TERMITES IN THE UNITED STATES. 5 



become unfavorable. A single colony may be spread over an extensive 

 area, and it is often impossible to define the limits of a colony. At 

 higher altitudes in the Appalachian Mountains, in the canyons of the 

 Southwest, and in high mountains in the West, termite colonies in 

 the earth and under stones are more common. Colonies of Eutermes 

 are commonly found in the earth. 



NUMBER OF INDIVIDUALS IN COLONIES. 



Average colonies probably contain several thousand individuals. 

 In old, long-established termite colonies the number of individuals 

 runs up into the tens of thousands. Young, recently established or 

 incipient colonies are small and the increase in numbers is slow. 



THE LIFE CYCLE. 



THE METAMORPHOSIS AND CASTE DIFFERENTIATION. 



The recently hatched termite larva? (fig. 2) are all similar or un- 

 differentiated, but are active from the first. At a later molt two types, 

 large and small headed larvae, 

 can be distinguished. The f ormer, 

 after a series of molts and quies- 

 cent stages of comparatively short 

 duration, develop to workers and 

 soldiers, the latter to reproduc- 

 tive forms. 



There is no apparent or ex- 

 ternal change in the development 

 of the worker, the larva being 

 active and of the same form as 

 the adult. There are marked 

 changes, however, in the develop- 

 ment Of the soldier, with narrow. FlG - ^.—Leucotermes flavipes: a, Newly 

 .. . i i Ti • hatched larva; b, same from below; 



elongate head and saberlike jaws. c , egg. ah enlarged. (From Mar- 

 from the round-headed worker- latt) 



like larva. The winged, pigmented, sexed adults and the several types 

 of neoteinic reproductive forms are developed from small-headed 

 larvae, there being still more radical changes, the former originating 

 from nymphs of the " first form," with long wing pads, the latter 

 from nymphs of the " second form " (Lespes) with short wing pads, 

 or from young larva?. 



However, in all stages of the development of termites, what may be 

 termed the " antlike " form of all castes can be recognized. There 

 are no long inactive larval and pupal stages as in the ants and other 

 social insects. 



In the life cycle of termites there is so much variation in the de- 

 velopment of the castes that there is consequently a rather complex 



