Nemoura arctica Esben-Petersen 1910
Creators: name: Grubbs, Scott A.
name: Baumann, Richard W.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Nemouridae
Nemoura
Nemoura arctica

description: 1. Nemoura arctica Esben-Petersen, 1910
Arctic Forestfly
http://lsid.speciesfile.org/urn:lsid: Plecoptera.speciesfile.org:TaxonName:6232
(Figs. 1, 9–18)
Nemoura arctica Esben-Petersen 1910:85. Holotype male (Museum unknown), Karasjok, Norway
Nemoura trispinosa Claassen, 1923:289. Syn. Grubbs et al., 2018:48
Nemoura trispinosa: Needham & Claassen, 1925:213
Nemoura arctica: Claassen, 1940:50
Nemoura trispinosa: Claassen, 1940:64
Nemoura trispinosa: Frison, 1942:261
Nemoura trispinosa: Harden, 1942:322
Nemoura trispinosa: Ricker, 1944:177
Nemoura arctica: Koponen & Brinck, 1949:7
Nemoura trispinosa: Weber, 1950:175
Nemoura arctica: Brinck, 1952:107
Nemoura trispinosa: Harden & Mickel, 1952:19
Nemoura (Nemoura) arctica: Ricker, 1952:36
Nemoura arctica: Zhiltzova, 1964:187
Nemoura arctica: Illies, 1966:194
Nemoura trispinosa: Illies, 1966:214
Nemoura (Nemoura) arctica: Harper & Hynes, 1971:1133
Nemoura (Nemoura) trispinosa: Harper & Hynes, 1971:1133
Nemoura arctica: Lillehammer, 1972:163
Nemoura trispinosa: Lillehammer, 1972:163
Nemoura arctica: Zwick, 1973:332
Nemoura trispinosa: Zwick, 1973:342
Nemoura (Nemoura) trispinosa: Hitchcock, 1974:107
Nemoura arctica: Lillehammer, 1974:82
Nemoura arctica: Baumann, 1975:51, 64 (in part)
Nemoura trispinosa: Baumann, 1975:51
Nemoura arctica: Baumann et al., 1977:34
Nemoura arctica: Lillehammer, 1988:113
Nemoura trispinosa: Stewart & Stark, 1988:169
Nemoura trispinosa: Stewart & Stark, 2002:196
Nemoura arctica: Zhiltzova, 2003:266
Nemoura arctica: Kondratieff & Baumann, 2004:114
Nemoura arctica: Stewart & Oswood, 2006:78
Nemoura arctica: Boumans, 2011:286
Nemoura arctica: Judson & Nelson, 2012:33
Nemoura arctica: Grubbs et al., 2018:48
Distribution (Nearctic only). Canada: AB, BC, LB, MB, NB, NF, NS, NT, NU, ON, PE, PQ, SK, YK; USA: AK, IA, IL, ME, MI, MN, NH, NY, OH, PA, SD, WI, WV, WY (DeWalt et al. 2022)
Male. Macropterous. Body length 4.7–5.9 mm, forewing length 4.1–6.1 mm (n = 25). Gills absent. Cerci sclerotized laterally and modified, outer edge produced and terminates typically in a pair of appressed spines that vary in length and degree of tapering, plus an outer spine that is variable (Figs. 9–13). The outer spine is distally forked (Fig. 13) or not (Fig. 12). Populations further westward vary from the eastern Nearctic males. For example, males from South Dakota have an outer spine that is rectangular and crenulated distally (Grubbs et al. 2018, their fig. 5). Paraproct outer lobes straight anteriorly and slightly trilobed posteriorly. The base of the cerci fit between the anterior and medial lobe. Epiproct short and robust, recurved anteriorly over the terminal abdominal segments (Figs. 9–11); in lateral aspect, the basal cushion occupies the anterior ca. ½ and is separated from the dorsal sclerite by smooth lateral areas (Fig. 14). The lateral areas are recurved slightly over the distal medial portion of the basal cushion. The dorsal sclerite appears scaly at high magnifications, especially apically (Fig. 14). The dorsal sclerite is open apically, exposing parallel, broad, hatchet-like apical prongs of the ventral sclerite (Figs. 11, 15–16) and prominent, scaly, apical prongs positioned ca. perpendicular to the ridges (Figs. 15–16). The prongs terminate laterally bearing two short, thick, grooved spines (Figs. 15–16).
Female. Macropterous. Body length 5.4–7.4 mm, forewing length 4.6–7.6 mm (n = 23). Gills absent. The 7 th sternum is produced as a broadly-subtruncate to subtriangular subgenital plate that extends over minimally across ½ of the 8 th sternum (Figs. 17–18).
Larva. Described by Brinck (1949, 1952), Harden & Mickel (1952, as N. trispinosa), and Harper & Hynes (1971, as N. trispinosa). A partial illustration was also given in Frison (1942, as N. trispinosa) and Harper & Stewart (1996). Stewart & Stark (1988, 2002) provided a description and full habitus illustration as N. trispinosa.
Comments. Grubbs et al. (2018) recently provided evidence with scanning electron micrographs that Nearctic N. trispinosa is a junior synonym of Holarctic N. arctica. Nemoura arctica is distributed extensively at mid- to northern latitudes across the Northern Hemisphere (DeWalt et al. 2022).
description: Published as part of Grubbs, Scott A. & Baumann, Richard W., 2023, The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic, pp. 1-53 in Zootaxa 5306 (1) on pages 6-7, DOI: 10.11646/zootaxa.5306.1.1, http://zenodo.org/record/8054287