90 



CEREAL AND FORAGE INSECTS. 



Elsewhere is given a description of the method of attack used by the fly in avoiding 

 the larval spines during oviposition. 



The pupal period of these flies is sixteen days. No data for the length of the larval 

 period could be obtained. 



Fig. 50. 



-Pimpla conquisitor: a, Larva; 6, head of same; c, pupa; d, adult female. 

 a, b, c, redrawn from 4th Rep. U. S. Ent. Comm.) 



Enlarged, (d, Original; 



After eggs of this tachinid had been observed on a number of Hemileuca larvae, near 

 the end of July, the first example being seen July 17, 1909, an effort was made to 

 observe the method of oviposition employed by the fly . Some 400 larvae were collected 

 and assembled on a large detached sod of Sporobolus airoides, a favorite food grass. 



Fig. 51.— Tachina mella: Adult. Enlarged. (Original.) 



These larvae were watched closely for several days, and on July 26 a tachinid fly was 

 seen in the vicinity of a large caterpillar that was resting quietly on a grass stem and 

 feeding leisurely at intervals. The attitude of the fly was peculiar, and attracted 

 attention at once. She stood about 4 inches from the larva, facing it, her antennae 



