Social insect colonies make for an interesting topic of study for entomologists, biologists and even engineers. The reason for the widespread fascination with the nature of social insects is largely due to their advanced behavior when compared to non-social insect species. As most people are well aware, insects are one of the first terrestrial animal groups to have emerged on earth, making them quite primitive when compared to animals that developed later during the course of evolution. In fact, social behavior itself is, for the most part, a relatively recent evolutionary development when considering the full 500 million year course of terrestrial animal evolution. Therefore, one cannot help to be shocked upon learning that some of the most ancient insect species are inherently social in their behavior. The most remarkable aspect of social insect behavior is the manner in which these insects communicate. In most social insect colonies, queens facilitate cooperative and constructive group behavior by transmitting both vibratory and pheromone messenger cues to her underlings. However, a research team has recently learned that a paper wasp queen has the ability to determine how her offspring develop. As it turns out, a paper wasp queen bangs her antennae against her colony’s nest in order to produce vibratory signals that induce her eggs into developing into worker wasps as opposed to a reproductive wasps.
A paper wasp colony contains a founding queen, her workers and secondary reproductives that establish future colonies. The caste of workers care for the offspring as well as build and maintain the nest. The secondary reproductive caste, also known as gynes, can lay eggs and become future queens. However, all of the eggs laid by paper wasp queens are genetically identical, which has long confused researchers, as these identical eggs will develop into either workers or gynes. So how can genetically identical eggs develop into two genetically separate castes? Amazingly, the queen’s antennal drumming induces larvae into developing into low body fat workers that cannot reproduce and have relatively short lifespans. But, eggs that are not exposed to this drumming will develop into gynes. Therefore, by creating rhythmic drum beats on the nest, paper wasp queens alter larval development to fit the immediate needs of the colony.
Do you know of any other insect species that communicates via vibratory signals?