Ptenos

Taxonomy

Family: Argidae
Family common name: argid sawflies
Subfamily: Sterictiphorinae
Genus: Ptenos Norton, 1872
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).

Ptenos are about 6–8 mm in length, and in North America are generally red and black in color. They are recognized by wing venation, large eyes, and characteristic 3-segmented antennae, which in males are distinctly forked, and in females are slightly curled (Smith 1971c, Smith 1992, Vikberg 2004).

Diversity

There are 31 species described worldwide, all restricted to the Americas. Eleven species occur in North America (Smith 1992, Taeger et al. 2010).

A key to Nearctic species of Ptenos (as Ptenus) is included in Smith 1970.

Diagnostic characteristics

May be confused with

The family Argidae can be distinguished by the single-segmented flagellum of the antenna. The genus Ptenos can be distinguished from other genera in the family by the lack of preapical spurs on the tibiae, the simple tarsal claws and a lack of vein Sc in the fore wing. Males are distinguished from related genera Arge and Atomacera by the conspicuous forked antennae (Smith 1992).

Exotic pest species of concern

none

Host associations

No hosts are known for Ptenos. One specimen of P. leucopoda is recorded feeding on “Inya sp.” which might be a misspelling of Inga (Fabaceae) (Smith 1992).

Life history

Larvae and life histories are unknown for Ptenos species (Smith and Middlekauff 1987).

Distribution

World: This genus ranges in North and South America, from as far north as the United States, as far south as Argentina (Smith 1992).

North America: Ptenos ranges throughout Mexico and Central America. Two species, P. dominicaensis and P. thoracicus, are only recorded from the West Indies, in the countries of Dominica and Grenada respectively. Two species occur in the United States: P. texanus known from Mexico north into Texas, and P. vanus known from northern Mexico into Arizona and New Mexico (Smith 1992).

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

Details about data used for maps can be found here.

Ptenos texanus female lateral habitus; photo by J. Orr, WSDA

Ptenos texanus female lateral habitus; photo by J. Orr, WSDA

Ptenos texanus female dorsal habitus; photo by J. Orr, WSDA

Ptenos texanus female dorsal habitus; photo by J. Orr, WSDA

Ptenos texanus female face; photo by Q. Baine, WSDA

Ptenos texanus female face; photo by Q. Baine, WSDA

Ptenos texanus male lateral habitus; photo by J. Orr, WSDA

Ptenos texanus male lateral habitus; photo by J. Orr, WSDA

Ptenos texanus male dorsal habitus; photo by J. Orr, WSDA

Ptenos texanus male dorsal habitus; photo by J. Orr, WSDA

Ptenos texanus male face; photo by Q. Baine, WSDA

Ptenos texanus male face; photo by Q. Baine, WSDA

Ptenos texanus fore wing; photo by J. Orr, WSDA

Ptenos texanus fore wing; photo by J. Orr, WSDA