Filacus

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Tenthredininae
Tribe: Sciapterygini
Genus: Filacus Smith & Gibson, 1984
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 Tenthredininae subfamily are relatively large compared to others in the family, often with distinct colorful markings. Some are wasp-like with black and yellow stripes (Goulet 1992). Many species’ life histories are not known. Some Tenthredininae species feed uniquely, as adults, on flower pollen and other insects (Smith 1993). They can be distinguished from other subfamilies by wing venation (Goulet 1992).

Filacus is a western North American genus of small, stout, black and yellow sawflies (Smith and Gibson 1984).

Diversity

There are four described extant species worldwide. All are restricted to the Western Hemisphere (Taeger et al. 2010).

A key to species is included in Smith and Gibson 1984.

Diagnostic characteristics

Subfamily characters

Genus characters

May be confused with

Filacus can be confused with similar species in the subfamily Tenthredininae. It can be distinguished from most other genera by the angle on the posteroventral area of metepimeron, and from closely related Zaschizonyx by the shallowly notched or straight clypeus (Goulet 1992).

Exotic pest species of concern

none

Host associations

Filacus larvae feed on plants of several families. Confirmed hosts include Phacelia (lacy phacelia), Amsinckia (fiddlenecks), and Ranunculus (buttercup) (Smith and Gibson 1984).

Adult Filacus have been observed visiting a variety of flowers from several plant families and carrying pollen on their bodies, making them a potential pollinator. It is not known if the adults feed on the nectar, pollen, or other flower parts (Smith and Gibson 1984).

Life history

unknown

Distribution

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

North America: Filacus is recorded in several counties in California and Arizona, south into Baja California Norte (Smith and Gibson 1984, Smith 2003b).

Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Filacus and the Smithsonian National Museum of Natural History Entomology Collection (USNM)

Details about data used for maps can be found here.

Filacus albipes female lateral habitus; photo by J. Orr, WSDA

Filacus albipes female lateral habitus; photo by J. Orr, WSDA

Filacus sp. female dorsal habitus; photo by Q. Baine, WSDA

Filacus sp. female dorsal habitus; photo by Q. Baine, WSDA

Filacus sp. female face; photo by Q. Baine, WSDA

Filacus sp. female face; photo by Q. Baine, WSDA

Filacus albipes male lateral habitus; photo by J. Orr, WSDA

Filacus albipes male lateral habitus; photo by J. Orr, WSDA

Filacus sp. male dorsal habitus; photo by Q. Baine, WSDA

Filacus sp. male dorsal habitus; photo by Q. Baine, WSDA

Filacus sp. male face; photo by Q. Baine, WSDA

Filacus sp. male face; photo by Q. Baine, WSDA

Filacus albipes wings; photo by J. Orr, WSDA

Filacus albipes wings; photo by J. Orr, WSDA