Thursday, October 2, 2008

Strange doesn't even cover it

A colleague at work, Ken Pendley, is quite the amateur entomologist and regularly produces all manner of insect oddities. He scored big time yesterday in the world of strange when he brought in a mantisfly. I can't resist quoting from the excellent book Field Guide to Insects of North America, by Eric Eaton and Kenn Kaufman: "Mantisflies resemble a science experiment gone horribly wrong. Imagine shrinking a praying mantis, then attaching its front end to the hind end of a lacewing, and you have a mantispid".

Sums it up pretty well.

Good thing its only about an inch long. It's from critters like this that the Japanese no doubt find the inspiration to create some of those god-awful creatures in B-movie horror flicks. But this one is real. They do look a lot like praying mantids, at least the forelegs. Mantisflies are predators, and even though they are closely allied with lacewings and not praying mantises, convergent evolution is at work here, and they have evolved similar powerful forelegs, the better to seize prey with.

There are a number of mantisflies, but I believe this one is Mantispa sayi. It has incredible cobalt-blue eyes with a star-shaped pattern in the center. You can see the Popeye-like forearms here. Wouldn't want to be the unfortunate insect that wandering into the path of this thing.

This excellent photo courtesy Tim Daniel, Ohio Division of Wildlife. The forelegs armed with stiff raptorial spines can be seen. Those stiff spines reduce - probably eliminate - any chance of slipping through the mantisfly's clutches.

The life cycle of most mantisflies is even stranger than their appearance. They lay dozens of tiny eggs along pathways regularly used by spiders. When the tiny mantispid hatches, it attempts to leap onto a passing spider. If successful, it clambers on top and works its way toward the base of the thorax, a location that is fairly safe from the spider's grasp.

Along it goes, like an Arab on a camel, until the spider begins construction of its nest. At just the right time, after the spider eggs have been laid but before the nest is to sealed in by webbing, the larval mantispid dismounts and scurries into the spider nest. This can only be a risky proposition, and may explain why these mantisflies are not very common.

Once the young spiderlets begin hatching, the larval mantisfly begins feeding on them. All goes well, and eventually another of the bizarre alienlike predators shown above emerges; the final stage of what is certainly one of the strangest insect life cycles there is.

This is almost too weird to believe, but true.


Lisa at Greenbow said...

eeeeewwwwwwwww. What a strange creature.

Kyle said...

Gotta show this one to my son. He loves insects -- the weirder, the better!