Leiophron simoni, 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 : 26-29

Leiophron simoni n. sp.

( Figs. 3 habitus, 42, 51, 56, Table 3)

Type material. Type locality: Canada, Quebec, vicinity of Dunham , 45°07'N 72°51'W. Holotype, female ( CNCI), labelled: [White] “ QUEBEC: Dunham (Missis[si]quoi), vignoble L’Orpailleur ECORC/CRDH/Ag­cord”; [Red] “ HOLOTYPE Leiophron simoni Goulet CNC No. 23473”. Condition of holotype: perfect. Allotype, male, labelled as holotype. Paratypes all specimens studied mentioned under “Material examined and range” .

Origin of species name. This species is named in honour of Simon Lachance who clarified the biology of several species of Leiophron and Peristenus . Simon was also the only person who reared this species.

Diagnosis. Forewing veins RS+M, 2RS, 1m­cu and 1CU spectral, notauli outlined by punctures in at least anterior half, propodeum, mesonotum and metanotum reddish brown to dark brown, wings clear, and anterior mesoscutellar fovea narrow (4–5 times as wide as long) with 5–8 septa.

Description. FEMALE. Colour. Head light reddish brown and face straw coloured; pronotum, light reddish brown, metasomal terga 2–8 brown (metasomal terga 4–9 are telescoped in and are brown to black, but are suspected to be reddish brown); surface near each ocellus, mesothorax, metathorax, propodeum and metasomal tergum 1 reddish brown to dark brown. Appendages straw coloured. Wings clear. Veins almost transparent except light reddish brown forewing veins 1M, C+Sc+R, 1A, RS and brown apical 0.7 of stigma ( Fig. 56 ).

Structure. Flagellum usually with 13 and occasionally 14 flagellomeres. Clypeus with two short and blunt teeth along anterior margin near middle (as in Fig. 14 ). Length of gena behind eye 1.1–1.4 times as long as length of eye. Height of eye 1.5–1.7 times as long as minimum distance between inner eye margins. Maximum width of head behind eyes subequal (0.92–0.98) to maximum head width at eye level. Occipital carina completely but finely developed dorsally. Mesoscutellar fovea about 4–5 times as wide as long and with about 5–8 septa ( Fig. 42 ). Metasomal tergum 1 in dorsal view with edges convergent (posterior margin 1.5–1.9 times as wide as narrowest width near base), quite short (length 1.6–2.0 times as long as maximum width), and margins clearly separated ventrally (as in Fig. 69 ). Veins RS+M, 1m­cu, 2RS, 1CU and 2CUa developed but rather clear and spectral ( Fig. 51 ). Basal cell of forewing with about 10–20 setae, clearly less setose than 1 st discal cell ( Fig. 51 ). 1 st discal cell mainly quadrate and vein 1m­cu about 0.5 of vein RS+M. Radial cell 0.25–0.35 as long as width of stigma. Subbasal cell of hind wing narrow: vein 1M 2.0 times as long as vein cu­a.

Sculpture. Punctures on vertex, frons (at side mainly), lower gena and mesoscutum about 5–7 µm in diameter (a little smaller than diameter of ommatidium). Punctures 20–50 µm apart on vertex, frons and on mesoscutum, and 10–15 µm apart on anterodorsal surface of mesopleuron. Clypeus glabrous except for row of long setae along anterior margin. Notaulus outlined at least in anterior half by row of punctures (15–20 µm). Metasomal tergum 1 with 6–8 longitudinal ridges.

Mesoscutellum with few punctures. Ventral 0.3 of mesopleuron in posterior 0.5 with parallel ridges slanted downward in most specimens, rarely smoother. Remaining body surfaces smooth.

MALE. Colour. As in female.

Structure. Flagellum occasionally with 13 or usually 14 flagellomeres. Clypeus anterior margin without teeth near middle (as in Fig. 13 ). Height of eye 1.2 times as long as minimum distance between inner eye margins. Mesosomal tergum 1 of metasoma with sides convergent: maximum width 1.6 times as long as minimum width. Otherwise structure and sculpture as in female.

Taxonomic notes. This species belongs to Loan’s (1974a) L. occipitalis (Muesebeck) species group as defined by the presence of forewing veins RS+M, 1CU, m­cu and 2RS and the small closed subbasal cell in the hind wing. The above veins are visible but very weakly outlined or spectral.

Within this group, the holotype of L. brevipetiolatus Loan is similar to specimens of L. simoni . In adults of both species, the wings are clear, the basal cell of the forewing has a few setae, and the postocellar length is shorter than the ocular­ocellar length. The specimen of L. brevipetiolatus has a reddish brown mesosoma, no notaulus over the mesoscutal disk; and a wide anterior mesoscutellar fovea (2.5 times as wide as long). The specimens of L. simoni , have a light reddish brown pronotum, a reddish brown to brown mesepisternum, and usually dark brown mesosnotum, metanotum and propodeum, a developed notaulus over the mesoscutum, and a narrow anterior mesoscutellar fovea (4–5 times as wide as long).

Adults of L. simoni differ from those of L. lygivorus and L. uniformis in body and forewing colour pattern, notauli development, proportion of mesoscutal fovea, and forewing venation. A summary of measurement differences between L. simoni and L. lygivorus or between L. simoni and L. uniformis is given in Table 3.

Adults of L. simoni differ from those of L. australis by the forewing development of veins 1CU, m­cu and 2RS, the notauli development in posterior half of mesoscutum, and proportions of the anterior mesoscutellar fovea. Because only one male and one female of L. australis are known, the measurements in Table 1 are difficult to compare with those of L. simoni . However, some means of L. simoni (i.e., the relative length of radial cell and stigmal width, the relative length of metasomal tergum 1 and its maximal width, and the relative distance between eyes and the height of the eye for each sex) differ by 4 to 7 standard deviations with the single measurement recorded for the male or female of L. australis and are very likely significant differences.

Though easily segregated from known Nearctic species, L. simoni is extremely similar to the European L. deficiens (Ruthe) . Adults of the two species are similar in colour pattern and colour variation, in size range, in structure and in surface sculpture. At first the species seemed to be an accidental introduction from Europe. However in specimens of P. simoni , the apical half of the flagellum is mainly pale to reddish whereas in those of P. deficiens it is mainly brown to dark brown. There were no other observed differences. Both are known parasitoids of Lygus spp. and the life cycle of both species starts earlier in spring and also sooner in early summer relative to that of parasitoid species normally associated with Lygus bugs. Based on field collected specimens, a portion of the adult activity period overlaps with that of Lygus spp. It is assumed that females of L. deficiens and L. simoni usually attack hosts other than Lygus nymphs. Leiophron simoni is bivoltine, as no other specimens were seen after late August. In mid summer L. deficiens was reared mainly from the second generation of Lygus nymphs, and most emerged without diapausing suggesting a third generation. Leiophron deficiens is a multivoltine species. Therefore, it is justifiable to describe L. simoni as new.

Most specimens of L. simoni come from sites in southern Quebec and eastern Ontario where wild and cultivated grapes grew in proximity. Leiophron deficiens is not associated with grapes.

Host and biological notes. Reared specimens have been recorded from Lygus lineolaris . Adults occur from mid May to late August. L. simoni is a bivoltine species with two generations a year.

Material examined and range. 52 (19♂ and 33♀) adults were studied. Of these, 5 were reared from Miridae and 47 were field collected. The species is recorded from southern Ontario and Quebec. Five specimens were reared .

CANADA. PE: Harrington (2♂) . QC: Dunham (13♂, 21♀) ; Iberville (1♂, 6♀) ; vicinity of Riviere Ouelle (1♀) ; Ste. Clotilde (1♀) . ON: Guelph (2♂, 3♀) ; London (1♀) ; Mountain (1♂) .

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

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

FIGURE 37–49. 37. Lateral view of antenna. 38–39. Last six flagellomeres in lateral view. 40–44. Dorsal view of mesosoma. 45–49. Lateral view of mesosoma.

FIGURES 67–78. 67–68. Dorsal view of metasomal tergum 1. 69–70. Ventral view of metasomal segment 1. 71–72. Lateral view of seven last flagellomeres. 73–74. Lateral view of first three flagellomeres. 75–76. Dorsal view of protarsus. 77–78. Lateral view of metasoma.