Ophrynon

Taxonomy

Family: Orussidae
Family common name: parasitic woodwasps
Subfamily: Ophrynopinae
Genus: Ophrynon Middlekauff, 1983
Subgenera: none

Background

The Orussidae are small, predominantly black sawflies with cylindrical bodies and globular heads (Eaton and Kaufman 2007). They are distinctive because they are the only sawfly family that is parasitic instead of phytophagous (Furniss and Carolin 1977). Current Hymenoptera phylogenies suggest that the Orussidae are the most closely related extant sawfly family to the suborder Apocrita, and specifically parasitic wasps (Vilhelmsen 2004).

Ophrynon are 8–14 mm in length (Furniss and Carolin 1977). They share several remarkable morphological characters with other Orussidae, including antennal insertions located extremely low on the face, reduced wing venation, and a relatively long and thin ovipositor (Vilhelmsen et al. 2014). This genus is extremely rare in collections and poorly known (Blank et al. 2010).

Diversity

There are only four described species worldwide. All four are Nearctic and known only from southern California (Blank et al. 2010).

A key to North American species of Ophrynon is included in Blank et al. 2010.

Diagnostic characteristics

May be confused with

Orussidae are morphologically distinct among sawfly families because of the body shape and location of antennae on head. Ophrynon, however, is easily confused with other genera of the family. It can be distinguished by the presence of longitudinal carinae between the eyes and the distinct shape of the mesoscutellum and the maxillary palpi (Middlekauff 1983).

Exotic pest species of concern

none

Host associations

The Orussidae are external parasitoids of other insects. The hosts for species of Ophrynon are unknown, but are presumed to be beetles of the family Buprestidae because of the biology of other orrusids and the geographic range of potential hosts. One Ophrynon levigatus was reared from a sample of Quercus dumosa (scrub oak) in which was also living several species of Buprestidae: Acmaeodera knullorum, A. linsleyi, A. vulturei, Acmaeoderopsis guttifera, and Hesperorhipis jacumbae. Blank et al. (2010) theorized that of these, the species of Acmaeodera are most likely the preferred host, because of larval body size.

Life history

Biology of Ophrynon species is unknown as only 10 adult specimens have been collected and/or observed (Blank et al. 2010). For a description of the life history of a closely related sawfly in the Orussidae, see Orussus.

Distribution

World: No species are documented outside of North America (Blank et al. 2010).

North America: Ophrynon has only been recorded from southern California. The four species range from Fresno County south to Riverside County, an area characterized by arid steppe and dry coniferous forest (Blank et al. 2010).

Map data from the Smithsonian National Museum of Natural History (USNM)

Details about data used for maps can be found here.

Ophrynon martini female dorsal habitus; photo by Q. Baine, WSDA

Ophrynon martini female dorsal habitus; photo by Q. Baine, WSDA

Ophrynon martini female lateral habitus; photo by Q. Baine, WSDA

Ophrynon martini female lateral habitus; photo by Q. Baine, WSDA

Ophrynon sp. male lateral habitus; photo by J. Orr, WSDA

Ophrynon sp. male lateral habitus; photo by J. Orr, WSDA

Ophrynon levigatus male dorsal habitus; photo by J. Orr, WSDA

Ophrynon levigatus male dorsal habitus; photo by J. Orr, WSDA

Ophrynon levigatus male face; photo by J. Orr, WSDA

Ophrynon levigatus male face; photo by J. Orr, WSDA

Ophrynon levigatus male fore wing; photo by J. Orr, WSDA

Ophrynon levigatus male fore wing; photo by J. Orr, WSDA