Dolerus

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

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