Vol. XXviii I ENTOMOLOGICAL NEWS. 365 



the ventral surface is glued fast to its support. Inasmuch as 

 the Aphelininae attack only the short-legged and smaller-bodied 

 species of aphids, it must be much easier for their larvae to 

 anchor the bodies of their hosts than for those parasites that 

 prey on the longer-legged forms like Macrosiphum and Rhopa- 

 losiphum. But even these larger forms are often fastened to 

 leaves and grain blades by their internal parasites. As the 

 process has never been watched, so far as I know, the exact 

 means used to bring the abdomen to a junction with the leaf 

 on which the aphid stands is unknown, but is probably simple 

 enough when once understood. 



An exception to this common practice among braconid para- 

 sites is that of the genus Praon which attacks the larger aphids. 

 In Insect Life, Vol. IV, p. 196, 1891, Dr. Howard calls atten- 

 tion to the fact, often since observed, that the larva of Praon 

 constructs a tent-like cocoon beneath the body of its host for 

 a pupation chamber. An opportunity was afforded the writer 

 during the summer of 1916 to watch the entire process of con- 

 structing this cocoon, and the details are presented herewith. 



July 15, 1916, a parasitized apterous Macrosiphum pisi was 

 taken on a leaflet of white clover just as the larval guest within 

 its body had deprived it of the power of motion. The dying 

 aphid, still standing on the leaflet, was placed within a small 

 vial where it would be undisturbed and could be easily ob- 

 served without interruption. 



Scarcely had it been secured in this way when the abdomen 

 of the aphid was rent ventrally by the activity of the imprisoned 

 larva. But the long sprawling legs of the aphid made it clearly 

 impossible to cement the body to the leaf and the problem be- 

 fore the larva was to somehow bridge this gap. It thrust its 

 head at once through the opening and appeared to be care- 

 fully investigating the situation. Without entirely leaving the 

 cavity of the aphid's body it swung its flexible head about, not 

 aimlessly as it very soon proved, for in less than five minutes 

 it was busily at work to form its cocoon. Touching the sur- 

 face of the leaf with the tip of its pointed head, it spun a fine 

 silk thread, attached to the leaf at its lower end, and attempted 



