although not as efficient as bees they deserve recognition for their job as pollinators. When it comes to feeding their babies, their diet is just as varied as the sugary one, ranging from living insects to cooked meat; from flies to bacon and hard boiled eggs. But, ordinarily, the main source of the baby food is insects that they catch in large numbers. They pounce on their prey, chew on it turning it into a pulp and feed this mush to the growing larvae in the colony.

An adult resident hornet. This one can't sting because it is a male

I would like to think that they specialize on harmful insects and leave beneficial ones alone; but, of course, this isn't true. They are equal opportunity predators and quickly attack anything available from honey bees to flies or caterpillars; as well as taking advantage of any dead meat available, be it a dead mouse or table scraps. However it seems that the bulk of their prey is made of fliesñ all sorts of flies, house flies, blow flies, robber flies, flower flies and everything in between. Many years ago a researcher counted 227 flies caught in an hour by a relatively small colony of about 60 wasps.

Caterpillars also figure prominently in their diet; once again they attack a wide range of species from butterflies to moths. Tent caterpillars are among the undesirable pests that they prey on; they may also feed their babies on Luna moths or painted ladies.

They have other connections with the rest of the living world. Some birds, such as the red eyed vireo use paper fragments from abandoned wasps nests to insulate and decorate their nests. Finally, hornets themselves are part of the food chain, providing nutrition to a number of other creatures, birds such as fly catchers, toads, bats, raccoons, etc. They are part of the web of life, linked to the plants they pollinate, the prey species they control and the species that they nourish.

My friend was wise in letting the wasp nest follow its natural course, rather than calling an exterminator. The busy hornets took care of countless insects all through the summer.

National Pollinator Week

2007-02-13T18:04:00.000-08:00

Pollinators are responsible for one third of the food we eat. Most fruits and vegetables have to be pollinated so that they can produce seeds. Also coffee, tea and chocolate need the services of pollinators.

Inkberry pollination

2006-06-08T16:07:00.000-07:00

Different flowers have different strategies for pollination. It is interesting to observe them and try to elucidate the interaction between flower and insect in the case of insect pollinated flowers. The small tree or shrub, inkberry (Ilex glabra), a relative of hollies, has numerous small flowers that attract a large number and variety of insects.

The name refers to the inky dark berries

I have observed insects of at least twenty five species visiting its flowers, among them: bees and bumblebees, several kinds of wasps, flies, butterflies and moths and also some beetles. Here are a few examples:

Maple flowers

2006-04-04T12:24:00.000-07:00

Are maples pollinated by the wind or by insects? It seem that some species use one method and some the other. Their flowers are rather insignificant, at least to our eyes, but it is possible that insects see them differently; anyways sugar maple seems to be one that receives numerous visits from hungry bees that can't find much food so early in the season. Look at the flower, it is greenish yellow, very small, although by growing in clusters, they become more conspicuous and attractive to visitors, and they have some shiny, glistening fluid on the surface, touch it with the tip of your tongue and you'll feel a very tiny taste of maple syrup. Yes, that would make them very attractive to bees.

Flowers schedule

2006-04-04T11:48:00.000-07:00

Some flowers are strongly influenced by the light and open or shut accordingly, others stay on schedule regardless of how cloudy and dark it is. This seems to be the case with bloodroot, Sanguinaria. These two pictures of the same clump of flowers were taken two hours apart, at 7:30 and 9:30 AM EST on a very cloudy day.

2006-02-12T12:52:00.000-08:00

Abejitas sin aguijón, Meliponinas en el hotel de Chichen Itza.

The butterflies of Yucatan

2006-02-08T17:33:00.000-08:00

Some common butterflies and moths seen in Yucatan in January, 2006.

ASCLEPIAS OR MILKWEED. Its Many Visitors

2005-12-22T16:52:00.000-08:00

Plants of the genus Asclepias, better known as milkweeds because of its white, sticky sap, attract a huge variety of insects and other creatures. Its most famous resident is the monarch butterfly that depends on milkweeds for nutrition; but it is not the only one. Here is a small sample of the menagerie that you can find on a single plant of Asclepias.

Milkweed beetle, Tetraopes tetrophthalmus (the four-eyed one)

Silver spotted skipper

Leaf-footed bug, with eggs of a parasitic fly on top of its head

Lady bug in search of aphids.

Flower flies

2005-10-07T08:23:00.000-07:00

Flower flies, those tiny imitators, don’t look at all like the familiar house fly, instead they look like bees; with a disguise of yellow and black stripes.

They fool birds that avoid them for fear of being stung although they are innocuous.

Like the bees they imitate, many of them are good pollinators. Who would have thought that flies could be so pretty and so useful!

Some of them go a step further on their usefulness and eat a large number of aphids while they are larvae. Here

Hummingbird Moth

2005-09-04T11:56:00.000-07:00

Don't let this little beauty fool you. It is not a tiny hummingbird, but a hawk moth. Not surprisingly it is called hummingbird moth. It is one of the few moths that are active during the day. It pollinates long throated flowers like this Monarda.

Lapachos of Cordoba, Argentina

2005-09-04T11:43:00.000-07:00

Bignoniaceae. A sea of flowers and it isn't spring yet, this is the end of August in Cordoba, Argentina. The weather is mild and some trees, such as these lapachos, cover themselves with flowers.