Peristenus otaniae Goulet & Mason 2006, n. sp.

Peristenus otaniae n. sp. (Figs. 18, 39, Table 13)

Type material. Type locality: Canada, Alberta, Mountain Trail near Beaverlodge. Holotype, female (CNCI), labelled: [White] “ CANADA, AB Beaverlodge, Mountain Trail 12.VIII.1999, emg. late VII.2000, J. Otani ”; [White] “EX: Lygus spp. Det: J. Otani, 2000”; [Red] “ HOLOTYPE Peristenus otaniae Goulet CNC No. 23477”. Condition of holotype: perfect. Allotype male labelled as holotype. Paratypes: all specimens mentioned under “Material examined and range”.

Origin of species name. This species is named in honour of Jennifer Otani who reared P. otaniae as well as other interesting species of Peristenus and Leiophron in northern Alberta.

Diagnosis. Clypeus reddish brown, range within boreal regions of North America, females generally with fewer than three subquadrate preapical flagellomeres and in both sexes generally with few punctures below median ocellus.

Description. FEMALE. Colour. Head and mesosoma black; metasoma usually brown, rarely black or reddish brown. Legs generally straw coloured, metacoxa occasionally light reddish brown and exceptionally reddish brown on dorsal surface. Base of metatibia usually straw coloured or light reddish brown. Apex of metatibia and metatarsomere 1 clearly darker than basal 0.5 of metatibia. Metatarsomeres 2–5 less dark than metatarsomere 1. Palpi, tegula and mandible (except apex) straw coloured. Scape to flagellomere 2 straw coloured, then gradually darkening to reddish brown in middle to brown or dark brown in apical 0.3. Stigma dark brown and straw coloured in basal third.

Structure. Flagellum with 18–20 flagellomeres (respectively 13%, 65% and 22% of 148 specimens) and flagellomeres enlarged in apical half. Few of the preapical flagellomeres subquadrate (none 35%, one 43%, two 19% and more 3%). Length of gena behind eye 0.80–1.09 times as long as length of eye. Height of eye 1.34–1.46 times as long as minimum distance between inner eye margins (Fig. 18). Maximum width of head behind eyes subequal (0.92–0.97) to maximum head width at eye level. Occipital carina developed in dorsal third. Metasomal tergum 1 with lateral edges clearly convergent (posterior margin 2.1–2.4 times as wide as narrowest width near base) and elongate (medial length of tergum 1.38–1.67 times maximum width at posterior end). Radial cell length 0.83–1.07 as long as stigma width (as in Figs. 58–63). Forewing vein r usually developed and short (as in Figs. 60, 61) and basal cell (except extreme base) pubescent (as in Fig. 54).

Sculpture. Punctures on vertex 5–10 µm in diameter, frons and mesoscutum about 10–15 µm in diameter (a little larger than diameter of ommatidia). Punctures 20–25 µm apart on vertex and 5–15 µm apart on frons to 5–10 µm apart near antennal socket, 20–25 µm apart on mesoscutum. Punctures in front of median ocellus in most specimens absent, few or fine and surrounding surface with punctures less dense (few or none 95%, many small 4% and coarse 1% based on 100 specimens). Punctures on mesopleuron generally dense, occasionally scattered. Clypeus generally punctate over surface, rarely almost impunctate. Metasomal tergum 1 with about 10–12 longitudinal ridges, these often anastomosing on disc and forming a puncture­like sculpture.

MALE. Colour. As in female.

Structure. Flagellum with 20–23 flagellomeres (respectively 6%, 27%, 54% and 11% of 98 specimens) and flagellomeres narrow in apical 0.5. Height of eye 1.00–1.14 times as long as minimum distance between inner eye margins. Otherwise structure and sculpture as in female.

Taxonomic notes. Adults of P. otaniae and P. mellipes are similar. The two species differ in the frequency distribution of flagellomere number, in geographic ranges, in life zones occupied, in the proportion of subquadrate preapical flagellomeres in females, and in type of puncture development in front of median ocellus. The nearest samples of each species are not more similar than distant samples. Therefore, there is no evidence of gene flow between the two species. A summary of measurement differences between P. otaniae and P. mellipes is given in Table 13.

Though the flight periods overlap widely between P. otaniae and P. pseudopallipes, the two species differ in life cycle, geographic range (allopatric), life zone occupied, in the proportion of subquadrate preapical flagellomeres in females, and in type of puncture development in front of median ocellus. A summary of measurement differences between P. otaniae and P. pseudopallipes is given in Table 13.

Host and biological notes. Adults of this species have been reared from various species of Lygus (65 specimens), Lygus lineolaris (5 specimens) and Adelphocoris lineolatus (6 specimens). Adults occur from early June to early August with peak abundance between late June and early July. This is a univoltine species. Females of this species parasitize nymphs of only the first generation even when an occasional second Lygus generation occurs at the southern end of its range. Loan and Craig (1976) described the biology of this species under P. pallipes. Braun et al. (2001) confirmed Loan’s and Craig’s data.

Material examined and range. 253 (97♂, 156♀) adults were studied. Of these, 76 were reared from Miridae and 165 were field collected. The species is known from the Rocky Mountains in south central British Columbia to Newfoundland. Most specimens and localities are in boreal regions of Canada and from the montane zone in the Rocky Mountains.

CANADA. NF: South Branch (2♀). QC: vic. La Corne 48º24'19"N 78º00'12"W (11♂, 38♀); La Verandrye Prov. Park 47º36'57"N 77º33'42"W (1♀); Matagami 49º45'08"N 77º37'14"W (3♂, 5♀). MB: Ninette (1♂); Riverton (1♂); 3 km N Stockton (1♀). SK: Brancepeth (1♂); vic. Saskatoon 52º09.1'N 106º34.9'W (9♂, 3♀); White Fox (10♂, 10♀). AB: vic. Bear Lake 55º12.863'N 118º58.743'W (1♀); Beaverlodge (7♂, 7♀); Mountain trail vic. Beaverlodge (21♂, 29♀); Dunvegan (3♀); Edmonton (5♀); Frank (1♀); Highway 667 (1♀); vic. La Crete 58º01.257'N 116º19.621'W (2♂, 4♀); Pincher (1♀); Saint Albert (1♀); Saskatoon Mountain 55º13.663'N 119º18.160'W (21♂, 30♀); Saskatoon Mountain 55º10.286'N 119º12.571'W (3♂); Spruce Grove (1♂). BC: Kishatinaw Riv. 56º14.448'N 120º30.082'W (3♀); Laird Hot Springs (1♀); Revelstoke (1♀). USA. CO: Estes Park (1♂, 1♀); 6 km SW Golden (2♂, 3♀); 3 km S Meeker (3♂, 3♀).