A SYNOPSIS OF THE APHIDIDAE 103 



The following brief description was made from specimens col- 

 lected from the first six host plants listed above, and is the one con- 

 sidered as Aphis euonomi Fabr. 



Alate viviparous female. Color apparently black, but on close 

 examination it seems that the ground color is a very dark brown, 

 covered with a blackish tinge, with the following parts decidedly 

 black: head, antennae, thoracic lobes, marginal spots and transverse 

 bands on the abdomen, cornicles, tarsi, coxae, tips of tibiae, and apical 

 one-half to two-thirds of the middle and hind femora.' The tibiae and 

 fore femora are pale, appearing whitish in life. The antennae are 

 shorter than the body, III being the longest segment, followed closely 

 by VI spur. In one case VI spur was slightly longer than III and 

 in another equal to III. In all other specimens III was the longer 

 segment. IV and V are subequal, V usually being slightly the 

 shorter. There are from eleven to twenty-one secondary sensoria on 

 III, of irregular size. These are scattered along the whole length of 

 the segment, the distal five or six being in a more or less even line. 

 The usual number is about twelve to fourteen. The number of 

 secondary sensoria on IV range from none to seven, the modal number 

 being two. In one specimen only were sensoria absent from IV; in 

 another, one antenna had seven, the other having two, while in a 

 third, one antenna had five, the other six. When there are more than 

 two or three sensoria, they are all quite small, and can be clearly 

 distinguished only by the higher power of a microscope. Two is the 

 usual number, being located about the middle of the segment. V is 

 usually without secondary sensoria, the primary sensorium being 

 always present, however. In one specimen the antennae had one or 

 two very small secondary sensoria on V, and in another specimen one 

 antenna had one small sensorium, the other none. The usual primary 

 and accessory sensoria are present on VI base. Lateral abdominal 

 tubercles are always present on the seventh segment, usually on the 

 first, and often on the second, third, fourth, or fifth. There are 

 always at least three pair of these tubercles, and oftentimes more. 

 One specimen had tubercles on the first, second, third, fourth, and 

 seventh segments. The cornicles are black, imbricated, and taper 

 noticeably from base to apex. They are quite constant in length, the 

 variation being not more than 0.05 mm. in all the specimens examined. 

 They are about half as long again as the hind tarsi. The cauda is 

 concolorous with the abdomen, short and conical or ensiform, and 

 subequal in length to the hind tarsi. The wings are normal, with the 

 typical Aphis venation. 



