Aphilodyctium

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Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Allantinae
Tribe: Empriini
Genus: Aphilodyctium 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).

Aphilodyctium are medium-sized, about 7–8 mm in length. There is a single North American species, A. fidum, and it is recognized by mostly orange legs, orange and black abdomen, and white tegulae (Smith 1979a).

Diversity

There is one described extant species worldwide, and it is Nearctic (Taeger et al. 2010).

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

Diagnostic characteristics

Subfamily characters

• fore wing vein M and 1m-cu parallel (Smith 1979a)
• fore wing vein 2A+3A complete, connected to 1A by crossvein (Smith 1979a)
• anal crossvein angled (Smith and Schiefer 1997)

Genus characters​

• mandibles bidentate (Smith 1979a)
• clypeus moderately notched; circularly emarginated (Smith 1979a)
• genal ridge extending to top of compound eye (Smith 1979a)
• second antennal segment as long as wide (Smith 1979a)
• fore wing vein 2r present (Smith 1979a)
• fore wing vein M intersecting Sc+R at the intersection of Sc+R and Rs+M (Smith 1979a)
• tarsal claw with indistinct basal lobe, bifid (Smith 1979a)

May be confused with

Aphilodyctium can be confused with similar species in the subfamily Allantinae or tribe Empriini. It can be distinguished from most other genera by the circular clypeus emargination and the lack of cell M in the hind wing (Smith 1979a).

Exotic pest species of concern

none

Host associations

In North America, A. fidum feeds on Rosa spp. (rose) (Smith 1979a).

Life history

Specific biology for A. fidum is not known. Larvae have been observed on the host plant. Adult A. fidum have emerged from a variety of plants other than the host, suggesting that the prepupae build cells to overwinter in secondary host plants, similarly to Ametastegia. Aphilodyctium fidum is univoltine (Smith 1979a).

Distribution

World: This genus is known only from North America (Smith 1979a, Taeger et al. 2010).

North America: Aphilodyctium fidum is widespread in northern United States and southern Canada, as far south as California and Arizona in the west, North Carolina in the east (Smith 1979a).

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

Details about data used for maps can be found here.