INSECTS AFFECTING GRAINS, GRASSES, ETC. 103 



to these egg-laying habits and the abundance of food on unculti- 

 vated land that this species always increases enormously on land 

 which has been flooded and then lies idle for a year or two. 



FIG. 83. A Locust-mite (Trombidium locustarum): a, the larva as seen on 

 locust's wing; c, male mite; d, female, the two latter appearing as when 

 egg-destroyers all greatly enlarged. (After Riley.) 



Most of the eggs are laid in August and early September. Each 

 female deposits a single egg mass of about 100 eggs just beneath 

 the surface of the soil. During this season the females may 

 frequently be found with the abdomens thrust deep in the 

 soil, as the process 

 of egg-laying re- 

 quires some time. 

 The eggs are yellow 

 and arranged irre- 

 gularly in a mass 

 which is coated 

 with a gluey sub- 

 stance to which the 

 earth adheres, 

 which protects 



them from variable _ 



.. . ,, . FIG. 84. Anthomyia egg-parasite, a, fly, o, puparmm; 



conditions of mois- c , larva; d, head of larva. (After Riley.) 



ture and temperature. 



Enemies. As before mentioned, large numbers of the nymphs 

 are destroyed before reaching maturity by their natural enemies. 

 Among these a minute fungus undoubtedly kills many of those 

 already somewhat exhausted, especially during damp weather. 



