PABASITE, APHIDIUS TESTACEIPES. 109 



Two adult Aphidius issued from those individuals included in the 

 first section of the table and 18 from those in the last section. In this 

 latter section Aphidius began to issue March 30 and the last issued on 

 April 3. Those that issued on the latter date were from those that 

 were adult winged adults when parasitized. 



All of these experiments were conducted indoors, and those of the 

 last division of Table XII, under a daily temperature ranging from 

 50° to 80° F. 



From Table XII it will be seen that Toxoptera that have molted 

 only twice before being parasitized may become winged adults, and 

 in some instances produce young. All of our observations show that 

 individuals that have molted three times and then been parasitized 

 will become adult and produce young, and in case they are wingless 

 they may produce 10 or more. Eleven is the maximum number of 

 young, according to our observations, produced by a single individual 

 after parasitization. 



MOVEMENT OF LARVA WITHIN THE HOST AND MANNER OP ATTACHING IT TO THE PLANT. 



Observations were made upon the movements of the larva (fig. 21) 

 within the host by the senior author at Manhattan, Kans., in 1907, and 

 published in the Proceedings of the Entomological Society of Wash- 

 ington. 1 



It appears that the larva of the parasite, at least until after it 

 attains some growth, moves little if at all within the body of the host, 

 and thus interferes with no vital functions of the Toxoptera. 



When the larva nears maturity, as shown by the yellowish color of 

 the abdomen of the " green bug," it becomes quite active, making a 

 number of revolutions within the body of its host, at which time the 

 latter seizes the leaf with a rigid death-grip and the last spark of life 

 soon fades. The object of the revolutions is, apparently, to mold the 

 body wall of the aphidid, while it is still plastic, into the most suitable 

 shape for pupation. An idea of how this desired end is accomplished 

 may be obtained by glancing at the accompanying illustrations. 

 Figure 22 shows the normal position of the parasitic larva within the 

 body of the host before the revolutions begin. It was found that a 

 fully developed larva (fig. 23) made three revolutions within the body 

 of the host, always going forward, in the space of 35 minutes. During 

 the next 5 minutes it made another revolution ; a fifth revolution was 

 completed in the next 10 minutes; the sixth during the following 8 

 minutes; the seventh in the next 9 minutes; the eighth after a space 

 of 4 minutes; the ninth in the following 4 minutes, after which, on 

 account of the opaqueness of the walls of the host, no further count 

 was kept of the revolutions, although several more were known to 

 have been made. Some of these different positions of the larva and 



i Proc. Ent. Soc. Wash., vol. 9, Nos. 1-4, pp. 110-114, 1907. 



