This North American genus is related to Pterocallis. They differ from that genus in having two pairs of anterior prothoracic marginal hairs and a small hair arising from the siphunculus, on the ventral side near its base.
The genus has only one species which feeds on Robinia (black locust).
Appendiseta robiniae (Black locust aphid)
All adult viviparae of Appendiseta robiniae are alate. The adult alate (not pictured) has two longitudinal white wax lines on the head and thorax, and four longitudinal rows of powdery white spots on the abdomen (the first picture below shows the nymph of the alate). The antennal terminal process is about 0.5 times the length of the base of the sixth antennal segment. The siphunculi are short, truncated cones with a single short hair attached at the base. The cauda is knobbed. The body length of the adult Appendiseta robiniae vivivipara is 1.6-1.9 mm.
The second picture above shows the curious elongate apterous ovipara
In September and October sexual forms are produced - the alate male and the apterous ovipara. Appendiseta robiniae is found on the undersides of leaves of black locust (Robinia pseudoacacia) and (much less commonly) on Robinia neomexicana and Sophora japonica. It is widespread in North America, and has been introduced to South America, much of Europe and the Middle East.
Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974), Stroyan (1977), Stroyan (1984), Blackman & Eastop (1984), Heie (1980-1995), Dixon & Thieme (2007) and Blackman (2010). We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).
- Blackman, R.L. & Eastop, V.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.