Peristenus mellipes (Cresson)

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 : 48-50

Peristenus mellipes (Cresson)

( Figs. 7 habitus, 12, 33, 37, 38, 48, 54, 66, 70, 71, 72, 73, 74, 75, 76, 83, 86, Table 12)

Euphorus mellipes Cresson, 1872: 227 . Type locality: U.S.A., New Jersey. Holotype, male (ANSP), labelled: [White] “N. J.”; [Red] “Type No. 1773.1 ”; [White with red frame] “ Euphorus Microctonus mellipes Cress ”. Condition: right and left flagellomeres beyond 15 (right flagellum glued on point), right protarsus, and left leg beyond metafemur missing.

Brachistes nocturnus Viereck, 1905: 279 . Type locality: U.S.A., Kansas, Lawrence. Holotype male (SEMC), labelled: [White] “May” [White] “At night Lawrence, Ks. E. S. Tucker. ” [Red with black frame] “ Brachistes nocturnus Type Vier ”. Condition: Head and Left fore leg missing. NEW SYNONYMY.

Peristenus pallipes ; Muesebeck and Wakley, 1951:103, nec pallipes Curtis.

Peristenus pallipes ; Loan 1974a: 837, nec pallipes Curtis.

Diagnosis. Clypeus pale, females with two to five subquadrate preapical flagellomeres, usually many fine punctures below median ocellus, and from temperate regions of eastern North America, in May or June.

Description. FEMALE. Colour. Head and mesosoma black; metasoma usually brown, rarely black or reddish brown. Legs generally straw coloured, metacoxa occasionally light reddish brown, exceptionally reddish brown. Base of metatibia usually straw coloured, occasionally light reddish brown. Apex of metatibia and metatarsomere 1 clearly darker than basal half of metatibia. Metatarsomeres 2–5 paler than metatarsomere 1. Palpi, tegula and mandible (except apex) straw coloured. Scape to flagellomere 2 straw coloured, 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 18–22 flagellomeres (respectively 1%, 6%, 44%, 44% and 5% of 234 specimens) and flagellomeres enlarged in apical 0.5. Many preapical flagellomeres subquadrate (three 18%, four 31%, five 27%, six 16% and more 8%). Length of gena behind eye 0.90–1.04 times as long as length of eye. Height of eye 1.27–1.41 times as long as minimum distance between inner eye margins (as in Fig. 18 ). Maximum width of head behind eyes subequal (0.94–0.98) to maximum head width at eye level. Occipital carina developed in dorsal third. Metasomal tergum 1 with lateral edges clearly convergent (posterior margin 2.0–2.5 times as wide as narrowest width near base) and elongate (medial length of tergum 1.6–1.9 times as long as maximum width at posterior end). Radial cell length 0.87–1.0 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 ( 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, 5–15 µm apart on frons to 5–10 µm apart near antennal socket, and 20–25 µm apart on mesoscutum. Punctures in front of median ocellus generally fine to moderate (few or none 21%, many small 78%, and coarse 1% based on 100 specimens), surrounding surface beyond, dense. Punctures on mesopleuron generally dense, occasionally scattered. Clypeus generally punctate over surface, rarely almost glabrous. 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 21–25 flagellomeres (respectively 1%, 22%, 42%, 29% and 6% of 119 specimens) and flagellomeres narrow in apical 0.5. Height of eye 0.90–1.17 times as long as minimum distance between inner eye margins. Otherwise structure and sculpture as in female.

Taxonomic notes. For structural and biological differences between P. mellipes and P. carcamoi , see “Taxonomic notes” under P. carcamoi . A summary of measurement differences between P. mellipes and P. carcamoi is given in Table 12.

Adults of P. mellipes differ from those of P. otaniae in their geographic range, the frequency of subquadrate preapical flagellomeres in females, and in type of puncture development in front of the median ocellus. The geographically 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. mellipes and P. otaniae is given in Table 12.

Adults of P. mellipes differ from those of P. pseudopallipes in type of life cycle, the frequency of flagellomeres, and puncture development in front of the median ocellus. Despite almost identical geographic ranges, the population characteristics remain constant over the range of each species. A summary of measurement differences between P. mellipes and P. pseudopallipes is given in Table 12.

Muesebeck (1936) synonymized P. mellipes with the European P. pallipes . Muesebeck et al. (1951), Loan (1974a) and Marsh (1979) accepted this synonymy. Though the work on European species of Peristenus , is not published yet (done in collaboration with K. van Achterberg), no adults of the Nearctic species associated with the P. pallipes complex matches those (including types) of any European species of the complex. Moreover, many species of the complex are recorded from Lygus nymphs in North America whereas only one, P. varisae Varis & Achterberg (2001) , is recorded from Lygus nymphs. P. varisae is an easily distinguished species. As discussed below, the oldest name for the P. pallipes of North American authors is P. mellipes .

The holotypes associated with P. mellipes were a challenge. The holotype of P. mellipes had incomplete antennae and no date of collection on the label. Both P. mellipes and P. pseudopallipes are recorded from New Jersey. The only decisive character state was the development of punctures in front of the median ocellus. The holotype was typical of specimens that attack the first nymphal generation. The male holotype of B. nocturnus was a greater challenge as there was no head left. The metacoxa of this old specimen is straw coloured, its metatibia is bleached but seems to be a little darker, and it was collected in May. This holotype is clearly similar to pale coloured species of the P. pallipes complex. A sample in May would eliminate P. pseudopallipes , and the range in eastern temperate North America would not support its association with P. carcamoi and P. otaniae , but would support an association with P. mellipes , the oldest name. Other studied structures of B. nocturnus are typical of P. mellipes males, hence the above synonymy.

Host and biological notes. Adults of this species have been reared commonly from Lygus lineolaris and rarely from Adelphocoris lineolatus . Adults occur from early May to early July, (in eastern Ontario and western Quebec, from the end of May to the start of July) with peak abundance between June 2 and 13. This is a univoltine species on nymphs of the first generation of Lygus . Loan (1965) described the biology of this species under P. pallipes associated with Lygus lineolaris . Lim et al. (1976) and our data confirm Loan’s biological observations.

Material examined and range. 1161 (506♂, 595♀) adults were studied. Of these, 212 were reared from Miridae and 949 were field collected. An eastern North American species recorded from southern Canada to Georgia.

CANADA. NB: Kouchibouguac Nat. Park (2♂) . NS: Cape Breton Highlands N. Park, 46º48'N 60º44'W (1♀) ; Cape Breton Highlands N. Park, 46º47'N 60º50'W (1♂) ; Cape Breton Highland Nat. park , Mackenzie Mtn. (1♂) ; vic. Cheticamp , 46º39.004'N 60º59.704'W (1♂) ; vic. Kentville , 45º05.075'N 64º35.402'W (1♂, 4♀) ; Kings Co., (1♀) ; vic. Lockhartville , 45º05.081'N 64º14.040'W (1♀) ; vic. Sheffield Mills , 45º08.165'N 64º29.489'W (1♂) ; Yarmouth (1♀) . QC: vic. Bois­Francs , 46º32'N 75º57'W (40♂, 77♀) ; vic. Cantley , 45º34'N 75º49'W (24♂, 45♀) ; vic. Chelsea , 45º34'N 75º52'W (7♂, 4♀) ; Duchesnay (2♀) ; vic. Dunham (4♂, 1♀) ; Forestville (1♀) ; vic. Frelighsburg , 45º05'N 72º50'W (125♂, 36♀) ; Gatineau Nat. Park (1♂) ; Gracefield (3♂, 1♀) ; vic. Hemmingford 45º02'N 73º32'W (67♂, 65♀) ; vic. Hemmingford 45º01'N 73º32'W (26♂, 37♀) ; Hull (1♂, 1♀) ; Lac â la Tortue (1♂) ; Lanoraie (1♂, 2♀) ; Nominingue (2♂) ; Old Chelsea (3♂, 1♀) ; Sherrington (3♂, 2♀) ; Ste. Anne­de­Bellevue (1♀) ; vic. Ste. Clotilde 45º07'N 73º36'W (5♀) ; vic. Ste. Clotilde 45º10'N 73º41'W (114♂, 158♀) ; Wakefield (4♂) ; vic. Wakefield , 45º38'N 75º56'W (16♀) . ON: Aberfoyle (1♂) ; Alfred (3♂) ; vic. Almonte , 45º15'N 76º09'W (2♂, 2♀) ; Ancaster (1♀) ; Belleville (5♂, 4♀) ; Cayuga (1♀) ; Chatham (1♀) ; vic. Fitzroy Harbour , 45º28'N 76º11'W (4♂, 3♀) ; Fuller (2♂) ; Grimsby (1♂, 1♀) ; Guelph (5♂, 18♀) ; Kanata , 45º20'N 75º56'W (1♀) ; Leamington (1♂) ; Listowel (1♂) ; vic. London , 43º01'N 81º12'W (9♂, 13♀) ; vic. London , 43º2.26'N 81º05.35'W (4♂, 6♀) ; Morepth (1♂) ; vic. Mountain , 45º02'N 75º27'W (5♂, 9♀) ; Ottawa (11♂, 17♀) ; Oxford Mills (1♀) ; Point Pelee (1♂) ; Port Ryerse (1♂) ; Simcoe (1♂) ; Shorthills Prov. Park , 43º06'N 79º16'W (1♂, 2♀) ; vic. Talbotville , 42º50'N 81º16'W (2♀) ; Thorold (1♀) ; vic. Vineland , 43º03'N 79º14'W (11♂, 9♀) . USA. DE: Mt. Holly (5 ♂ / ♀; USDA); Newark (3♂, 1♀; 8 ♂ / ♀; CNCI, ESUW, USDA); GA: Brasstown bald, 4,800' (1♀) ; Forsyth (1♂) ; Rabun Co., Pine Mtn. , 1,500' (1♂) . IL: Union Co., Shawnee State For. (13♂) . KS: Lawrence (1♀; SEMC) . MA: Mt. Greylock , summit (1♀) . MD: Laurel (2♂, 1♀) ; Patuxent wildlife refuge, vic. Bowie (1♂) . ME: Sherman Mills (1♀) . MI: Livonia (1♂; ESUW) . MO: Williamsville (1♂) . MS: Pontotoc Co., Pontotoc , 34º08'N 89º00'W (1♂ / ♀; USDA). NC: Great Smoky Mountain Nat. park , Clingman’s Dome, 6,300' (1♀) ; Macon Co. (1♀; ESUW) . NJ: Blairstown (10♂, 30♀; 51 ♂ / ♀; ESUW, USDA, USNM); Newton (1♂, 1♀) ; Woodstown (1 ♂ / ♀; USDA). NY: Albany (1♀) ; Argyle (1♂) ; Ithaca (10♂, 2♀) ; MacClean bog, vic. Ithaca (2♂) ; Slaterville Springs (2♂) . SC: vic. Lexington , 34º02'N 81º17'W (1♂) . VA: Louisa Co., 6 km S. Cockoo (5♂) ; Page Co., Shenadoah Nat. park , Compton Gap (3♂) .

Figures

FIGURES 6–12. 6–9. Habitus with frontal view of head. Codes: “a” clypeal colour; “c” metacoxal colour; “f” metafemoral colour; “g” facial colour; “h” genal spot. 10–12. Lateral view of metatibia.

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.