Family common name: common sawflies
Genus: Lagonis Ross, 1937
The Tenthredinidae are the most species-rich family and are found throughout the world, in all continents but Antarctica. They are known as the “common sawflies.” They can generally be recognized by a cylindrical body and long, segmented antennae. Otherwise, they come in a variety of colors, sizes, and forms (Goulet 1992).
Sawflies in the subfamily Blennocampinae have a diverse set of life histories and habits. Many species are restricted to subtropical and tropical regions, but the genus is still fairly species-rich in North America. Blennocampinae includes many sawflies that feed on ornamental and forestry crops. This subfamily can be recognized by wing venation and bidentate mandibles (Smith 1969d).
Lagonis is monotypic in North America. Lagonis nevadensis is about 8 mm in length and mostly black with white abdominal striping. The species has slightly different coloring along a latitudinal gradient of its range: thorax mostly red in the south and entirely black in the north (Smith 1969d).
Lagonis can be confused with similar species in the subfamily Blennocampinae. It can be distinguished from most other genera by the large pits on the mesoscutellum and mesepisternum and the upwardly curved apex to veins 2A and 3A of fore wing (Smith 1969d, Goulet 1992).
North America: Lagonis nevadensis occurs west of the Rocky Mountains, from southern California north to British Columbia and as far as Wyoming and Alberta in the eastern part of the range (Smith 1969d).
Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Lagonis
Details about data used for maps can be found here.