March, '09] ENTOMOLOGICAL NEWS. in 



body turned to a normal position, feet down. Within a min- 

 ute or two the body was found to have become firmly fastened 

 to the slide. The slide was then turned over and returned to 

 the stage, the body of the aphid suspended below. Through 

 the glass the now active larva could be seen as through a win- 

 dow, while it completed its task of making the aphid's skin 

 fast to the slide. A smear of glutinous fluid along the torn 

 edges of the opening seemed to have been the first move, fol- 

 lowed by ceaseless spinning of a silken thread from the mouth 

 of the larva back and forth across the rent and then all over 

 the interior of the aphid's body, thus making a delicate cocoon 

 for itself. The drying of this silken tissue and the gradual 

 increase of threads spun across the opening through which 

 watch was kept, rendered the view more difficult as time went 

 on, and finally it was impossible to distinguish clearly what was 

 taking place within because of the opacity. 



Several more parasitized aphids of the same species, taken 

 at about the same point of development of the larvae within, 

 were placed under constant observation, and it was learned 

 that each was torn or split down the median ventral line, al- 

 most from coxae to cauda, by the muscular movements of the 

 enclosed larva. This clearly did not happen by accident, for 

 each larva went through the very same performance described 

 above. Why the aphid's body should open along the median 

 ventral line, the only place where it could be utilized by the 

 helpess larva within rather than across the back where it would 

 be disastrous, is not known at present, but the fact remains 

 that the larva is in this manner afforded an opportunity to se- 

 cure itself against possible danger by fastening its frail cover 

 strongly to the plant. 



Previous to the appearance of this opening, one larva, not 

 as far advanced, was watched through the thin walls of the 

 aphid's body, and was seen to make a complete circuit of the 

 interior in twenty-one minutes, driven slowly around by a series 

 of pulsations, one hundred and eleven of which were required 

 to bring the head again to the point from which it started. 

 These movements probably vary with the temperature, time 

 of year and maturity of the larvae. 



