110 PROC. ENT. SOC. WASH., VOL. 22, NO. 6, JUNE, IQ2O 



Results of Breeding Experiments: 



Progeny of first form adults 136 



Progeny of second form adults 139 



Progeny of third form adults 142 



Progeny of "intermediate" reproductive forms of termites 143 



Infertility of termite soldiers with wing vestiges 143 



Attempts at Cross-breeding: 



Methods 144 



Results 144 



Summary and Conclusions 145 



Literature Cited 148 



Introduction. 



Interest is always attracted by unusual flights of any animals, 

 whether birds or the less conspicuous insects. In tropical coun- 

 tries, even to the scientist, there is almost an element of magic 

 attendant upon a termite swarm. Apertures are opened in the 

 ground or parent colony mound and suddenly the air is alive with 

 fluttering winged hordes which emerge from these exits. After 

 the flight, the holes are closed from within by workers and all 

 trace of life disappears as suddenly as it appeared. The only 

 evidence of the swarm is the discarded wings lying upon the 

 ground. 



Every year the Department of Agriculture receives numerous 

 requests from householders in the United States for information 

 in regard to "flying ants" in buildings. These so-called flying 

 ants are in reality colonizing male and female adult termites, 

 which leave the parent nest or colony in the woodwork of the build- 

 ing and fly or "swarm" in large numbers for the purpose of estab- 

 lishing new colonies. Similar swarms may be observed issuing 

 from colonies in decaying stumps and logs in the forest on warm 

 sunny days. 



It is not known what causes this annual swarm or exodus of 

 the winged adults. Possibly they are impelled to leave the 

 parent colony by some instinct, as by the call of sex, or there may 

 be a "spirit of the colony" similar to that which Maeterlinck so 

 aptly described in "The Life of the Bee" (1904) as the "spirit of 

 the hive." It is not the queen honey bee who rules the hive 

 and induces the swarm of queen, drones and workers, but this 

 elusive "spirit of the hive," evidenced in the assembly of the 

 workers, which are said to have the larger brain. In the case of 

 the termites, however, the winged males and females which 

 alone swarm have a far larger brain than the worker, Thomp- 

 son (1916). This "spirit of the colony" in termites may be merely 



