Burying Beetle, Nicrophorus sayi

The Nicrophorus sayi beetle feeds its young on a mouse ball! Two adult beetles, working as soon-to-be parents, find a dead animal, usually a mouse, and bury it by digging out the soil beneath the corpse. They then strip some or all of the carcass, make the flesh into a ball, and coat it with secretions that scientists think may help to prevent or slow the decay of the mouse corpse.

The female then lays her eggs in soil nearby. When they hatch, the larvae move into a crevice their mother has excavated in the mouse ball, where they are fed liquid food regurgitated by their mother until they can eat the mouse by themselves. With their mother near, protecting them from competitors (like other insects who'd eat them or the mouse) the larvae spend five to eight days eating (usually the whole mouse) and developing very rapidly. When they're done the larvae move back into the soil and pupate. Two weeks later, and voilà!, they're adults too. Meanwhile, if there are any mouse leftovers, the mother may lay more eggs.

Illustrations by Roelof Idema, after illustrations from Scientific American 235: 84-49.

Nurturing behaviours, like feeding and guarding, are very unusual in the insect world, and are usually only seen in insects with highly developed social behaviour, like wasps, termites, ants and social bees.

Animals

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