"Caterpillar Species Spins Webs to Prey on Snails"

SCIENCE FILE

Caterpillar Species Spins Webs to Prey on Snails

By Alex Raksin - Times Staff Writer

July 23, 2005

Biologists have discovered a new species of caterpillar in the Hawaiian rain
forest that ensnares snails in silken webs, then feasts on them until
nothing but the shell is left.

It's the first time such behavior has been documented in caterpillars ? or
any member of its biological order, Lepidoptera, which includes moths and
butterflies.

"It was like finding a wolf that dives for clams," said University of Hawaii
biologist and entomologist Daniel Rubinoff, who reported the discovery with
William P. Haines, a biologist at the university, in Friday's edition of the
journal Science.

Though all caterpillars have silk glands, this species is the first to be
seen using theirs like a spider does. And though nearly all lepidopterans
are vegetarians, "this caterpillar wouldn't sample foliage even if it were
starving," Rubinoff said.

Rubinoff said the new species, Hyposmocoma molluscivora, would not have been
able to develop such a novel feeding strategy without the isolation of the
Hawaiian archipelago.

Such isolation, as Charles Darwin noted in his 19th century study of the
Galapagos archipelago, favors the evolution of unique species, giving them
millions of years of relaxed ecological competition in which to develop new
ways of milking the most out of their environment.

With the destruction of much of the caterpillar's habitat, that isolation
may have ended, Rubinoff said. But part of the habitat is protected, giving
researchers "the chance to decipher more of their mysteries," he said. "We
may find yet other novel, uniquely Hawaiian species."

Original: http://tinyurl.com/a7hqw




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