Allantus

Taxonomy

Family: Tenthredinidae
Family Common Name: common sawflies
Subfamily: Allantinae
Tribe: Allantini
Genus: Allantus Panzer, 1801
Subgenera: Allantus, Emphytus

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).

Allantus are medium-sized, about 7–8 mm in length, and generally black and white in color. The genus is species-rich worldwide, with a few native and a few introduced species in North America. Some species are known pests of roses (Smith 1979a).

Diversity

There are 48 described extant species worldwide. Nine occur in North America (Taeger et al. 2010).

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

Diagnostic characteristics

Subfamily characters

Genus characters​

May be confused with

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

Exotic pest species of concern

Allantus luctifer feeds on species of Rumex (dock) native to east Asia. Dock is a weedy plant considered to be a pernicious and poisonous weed throughout the world, and because of this, A. luctifer was being considered as a potential biocontrol insect in South Korea (Park et al. 2008). However, CABI was not able to show sufficient host-specificity, and it was not approved for release in the United States (Grevstad et al. 2018). Similarly, A. nigrocaeruleus in China was tested for potential use as a biocontrol agent of Polygonum perfoliatum (mile-a-minute), an invasive weed in the eastern United States, but results on host-specificity are incomplete (Ding et al. 2004).

Host associations

In North America, Allantus feeds on species of rose, including Rosa canina (dog rose), Rosa rugosa (saltspray rose), Rosa pendulina (alpine rose), Rosa glauca (red leaf rose), Rosa rugibinosa (sweetbriar rose), Rosa spinosissima (Scotch rose), and Rosa gallica (French rose). Allantus also feeds on species of Rubus (blackberry), Ribes (currant), and Fragaria (strawberry) (Smith 1979a). One species, Allantus umbonatus is known to feed on the non-Rosaceae tree Betula papyrifera (paper birch) (Wong 1966).

Life history

Female Allantus lay eggs into the upper side of the leaf. Larvae feed externally and then overwinter either in stems or in the soil of the host plant. Most species are univoltine (Smith 1979a).

Allantus viennensis is known as the rose minor leaf-eating sawfly and is a pest of roses (Hosseini and Sahragard 2003) (Smith 1979a). The female lays eggs in young shoots of the plant, and the hatched larvae feed gregariously on the parenchyma of the foliage. As they mature, the larvae transition to eating the entire leaf and defoliating the plant. Larvae will also feed on flower petals. At maturity, prepupae burrow into stems or shoots and pupate. Allantus viennensis is multivoltine; in studies in Iran it undergoes 3 generations per year (Hosseini and Sahragard 2003).

Allantus cinctus, known as the curled rose sawfly or coiled roseworm, and A. basalis, are also rose pests introduced from Europe (Smith 1979a, Mattson et al. 1994, Stroom et al. 1997). Allantus cinctus is bivoltine in the southern part of its range (Smith 1979a).

Allantus nigritibialis, native to east Asia, was reportedly introduced to eastern North America, but few collections have been made and it is likely there is no population established (Smith 1979a, Taeger et al. 2010).

Distribution

World: This genus is known from North America, Europe, northern Africa, and throughout Asia (Smith 1979a, Taeger et al. 2010).

North America: Allantus is widespread in northern United States and Canada and occurs as far north as Alaska and the Northern Territories. There are aberrant collections in Florida and Tennessee (Smith 1979a).

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

Details about data used for maps can be found here.

Allantus viennensis female lateral habitus; photo by J. Orr, WSDA

Allantus viennensis female lateral habitus; photo by J. Orr, WSDA

Allantus albolabris female dorsal habitus; photo by J. Orr, WSDA

Allantus albolabris female dorsal habitus; photo by J. Orr, WSDA

Allantus albolabris female face; photo by Q. Baine, WSDA

Allantus albolabris female face; photo by Q. Baine, WSDA

Allantus cinctus male lateral habitus; photo by J. Orr, WSDA

Allantus cinctus male lateral habitus; photo by J. Orr, WSDA

Allantus cinctus male dorsal habitus; photo by J. Orr, WSDA

Allantus cinctus male dorsal habitus; photo by J. Orr, WSDA

Allantus viennensis fore wing; photo by J. Orr, WSDA

Allantus viennensis fore wing; photo by J. Orr, WSDA