Family common name: common sawflies
Genus: Nesoselandria Rohwer, 1910
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 Selandriinae subfamily are relatively small and slender. The range of Selandriinae is worldwide; it occurs on all continents except Antarctica (Goulet 1992). It is the most common and diverse group of tenthredinids in tropical regions, particularly in Central America, South America, and Southeast Asia (Smith 1969e). Selandriinae contains the only known sawflies that feed on non-vascular plants, specifically ferns (Smith et al. 2013). The subfamily can be distinguished from other subfamilies by wing venation (Goulet 1992).
Nesoselandria is monotypic in the Nearctic region. Nesoselandria morio are small and stout, about 4.5 mm in length, and mostly black with orange legs and darkened wings (Smith 1969e). Though many sawfly hosts are unknown, Nesoselandria is the only genus known to feed on mosses (Vikberg and Nuorteva 1997).
Nesoselandria can be confused with similar species in the subfamily Selandriinae or tribe Aneugmenini. It can be distinguished from most other genera by the absence of a fore wing anal crossvein, from closely related Aneugmenus by the lack of an occipital ridge, and from Birka by the malar space length (Smith 1969e).
Hosts for N. morio in North America are not known. In Europe, N. morio feeds on mosses in the class Bryopsida, including Ceratodon purpureus (purple moss), Plagiomnium cuspidatum (baby tooth moss), Hedwigia ciliata (white-tipped moss), Plagiothecium denticulatum (toothed plagiothecium moss), and Polytrichum commune (common haircap moss) (Vikberg and Nuorteva 1997).
Female N. morio deposit eggs on the leaves. Larvae are gray and shiny with light brown head capsules. At maturity, prepupae fall to the ground and make sand cocoons. In experiments, N. morio pupated in less than two months, implying multiple generations per year (Vikberg and Nuorteva 1997).
Nesoselandria morio was first discovered in North America in British Columbia, Ontario, and Quebec in 1967. Because this species historically is known from both Europe and Japan, it is not clear from where or how the species was introduced (Smith 1967b). Only females are known in North America (Smith 1969e).
North America: Nesoselandria morio is established in New Hampshire, Quebec, and Ontario in the east and British Columbia in the west (Smith 1969e). South of the United States, N. crassa is known from Panama and N. rufonota is known from Acapulco, Mexico (Rohwer 1911, Rohwer 1912).
Map data from: GBIF.org (29 October 2019) GBIF Occurrence Download Nesoselandria
Details about data used for maps can be found here.