5O HAROLD HEATH. 



workers (absent in Calotermes) and perfect insects together with 

 larva: in all stages of growth. The peculiarities of these castes 

 in the California species will be discussed in connection with their 

 breeding habits and the establishment of new colonies. 



In the case of Tcnnopsis the nymphs (larvae of perfect insects 

 with plainly visible wing buds) that have developed during the 

 year, undergo their last molt in from ten to twenty minutes, some- 

 times in the late summer or early autumn, unfold their wings 

 during the next two hours and within a fortnight have changed 

 from relatively helpless individuals to the active, dark-hued in- 

 sects ready for their extended nuptial flight. This takes place 

 just at dusk and is preceded by a period of great restlessness. 

 From openings which have been made for them by the workers 

 they issue rapidly by twos and threes and, with scarcely any pre- 

 liminary movements, rise into the air. Some soon fall to the 

 ground but in an open country others may continue their flight 

 fully a mile. At this time they are occasionally beset by numer- 

 ous woodpeckers, bluejays, tohees, wrens and sparrows who, with 

 much wrangling and chattering, banquet themselves far beyond 

 their usual bedtime. When darkness has compelled them to desist 

 bats continue the pursuit for another hour. So intent are these 

 creatures upon the chase that it is not a difficult feat to strike 

 them down, and in a woodpecker so secured twenty-six termites 

 were found while a bat had captured thirty-three. 



Despite these ravages a large number of insects escape and 

 may be seen flying from one tree to another in search of a suit- 

 able spot for the establishment of a colony. Several times I 

 have seen them dashing at door knobs and nail holes in houses 

 and against discolored spots on trees and logs in search of a 

 place where decay has begun. Succeeding in this they frequently 

 shed their wings, though with some this act is accomplished al- 

 most at the moment of alighting, while with others it may be 

 postponed until after their excavations have reached a consider- 

 able size. Curving the abdomen until it rests across the wings 

 of one side they move backward and usually sidewise, thus bring- 

 ing the tip of the wings against some construction and causing 

 them to buckle and break off along the line of weakness at their 

 base. The wings are never gnawed off. 



It appears that in most cases a female selects the site for the 



