Leiophron australis, 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 : 22-24

Leiophron australis n. sp.

( Figs. 2 habitus, 13, Table 1)

Type material. Type locality: USA, New York, Greene Co. Holotype, female ( USNM), labelled: [White] “ USA: NY, Greene Co. , Host col.: 14.VI. 1995 Em.: 21.VI.1996 W.H. Day ”; [White] “Ex: Lygus lineolaris (Palisot) ”; [Red] “ HOLOTYPE Leiophron australis Goulet ” Condition: excellent. Allotype male labelled: “ USA, Delaware, Newark, 22.VII.1982 ” .

Origin of species name. Word derived from Latin meaning “southern”. This species is the most southerly species included here.

Diagnosis. Forewing vein RS+M developed, head and thorax reddish brown, and lateral margins of metasomal tergum 1 almost parallel.

Description. FEMALE. Colour. Body generally reddish brown except for small black spot anterior to ocelli; propodeum, metanotum and metasomal tergum 1 brown ( Fig. 42 ), and face and clypeus dark straw coloured (as in Fig. 13 ) (metasomal tergum 3 is as pale as preceding tergum, but appears brown due to telescoping of the more apical segments under it). Appendages straw coloured except apical third of flagellum fading to brown ( Fig. 2 ). Forewing clear except for two dark coloured bands aligned with 1 st discal cell and below apical 0.7 of stigma (apical band fading to clear toward apex) ( Fig. 2 ); radial cell clear, but surrounded by apical dark band. Wing veins light straw coloured, but brown on 1M, 1cu­a, RS R1 and RS+M and on apical 0.7 of stigma.

Structure. Flagellum with 13 flagellomeres. Clypeus with two short and sharp teeth along anterior margin near middle (as in Fig. 14 ). Length of gena behind eye 1.1 times as long as length of eye. Height of eye 1.8 times as long as minimum distance between inner eye margins. Maximum width of head behind eyes subequal to maximum head width at eye level. Occipital carina either absent in dorsal 0.3 or abruptly reduced to a trace in dorsal 0.3. Mesoscutellar fovea about 2–3 times as wide as long and with 4 septa (as in Fig. 40 ). Metasomal tergum 1 with lateral margins almost parallel (posterior margin 1.3 times as wide as narrowest width near base), long (length 2.8 times maximum width), and almost meeting ventrally in anterior 0.3. Radial cell near stigma, and forewing vein RS+M developed (as in Fig. 51 ). Basal cell of forewing with 0–3 setae, clearly less densely setose than 1 st discal cell (as in Fig. 53 ). Veins 1CU and 1m­cu not usually developed, or if developed then 1 st discal cell almost triangular because vein 1m­cu about 0.2 times as long as vein RS+M. Radial cell 0.5 as long as width of stigma (as in Fig. 55 ). Subbasal cell of hind wing narrow: vein 1M 3.0 times as long as vein cu­a (as in Fig. 65 ).

Sculpture. Punctures on vertex, frons and mesoscutum about 10 µm in diameter (similar to diameter of ommatidia). Punctures 20–30 µm apart on vertex and frons, 30–60 µm apart on mesoscutum, and 60–80 µm apart on mesopleuron. Clypeus generally glabrous except for row of long setae along anterior margin. Notaulus not outlined in anterior half (as in Fig. 41 ). Metasomal tergum 1 with about 6 longitudinal ridges.

Frons and anterior region of vertex with very lightly impressed meshes. Mesoscutum with transverse, barely outlined, ridges medially in posterior one quarter. Mesopleuron with weakly outlined parallel ridges slanted downward. Remaining body surfaces smooth.

MALE. Colour. As in female, except propodeum, metanotum and metasomal tergum 1 as pale as body.

Structure. Clypeal anterior margin without teeth near middle ( Fig. 13 ). Height of eye 1.2 times as long as minimum distance between inner eye margins. Tergum 1 of metasoma with sides little divergent (maximum width 1.4 times as long as minimum width), and long (length 2.6 times maximum width). Otherwise structure and sculpture as in female.

Taxonomic notes. This species belongs to the L. maculipennis (Ashmead) group as defined by Loan (1974a), based on the shared presence of forewing veins RS+M and the lack of forewing veins 1CU, m­cu and 2RS. Within this group, L. australis is closest to L. maculipennis because both species share the reduced number of flagellomeres (12 or 13 in females, and 14 or 15 in males) and the lack of submedial teeth on the anterior margin of the clypeus in males. In adults of L. maculipennis , flagellomere 1 is short (2.3 times as long as wide), 4–5 preapical flagellomeres are as wide as or wider than long, and the flagellum is completely straw coloured. Freshly collected adults of L. maculipennis are darker with a brown metasoma and the body is similarly coloured in both sexes. In L. australis flagellomere 1 is long (2.7–3.0 times as long as wide), no preapical flagellomeres are as wide as long, and the flagellum fades to brown in the apical third. Adults are paler with a straw coloured metasoma and the propodeum is brown in females and straw coloured in males.

Adults of L. australis differ from those of L. lygivorus (Loan) and L. uniformis (Gahan) by the body colour pattern and forewing venation.

Adults of L. australis differ from those of L. simoni by the forewing veins 1CU, m­cu and 2RS, the size of the radial cell relative to the stigmal length, notauli development, and the anterior mesoscutellar fovea proportions. A summary of measurements of L. australis is given in Table 1. Because only one male and one female are known, the measurements are not discussed further.

Host and biological notes. The host is Lygus lineolaris . The species must be bivoltine as one specimen was collected from a nymph in mid­June from the first nymphal

generation and a second specimen was collected from a nymph in late July from the second nymphal generation.

Material examined and range. Warm temperate regions along the Atlantic coast of the United States (DE and NY). Two reared specimens (1♂ and 1♀) were studied .

USA. NY: Greene Co., (1♀; USNM). DE: Newark , 22.VII.1982 (1♂; USDA) .

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.

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 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.