Friday, June 09, 2006

Aliens Above? How About Below?

SECRET WEAPONS: Defenses of Insects, Spiders, Scorpions, and Other Many-Legged Creatures / (2005) / A book by Thomas Eisner, Maria Eisner, Melody Siegler.

Scanning the night sky, wondering what kinds of life exist Out There. But maybe some clues are creeping around your feet. Or are tunneling right under your shoes.

I picked up this book to see what “alien” life-forms exist among us. Insects and similar critters occupy their own strange world, one that can be creepy, even disgusting.

For example, how about insects that use their own dung as a defensive shield? A tortoise beetle –- known by the Latin appellation of Gratiana pallidula -- in its larval form has a two-pronged fork extending from near its anus back over its body towards its head. This fork accumulates waste matter, forming a pasty barrier. Even when the larva molts, it retains this shield that keeps growing through each larval stage. The shield can be tilted to fend off attacks from enemies such as spiders and ants.

Other insects can bleed defensive chemicals from their joints. In a couple of disturbing photographs, the authors show how Epilachna varivestis, the Mexican bean beetle, emits yellow drops of blood from its knees when its hindlegs are pinched by tweezers. These drops contain defensive alkaloids that ants and spiders find unappetizing.

Then there’s a harvestman known by the Latin name of Vonones sayi that uses an oral fluid in its mouth to make meals digestible. The same regurgitated fluid can be wielded as a weapon: the harvestman wipes its leg against the fluid, forming a droplet on its multi-jointed limb that can be used defensively at different angles.

And let’s not overlook the sticky stuff. No, I don’t mean web-wielding spiders. I mean termites. Nasutitermes exitiosus comes in a soldier version with a rostrum (tapered snout) that squirts a filament that is irritating and sticky. This spray from a number of soldiers acts like an accumulating glue, leaving the victim unable to move.

Also, these termite soldiers, who are almost completely blind, emit pheromones to communicate alarm. Pheromones act like chemical communicators among many organisms, from plants to animals.

Secret Weapons is illustrated will all sorts of squirting, bleeding, stinging, and spraying little critters that are as alien as anything I’ve seen in a SF novel.

One wonders: are there intelligent civilizations Out There that evolved from entomoids?

When contact is finally made, what should concern us is not the aliens have beliefs and knowledge that will cause a culture shock for mankind. Maybe aspects of their biology are just disgusting to us, even obscene.

Imagine an entomoid visitor crawling down the ramp of his flying saucer, his defensive dung shield in place, bloody drops clinging to his flexible forelegs.

Some humans start gagging, detecting the miasmic pheromone being emitted by the buggy being from beyond.

But the visitor can’t help it. He finds humans to be so revolting that his defenses have automatically activated. He’s doing his best be diplomatic. He extends his sticky foreleg to shake hands…

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