Metopolophium (aphids) identification, images, ecology

Medium to large aphids, the adult viviparae of which may be winged or wingless. Wingless adults have well-marked, rather divergent antennal tubercles, and a rather distinct though lower median tubercle. The siphunculi are cylindrical, rather expanded at the base; pale, not reticulate apically, and with a small to moderate apical flange. The cauda is elongate and rather blunt. Wingless forms not usually pigmented, but winged forms may be.

Some species host alternate between rose (Rosaceae) and many species of grasses (Poaceae). They commonly have a sexual stage in the life cycle overwintering as eggs. However, some species spend the whole year on grasses overwintering viviparously.

Metopolophium dirhodum (Rose - grain aphid)

A medium sized spindle shaped aphid which ranges from green to yellowish green with a brighter green longitudinal mid-dorsal stripe. The antennae are pale and about 0.75 times the body length. The siphunculi are long and pale, with slightly dusky tips. The body length of apterae is 1.6-2.9 mm. The winged form is similar and does not have any dark markings.

Metopolophium dirhodum (rose-grass aphid) aptera on cereal leaf near Fore Wood, Crowhurst, East Sussex, UK on 14/6/08 at 11.23 h. Metopolophium dirhodum (rose - grain aphid) alate on barley at Crowhurst, East Sussex, UK on 14/6/08 at 11.20 h.

The rose - grain aphid host alternates from rose (Rosa sp) as the primary host in spring and early summer to cereals and grasses, especially wheat, barley and maize, as the secondary host. Large numbers on cereals can cause economic damage. They also transmit maize mosaic virus and barley yellow dwarf virus.

Acknowledgements
We have made provisional 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

References

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

Genus Metopolophium

Rose - grass aphids

Genus Metopolophium [Macrosiphini]

Metopolophium dirhodum (Rose - grain aphid)

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References