Adult apterae of Neotoxoptera are shining magenta-red to dark reddish brown or almost black, immatures are similarly coloured. The body length of the adult aptera is 1.6 to 2.3 mm. N. formosana alatae are very dark red to black with the wing veins heavily black-bordered. 

Good close-up photographs required.  Please state the host plant.

Associated with plants of the Onion family. 

Summer to Autumn.

The onion aphid does not host alternate, but spends it entire life cycle on onion (Allium), either on the leaves or on bulbs in store. There are no sexual forms, so the species reproduces parthenogenetically all year round.

The Onion Aphid was first reported in Britain on onion at RHS Wisley in October 1999.

Status in Leicestershire and Rutland not known.

https://influentialpoints.com/Gallery/Neotoxoptera_formosana_onion_aphid.htm