Sterictiphora

Taxonomy

Family: Argidae
Family common name: argid sawflies
Subfamily: Sterictiphorinae
Genus: Sterictiphora Billberg, 1820
Subgenera: none

Background

Argidae are found in all non-polar regions of the world (Smith and Middlekauff 1987, Smith 1992). They are external foliage feeders with a wide range of host plants. Additionally, the family exhibits some uncommon behaviors like the excretion of defensive compounds and subsocial habits (Smith 1992).

Sterictiphora are about 6–7 mm in length, and are generally black or orange and black in color. Adults are rarely observed, as they only fly in the early spring. Larvae have a distinct feeding habit that can be easily recognized in the field (Smith 1969c, Eiseman 2015).

Diversity

There are 39 species described worldwide restricted to the Northern Hemisphere. Six are endemic to North America (Taeger et al. 2010).

A key to North American species of Sterictiphora is included in Smith 1969c.

Diagnostic characteristics

May be confused with

The family Argidae can be distinguished from other sawflies by the single-segmented flagellum of the antenna. The genus Sterictiphora can be distinguished from other genera in the family by the wing venation, interantennal carina, and the simple tarsal claws. Males differ from related genera Arge and Atomacera because of their conspicuous forked antennae (Smith 1992).

Exotic pest species of concern

none

Host associations

Larvae are external leaf feeders on trees from Rosaceae, most commonly Prunus pensylvanica (fire cherry) and Prunus serotina (black cherry), but also other Prunus sp. and Amelanchier canadensis (Canadian serviceberry) (Smith 1969c).

Life history

The female deposits eggs into the margins of leaves. Upon hatching, larvae feed in a unique manner; starting at the leaf margin working towards the midrib, the larva chews a channel, about 8 mm in width and 10 mm in length, that winds back-and-forth in a repeating “S” pattern, much like a meandering river. The body of the larva fits along the curved inside edge as it feeds. Mature larvae are translucent green and measure about 13 mm in length. Prepupae burrow into the soil and construct brown, loosely woven cocoons, in which they overwinter and emerge the following spring (Eiseman 2015).

Distribution

World: This genus is generally Holarctic, and is widespread in Europe, northern Asia, northern Africa, and North America (Taeger et al. 2010).

North America: Sterictiphora generally has two distinct ranges, one west of the Rocky Mountains, and one in the mid-Atlantic north through New England and eastern Canada. There are also records of one species, S. transversa in Alaska and Alberta (Smith 1969c).

Map data from: GBIF.org (26 June 2019) GBIF Occurrence Download Sterictiphora

Details about data used for maps can be found here.

Sterictiphora maura female lateral habitus; photo by J. Orr, WSDA

Sterictiphora maura female lateral habitus; photo by J. Orr, WSDA

Sterictiphora maura female dorsal habitus; photo by J. Orr, WSDA

Sterictiphora maura female dorsal habitus; photo by J. Orr, WSDA

Sterictiphora maura female face; photo by J. Orr, WSDA

Sterictiphora maura female face; photo by J. Orr, WSDA

Sterictiphora maura male lateral habitus; photo by J. Orr, WSDA

Sterictiphora maura male lateral habitus; photo by J. Orr, WSDA

Sterictiphora maura male dorsal habitus; photo by J. Orr, WSDA

Sterictiphora maura male dorsal habitus; photo by J. Orr, WSDA

Sterictiphora maura male face; photo by J. Orr, WSDA

Sterictiphora maura male face; photo by J. Orr, WSDA

Sterictiphora maura wing; photo by J. Orr, WSDA

Sterictiphora maura wing; photo by J. Orr, WSDA

Sterictiphora maura male head; photo by J. Orr, WSDA

Sterictiphora maura male head; photo by J. Orr, WSDA

Sterictiphora maura male thorax; photo by J. Orr, WSDA

Sterictiphora maura male thorax; photo by J. Orr, WSDA