Dolerus

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Selandriinae
Tribe: Dolerini
Genus: Dolerus Panzer, 1801
Subgenera: Dolerus, Achaetoprion, Cyperolerus, Dicrodolerus, Equidolerus, Loderus, Neodolerus, Oncodolerus, Poodolerus

Background

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 Selandriinae subfamily are relatively small and slender. The range of Selandriinae is worldwide; it occurs on all continents except Antarctica (Goulet 1992). It is the most common and diverse group of tenthredinids in tropical regions, particularly in Central America, South America, and Southeast Asia (Smith 1969e). Selandriinae contains the only known sawflies that feed on non-vascular plants, specifically ferns (Smith et al. 2013). The subfamily can be distinguished from other subfamilies by wing venation (Goulet 1992).

Dolerus is a species-rich genus recorded throughout the world (Taeger et al. 2010). There are many forms, but the genus is best recognized by distinctive pits on the head and mesoscutum of the thorax (Goulet 1992).

Diversity

There are 260 described extant species worldwide. Eighty-four species occur in North America (Taeger et al. 2010).

A key to Nearctic species is included in Goulet 1986.

Diagnostic characteristics

Subfamily characters

Genus characters​

May be confused with

Dolerus can be confused with similar species in the subfamily Selandriinae. It can be distinguished from most other genera by the distinct punctures on the head and mesoscutum, and from the other Dolerini genus in the tribe: Prionourgus by the malar space length and the clypeus margin (Goulet 1992).

Exotic pest species of concern

Because Dolerus feeds on grasses, many of which are of agricultural importance, some species are considered pests. Dolerus puncticollis, also known as the wheat sawfly, is a minor pest of Triticum (wheat) in central Europe and in Iran (Ebrahimi et al. 2015); D. hematodes is a pest of various cereals, including Lolium perenne (perennial ryegrass), Festuca rubra (red fescue), Hordeum vulgare (spring barley), and Triticum (wheat) in Europe (Barker and Reynolds 2004); D. nigratus is a pest of Triticum (wheat) in Europe (Zvankovich 2005); D. tritici is a pest of Triticum (wheat) in China; D. hordei is a pest of Hordeum (barley) in Japan (Haris 2000); and D. ephippiatus and D. lewisi are pests of Triticum (wheat) in Japan (Hill 1987).

Dolerus nitens is introduced from Europe and is a pest of Festuca rubra (red fescue), reported as having caused extensive damage in some growing operations in Oregon (Smith 2006b)Dolerus brevicornis may also be introduced in North America (Heidemaa et al. 2004, Taeger et al. 2010)

Native or introduced pest species

Dolerus nitens is introduced from Europe and is a pest of Festuca rubra (red fescue), reported as having caused extensive damage in some growing operations in Oregon (Smith 2006b)Dolerus brevicornis may also be introduced in North America (Heidemaa et al. 2004, Taeger et al. 2010)

Host associations

In North America, Dolerus feeds on rushes, grasses including Triticum (wheat) and Festuca (fescue), Carex (sedges), and Equisetum (horsetail) (Goulet 1986, Leblanc and Goulet 1992).

Life history

Female Dolerus deposit eggs into plant tissue. Larvae feed for about one month before entering maturity and dropping to the ground, where they burrow into the soil and build cells in which to overwinter. Dolerus is univoltine (Goulet 1986).

Dolerus also feed as adults on tree sap from Acer (maple), Malus (apple), and Pyrus (pear), and on nectar from flowers of Salix (willow) and Prunus (cherry, plum) (Goulet 1986).

Distribution

World: The genus is widespread throughout North America, Europe and Asia, with one species in eastern Africa (Goulet 1992, Taeger et al. 2010)

North America: Dolerus occurs throughout the United States and Canada, as far north as Alaska, and as far south as Arizona (Goulet 1986).

Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Dolerus

Details about data used for maps can be found here.

Dolerus nitens female lateral habitus; photo by J. Orr, WSDA

Dolerus nitens female lateral habitus; photo by J. Orr, WSDA

Dolerus nitens female face; photo by Q. Baine, WSDA

Dolerus nitens female face; photo by Q. Baine, WSDA

Dolerus sp. male lateral habitus; photo by Q. Baine, WSDA

Dolerus sp. male lateral habitus; photo by Q. Baine, WSDA

Dolerus sp. male face; photo by Q. Baine, WSDA

Dolerus sp. male face; photo by Q. Baine, WSDA

Dolerus gilvipes wings; photo by Q. Baine, WSDA

Dolerus gilvipes wings; photo by Q. Baine, WSDA