A Bittersweet Millipede

PROMO Intro Millipede 512x219

In the dank forests along the Pacific coast there can be found a leggy little creature, scarcely two inches in length, crawling among the sodden leaf litter and conifer needles and mossy, moldering woodrot at a methodical plod. Its elongate form is clearly arthropodal; closer inspection reveals roughly twenty shining segments, each painted an aposematic yellow and black. Thirty-odd pairs of legs undulate along the span of its body, starting from the rear and rippling toward the head in a locomotive wave. Its movements embody the can-can in slow motion, thirty kicking limbs on either side. The millipede chugs along, unhurried and unafraid.

Whence arises its nonchalance, its poise? The Yellow-spotted Millipede (Harpaphe haydeniana) is a denizen of the forest floor, a decomposer of humble mien. It consumes dead plant matter and expedites the leaf litter’s decay, breaking down cellulose and lignin in its gut and excreting ready-to-use fertilizer in its wake. Like earthworms, the millipedes provide an immeasurable benefit to the health of the forest, aerating soil, cycling nutrients, and generally keeping plant waste at a manageable level. Unlike earthworms, however, the yellow-spotted millipede has a toxic leg-up: when threatened, it emits sweet-smelling hydrogen cyanide from its sides, in a dose powerful enough to deter shrews and beetles and most other smallish predators. The cyanide is redolent of almonds, hence the common names “almond-scented millipede” or “cyanide millipede” for this oft-encountered critter.