232 A NATURALIST IN HIMALAYA 



After the wings have fallen the insects then hide 

 themselves beneath the stones or make their way into 

 the crevices in the ground. They commence to dig 

 but make only slow progress. By the following 

 morning many are still so near the surface that they 

 are unearthed by the hungry crows. I do not know 

 at what moment sexual union actually occurs. Any 

 one who has watched a flight of termites will have 

 noticed how, after the wings have fallen, the insects 

 do not wander indiscriminately about, but rather 

 separate themselves into distinct pairs. The ground 

 is often covered with these segregated couples, yet 

 actual union is never seen. I am inclined to think 

 that the object of the termites in separating into 

 sexual pairs is not, as might at first be imagined, to 

 secure immediate union. It is rather a device to 

 make certain that each new nest which is established 

 should contain a productive pair. The loss of life 

 amongst the termites is so severe that certain special 

 provisions must be made to help the survival of the 

 race. This is one of these provisions : that whenever 

 the time of union comes, the sexes may be found 

 distributed through the ground in suitable sexual pairs. 



I pass to another neuropterous insect. Loose 

 sandy patches, often on the summit of a low, rounded 

 hill, might be found occupied by a colony of Myrme- 

 leonid larvae. These ant-lions are well known, especi- 

 ally the pits that they excavate in the sand to capture 

 their prey. The hilly country was unsuited to their 

 work, and I never saw them above 5000 feet. 



The larvae are very small, not more than one-quarter 

 of an inch in length. Each possesses a stout oval 

 abdomen and a small head furnished with strong 



