Peristenus broadbenti, Goulet & Mason, 2006

Goulet, Henri & Mason, Peter G., 2006, Review of the Nearctic species of Leiophron and Peristenus (Hymenoptera Braconidae: Euphorinae) parasitizing Lygus (Hemiptera: Miridae: Mirini:), Zootaxa 1323 (1), pp. 1-118 : 56-58

Peristenus broadbenti n. sp.

( Figs. 4 habitus, 10, 16, 47, 52a, 52b, 58, 61, 62, 63, 85, Table 15)

Type material. Type locality: Canada, Alberta, Lethbridge. Holotype, female ( CNCI), labelled: [ White ] “ Canada, Alberta, Lethbridge, Victoria Church, alfalfa­weed mix, Coll. 24.VII.2002 49º42.279'N 112º44.951'W C. Herle, Cage ID: 3D”; [White] “Lab. emg. 10.VI.2003 – 4.VII.2003 Ex. Lygus nymph”; [Red] “ HOLOTYPE Peristenus broadbenti CNC No. 23478”. Condition of holotype: Perfect. Allotype male from same locality and emergence date, but cage “ID: 11B”. Paratypes: all specimens from above locality .

Origin of species name. This species is named in honour of Bruce Broadbent who worked for many years on Lygus endoparasitoids. He reared several species, which benefited markedly our species concept for southern Ontario. Because all species he worked on in Ontario are named, this species is dedicated to him as acknowledgement for his long support of systematic research of mirid parasitoids.

Diagnosis. Clypeus black or dark brown, Frons not densely punctate (especially between lateral ocellus and inner eye margin), forewing vein r generally developed and a univoltine life cycle associated with the second nymphal generation of Lygus .

Description. FEMALE. Colour. Head and mesosoma black; metasoma black. Legs generally straw coloured, metacoxa brown to black; basal 0.3–0.5 of metatibia usually straw coloured or occasionally light reddish brown, and apical 0.5–0.7 of metatibia, metatarsomere 1 clearly darker than basal half of metatibia, but metatarsomeres 2–5 less dark than metatarsomere 1. Palpi, tegula and mandible (except apex) straw coloured. Scape to flagellomere 2 straw coloured, threafter brown to dark brown. Stigma dark brown and straw coloured in basal 0.3. See habitus ( Fig. 4 ).

Structure. Flagellum with 18–20 flagellomeres (respectively 3%, 59% and 35% of 32 specimens) and flagellomeres enlarged in apical 0.5. Few preapical flagellomeres subquadrate (none 60%, one 34% and two 6%). Length of gena behind eye 0.91–1.09 times as long as length of eye. Height of eye 1.30–1.42 times as long as minimum distance between inner eye margins (as in Fig. 18 ). Maximum width of head behind eyes subequal (0.91–0.96) to maximum head width at eye level. Occipital carina developed in dorsal third. Metasomal tergum 1 with lateral edges clearly convergent (posterior margin 2.2–2.3 times as wide as narrowest width near base) and elongate (medial length of tergum 1.5–1.8 times maximum width at posterior end). Radial cell length 0.94–1.06 as long as stigma width ( Figs. 58 , 61–63 ). Forewing vein r usually developed (85% based on 50 specimens) and short ( Figs. 58 , 61–63 ) and basal cell of forewing (except extreme base) pubescent (as in Fig. 54 ).

Sculpture. Punctures on vertex 5–10 µm in diameter, on frons and mesoscutum about 10–15 µm in diameter (a little larger than diameter of ommatidia). Punctures 20–25 µm apart on vertex (especially between lateral ocellus and inner eye margin), 5–15 µm apart on frons to 5–10 µm apart near antennal socket, and 20–25 µm apart on mesoscutum. Punctures on mesopleuron generally dense, occasionally scattered. Clypeus generally smooth, rarely punctate over disc. 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 7%, 45%, 42% and 5% of 40 specimens) and flagellomeres narrow in apical 0.5. Height of eye 1.00–1.11 times as long as minimum distance between inner eye margins. Otherwise structure and sculpture as in female.

Taxonomic notes. Among the species of the P. pallipes complex with a black or dark brown clypeus, P. broadbenti is nearest to P. gillespiei . Almost no structural differences were found between the two species. However, adults of the species differ in their life cycle and their almost allopatric range (narrowly sympatric in the Cascade Mountains). Though the data on reared specimens is limited, the Cascades samples from the Harrison Lake support the lack of gene flow between the two species. The emergence data from this locality are consistant with the typical P. gillespiei early emergence and the typical P. broadbenti late emergence. A summary of measurement differences between P. broadbenti and P.gillespiei is given in Table 15.

Adults of P. broadbenti differ from those of P.howardi in the development of forewing vein r, the presence of males, and a univoltine life cycle. A summary of measurement differences between P. broadbenti and P. howardi is given in Table 15.

Adults of P. broadbenti could easily be confused with those of P. braunae a darkly coloured species. They are easily distinguished from those of P. braunae by the colour of the clypeus and metatibia, by the puncture density on the vertex especially between the lateral ocellus and the inner eye margin, by the the ratio of eye height to minimal distance between eye inner margins, and the ratio of length of flagellum to maximum width of head between outer eye margins.

Host and biological notes. Adults of P. broadbenti have been reared from various species of Lygus . Adults occur from late June till late August with peak abundance probably in mid July. This is a univoltine species. Females of this species parasitize nymphs of only the second generation of Lygus .

Material examined and range. 116 (36♂, 80♀) adults were studied. Of these, 42 were reared from Miridae hosts and 74 were field collected. The species is known from temperate regions where two full Lygus generations occur from southwestern Alberta and southern British Columbia south to Nevada and Wyoming.

CANADA. AB: Eisenhower jct. Banff Nat. Park (1♀) ; Johnston Canyon, vic. Banff (3♀) ; Hardstead (1♀); Hendrickson (1♀); Lethbridge (7♂, 9♀); Lethbridge, 49º42.279'N 112º44.951'W (22♂, 16♀); Lethbridge, Pavan Park, 49º45.294'N 112º50.525'W (1♂, 6♀); Rolling Hills (2♂, 6♀); Rosdal (1♀); Waklin (1♂, 2♀); Waterton Lakes Nat. Park , 1300 m (1♂, 6♀) . BC: Diamond Head Trail, vic. Squamish , 1000 m (5♀) ; Hatzic Lake (3♀) ; Harrison Lake (1♀) ; Harrison Mills (1♀); MacGillivray Creek , vic. Chilliwack (1♀) ; Prince Rupert (1♀); Robson (1♂); Terrace (2♀); Summerland (1♀); West Harrison Rd. , 49º16'26"N 121º52'41"W (2♀) . USA. MT: Beaverhead Co., Clark Canyon Dam Rd. (1♀; ESUW) . NV: 19 km SW Wells , 2700 m (1♀) . OR: Lincoln Co., 13 km E Eddyville (6♀) . WA: Lewis Co., Meskill, 1.6 km W Hwy. 6 (2♀) ; Pacific Co., Idwaco, 28 km N Hwy 101 (1♀) . WY: Albany Co., Medecine Bow Nat. For. , 0.8 km NE Lincoln Monument (1♀; ESUW) ; Albany Co., Medecine Bow Nat. For. , 1.6 km N Lincoln Monument (1♀; E SUW) ; Albany Co., Medecine Bow Nat. For. , 0.6 km S Lincoln Monument (1♀; ESUW) ; Albany Co., Pole Mtn. (1♀; ESUW) ; Battle Lake Rd. , Sierra Madre Range (1♀; ESUW) .

Figures

FIGURES 1–5. Habitus with frontal view of head. Codes: “a” clypeal colour; “b” metatibial colour; “c” metacoxal colour; “d” forewing colour; “e” mesoscutal colour.

FIGURES 13–24. 13–22. Frontal view of head. Code: “a” ventral edge of clypeus. 23–24. Dorsal view of head.

FIGURES 50–58. 50–52. Forewing. 53–54. Basal and subbasal cells of forewing. 55–58. Radial cell and stigma of forewing.

FIGURES 59–66. 59–63. Radial cell and stigma of forewing. 64. Hind wing. 65–66. Basal and subbasal cells of hind wing.