Adult apterae of Schizaphis graminum are small and elongate-oval. The head and prothorax is yellowish or greenish straw-coloured. The rest of the thorax and the abdomen are yellowish green to bluish green with a noticeable darker green spinal stripe. The antennae are uniformly dusky. The antennal terminal process is 2.8-4.7 times the length of the base of antennal segment VI. The apical rostral segment (RIV+V) is 0.65-0.8 times the length of the second hind tarsal segment (HTII) (cf. Schizaphis holci in which RIV+V is 0.80-1.0 times the length of HTII). The siphunculi are pale with slightly flared and darkened tips and are 1.3-1.7 times the length of the cauda (cf. Schizaphis holci which has the siphunculi 1.25-1.4 times the length of the cauda). The Schizaphis graminum aptera body length is 1.3 to 2.1 mm.
First image: Kent Loeffler (Public domain). Second image: Alton N. Sparks (Creative Common Attribution 3.0 Unported license).
Schizaphis graminum alatae have a brownish-yellow head and prothorax, black thoracic lobes and a yellowish green to dark green abdomen.
The preferred hosts are grasses and cereals, where Schizaphis graminum can be a major pest. It causes severe feeding damage - initially yellow or red leaf spots which can lead to leaf and root death. It also transmits several plant viruses including barley yellow dwarf virus. Schizaphis graminum develops sexual forms in cold temperate climates, where overwintering in the egg stage occurs predominantly on Poa pratensis, but it continues to reproduce parthenogenetically wherever the climate allows. Schizaphis graminum is not ant attended. Schizaphis graminum is of Palaearctic origin, but is now widely distributed in southern Europe, Middle East, Central and South Asia, Africa and the Americas. Despite the fact that two alatae trapped in UK had identical DNA sequences to the sorghum-adapted form in the USA, there are no records from field crops in northern Europe.
We discuss why Schizaphis graminum has failed to establish itself in Western Europe in our rare aphids page.
Other aphids on same host:
Blackman & Eastop list 34 species of aphid as feeding on Kentucky bluegrass, smooth meadow-grass, or common meadow-grass (Poa pratensis) worldwide, and provide formal identification keys
(Show World list).
Schizaphis graminum has been recorded on 8 species of the Hordeum genus (Hordeum bulbosum, Hordeum distichon, Hordeum jubatum, Hordeum murinum, Hordeum murinum leporinum, Hordeum pusillum, Hordeum stenostachys, Hordeum vulgare).
We especially thank Kent Loeffler and Alton N. Sparks for use of their images, above.
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).