JANUARY
1988

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

01-21-88

Insects Don't Add; They Multiply

It has to do with the birds and the bees—mainly the bees!  Bees and other insects are very good at laying eggs in very large numbers. Scientists believe that rapid reproduction is one reason for the phenomenal success of insects on earth.

Consider the honey bee queen. In the warm months of June and July, she can lay between 1,500 and 2,000 eggs each day. Since she must deposit each in a cell of the comb, that production represents a good day's work. You might say she's “busy as a bee” during that time. A honey been queen will produce around 100,000 eggs during her average 3-year life span. Not a bad record.

But honey bee egg production pales in comparison to that of the large queen termites of Africa. Such queens, real egg-laying machines, may lay as many as 36,000 eggs in 24 hours. That's about 25 eggs a minute and totals over 13,000,000 per year. Such queen termites are believed to live between 50 and 100 years. That figures out to be over a billion eggs produced by one queen.

While the old housefly is no queen termite when it comes to laying eggs, she isn't a slouch either. Average egg production during the life of a housefly is probably around 800 eggs. The record number of eggs measure for one fly is 2,387. But the success of the housefly is not solely due to the rate of egg-laying; it is also due to the speed with which the insect goes through its life cycle.

The same is true for the fruit fly, an insect hat almost everyone recognizes. Fruit flies seem to magically appear around overripe vegetables or fruit. The appearance of large numbers of fruit flies in a short time shows how fast this insect develops. Under ideal conditions, fruit flies may produce 25 generations per year. Each female may lay up to 100 eggs, of which about half will hatch into females and half into males.

It has been calculated that by starting with one pair of fruit flies and allowing the original and all succeeding females to reproduce under ideal conditions for one year, the number of flies would be fantastic—about 1041 .  (That's 10 with 41 zeros behind it.)  All those flies would form a ball 96 million miles in diameter, if you assume that 1,000 would fit in a cubic inch. A ball that size would almost reach the sun from the earth!

Of course, all insects that hatch don't survive to reproduce. Many insects die of starvation or exposure to lethal temperatures or are consumed as food by other animals. Among insects, many are hatched so that a few survive. You could say that in the insect world, the battle cry is, “The more, the merrier!”

 

Writer: Tom Turpin
Editor: Steve Cain