Dineura

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Nematinae
Tribe: Nematini
Genus: Dineura Dahlbom, 1835
Subgenera: none

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).

Nematinae is the second-largest subfamily of Tenthredinidae, with over 1,250 species (Prous et al. 2014). They are most diverse in northern Eurasia and North America; only a few species occur in the Southern Hemisphere. Nematinae sawflies have a variety of feeding habits including external leaf feeding, leaf mining, and gall forming, and feed on a variety of hosts (Smith 2003b).

The Nematinae have been subject to numerous revisions in recent years. As of 2021, there are no comprehensive keys to many of the North American species of Nematinae (Prous et al. 2014). Because of changing taxonomy and extreme variability in morphology, identifying genera and species in the Nematinae may be more challenging than in other subfamilies of Tenthredindae. For this reason, knowing the host or behaviors of a specimen can be extremely helpful for identification within this subfamily.

Dineura is monotypic in North America. Dineura militaris is variable in color patterning, but is always black and orange and somewhat small in size (about 6–8 mm in length) (Smith 1975).

Diversity

There are 19 described species worldwide. One species occurs in North America (Taeger et al. 2018).

Diagnostic characteristics

Subfamily characters​

Genus characters

May be confused with

Dineura may be confused with other genera in the subfamily Nematinae — especially Hemichroa — but can be distinguished from it and most other genera that have fore wing vein 2A+3A curved upwards by the long antennae, the short pulvilli, the absence of the velum on the larger fore tibial spur, and the absence of fore wing vein 2r-rs (Smith 1975, Goulet 1992).

Exotic pest species of concern

none

Host associations

Dineura militaris feeds on Amelanchier (serviceberry) (Smith 1975).

Life history

The larvae feed on the underside of the leaf. At maturity, the larvae fall to the ground to pupate or overwinter in the soil. Dineura militaris is univoltine (Smith 1975).

Distribution

World: The genus is known from North America, throughout Europe, Russia, China, Japan, and Thailand (Taeger et al. 2018).

North America: Dineura militaris occurs throughout the northern United States and Canada, and as far north as Alaska (Smith 1975).

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

Details about data used for maps can be found here.

Dineura militaris female face; photo by Q. Baine, WSDA

Dineura militaris female face; photo by Q. Baine, WSDA

Dineura militaris male lateral habitus; photo by J. Orr, WSDA

Dineura militaris male lateral habitus; photo by J. Orr, WSDA

Dineura militaris male dorsal habitus; photo by J. Orr, WSDA

Dineura militaris male dorsal habitus; photo by J. Orr, WSDA

Dineura militaris male face; photo by Q. Baine, WSDA

Dineura militaris male face; photo by Q. Baine, WSDA