8 PROCEEDINGS OF THE ACADEMY OF [Jan., 



without growing perceptibly in size. These develop into stem-mothers 

 upon the red fir the following spring and are probably the chief, but 

 not the only, cause of the form described below as coiceni occurring upon 

 the red fir. It is also strongly probable that the stem-mothers for the 

 two summer broods of Chermes cooleyi come in a similar manner from 

 the winged females of variety coiceni of the red fir that SAvarm upon the 

 blue spruce in May, as described in my mention of the life history of 

 that form below, though it is possible that the few females of cooleyi 

 settling upon the blue spruce also give rise to stem-mothers the follow- 

 ing spring, though in my attempts to follow these lice through the fall 

 they have always perished. This brood of eggs laid by the winged 

 females are practically all hatched by the end of July at Fort Collins. 



Host Plants and Habitat. — I have found this species occurring in 

 Colorado at Fort Collins, Greeley, Loveland, Boulder, Denver, Colo- 

 rado Springs, Palmer Lake, Estes Park, and up Long's Peak and Pike's 

 Peak to timber line. l\\ the lower altitudes (from 4,000 to 8,000 feet) 

 I have observed this gall chiefly upon blue spruce, but from 8,000 feet 

 to timber line I have noticed it chiefly upon Engelmann spruce (Picea 

 engelmanni). On August 15, 1903, I noted this gall as being very 

 abundant on Engelmann spruce along the trail from Mill's Ranch to 

 timber line on Long's Peak, and I have received the galls from the same 

 locality sent by ]\Ir. Enos Mills. The galls occm- in small numbers to 

 the limit of timber, but they become specially abundant three or four 

 hmidred feet lower down. The galls at timber line on August 15 were 

 still closed, but a few hundred feet lower the lice were emerging. I 

 have also received galls from the Sitcha spruce from the mountains of 

 western Canada, sent me by Dr. James Fletcher, that seem undoubtedly 

 to be of this species. This Chermes is surely a native of the Rocky 

 Mountain region and, so far as I know, occurs only upon the trees 

 mentioned. I find the galls most numerous in parks or lawns where 

 the blue spruce and red fir are clustered together. 



Stem-mother. — The stem-mother, in winter or early spring, is a 

 grayish appearing object, about .6 mm. long b}" .3 mm. wide. The 

 body of the louse is almost black, and the dark color shows through the 

 white secretion which radiates in short stout threads about the margins 

 of the bod}^ and rises in a crest down the median line of the back (PI. 

 Ill, fig. A). These hibernating lice are removed with some difficulty 

 on account of the long setse which are inserted deeply into the bark. 

 After shedding the heavy winter coat the louse appears dark green in 

 color, being lighter beneath and towards the posterior end of the 

 abdomen, and becomes rusty brown later. 



