CHERMES OF MAINE CONIFERS. 29! 



continues its growth from the apex of the gall, while in others 

 the gall is produced in a one sided manner only partly encircling 

 the twig. The cells of the gall are closed. A sample gall 

 about J inches long contained about 50 cells each holding from 

 8 to 12 nymphs. This count was made August 13. 



About the middle of August at Orono the mouths of the 

 cells open and the pupae emerge to molt. 



Nymphs, the Gall Generation. Specimens taken from galls 

 June 23, 1904, are recorded as greenish yellow. July 24, 1909, 

 nymphs are recorded as very pale yellow covered with white 

 pulverulency. Molted skins attached to caudal extremity were 

 filled with liquid so as to retain their shape. Many nymphs 

 had two such molts attached so that three successive stages 

 of the insect were in line. The excreted liquid being largely 

 disposed of in this manner, the cell wall of abietis is clean and 

 dry, a condition made further possible by a slight covering of 

 waxy powder. 



Pupae. Body length of full-grown pupa 1.9 mm. Speci- 

 mens taken from galls on Norway spruce August 4, 1909, were 

 very pale yellow, slightly pulverulent. Others taken from galls 

 on white spruce August 17, 1909, were a little darker yellow 

 and the finely-pulverulent abdomen had a slight rosy tint. The 

 pupae leave the galls before molting. The time of most plen- 

 tiful emergence is from about the middle to the last of August 

 for the vicinity of Orono, though the galls in more exposed 

 sunny places are about a week earlier in opening than the aver- 

 age shaded ones. The pupae creep from the open cells of the 

 galls in a sluggish manner and often rest in Indian files on the 

 needles near the gall, where they molt and become the winged 

 individuals. The cast skins remain in white rows upon the 

 needles for some time unless dislodged by rain. See Fig. 140. 



The wax pores for the pupa are: (Fig. 117) head with an 

 anterior group of pores near base of each antenna and two 

 median groups at posterior margin ; prothorax with lateral gland 

 area, an anterior median pair of groups, a small group (4 pores) 

 between the lateral and median ones, and four groups near 

 posterior margin of prothorax; mesothorax with an anterior 

 lateral area; metathorax with two separated median groups; 

 abdomen with small and widely separated median groups on 

 segments I-VI, those on I being composed of about 6 pores, 



