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Aphididae : Aphidinae : Macrosiphini : Neotoxoptera


Genus Neotoxoptera

Onion aphids

On this page: Neotoxoptera formosana

Genus Neotoxoptera [Macrosiphini]

Neotoxoptera are medium-sized aphids which look rather like some Myzus species. The adult viviparae may be winged or wingless. The siphunculi are swollen and the wing veins are dark-bordered.

There are 6 species of Neotoxoptera. Three species do not host alternate but spend their entire life cycle on onion (Alliaceae), Caryophyllaceae or Violaceae. They have no sexual stage in the life cycle but reproduce all year parthenogenetically. The other three species host alternate from Caprifoliaceae to generally unknown secondary hosts.


Neotoxoptera formosana (Onion aphid) East & South-east Asia, Australasia, North & South America, North-west Europe

Apterae of Neotoxoptera formosana are shining magenta-red to dark reddish brown or almost black. The first and second antennal segments and the distal parts of the femora are all black (cf. Myzus ascalonicus which has the first and second antennal segments, and the distal parts of the femora, all pale). The minimum diameter of the 'stem' of the siphunculi is greater than the diameter of the hind tibia at its midpoint (cf. Myzus ascalonicus which has minimum diameter of the 'stem' of the siphunculi slightly less than the diameter of the hind tibia at its midpoint). The body length of the adult aptera is 1.6-2.3 mm.

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Neotoxoptera formosana alates are very dark red to black with the wing veins heavily black-bordered. The borders on their wing veins are of rather constant width along the lengths of the veins (cf. Neotoxoptera oliveri where the borders widen out at the base and apex of each vein).

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. Neotoxoptera formosana is native to east and south-east Asia, but is invasive in Australia, New Zealand, Hawaii, North & South America, and north-west Europe.


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).

Useful weblinks


  • Blackman, R.L. & Eastop, V.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.