

Vol. XLI. GUELPH, FEBRUARY, 1909. No. 2. 



PHYLLAPHIS COWENI, CKLL. (Plate I, Figures 1 to 6). 



BY C. P. GILLETTE, FORT COLLINS, COLORADO. 



Aphid. Covven : Bull. 31, Tech. Ser., Colo. Ex. St., p, 125, 1895. 

 Pemphigus Coweni, Cockerell, Can. Ent., XXXVII, p. 391, 1905. 



Mr. Cowen being unable to place this louse in a genus known to him, 

 did not attach a name to it, though his descriptions of both gall and louse 

 make it certain that he was studying the species under consideration. 



The louse has the general appearance and habits of a Pemphigus., 

 and was so placed by Prof. Cockerell, who saw only the apterous form 

 and pupae. On Aug. 5th, 1908. the writer was in the foothills a few miles 

 west of Fort Collins, at an altitude of about 8,000 feet, where Bearberry 

 ( Arctostaphylos uva-ursi), the host-plant of this louse, grows in great 

 abundance. Apparently every plant was infested, as was evident from the 

 numerous pod-like leaves that were conspicuous everywhere. The galls 

 are formed by about one-third of the leaf surface folding lengthwise upon 

 the other two-thirds, inclosing the lice and becoming swollen so as to 

 resemble minute pea-pods. If the galls were beneath leaves so as to be 

 shaded, they were green in colour, but if exposed to the sun they were 

 more or less deep red in colour. The galls varied between 10 and 20 mm. 

 in length. 



Many apterous lice, including stem-mothers, and numerous pupae, 

 were present in the galls, but no adult alate forms were seen, and 

 apparently all the lice, except stem-mothers, were to become winged. 

 Syrphus larvae were common in the galls. 



Plants bearing galls were taken and placed in the insectary, where 

 syrphus flies and great numbers of the alate viviparous females, alate 

 oviparous* females and alate males were reared. These I have described 

 below. 



A glance at either of the alate forms figured in the accompanying 

 plate will be sufficient to see that this can not be a Pemphigus, as the fore 

 wing has the cubital vein with two forks, when it should have none. I 



*This is the only species, except in Chermes, where I have seen alate ovipa- 

 rous females. 



