In today’s Academic Minute, Dr. Oliver Beckers of Indiana University explains how parasitism and impending death influence the mate choice of once insect species.
Oliver Beckers is a postdoctoral research fellow at Indiana University where he studies the evolution of insects in the Moczek Lab. His current project examines the influence of an eavesdropping parasite on the communication systems of crickets. He holds a Ph.D. from the University of Missouri.
Dr. Oliver Beckers – Parasitism and Mate Selection
If you have spent a summer night outside, you probably have noticed all kinds of animal sounds. Many of these sounds are the songs of crickets. Males sing to attract females for mating and to guide the females to his location. Unfortunately, the conspicuous guys also attract some unwanted attention. Parasites eavesdrop on the mating songs to find the singer and turn him into a meal. This species interaction sets up a fascinating evolutionary arms race pitting survival against reproduction.
I study the evolution between a parasitic fly and its cricket host. The fly tracks down singing males and deposits its larvae on the cricket. The larvae burrow into the cricket, feed on him, grow, and kill him when they emerge. But the drama does not end here. The fly also places larvae around the male to infest female crickets that approach the male for mating. Healthy female crickets prefer males that have fast songs and will go out of their way to find these males.
I tested whether being parasitized will cause females to become less picky about their mates. Indeed, I found that once parasitized and facing imminent death, females are just as likely to choose a slow singing male as a fast one. With their mating standards lowered, parasitized females insure that they reproduce before they die. These lowered standards also mean that not only the ‘sexist’ guys but also the ‘average Joe’s’ get a chance to mate. Isn't it amazing that all of this drama involving love, murder, and evolution happens outside in your backyard?