Tenthredo

Taxonomy

Family: Tenthredinidae
Family common name: common sawflies
Subfamily: Tenthredininae
Tribe: Tenthredinini
Genus: Tenthredo Linnaeus, 1758
Subgenera: Tenthredo, Adungia, Casipteryx, Cephaledo, Dorhettenyx, Elinopsis, Elinora, Endotethryx, Eurogaster, Maculedo, Metallopeus, Olivacedo, Paratenthredo, Peus, Propodea, Temuledo, Tenthredella, Tenthredina, Zonuledo

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, size and form (Goulet 1992).

Sawflies in the Tenthredininae subfamily are relatively large 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).

Tenthredo is the most species-rich sawfly genus, with incredibly diverse forms, host plants, and behaviors. Species can be recognized by the relatively large size, slender body, angular face features, and often by bright colors and patterns (Smith 1979b, Goulet 1992).

Diversity

There are 978 described extant species worldwide. There are 143 species that occur in North America (Taeger et al. 2010).

Diagnostic characteristics

Subfamily characters

Genus characters

May be confused with

Tenthredo can be confused with similar species in the subfamily Tenthredininae. It can be distinguished from most other genera by the obtuse angle on the posteroventral area of the metepimeron and the ventral angle of the compound eye. Tenthredo can be distinguished from closely related Rhogogaster by the size of the eye, the apical margin of the labrum, and a furrow on the anterior pronotum (Goulet 1992).

Exotic pest species of concern

In China, T. nubipennis is considered a pest because of records of wide-scale damage in Phyllostachys bamboo forests. The species is univoltine (Liang 2012). In Turkey, T. livida is a defoliating pest of Rosa spp. (rose) (Özbek and Çalmaşur 2005).

Host associations

Tenthredo in Europe feeds on a great diversity of plants from several plant families, but most hosts for species in North America are unknown. Species are often host-specific (Goulet 1992, Goulet 1996). Tenthredo xantha feeds on Rubus (blackberry) (Smith and Middlekauff 1987), and T. grandis feeds on Chelone (turtlehead) (Stamp 1984).

Life history

Specific biology for many species is unknown. Tenthredo is univoltine, and prepupae often overwinter in cells or cocoons in the ground (Smith and Middlekauff 1987).

Tenthredo grandis has been recorded causing severe defoliation of turtlehead in the eastern United States. This feeding preference imposes limitations on Euphdryas phaeton (Baltimore checkerspot), a butterfly that shares this host, resulting in possible population decline of this rare and threatened butterfly (Stamp 1984).

Adults are recorded feeding on pollen and nectar of non-host plant flowers, pollinating the plant in the process. Tenthredo and closely related Rhogogaster are the only confirmed North American sawfly pollinators (there is evidence of Arge carrying pollen). There are also records of adults predating on other insects, including Syrphidae flies and other, smaller sawflies. Pollination and predation are ecosystem services that may provide positive economic impact (Smith 1979b, Liston 1980, Goulet 1996).

Some plants pollinated by Tenthredo in North America include Potentilla (cinquefoil), Luetkia (partridge-foot), Ledum (wild rosemary), Monardella, Cymopterus (springparsley), Senecio (ragwort), Solidago (goldenrod), Pedicularis, Salix (willow), Horkelia, Ranunculus (buttercup), Arnica, Valeriana (valerian), Polygonum (knotweed), Phacelia, and Hackelia (Goulet 1996).

Distribution

World: The genus is generally Holarctic, present throughout North America, Europe, North Africa, and Asia (Smith 2003b, Taeger et al. 2010).

North America: Tenthredo occurs throughout Canada and the northern United States. One species, T. ocampa, is recorded farther south in Chihuahua, Mexico (Smith 2003b).

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

Details about data used for maps can be found here.

Tenthredo xantha female lateral habitus; photo by J. Orr, WSDA

Tenthredo xantha female lateral habitus; photo by J. Orr, WSDA

Tenthredo xantha female dorsal habitus; photo by J. Orr, WSDA

Tenthredo xantha female dorsal habitus; photo by J. Orr, WSDA

Tenthredo xantha female face; photo by Q. Baine, WSDA

Tenthredo xantha female face; photo by Q. Baine, WSDA

Tenthredo rhammisia male lateral habitus; photo by J. Orr, WSDA

Tenthredo rhammisia male lateral habitus; photo by J. Orr, WSDA

Tenthredo sp. male dorsal habitus; photo by J. Orr, WSDA

Tenthredo sp. male dorsal habitus; photo by J. Orr, WSDA

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

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

Tenthredo maxima female wings; photo by P. Jones, WSDA

Tenthredo maxima female wings; photo by P. Jones, WSDA

Tenthredo sp. male wings; photo by P. Jones, WSDA

Tenthredo sp. male wings; photo by P. Jones, WSDA