JULY
1990

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

7-09-90

Vive la Difference

In the insect world, male and female insects are different in ways other than the obvious physical attributes.

In the insect version of the dating game, insect sounds for attracting a mate are always produced by the male.  The songs of crickets, grasshoppers and katydids emanate from an all-male choir.  And the not-so-melodious shrill of cicadas results from the vibrations of a drumlike membrane on the abdomen of the males.

In fact, ancient Greeks recognized that male cicadas sang, while females were mute.  The old Greek philosopher Zenarchus summarized this fact in his comment, “Happy are the cicadas' lives for they have voiceless wives.”

Female insects have their own ways of dealing with the opposite sex.  Many females produce mating perfumes called pheromones.  Upon release, these chemicals, which are emitted from specialized organs, attract males from considerable distances.  Some of the large moths may travel up to 5 miles while following the pheromone trail of a female.  Although females dominate the insect perfumery business, a few male insects, such as some of the bark beetles, produce pheromones, too.

Following mating, many male insects go their merry way while the task of laying eggs and caring for the young is left to the females.  But some female insects don't let the males get off that easy.

For example, the giant water bug female captures a male and attaches her eggs to his back for him to carry until they hatch.  Other females – such as the praying mantids, some dance flies and even some fireflies – who just make a meal of their mate.

In some insect species, the number of males are reduced.  The engraver beetle populations are made up of 200 females to each male.  And some aphids have eliminated males all together.  These females produce without benefit of mating through a process called parthenogenesis.

Son in the insect world, it may be the males that do the singing, but more often than not, it is the female that has the last laugh!

 

Writer: Tom Turpin
Editor: Carol McGrew