THE CANADIAN KM'OMOLOGlfeT, 157 



seems little doubt but that the Oregon species is the same as the one 

 described by Boyer. 



Stem-mother. — The first stem-mothers were collected on the 23rd of 

 March and at that time they were about full grown. 



General colour light green. Antennse towards tips dusky ; distal end 

 of tibise and tarsi dusky. In this stage the characters resemble those of 

 Aphis more than anything else. The antennae are stout and measure less 

 than one-half the length of the body. The legs are short and the antennce 

 and Cauda are as in Aphis. Antennal tubercles distinct, but not long. 



Measurements : Length of body from forehead to tip of cauda, 

 2.65 mm.; width, 1.30 mm. Length of antennal segments, I, .154; II, 

 .066; III, .33 ; IV, .242 ; V, .27 ; VI, .11 ; spur, .44 mm.; total length, 

 1. 612 mm. Length of nectaries, .5 mm. Length of cauda, .176 mm. 



Viviparous apterous female of the summer generations collected June 

 4th, iQii, on underside of leaves of tree on college campus; pupa and 

 alate forms also present. 



General colour light green or lemon-yellow throughout, but the 

 characters are like those of Myzus, and this form is quite distinct from 

 the stem-mothers. The antennae are quite long and slender and placed 

 on prominent tubercles. First antennal segment strongly gibbous on 

 inner side. Sixth antennal segment and spur almost setaceous in form. 

 For comparative lengths see measurements. Legs rather stout, short and 

 sparsely hairy. Nectaries thick at the base and slightly tapering with a 

 slight inward curve. Cauda medium in length and blunt at the tip. 



Measurements : Length of body, 2.5 mm.; width, i mm. Length of 

 antennal segments, I, .135 ; II, .09 ; III, .778 ; IV, .55 ; V, .51 ; VI, .154; 

 spur, .98 mm.; total length, 3.197 mm. Length of nectaries, .778 mm. 

 Length of cauda, .154 mm. 



Spring Migrant. — Collected on underside of leaves June 4th, 1911. 



General colour lemon-yellow. Head and thoracic shield light orange. 

 First two antennal segments green, the base of the third green, remainder 

 of antennae dusky to black. Basal half of nectaries green to dusky, outer 

 half darker to black. Some specimens with an orange spot in the centre 

 of the body just back of the thorax. Antennae long and slender and 

 placed on prominent tubercles. First segment large and strongly gibbous 

 on the under side. Second segment small. Third segment with about 

 twenty-five nearly circular sensoria of variable sizes and irregularly placed. 

 Frontal tubercle of head quite prominent. Legs long and slender. 



