2 BULLETIN 333, U. S. DEPARTMENT OF AGRICULTURE. 



in colonies which are made up of various highly specialized forms or 

 castes, are naturally to be classed among the so-called social insects, 

 comprising the ants, bees, and wasps. Each of these forms has a 

 duty in this organization and there is a division of labor. In the 

 systematic classification of insects, however, termites are widely sep- 

 arated from the other social insects, which represent the highest and 

 most specialized development, while termites are among the lowest 

 and oldest insects. Further, in many points in their life habits ter- 

 mites differ widely from the other social insects. 



DESCRIPTION OF THE INSECTS. 



THE DIFFERENT FORMS OR CASTES IN THE COLONY. 



Since the work of termites is largely subterranean, or under cover, 

 the insects are rarely observed at work and the injury is often hidden 



Fig. 1. — Leucotermes flavipes: a, Adult male; ~b, terminal abdominal segments from below; 

 c, same of female ; d, male, side view, somewhat inflated by treatment with ammonia ; 

 e, abdomen of female, side view ; /, tarsus, showing joints and claws, a, d, e, Enlarged ; 

 6j c> 1> greatly enlarged. (After Marlatt.) 



until the destruction of the wood that they are inhabiting is complete. 

 An indication of the presence of termites is the annual flight or 

 swarm of the winged colonizing sexed adults which emerge in enor- 

 mous numbers from the ground and crevices or holes in infested 

 wood. 



In the communal societies of termites, however, there are both 

 wingless and winged mature individuals, as well as the young of the 

 different forms in various stages of development. The brownish or 

 blackish, elongate, slender, antlike adults (fig. 1) with long white 

 wings are not the most destructive form, although they have biting 

 mouthparts, but are migratory individuals which have the sexual 

 organs developed, and appear normally only once a year during a cer- 

 tain season, which varies with the species. These male and female 



