Dimorphopteryx

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Allantinae
Tribe: Eriocampini
Genus: Dimorphopteryx Ashmead 1898
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).

Sawflies in the Allantinae subfamily are mostly black and shining, sometimes with other colors. They have agricultural importance as some species are pests on cultivated and ornamental plants (Smith 1979a). They can be distinguished from other subfamilies by wing venation (Smith 2003a).

Dimorphopteryx are medium-sized, about 6–8 mm in length. All North American species are mostly black with orange on parts of the thorax and legs, and have long, laterally flattened antennae (Smith 1979a).

Diversity

There are five described extant species worldwide, and all are Nearctic (Taeger et al. 2010).

A Nearctic key to species is included in Smith 1979a.

Diagnostic characteristics

Subfamily characters

Genus characters​

May be confused with

Dimorphopteryx can be confused with similar species in the subfamily Allantinae or tribe Eriocampini. It can be distinguished by the flattened antennal segments and peripheral vein in the male hind wing (Smith 1979a).

Exotic pest species of concern

none

Host associations

In North America, Dimorphopteryx feeds on Tilia (linden), Acer (maple), Prunus (cherry), Pyrus (pear), Malus (apple), Amelanchier (serviceberry), Crataegus (hawthorn), Quercus velutina (black oak), Betula papyrifera (paper birch), Betula alleghaniensis (yellow birch), Alnus (alder), and Castanea dentata (American chestnut) (Rohwer 1915, Smith 1979a, Smith and Middlekauff 1987).

Life history

The female Dimorphopteryx lays eggs into the upper side of the leaf of the host plant. Larvae are sometimes green, sometimes reddish, wide and slightly flattened like a slug, dull, and finely textured. The young larvae feed singly on the upper cuticle and parenchyma of the leaf and transition to eating the entire leaf as they mature. At maturity they drop to the ground and build cocoons with dirt and sand, where they overwinter. Adults emerge in early summer. Described species of Dimporphopteryx are univoltine (Middleton 1915).

Distribution

World: This genus is known only from North America (Taeger et al. 2010).

North America: Dimorphopteryx species occur in the eastern and midwestern United States and Canada, from New England and Quebec south to Tennessee, and as far west as the Rocky Mountains (Rohwer 1915, Smith 1979a).

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

Details about data used for maps can be found here.

Dimorphopteryx virginicus female lateral habitus; photo by J. Orr, WSDA

Dimorphopteryx virginicus female lateral habitus; photo by J. Orr, WSDA

Dimorphopteryx virginicus female dorsal habitus; photo by J. Orr, WSDA

Dimorphopteryx virginicus female dorsal habitus; photo by J. Orr, WSDA

Dimorphopterx virginicus female face photo by Q. Baine, WSDA

Dimorphopterx virginicus female face photo by Q. Baine, WSDA

Dimorphopteryx virginicus wings; photo by J. Orr, WSDA

Dimorphopteryx virginicus wings; photo by J. Orr, WSDA