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| Caterpillar shelter |
Many insects eat rather non nutritious plant parts. So they need to consume
large amounts, extract the nourishment, such as proteins, and discard the rest
at the other end. In simpler words: they eat a lot and poop a lot, or if you
prefer, they produce large amounts of frass or waste material.
Wasps are some of the worst enemies of caterpillars. They are constantly
seeking them to feed their young. Many wasps are superb at controlling insect
pests. I would think twice before hurting one of them; they are our friends.
Without them, there would be population explosions of plant-eating
caterpillars.
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| Leaf-roller caterpillar and its frass |
Caterpillars have devised different ways to hide and keep these ferocious
predators from finding them. The so-called leaf-rollers fold a leaf, stitch it
together with their silk and stay inside the little tunnel munching away in
relative safety. The amount of frass that accumulates inside these little
shelters can be impressive. One wonders how they can live in such conditions.
Not pretty!
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| Tiny black dots of frass hurled by caterpillar |
Unfortunately for the caterpillar, the smell of their poop is an excellent
clue to their presence. You may say that predatory and parasitic wasps have a
nose for food-related aromas. So, certain caterpillars have developed a
singular strategy. They throw their waste material as far as they can; which
can be pretty far. Eight to twelve inches for a caterpillar not much bigger
than a grain of rice! That is as if you could throw the you-know-what several
yards away.
The curious thing is that many moths and butterflies belonging to different
families have come up with the same poop-flinging solution to hide from
predators. Among them there is a skipper that you may probably have seen
visiting flowers, the silver spotted skipper. It gets its name from the
brilliant spot on its hind wings. When this skipper was a caterpillar it regularly
shot cannon balls of its own frass as far as a couple of yards away. How about
that!
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Silver-spotted skipper
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Bird-dropping caterpillar
(by
Malcom NQ, Flickr)
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Another poop strategy of sorts is that used by many
caterpillars called bird-dropping caterpillars. Their appearance, as the name
tells you, resembles a bird dropping. Apparently the ruse is convincing enough
to discourage would be predators. No real poop is involved here, but it is
worth mentioning in an article about poop strategies.
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| Leaf beetle larva hiding under its poop |
And then, there are other insects, particularly a group of
leaf beetles that have turned things around completely. Instead of leaving
their poop behind, they proudly carry it around as a shield. Some build a sort
of basket or nest above and around them. Others have a projection shaped like a
coat rack, from which they hang their byproducts, castoff skin and poop. You
can read more about one of them in
The Poop Bug and the Golden Beetle
More on frass strategies
List of articles
© Beatriz Moisset. 2012
1 comment:
Fantastic!
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