The Elements of Evolution (43-14-8) Hawaiian Crickets

 Hawaiian Crickets

If you’re a male cricket, your life is defined by calling. How are you going to find a female, and once you do, how are you going to get her to mate with you without your call? ~ American evolutionary zoologist Marlene Zuk

Male crickets usually sing to attract a mate. Cricket singing is done by rubbing wings. The evolutionary changes described pertain to alterations in wing design.

The crickets on Hawaii discovered that their marital crooning made them easy targets for parasitic flies. The flies deposit their maggots on the crickets. The maggots burrow into the cricket and eat it alive.

Within a few generations of the parasites becoming a plague male crickets evolved to stay silent. Shortly thereafter they regained their voice: a cat-like purr at a lower register than the parasitic flies could hear. Understanding female crickets mated with quiet males until they could get their singing act back and have adjusted to the new register. These cricket adaptations recurred independently on the different islands of Hawaii – an instance of convergent evolution.

Purring crickets communicate with potential mates. ~ American evolutionary behavioralist Ann Hedrick