Insects, for most of us, just aren’t lovable. This is the sad fact that poor Gregor Samsa, in Kafka’s great story “The Metamorphosis,” learned to his cost. Transformed overnight into a man-sized beetle, Gregor endured the pitiless ostracism we mete out to anything too radically different from ourselves and died of terminal neglect, ending up at last in a garbage can. Robert Frost, contemplating a “fat and dimpled” spider lurking in its web, could wonder whether “design governs in a thing so small,” as though there might be sinister loopholes in creation through which anomalous life-forms scuttle, disrupting all our notions of providential order.

Certain insects — butterflies and moths, many beetles — are beautiful. The vanes on the slender wings of the green lacewing look like Venetian glass inset with delicate filaments; the common Ladybird beetle has glossy contours sleeker than any Lamborghini’s. But their bizarre loveliness doesn’t endear insects and spiders to us; if anything, it makes them more alarming.

When we look at a grasshopper headon we seem to confront something like a countenance that looks back at us. It’s an antithetical face, without recognition or response; it not only disregards us, it cannot be read. The face of an arthropod is a mask worn by something unknowable to us. The social insects — ants,bees,and termites — live in densely organized communities that serve as models, as well as parodies, of our own. Is it such distant affinities that unsettle us in the end? Do we have more in common with scarabs and woolly aphids than we like to admit?

Certainly poets and fabulists from Aesop onward have used creepycrawlies to point morals. “Turn to the ant, thou sluggard,” the Bible advises us, “consider her ways and be wise.” (I note that industrious animals, such as bees and ants, are always held up as models, while the feckless grasshopper invariably comes in for prim disapproval.) But why not turn to the Vinegaroon or the Io moth or the Darkling beetle and consider their ways? These creatures might not teach us wisdom, but we’d learn a lot about techniques of self-defense.

For decades now the remarkable Thomas Eisner, professor of chemical ecology at Cornell, has been doing just that. His latest book, “Secret Weapons: Defenses of Insects, Spiders, Scorpions, and other Many-Legged Creatures” (Harvard University Press; 382 pages; $29.95), is co-authored with Maria Eisner and Melody Siegler. Arranged as a series of case studies of arthropods, together with a few “non-insectans,” this extraordinary book lays bare the almost incredible array of chemical stratagems these otherwise vulnerable creatures have adapted for their survival. If the case studies are astonishing, the numerous color photographs are even more so.

Though many of the critters described here are armed with pincers, stings, spines, and biting mouthparts, their most effective defenses are chemical. These range from outright venoms in the case of scorpions and spiders, injected through fangs, to noxious compounds, sprayed or regurgitated or even dabbed on hapless predators,in the case of grasshoppers and earwigs. I was surprised to encounter some old acquaintances in these pages. Growing up in South Florida I used to catch the big Lubber grasshoppers whose gaudy overlapping platelets reminded me of Samurai armor; it was part of the fun that once caught, these imperturbable highjumpers hissed like a bike tire with a puncture and coughed up a nasty tobacco-brown fluid all over my triumphant fist. I now learn, with retrospective distaste, that this stuff was “a bubbling froth from the metathoracic spiracles.” As the authors neatly put it, “The thoracic froth is emitted with a hiss and, as a consequence of the bursting of its bubbles, results in the formation of a fine, malodorous mist.”

Chemical defenses are not invariably so unsubtle. If the Rattlebox moth blunders into a spider web it settles down calmly with folded wings.When the resident spider darts out to welcome the prey to her parlor, she palps the moth carefully then cuts it loose (there is a stunning photograph of this process in the book). Rattlebox moths feed on plants containing a poisonous alkaloid and spiders know better than to eat them. But perhaps the most dramatic example is the Bombardier beetle, a bug that has made Mr.Eisner famous on the lecture circuit. The Bombardier, a trim little beast with black and saffron wing covers, produces a searing jet of benzoquinone, which it shoots with a loud pop, and with pinpoint accuracy, at aggressors. Even more remarkably, the bombardier produces its hot-shot at the instant of discharge in what Mr. Eisner aptly terms an “explosive synthesis.” Mr. Eisner’s affection for this six-legged howitzer is catching, but when he provides detailed instructions on how to catch a Bombardier and then fasten it to a tether, the better to observe its marksmanship, even hardened insectlovers may recoil.

It’s impossible to read this beautifully written and gorgeously illustrated book without feeling a heightened sense of wonder. Predator and prey are shown to be fatally entwined in a world of interlocking appetites; a world moreover where survival entails well-nigh molecular ingenuity. No doubt some readers will find evidence of “intelligent design” in these studies, but I have my doubts. Like Frost I have trouble detecting conscious design in the “large, shiny, spectacularly beautiful” Darkling beetle, though I can envision a creator sophisticated enough to have set in motion the whole intricate and mysterious process that eventually produced such a marvel. The British geneticist J.B.S. Haldane once quipped that the only inference we could draw from nature about a possible Creator was that He displayed “an inordinate fondness for beetles.” Mr Eisner and his collaborators not only share this fondness but, even better, they demonstrate that the divine preference is thoroughly justified.

eormsby@nysun.com