The XX Factor

When Kvetching Kills

Whining is universal. From the frantic peeping of baby birds to the whimpering of a kid deprived of Chocolate Frosted Sugar Bombs in the supermarket checkout line, young critters know how to get their parents to feed them. Crying or squeaking or mewing tells the baby’s caretaker that they have needs that must be met NOW!!! But in the case of the European earwig, begging is a fatal miscalculation. Whiny earwig babies don’t get sent to their earwiggy rooms-they get starved to death by their mothers.

European earwigs , easily recognized by the giant pinchers adorning their buttocks, are a common garden pest that eats other insects, plants, and fruit. Despite their crawly appearance, female earwigs are good mommies, taking care of their 50-100 babies by feeding them regurgitated glop. Baby earwigs, called “nymphs,” don’t make sounds, but they do signal their hunger with chemical signals.

To figure out how the mother earwig responds to her offsprings’ hunger, researchers ground up well-fed nymphs and poorly-fed nymphs, extracted the oils from their bodies with solvent, and dosed intact earwig nests with eau de baby. They found that nymphs treated with the happy-baby smell got fed, while nymphs treated with the sad-baby smell were ignored. Mother earwigs concentrated their efforts on the least needy babies , while the nymphs that smelled like whining were left to starve.

Despite its cruelty, this makes evolutionary sense for animals with lots of babies that aren’t expected to live to adulthood. Why spend your time feeding whimpering weaklings when you could prepare your very best offspring to be all they can be? Unfortunately for people stuck on airplanes with whining Homo sapiens offspring, evolution dictates that species that invest a lot in a single baby have to take better care of it. Still, don’t you think the “Tale of the Begging Earwig” would make a great bedtime story?

Image by Menchi/Wikimedia