Necremnus navonei, Gebiola, Marco, Bernardo, Umberto, Ribes, Antoni & Gibson, Gary A. P., 2015

Gebiola, Marco, Bernardo, Umberto, Ribes, Antoni & Gibson, Gary A. P., 2015, An integrative study of Necremnus Thomson (Hymenoptera: Eulophidae) associated with invasive pests in Europe and North America: taxonomic and ecological implications, Zoological Journal of the Linnean Society 173 (2), pp. 352-423 : 379-381

NECREMNUS NAVONEI RIBES SP. NOV. ( FIGS 40–47 )

Etymology

Named after Paolo Navone ( Italy), who first collected this species.

Type material

Holotype ♀: FRANCE: Quiberon, Pointe du Conguel, ex. Dialectica scalariella on Echium vulgare , col. 11.vii.2012, em. 17.vii.2012, leg. P. Navone. Allotype ♂: Same data as holotype. Paratypes (6♀): 1♀, same data as holotype; 5♀ progeny of holotype (F1), viii.2012. The holotype, allotype, and some paratypes are deposited in CNC, and some paratypes in BMNH.

Additional material (3♀ 1♂): FRANCE: 1♀ 1♂, same data as holotype; 1♀, Fos-sur-Mer, 19.viii.2011, sweeping herbaceous layer, leg. G. Delvare. ITALY: 1♀, Ventimiglia (IM), Liguria, ex. Dialectica scalariella on Echium vulgare , 2.i.2006, leg. P. Navone.

Diagnosis

Female

Gaster ( Figs 40, 42 ) long-ovate, 2.35–2.8 × as long as broad, 1.45–1.55 × as long as mesosoma, and 1.1– 1.3 × as long as head plus mesosoma. Propodeum with weak, superficially reticulate or coriaceous sculpture to partly smooth ( Fig. 45 ). Malar space long, 0.48– 0.52 × as long as eye height. Tibiae often very dark with apical half and pale within basal half, the colours sharply contrasted ( Figs 40, 42 ). Fore wing bimaculate ( Fig. 43 ) to almost hyaline, but at least with very faint infuscate areas behind stigmal vein and behind base of marginal vein.

Description

Female

Body length 2.1–2.7 mm. Head and mesosoma dark green, with purplish reflections on scutellum ( Figs 42, 44 ). Antenna ( Fig. 46 ) with scape black or testaceous on anterior margin; pedicel and flagellum dark brown. Tegula black. Legs ( Figs 40, 42 ) with coxae coloured as body; femora black with metallic reflections, narrowly testaceous at knees; tibiae often very darkened in apical half and pale in basal half with colours sharply contrasted; protarsus brown, meso- and metatarsi with basal two tarsomeres testaceous. Fore wing bimaculate ( Fig. 43 ), with a brownish area beneath stigmal vein and another brown stripe under proximal end of marginal vein, although the infuscate areas usually very faint; wing venation brownish. Gaster dark brown, dorsally with bronze reflections basally and apically ( Fig. 42 ).

Head in dorsal view 1.2–1.3 × as broad as mesoscutum and 2.6–2.7 × as broad as long; in frontal view transverse-oval, 1.2–1.37 × wider than high; temple 0.1– 0.15 × as long as eye length. POL 1.65–2 × OOL, OOL 1.75–2.45 × OD. Eyes 1.3–1.5 × as long as high, separated by 1–1.13 × their length, almost glabrous, but with very short, sparse setae. Malar space 0.48– 0.52 × height of eye. Mouth opening 1.2–1.27 × as broad as malar space. Frons flattened on sides, without piliferous punctures.

Antennae ( Fig. 46 ) inserted with ventral margins of toruli at level of ventral margins of eyes. Scape 6–7 × as long as broad and 0.9–0.94 × as long as height of eye, not reaching median ocellus. Pedicel + flagellum 1.15–1.3 × as long as breadth of head and 1.45–1.6 × as long as breadth of mesoscutum. Pedicel in profile 1.7–2 × as long as broad. Funicle with three funicular segments decreasing in length, funicle proximally slightly stouter (1.2–1.35 ×) than pedicel, distally very slightly thickening (F3 1.15–1.35 × as broad as F1); F1 distinctly longer (1.8–2 ×) than pedicel, F1–F3 2.6– 2.9, 2.15–2.5, and 1.7–2.1 × as long as broad, respectively. Clava three-segmented, compact, acute apically, nearly as broad as F3, 3.4–3.85 × as long as broad and 0.88–0.95 × as long as F2 + F3; C1 1.3–1.65 × as long as broad and 0.4 × length of clava. Flagellum with sensilla placed in three or rarely two irregular rows on F1–F3, and in two or rarely three rows on C1; with short, dense, decumbent setae.

Mesosoma in dorsal view ( Figs 42, 44 ) 1.67–1.73 × as long as broad, in lateral view ( Fig. 40 ) weakly convex dorsally, 1.8–1.85 × as long as high with propodeum sloping at about 45° with respect to plane of mesoscutum and scutellum. Pronotum 0.3–0.35 × as long as mesoscutum. Mesoscutum transverse, 1.4–1.7 × as broad as long, and 1.1–1.3 × as long as scutellum; moderately strongly reticulate with isodiametric reticulations; setae sparse, dark, short, and strong. Scutellum convex, 1.05–1.1 × as long as broad, with two pairs of very, dark setae; sculpture of scutellum and axillae finer and not as strong as mesoscutum, the scutellum anteriorly with slightly elongate reticulations. Dorsellum coriaceous ( Fig. 45 ). Propodeum ( Figs 44, 45 ) medially 1.5–2 × as long as dorsellum and 0.45–0.5 × as long as scutellum; with very weak, superficially reticulate or coriaceous sculpture, and shiny and almost smooth posteriorly towards nucha and part of median panels; with fine median carina reaching 0.4–0.5 × its length; plical carina indistinct; callus with long, white setae; spiracles of medium size, short-oval, separated from metanotum by 0.4–0.6 × smallest diameter.

Fore wing ( Fig. 43 ) 2.4–2.5 × as long as broad. Costal cell 1.2–1.3 × as long as marginal vein, 9–11 × as long as broad; ventrally with a complete row of setae and some sparse setae apically, and dorsally with a very short row of usually two or three but rarely up to five setae apically. Submarginal vein with 13–15 dorsal setae. Marginal vein 2.9–3.4 × as long as stigmal vein. Stigmal vein at an angle of 40–43° to the costal wing margin, moderately thin basally; stigma elongate, hardly thickened. Postmarginal vein 1.5–1.7 × as long as stigmal vein and 0.5–0.55 × as long as marginal vein. Basal fold pilose, with four to six setae; basal cell at least mostly open posteriorly, usually with one but sometimes with zero to three setae at apex of mediocubital fold, dorsally bare and ventrally with one to four hair bases near submarginal vein. Speculum of moderate size, reaching almost to base of marginal vein, closed posteriorly by dense or sparse setae, with two to four hair bases at lower surface. Fore wing dark, moderately dense pilosity beyond the speculum; marginal fringe short. Hind wing rounded at apex.

Gaster ( Fig. 42 ) long-ovate, 2.35–2.8 × as long as broad, 1.45–1.55 × as long as mesosoma, 1.1–1.3 × as long as head plus mesosoma, and 0.95–1.05 × as broad as mesosoma; acute apically with syntergum transverse, 0.67–0.8 × as long as broad; T1 with posterior margin convex, reaching 0.2–0.25 × length of gaster. Ovipositor slightly protruding; cercal setae of similar length, not reaching apex of ovipositor. Hypopygium reaching 0.3–0.35 × length of gaster.

Male ( Fig. 41 )

Similar to female except in structure of antennae and gaster, and hyaline wings. Body length 1.65–1.8 mm. Antenna ( Fig. 47 ) with scape 4.2–4.7 × as long as broad. Pedicel + flagellum 1.6 × as long as breadth of head, and 1.75 × as long as breadth of mesoscutum. Flagellum with four funicular segments and three-segmented clava, F4 1.3 × as long as F3 and 0.8–0.9 × as long as clava. Funicle with three long, thin, subcylindrical rami on F1–F3, the rami with long, hair-like setae; funicular segments and all three rami with mps, but denser on all sides of R2 and R3, and sparsely on frontal surface of R1. Fore wing with marginal vein 2.7 × as long as stigmal vein; stigmal vein at an angle of 41– 43° to the costal wing margin; postmarginal vein 1.5– 1.65 × as long as stigmal vein and 0.55–0.6 × as long as marginal vein. Costal cell dorsally with a short marginal row of three to six setae. Legs with mesotibia darkened in apical 0.45–0.6 and metatibia darkened in apical 0.5–0.55, the dark portions dark brown to black; tarsi with basal tarsomeres pale. Gaster 2.35– 2.4 × as long as broad, 0.9–1 × as long as mesosoma, and 0.7–0.75 × as long as head plus mesosoma.

Hosts

Dialectica scalariella on Echium vulgare L. ( Boraginaceae ), based on sequenced specimens.

Variation

There is little variation in the specimens seen.

Discussion

Females of N. navonei have the typical characters of the N. artynes group, including bimaculate fore wings ( Fig. 43 ), an elongate body ( Fig. 42 ) and antennae ( Fig. 46 ), and tibiae that are pale basally and dark in the apical half ( Figs 40, 42 ). Females most closely resemble those of N. artynes and N. tutae in general appearance. Although some features overlap and there are few differences, they are confirmed by the molecular analyses. Furthermore, the host of N. navonei is in a different family of Lepidoptera than N. artynes and N. tutae and it has not been reared as a parasitoid of T. absoluta . Even though proportions sometimes overlap, females of N. navonei usually differ from those of N. artynes in having a slightly less elongate gaster (2.35– 2.8 × vs. 2.6–3.15 × as long as broad, 1.45–1.55 × vs. 1.5–1.9 × as long as mesosoma, and 1.1–1.3 × vs. 1.2– 1.4 × as long as head plus mesosoma in N. artynes ). Additionally, the syntergum is transverse, 0.67–0.8 × as long as broad, whereas it is usually slightly elongate or barely transverse, 0.9–1.3 ×, in N. artynes . Females of N. navonei also usually have fainter fore wing infuscation, and although tibial colour pattern can be similar in both, with the apical half of the meso- and metatibiae being strongly darkened and the colours sharply contrasted, N. artynes sometimes has paler tibiae with only the extreme apex dark. Even though proportions sometimes overlap, females of N. navonei usually differ from those of N. tutae in having a slightly more elongate gaster (in N. tutae 1.9–2.4 × as long as broad, 1.2–1.5 × as long as mesosoma, and 0.95– 1.2 × as long as head plus mesosoma). Females of N. navonei also differ in having a longer malar space, 0.48–0.52 × vs. 0.4–0.45 × eye height in N. tutae , and a longer clava, 3.4–3.85 × vs. 2.8–3.5 × as long as broad in N. tutae . Males of N. navonei are very similar to related species. Details of the sensorial pores of the scape were not observed, but observed specimens have a broader clava, 3.1–3.35 × vs. 3.75–5 × as long as broad in related species, usually narrower scape, 4.2–4.7 × vs. 3.5–4.5 × as long as broad in related species, and legs that are darkened in the apical half. Males of related species sometimes have a similar leg colour pattern, although usually they are paler.

Figures

Figures 40–47. Necremnus navonei sp. nov. 40–42, habitus: 40, ♀ lateral; 41, ♂ lateral; 42, ♀ dorsal (2013-65). 43–46, ♀ (2013-65): 43, fore wing; 44, dorsal mesosoma; 45, metanotum and propodeum; 46, antenna. 47, ♂ antenna (2013-66).