1913] Pemphigince Attacking Populiis In Colorado. 487 



equal; joint 4 shortest; joints 1 and 2 and 4 about equal; 1 and 2 together 

 about Jis long as joint 3 ; permanent sensoria only, and these are surround- 

 ed with cilia. 



Described from specimens taken at Manitou and Colorado 

 Springs, Colorado, June 25, 1913, by the writer. 



Alate Fundatrigenia. 



This seems undoubtedly to be the form originally described by Dr. 

 Riley, and is distinguished by the sensoria of the antenna in his draw- 

 ing. Riley shows three transverse sensoria on joints 4 and 5, and this 

 is the common number in the examples we have had for study, while 

 in the later and smaller winged sexupara there are usually no sensoria 

 on joint 5 but the permanent one. On joint 3 (figure 4) there are from 

 six to nine, usually seven or eight, sensoria present and there are three 

 to four, usually three, on joint 4; two to four on joint 5, but usually 

 three ; none but the permanent sensorium on joint 6 ; and a well developed 

 spine near the base of joint 3. Our examples differ from^those described 

 by Riley by being somewhat larger, as indicated by the alar expanse, 

 which, in our examples, varies little from 9 mm.; and in the length of 

 the body, which, in our examples, measures from 2.75 to 3.00. 

 The Apterous Fundatrigenia. 



What I take to be this form are light cinnamon brown in color with 

 head and tarsi black and with more or less darkened antennee and legs. 

 Length, 3.00; width, 1.90; antenna, .60; hind femora, .55; tibia, .45; 

 beak very short, not reaching the second pair of coxee; joints 1 and 2, 

 and 4 and 5 of the antenna (figure 6), sub-equal; joint 6 longest; joint 

 3 nearly as long as joint 6 without the spur; joints 4 and 5, swollen and 

 somewhat bead-like in appearance; permanent sensoria with cilia 

 about their margins. 



Described from specimens taken in the foothills near Fort 

 Collins from July 19th to August 14th, and at Manitou August 

 9th. 



On August 9th, I spent the day at Manitou studying this 

 louse. The mature galls Ihat were occupied were found 

 inhabited in each case by one apterous female, probably a 

 fundatrigenia; a few, 6 to 10, growing larvas and pupse, and 

 a small number of first instar lice ; some of the last were migrating 

 to terminal leaves and forming new galls just as the young 

 from the stem-mothers did earlier in the season. The partly 

 grown lice that were staying with the gall-mothers seemed all 

 to be developing into winged individuals. All that were half 

 grown or more gave plain evidence of this, and in one gall I 

 found a winged adult with the apterous mother and numerous 

 pupae and young lice. The alate louse was a sexupara and 

 is like the many mounted specimens that we have of this form 

 taken in former years and again this year, late in the season. 



