Family common name: common sawflies
Genus: Halidamia Benson, 1939
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).
Halidamia is monotypic. Halidamia affinis is about 5–6.5 mm in length, with a black-colored head and thorax, orange legs and abdomen, and slightly darkened wings. The male is not known in North America (Smith 1969d).
Halidamia can be distinguished from other genera in the subfamily Blennocampinae by the lack of pulvilli on the basal tarsomeres and short apical antennal segments, and from closely related Waldheimia by the curved apex of the fore wing veins 2A and 3A (Smith 1969d).
In North America, the host for H. affinis is not known. In Europe, H. affinis feeds on species of Galium (cleavers), including Galium aparine (stickywilly) and Galium mollugo (false baby’s breath) (Smith 1969d).
World: This species is known from North America and throughout Europe (Smith 1969d).
North America: Halidamia affinis is an introduced species that was first discovered in North America in New York in 1931 (Greenbaum 1977). It now occurs in the northeastern United States, as far west as Wisconsin and Kansas, and on the Pacific coast in Washington and California (Smith 1969d, Greenbaum 1977, Looney et al. 2016).
Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Halidamia
Details about data used for maps can be found here.