Eusocial insects

The highest recorded fecundities are found in the eusocial insects. Indeed most eusocial insects have high fecundity. Fenton (1952) states in his textbook that the queen of the termite Termes bellicosus (=Macrotermes natalensis) lays an estimated 30,000 eggs each day and, on average, lives 10 years. This calculates to more than 109 million in a lifetime. However, Fenton gives no primary source for his estimates, making it difficult to evaluate their worth. The honey bee queen (Apis mellifera), can produce up to 200,000 eggs each year (Bodenheimer & Nerya 1937), and has a life span of 3-4 years.

Army ants and driver ants appear to have the highest fecundities among ants, though the longevity of the queens is not known. The army ant Eciton burchelli, can lay a new brood of 120,000 eggs every 36 days (Schneirla 1957). Queens of the African driver ant Dorylus wilverthi can lay broods with up to 3-4 million eggs every 25 days (Raigner and van Boven 1955). Other driver ants have similar fecundity, 1-2 million eggs in a month (Holldöbler and Wilson 1990). The queens are the largest among the ants and have up to 15,000 ovarioles. They lay egg more or less continually, but with bursts of high production every three weeks that last for five or six days.

All values for egg number in eusocial insects are fairly rough estimates. The insect with the highest fecundity is certainly eusocial, but it is impossible to say which is really highest. The best candidate so far is D. wilverthi.

The eusocial insects have a highly organized social system, usually with only one female that does all of the egg laying (Wilson 1971). The other members of the colony provide her with food, and tend her eggs as well as doing all of the foraging and nest defense; instead of laying their own eggs, they help the queen to achieve as high a fecundity as possible. Generally, increasing parental care is associated with decreasing fecundity (Roff 1992). In eusocial insects we have intensive care of offspring, but not by the mother, who is freed of all responsibilities other than egg-laying. This division of labor makes it possible for a queen to have extreme specializations for fecundity.