Classification
Aphidinae: Aphidini
Common name(s)
Soybean aphid
Diagnosis
Small yellow aphids with black siphunculi and pale yellow cauda, found colonising the stem apices and young leaves of growing soybean plants, and undersides of leaves of mature plants; sometimes even colonize the pods. Body 5-6 times as long as siphunculi. Antenna approximately 1.3 times as long as body. Cauda with 8-10 hairs.
Host plant(s)
Fabaceae: Glycine max L., Glycine wightii (Wight & Arn. ex. Arn.) Verdc.; Poaceae: Centotheca lappacea (L.) Desvaux.
Only alates were collected on Centotheca lappacea which was grown on the soybean field bunds. As it belongs to Poaceae, the aphid is less likely to colonise on this plant, however, as alates were found in large numbers, it was recorded as the host plant.
Measurements
Aptera: Length of body 1.35, width 0.72; antennae 1.05, segments III: IV: V: VI 0.24: 0.15: 0.18: (0.12+0.28); u.r.s. 0.11; h.t.2 0.09; siphunculus 0.23; cauda 0.21.
Alata: Length of body 1.37, width 0.81; antennae 1.06, segments III: IV: V: VI 0.28: 0.20: 0.22: (0.13+0.30); u.r.s. 0.12; h.t.2 0.10; siphunculus 0.22; cauda 0.19.
Seasonal occurrence
January-February