Platygaster nixoni, Buhl, 2009

Buhl, Peter Neerup, 2009, Six new species of Platygastrinae from the British Isles (Hymenoptera, Platygastridae), Journal of Natural History 43 (11 - 12), pp. 687-699 : 689-691

Platygaster nixoni sp. nov.

( Figure 2 )

Diagnosis

Occiput weakly striate, postero-medially longitudinally so; female A9 very slightly longer than wide; notauli weak, missing anteriorly; female metasoma short, T2 striated to 0.5, hairs on T4–T5 inserted in rather deep punctures; legs including coxae and basal half of antennae pale.

Description

Female. Length 1.3 mm. Black; A1–A5 and legs including coxae yellowish brown; A6–A10, mandibles, tegulae and last segment of tarsi dark brown.

Head from above ( Figure 2A ) 1.9 times as wide as long, almost 1.2 times as wide as mesosoma; occiput postero-medially more or less longitudinally striated, in anterior half weakly transversely striated, laterally finely reticulate-coriaceous; vertex finely reticulate-coriaceous (not transversely so); frons with very fine reticulate-coriaceous sculpture, fan-like arranged at sides of smoother medial longitudinal line. OOL:LOL54:3. Head in frontal view 1.3 times as wide as high. Antenna ( Figure 2B ) with A1 0.85 times as long as height of head, as long as distance between inner orbits; A9 1.1 times as long as wide.

Mesosoma 1.5 times as long as wide, 1.1 times as high as wide. Sides of pronotum moderately reticulate-coriaceous (not longitudinally so), only a rather narrow hind margin smooth. Mesoscutum sparsely hairy, weakly reticulatecoriaceous, medial zone smooth anteriorly and posteriorly; most of lateral lobes smooth; notauli weak, missing in about anterior 0.2; mid lobe slightly, bluntly prolonged to base of scutellar disc; scuto-scutellar grooves distinct, with rather dense (each with about 10) long hairs. Mesopleuron smooth. Scutellum ( Figure 2C ) evenly convex, smooth, bare medially, along sides with numerous hairs. Metapleuron with pilosity all over. Propodeal carinae parallel; area between them smooth and shiny, very slightly transverse.

Fore wing 0.9 times as long as entire body, 2.6 times as long as wide, almost hyaline, with dense and moderately long microtrichia; marginal cilia fully 0.1 times the width of wing. Hind wing 5.1 times as long as wide, with two hamuli; marginal cilia hardly 0.4 times the width of wing.

Metasoma ( Figure 2D ) as long as head and mesosoma combined, 1.1 times as wide as mesosoma. T1 with about six irregular longitudinal carinae. T2 striated from basal foveae to midlength, medial striation only one-third as long as striation from basal foveae; rest of T2 as well as T3–T5 smooth; T6 slightly dull; T3 on each side with three fine hairs, which are inserted in shallow punctures; T4 on each side with five hairs which are inserted in rather deep punctures, forming a medially interrupted transverse row; T5 with seven such hairs on each side, forming a slightly irregular, complete transverse row; T6 with eight hairs.

Material examined

Holotype female: England, West Kent, Eynsford , 7.vi.1931, G.E.J. Nixon.

Affinities

Similar to P. fennica Buhl, 2003 , but this species has head more narrowed behind eyes, occiput stronger striated, marginal cilia of wings shorter, and T3–T6 longer than in P. nixoni , with hairs in shallow punctures only, and coxae in P. fennica are darkened. P. clavata Buhl, 1994 has female antennae shorter than in P. nixoni , and T2 less striated. P. chloropus Thomson, 1859 and P. indefinita Buhl, 2006 have less

striated occiput and hairs on apical tergites inserted in less deep punctures, cf. Buhl (2006).

Etymology

Named after the collector.

Figures

Figures 2. P. nixoni sp. nov., female. (A) head, dorsal; (B) antenna; (C) scutellum and propodeum, lateral; (D) metasoma, dorsal.