154 THE CANADIAN ENTOMOLOGIST 



Stem-mother. — On March i8, 191 1, the stem-mothers of this species, 

 with newly-born young, were plentiful in the just opening leaf buds of the 

 host plant. 



General colour light green throughout with legs and antennae slightly 

 paler green. Body large and robust. Antennae about two-thirds the 

 length of body and quite slender. Nectaries quite slender and about 

 one-fourth as long as the body. Cauda short and triangular in shape. 



Measurements : Length of body, 3.33 mm.; width, 1.8 mm. Length 

 of antennal segments, I, 0.135; II, 0.04; III, 0.7; IV, .33; V, .38; 

 VI, .2; spur, .51 mm.; total length, 2.295 ^^'"^''- Length of nectaries, 

 .73 mm. Length of cauda, 0.22 mm. 



Spring Migrant. — April 25th; what is probably the third generation 

 of this species found abundantly on under side of leaves ; numerous young 

 present. 



General colour light green ; head and thorax orange ; antennae with 

 six segments ; spur of sixth as long or longer than third segment ; sixth 

 segment and spur dusky and basal two-thirds of third segment also dusky ; 

 legs light green except distal end of tibia and tarsi, which are nearly black. 

 Wings hyaline and large. Nectaries long and cylindrical, slightly con- 

 stricted at tip. Cauda large, slightly turned up and blunt at point. Third 

 antennal segment with from 24 to 28 small, irregularly-placed sensoria, 

 most of them scattering. Antenna! tubercles large and distinct, and 

 strongly gibbous ; at upper inner edge two bristle-like hairs at highest 

 part. First segment large and strongly gibbous ; second segment small in 

 comparison. 



Measurements : Length of body, i.'^'èi mm,; width, 1.22 mm. Length 

 of antennal segments, I, .176 ; II, .09 ; III, i.ii ; IV, .84 ; V, .75 ; VI, 

 .26; spur, I.II mm.; total length, 4.336 mm. Length of wing, 5.7 mm.; 

 total expanse, 12.4 mm. Length of nectaries, i mm. Length of cauda, 

 .44 mm. 



Fall Migrant. — Oct. 1 1 ; winged individuals not very common and 

 producing young on leaves of Osmoronia about Corvallis. 



General colour green with head and thorax orange coloured. This 

 form resembles the previous form entirely, except in the antennae and 

 size, the fall migrant being slightly smaller, and the third segment of the 

 antennae bears from 18 to 22 regularly placed round sensoria lying in a 

 straight line along the outer edge. 



Oviparous Female. — The egg-laying female is orange-green in colour, 

 and is quite small in comparison with the stem-mother. The legs are a 



