Dolerus
Dolerus is for the large part a temperate and subarctic genus. Formerly the genus was split into two genera: Lodolerus and Dolerus. The genus is readily recognised from the forewing venation having a strongly curved vein Rs+M on cell 1R1 and the absence of vein 2r-m between cells 1RS and 2RS. All species are black, or marked with red on the thorax, abdomen and or legs. Some species are variable and may be wholly black or marked with red to varying extents.
Larvae are solitary feeders hiding at the base of the plant and climbing up the stem to feed in low light levels. Larvae can be spilt into grass feeders in drier habitats and rush, sedge or horsetail feeders in wetter habitats. Several of the grass feeding species can be a pest in cereal crops. Dolerus species overwinter in a pupal state rather than a pre-pupal state that is usual in the majority of sawflies. They pupate in soil in excavated cavities without any structural cocoon.
There are at least 120 species worldwide, of which 35 occur in Britain and 20 in Ireland.
Whilst species exhibit some colour variation and may of course be found in differing locations, there division by habitat and colour scheme can be an aid towards identification.
Drier grassland
habitats:
Entirely black species:
Dolerus (Poodolerus) aeneus Hartig, 1837
Dolerus (Poodolerus) anthracinus (Klug, 1818)
Dolerus (Poodolerus) asper Zaddach, 1859
Dolerus (Poodolerus) brevicornis Zaddach, 1859
Dolerus (Poodolerus) fumosus Stephens, 1835
Dolerus (Poodolerus) niger (Linnaeus, 1767)
Dolerus (Poodolerus) nigratus (Müller, 1776)
Dolerus (Poodolerus) nitens Zaddach, 1859
Dolerus (Poodolerus) picipes (Klug, 1818)
Dolerus (Poodolerus) possilensis Cameron, 1882
Dolerus (Poodolerus) varispinus Hartig, 1837
Species with red on the thorax or abdomen:
Dolerus (Poodolerus) haematodes (Schrank, 1781)
Species with only the legs marked with red:
Dolerus (Poodolerus) gonager (Fabricius, 1781)
Dolerus (Poodolerus) liogaster Thomson, 1871
Dolerus (Poodolerus) puncticollis Thomson, 1871
Dolerus (Poodolerus) schmidti Konow, 1884
Wetter rush, sedge
and horsetail habitats:
Entirely black species:
Dolerus (Achaetoprion) pachycerus Hartig, 1837
Dolerus (Equidolerus) pratensis (Linnaeus, 1758)
Dolerus (Poodolerus) asper Zaddach, 1859
Dolerus (Poodolerus) coracinus (Klug, 1818)
Dolerus (Poodolerus) harwoodi Benson, 1947
Dolerus (Poodolerus) possilensis Cameron, 1882
Dolerus (Poodolerus) stygius Förster, 1860
Species with red on the thorax or abdomen
Dolerus (Achaetoprion) ferrugatus Serville, 1823
Dolerus (Achaetoprion) madidus (Klug, 1818)
Dolerus (Achaetoprion) triplicatus (Klug, 1818)
Dolerus (Cyperolerus) anticus (Klug, 1818)
Dolerus (Dicrodolerus) vestigialis (Klug, 1818)
Dolerus (Dolerus) aericeps Thomson, 1871
Dolerus (Dolerus) bimaculatus (Geoffroy, 1785)
Dolerus (Dolerus) cothurnatus Serville, 1823
Dolerus (Dolerus) germanicus (Fabricius, 1775)
Dolerus (Dolerus) gessneri André, 1880
Dolerus (Dolerus) yukonensis Norton, 1872
Dolerus (Equidolerus) pratensis (Linnaeus, 1758)
Dolerus (Loderus) gilvipes (Klug, 1818)
Dolerus (Loderus) pratorum (Fallén, 1808)
Dolerus (Poodolerus) haematodes (Schrank, 1781)
Species with only the legs marked with red:
Dolerus (Dicrodolerus) vestigialis (Klug, 1818)
Dolerus (Dolerus) gessneri André, 1880
Dolerus (Oncodolerus) eversmanni Kirby, 1882
- Dolerus aericeps female Credit Andrew Green
- Dolerus anthracinus female Credit Andrew Green
- Dolerus aericeps male Credit Andrew Green
- Dolerus ferrugatus male Credit Andrew Green
- Dolerus niger female Credit Andrew Green
- Dolerus schmidti female
- Dolerus gonager female
References:
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168