A SYNOPSIS OF THE APHIDIDAE 55 



Contra Costa County. The author has recently received specimens 

 from Gillette of an alate viviparous female and apterous oviparous 

 females taken in the vicinity of Fort Collins, Colorado. Inasmuch as 

 the descriptions of this species are inadequate and not readily acces- 

 sible it has been thought best to give here brief descriptions of the 

 different forms. As no color notes were received with the specimens 

 they must necessarily be omitted. 



Alate viviparous female (from Fort Collins, Colorado). Antennae 

 half as long again as the body, dusky, and placed on small but distinct 

 tubercles. From the mounted material it appears as if III were 

 dusky, IV, pale with extreme tip dusky ; V, pale with apical one-third 

 dusky; and VI dusky. VI spur is the longest segment, followed by 

 III, IV, V, VI base, I, and II. The usual primary and accessory 

 sensoria are present on VI base, and the primary sensorium on V. 

 Secondary sensoria are present only on III. These are small, circular, 

 irregular-sized, and irregularly placed along the whole length of the 

 segment. The number (35 to 40) is such as to make the segment 

 appear tuberculate. The beak is quite large and long, reaching to or 

 slightly beyond the third coxae. The thorax is dusky. The wings 

 fairly large, and normal. The second branch of the third discoidal 

 vein arises nearer to the base of the first branch than to the apex of 

 the wing. Normally the measurements are as follows : From the base 

 of the second branch of the third discoidal to the tip of the wing is 

 about 0.8 mm., from the base of the first branch to the base of the 

 second 0.4 mm., from the apex of the first branch to the apex of the 

 second 0.29 mm. In one case the base of the second branch was 1.02 

 mm. from the apex of the wing, and but 0.034 mm. from the base of 

 the second, while the apices of the two branches were but 0.187 mm. 

 apart. The legs are long, femora pale with apical one-fourth dusky, 

 tibiae and tarsi dusky. The abdomen is pale with some slight dorsal 

 dark markings, these being indistinct in the mounted specimens. The 

 cornicles are fairly long, clavate on the apical one-half or two-thirds, 

 dusky throughout, and with the extreme tip reticulated. In length 

 they are somewhat shorter than III, but longer than IV. The cauda 

 is pale, short, and triangular, being about equal in length to the 

 hind tarsi. 



Measurements : body length, 1.785 mm. ; antennae total, 2.788 mm. ; 

 III, 0.68 mm. ; IV, 0.51 mm. ; V, 0.408 to 0.425 mm. ; VI, base, 0.12 

 mm.; VI, spur, 0.867 to 0.884 mm.; cornicles, 0.578 to 0.646 mm.; 

 cauda, 0.102 mm.; hind tarsi, 0.102 mm.; wing length, 3.128 mm.; 

 width, 1.292 mm. ; expansion, 6.8 mm. 



