Wasps are generally recognized as being more aggressive and more dangerous to humans than bees, but wasps are also the bullies of the insect world. Despite their relatively small size, many wasps prey on large insects and spiders, such as cockroaches and tarantulas. Although wasps are known for their brutal killing methods, female wasps make for caring mothers. In fact, the large insects and spiders that wasps prey upon are ultimately used to provide a safe nesting habitat and a ready source of food for their developing offspring. However, back in 2014, researchers discovered a new wasp species that had been observed abandoning its nest with its offspring sealed inside. While this behavior seemed at odds with the strong maternal instincts exhibited by most wasp species, researchers were more focused on this new species’ odd habit of using piles of ant corpses to seal their young within their nests before abandoning them permanently. As it turns out, this seemingly cold act of parenting may be the best thing that these wasps can do for their young, as the ant corpses were found to repel predatory insects from the nests.
During the summer of 2014, researchers described a new species of wasp that they named Deuteragenia ossarium, or the bone-house wasp, as they are more commonly known. Unlike most wasp species, bone-house wasps do not excavate their own nesting sites; instead, they locate abandoned nests that had been created by other insects, most often wood-boring beetles. After placing their developing offspring within the nests, the mother wasp proceeds to seal the only entrance to the nest with piles of dead ants. The mother wasp then abandons the nest, leaving its offspring with nothing more than their nest as protection from predators. However, the nest is all the offspring require, as the ant corpses fool predators into perceiving the nest as being occupied by an active colony of ants. Predators are deterred from entering the nest due to pheromones that the ant corpses continue to emit from their exoskeletons. Researchers found that of all the ant-containing nests, only three percent had become infiltrated with parasites that killed the wasp offspring. Researchers removed the ants from many other nests in order to see how they fared against parasitic organisms and other predators. Sixteen percent of the antless nests had become infected with parasites, proving that the ant corpses were effective at deterring predators.
Do you think that all social insect species exhibit a natural instinct for maternal care?