Gnypeta caerulea

8. Gnypeta caerulea (Sahlberg)

(Figs 10, 28 a, b, 99-107, 197)

Aleochara caerulea C.R. Sahlberg 1830: 351. As Gnypeta: Bernhauer and Scheerpeltz 1926: 587; Palm 1966: 138; Muona 1984: 228; Campbell and Davies 1991: 100; Smetana 2004: 489. TYPE LOCALITY: FINLAND, Helsinki [in orig. description: “Ad Helsingforsiam semel tantum capta”]. Holotype not examined.

Material examined

Specimens are listed in Appendix A.

Diagnosis

This species can be recognized by the following combination of characters: body length 3.0-3.5 mm (Fig. 10); elytra (at suture) about as long as pronotum and at least 1/4 wider than maximum width of pronotum (Fig. 10); abdomen at base narrower than elytra and subparallel (Fig. 10); antennal articles 4-10 strongly to moderately elongate and increasingly less so toward the apex of antennae (Figs 28 a, b); median lobe of aedeagus with apical part broadly triangular in lateral view (Fig. 99); spermatheca with capsule mushroom-shaped (Fig. 105); stem sinuate and slightly swollen basally (Fig. 105); male tergite 8 truncate and with two minute lateral dents at apical margin (Fig. 103). Gnypeta caerulea is readily distinguishable from G. lohsei by larger, slimmer and strongly glossy body and by the elongate antennal articles 6-10, which are quadrate to slightly transverse in G. lohsei (Fig. 28).

Description

Body length 3.0-3.5 mm; uniformly dark brown to black, sometimes central part of elytra rust brown, tarsi and sometimes entire legs rust brown (Fig. 10); integument strongly glossy; pubescence yellowish grey and moderately long and dense; antennal article 4 strongly elongate, 5-10 moderately to strongly elongate, and increasingly less so toward the apex of antennae (Figs 28 a, b); head and pronotum of about the same width (Fig. 10); elytra and abdomen wider than either head or pronotum; head rounded posteriorly; pronotum broadest in apical third, pubescence directed anterad along midline and laterad elsewhere; elytra at suture slightly longer than pronotum and at least 1/4 wider than maximum width of pronotum, pubescence directed obliquely postero-laterad, in wavy pattern medially on each side of disc (Fig. 10); abdomen subparallel, narrower than elytra at base (Fig. 10), three basal tergites with deep basal impressions bearing large punctures; metatarsus with two basal articles of about the same length and the third one slightly shorter. Male. Tergite 8 transverse and truncate apically, with two minute apical dents (Fig. 103). Sternite 8 about as long as wide and rounded apically (Fig. 104). Median lobe of aedeagus with broadly triangular apical part of tubus and edges approximately straight in lateral view (Fig. 99); bulbus moderately large with two small anterior projections in dorsal view (Fig. 100); internal sac with structures as illustrated (Figs 99, 100). Female. Tergite 8 truncate apically (Fig. 106). Sternite 8 broadly rounded apically (Fig. 107). Spermatheca with capsule elongate, mushroom-shaped (Fig. 105); stem sinuate and slightly swollen basally (Fig. 105).

Distribution (Fig. 197)

Gnypeta caerulea is a Holarctic species with circumpolar distribution. Smetana (2004) listed this species from Europe, Asia, and North America. Muona (1984), Campbell and Davies (1991), and Gouix and Klimaszewski (2007) recorded this species from Newfoundland. Majka and Klimaszewski (2008) provided new records for Nova Scotia and Prince Edward Island. We report this species for the first time from New Brunswick, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, Yukon Territory, Northwest Territories and Alaska.

Collection and habitat data

In the United Kingdom, G. caerulea was reported from river margins and in wet moss growing on boulders and rocks in rivers, waterfalls and streams (Hyman and Parsons 1994). In Canada, adults were collected in May, June, July, and September in marshy habitats, from vegetation around beaver ponds, from edges of ponds with sphagnum, and from swamp sedges.

Comments

The late Steve Ashe (University of Kansas) worked on a revision of Nearctic Gnypeta but was not able to complete it. Some CNC specimens, which belong to this species, bear his misidentification labels as “ G. nebulosa Ashe ” and “ G. dialepta Ashe ” [1987 manuscript – unpublished names].