112 



THE SPRING GRAIX-APHIS OR ' ' GREEX BUG. ' ' 



wdtli winch they come in contact. The body of the aphidid is 

 cemented firmly to the object upon which it finally comes to rest. 

 The inner abdominal walls of the plant-louse are also lined with silk, 



which firmly adheres to them, and it may be 

 that the silk also acts as a tanning substance 

 for the body of the aphidid, as the latter be- 

 comes leathery and is apparently impervious 

 to water ; the old leathery bodies of the plant- 

 He e may often be found firmly attached to 

 plants after a heavy rain. After the cocoon 

 is completed the larva becomes quiet and in 

 most cases assumes, according to the junior 

 author, a position directly opposite to that 

 which it assumed while feeding and develop- 

 ing. Figure 22 shows a larva feeding, how- 

 ever, in the reversed position: this seems to 

 be unusual, the normal position being as 

 shown in Figure 21, Z. The larva oftentimes, 

 on becoming fully developed, is in some way 

 dislodged from the body of the aphidid. 

 This is probably due to some interference 

 while attaching the host to the leaf. These 

 cases are quite numerous in badly infested fields and the larva? appar- 

 ently never become adult. Figure 25 is a graphic illustration of 

 one of these accidents. 



Mr. Kelly found that the pupal stage lasted from 3 to 4 days. 



Fig. 24.— LarxaoiApliidiustesta- 

 ceipes spinning its cocoon in the 

 dead body of the spring grain- 

 aphis, showing the slit or open- 

 ing in walls of underside of 

 host insect. Much enlarged. 

 (Original.) 



Fig. 25.— Larvaof A ph iditi-* testactipes work- 

 ing its way prematurely from the body of 

 the spring grain-aphis. (From Webster. ) 



Fig. 26.— Full-grown larva of Aphidius 

 tataedpt': a Lateral view just prior to 

 pupation;b, front view of head. Greatly 

 enlarged. (Original.) 



Figure 26 shows the larva just prior to pupation. These observa- 

 tions were made indoors, during the winter, at the ordinary room 

 temperature. It requires from 3 to 5 hours for the Aphidius to 



