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NATIONAL WILDLIFE MAGAZINE
Aug/Sep 2002, vol. 40 no. 5
Of Killer Caterpillars and Vampire Bugs
By Cynthia Berger
Below is a summary of the article :
Almost everywhere else in the world, caterpillars are gentle plant eaters. Only Hawaii has carnivorous inchworms that ambush their prey. And not just one kind: Here, in mid-ocean isolation, at least 18 species of killer caterpillars have evolved to fill the ecological niches that preying mantises occupy elsewhere. Carnivorous caterpillars are not Hawaii's only insect oddballs. There are flightless flies, a terrestrial water treader, underground tree crickets and summit vampire bugs that suck the juice from insect corpses, just to name a few. Many of these wacky Hawaiians are endemics--found nowhere else on earth.
A VORACIOUS predator hides somewhere in this lush Hawaiian rain forest, and photographer Bill Mull has offered to lead me to it. We walk beneath lichen-crusted ohi'a trees until Mull waves me to a stop near a clump of wild ginger. He bends down for a closer look, fishes a hand lens from his pocket . . . and there it is, the killer I've come to see: an inch-long caterpillar, straddling the edge of a leaf.
At first glance it looks like any inchworm: green, soft-bodied, nonthreatening. Then Mull lets me peer through his lens at the three pairs of wicked-looking tarsal claws.
Later I see those claws in action, need I say more.
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Killer Caterpillar Eats Snails Alive
By Bjorn Carey, LiveScience Staff Writer
posted: 21 July, 2005 2:00pm ET
Below is a summary :
Caterpillars in Hawaii trap snails with silk webs and devour their captive prey alive. There is a new species called, Hyposmocoma molluscivora, is the only known moth or butterfly larva to eat shelled animals like snails. The caterpillars are small -- only about eight millimeters -- and lug their silk casings from leaf to leaf.
There is a species of snail-eating caterpillar from Maui. This caterpillar can use silk, like a spider, to pin down its snail prey. Having rendered the snail helpless and immobile, the caterpillar is entering the snail's shell to being feeding on its soft flesh.
The caterpillar webbing apparently prevents the snail from sealing itself against attack or fleeing by dropping to the ground. Then, the caterpillar wedges its case next to or inside the opening of the snail's shell.
It stretches its body out from the case, and corners the snail in the back of its own home. There is no place for the snail to run or hide as the caterpillar eats it alive, leaving nothing but an empty shell.
And that's not even the trickiest part. Many caterpillar casings were observed to have the tiny shells stuck to them, probably as camouflage.
Predatory caterpillars are very rare -- only a few other species are known in the world. Of the 150,000 species of moths and butterflies known worldwide, only about 200 are predatory.
The new caterpillars join a collection of unusual insects native only to Hawaii. Ambush caterpillars, damselflies with nymphs that live on the ground, and spiders that spear their prey in flight are all examples of Hawaiian insect oddities.
The Hawaiian island chain is the most isolated land mass in the world, and the authors say this discovery provides further evidence for how species isolation leads to the evolution of unusual hunting strategies and other traits.
Although these caterpillars have only been recently discovered, it's possible they may not be around for long. Current widespread destruction of lowland habitats and the wiping out of large numbers of Native Hawaiian plant species could lead to the caterpillar's extinction.
Today, some of the last bits of the forests these snail-eating caterpillars call home are located in nature preserves.
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