THE ORGANIZATION OF INSECT SOCIETIES 



423 



to the physiological age of an individual. 

 Replacement of repioducti\es and ecologi- 

 cal stability may result in a potential im- 

 mortality of the colony as a whole (Emer- 

 son, 1939a). 



The fertilized queen founds the colony 

 in the social Hymenoptera. In temperate 

 climates, the queen wasp or bumblebee 

 may liibernate over winter and start the 

 colony in the spring. Among the primitive 

 social insects, such as the wasps, bumble- 

 bees, and certain Ponerine ants in AustraUa, 

 the queen acts in a similar manner to a 

 female of its solitary presocial ancestors. 

 She constructs the first shelter and forages 

 for food for her young. The colonizing 

 queen of most Ponerine ants and all the 

 higher ants does not forage for food, but 

 feeds the larvae with glandular secretions 

 derived through the absorption of wing 

 muscles. She often does not eat until small 

 workers have developed that break out of 

 the shelter and forage for food. During this 

 period, however, she may eat a few of her 

 own eggs. 



The young honeybee queen founds a 

 new colony after a swarming flight accom- 

 panied by many workers from the old 

 colony, so that she never exhibits the inde- 

 pendent behavior of her solitary ancestors. 

 Swarming is more likely to occur from 

 colonies headed by old queens than from 

 those with young queens. There is no doubt 

 that numerous complex social factors are 

 involved in the swarming behavior of 

 honeybees. It has been found, for example, 

 that a certain critical surplus in the propor- 

 tional number of nurse worker bees, with 

 consequent super-abundance of brood food 

 secreted by the nurse bees, is associated 

 with the construction of queen cells in prep- 

 aration for swarming (Morland, 1930). 

 Temperature and crowding within a colony 

 also seem to play a role preceding the 

 swarming flight. During the flight, emission 

 of an odor from the dorsal scent gland of 

 the queen is one stimulus in the formation 

 of the cluster. 



It is not only honeybees that found new 

 colonies by division of the old colony. The 

 colonizing wingless and worker-like queen 

 of the army ants (Eciton) also is accom- 

 panied by a large number of workers when 

 the old colony buds into two. Colonies of 

 other ants (i.e., Formica) also are known 

 to bud. 



New colonies of termites are almost in- 

 variably founded by a colonizing male and 

 female following a flight from the old 

 colony or colonies. The workers dig exit 

 holes preparatory to the colonizing flight, 

 and occasionally platforms are constructed 

 that faciUtate the flight (reported for Copto- 

 termes testaceus). The exit holes are often 

 guarded by soldiers. The alate reproductives 

 of Reticiditennes become photopositive and 

 geonegative, fly from the nest in various 

 directions, come to earth, and shed their 

 wings along the basal suture line. They 

 pair by means of a scent emitted by the 

 raised abdomen of the female, lose their 

 photopositive reaction and move to a 

 humid shelter site in tandem, the male fol- 

 lowing the female by means of a symmetri- 

 cal antennal tactile response (p. 434). To- 

 gether they dig out a cell in the soil or in 

 dead wood, plug the entrance hole, and 

 later copulate, produce eggs, and care for 

 the developing nymphs. 



NUTRITION AMONG SOCIAL INSECTS 



The workers are the nutritive caste. They 

 are somewhat analogous to the gastrovas- 

 cular system of the organism. They collect 

 the food from the habitat, comminute the 

 particles, transport food directly to the 

 other castes and young, or indirectly sup- 

 ply secretions and excretions of nutritive 

 or physiological value. The food area of the 

 colony is known as the trophoporic field. 

 The workers also transport waste products 

 and debris to the exterior of the nest. They 

 are primarily responsible for the building 

 of the shelters and nests. 



A variety of foods are used by the var- 

 ious social insects. The social Hymenoptera 

 evolved from sohtary predaceous wasps. 

 The social wasps retain their predaceous 

 behavior, but some visit flowers for supple- 

 mentary pollen food. The social bees are 

 primarily pollen and nectar feeders. The 

 primitive ants are predators, but many spe- 

 cialized ants have become scavengers or 

 herbivores, and a few have become slave- 

 makers or social parasites of other ants. 

 The termites are primarily cellulose eaters. 

 Their food is taken from wood, leaves, or 

 fungus with occasional supplementation 

 from animal feces, bones, leather, or other 

 materials. 



The Doryhne ants furnish a remarkable 

 example of predatory activity. The army 



