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Genus Brevicoryne

Mealy cabbage aphids

On this page: Genus Brevicoryne  Brevicoryne brassicae 

Genus Brevicoryne [Macrosiphini]

Medium sized aphids that are grey or green with a dark head. Adult viviparae may be winged or wingless. The antennal tubercles are not developed. The body is covered with greyish-white mealy wax. The antennae are usually about half as long as body. The siphunculi are dusky or dark, barrel shaped and usually somewhat shorter than the cauda.

There are about 9 species mainly feeding on different species of the cabbage family (Brassicaceae) but with some species on other plants such as goosefoot (Chenopodium: Amaranthaceae) and honeysuckle (Caprifoliaceae). They do not host alternate, but generally retain a sexual stage in the life cycle, with eggs produced to overwinter. They are not attended by ants. One species is an important pest of Brassica crops.

 

Brevicoryne brassicae (Mealy cabbage aphid)

Brevicoryne brassicae apterae are green and covered with a greyish white mealy wax that is also secreted on the plant and spreads throughout the colony (see first picture below). The head, tips of the antennae and the legs are dark. Some abdominal segments have small sclerites and there are also intersegmental muscle sclerites. Their siphunculi are thick and very short, 0.06-0.07 times the body length. and 0.8-1.0 times the length of the cauda. The cauda is triangular and broad. The body length of Brevicoryne brassicae apterae is 1.9-2.7 mm.

The alate (see second picture above) is with her group of offspring. The alate Brevicoryne brassicae has a dark head and thorax, 50-70 secondary rhinaria on the third antennal segment, marginal sclerites and dark dorsal cross bands.

The mealy cabbage aphid does not host alternate but spends its entire life cycle on cabbage (Brassica oleraceae) or other brassicas. In cold climates oviparae and small thin winged males occur in autumn, and the population overwinters as eggs. Where winters are mild Brevicoryne brassicae overwinters parthenogenetically. It has a cosmopolitan distribution.

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.