Necremnus cosmopterix, 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 : 371-374

NECREMNUS COSMOPTERIX RIBES & BERNARDO SP. NOV. ( FIGS 17–25 )

Etymology

Named after the genus of one of its hosts, Cosmopterix pulchrimella Chambers.

Type material

Holotype ♀: ITALY: Portici (NA), Campania, ex. Cosmopterix pulchrimella on Parietaria judaica , 20.vii.2003, leg. U. Bernardo. Allotype ♂: Same data as holotype. Paratypes (4♀ 3♂): ITALY: 1♀ 1♂, same data as holotype; 2♀ 2♂, Arma di Taggia, ex. Tuta absoluta on Solanum lycopersicum, 2009 , Bioplanet culture; 1♀, Cariati (CS), Calabria, ex. Cosmopterix pulchrimella on Parietaria judaica , 25.iv.2007, leg. U. Bernardo. The holotype, allotype, and some paratypes are deposited in BMNH, and some paratypes in CNC. Additional material (8♀ 16♂): ITALY: 1♀ 1♂, Cariati (CS), Calabria, ex. Cosmopterix pulchrimella on Parietaria judaica , 25.iv.2006, leg. U. Bernardo; 2♀ 1♂, Moncalieri (TO), Piamonte, ex. Cosmopterix pulchrimella on Parietaria judaica , 4–15.viii.2010, leg. P. Navone; 3♂, San Giorgio a Cremano (NA), Campania, ex. Cosmopterix pulchrimella on Parietaria judaica , 13.ix.2006, leg. U. Bernardo; 5♀ 10♂, Portici (NA), Campania, ex. Cosmopterix pulchrimella on Parietaria judaica , v.2006, leg. U. Bernardo; 1♂, Noli (SV), ex. Selania capparidana on Capparis spinosa , 18.ix.2012, leg. P. Navone.

Diagnosis

Female

Fore wings hyaline ( Fig. 20 ). Postmarginal vein long, (1.65)1.85–2.15 × as long as stigmal vein. Tibiae entirely dark or rarely pale, tarsi usually with only basitarsi pale. Propodeum uniformly reticulate, but not strongly so ( Fig. 23 ). Antenna ( Fig. 22 ) with flagellum elongate, pedicel + flagellum 1.2–1.35 × as long as breadth of head, combined length of F1 + anelli 1.9– 2.4 × as long as pedicel, and 2.8–3.4 × as long as broad. Gaster 1.9–2.4(3) × as long as broad ( Fig. 19 ).

Description

Female

Body length 1.8–2.7 mm. Head and mesosoma dark bluish ( Figs 17, 19 ). Antenna ( Fig. 22 ) with scape black, pedicel and flagellum dark brown. Tegula black. Legs ( Fig. 17 ) with coxae coloured as body; femora black with metallic reflections; tibiae usually entirely black, narrowly testaceous on knees, sometimes with basal third testaceous or rarely mainly testaceous in some pale forms; tarsi usually with only basal tarsomeres testaceous, rarely basal two tarsomeres in pale forms. Fore wing ( Fig. 20 ) hyaline; wing venation brownish. Gaster ( Fig. 19 ) dark brown, with violaceous reflections dorsally basally and apically.

Head in dorsal view ( Fig. 19 ) 1.21–1.29 × as broad as mesoscutum and 2.2–2.7 × as broad as long; in frontal view transverse-oval, 1.25–1.38 × wider than high; temple 0.15–0.2 × as long as eye length. POL 1.6–2(2.3) × OOL, OOL (1.25)2–2.3 × OD. Eyes 1.35–1.43 × as high as broad, separated by 0.9– 1.05 × their length, eyes glabrous. Malar space 0.4– 0.47 × length of eye, malar sulcus present. Mouth opening 1.3–1.5 × as broad as malar space. Frons flattened on sides, without piliferous punctures.

Antennae ( Fig. 22 ) inserted with ventral margins of toruli at level of ventral margins of eyes. Scape 5–5.5 × as long as broad, 0.85–0.9 × as long as height of eye, not reaching median ocellus. Pedicel + flagellum 1.2– 1.35 × as long as breadth of head and 1.5–1.65 × as long as breadth of mesoscutum. Pedicel in profile 1.6– 2 × as long as broad. Funicle with two anelli and three funicular segments, the first anellus laminar, the second discoidal; funicular segments decreasing in length, funicle proximally slightly (1.1–1.3 ×) stouter than pedicel, distally very slightly thickened (F3 1.1– 1.25 × as broad as F1); F1 distinctly longer (1.75– 2.2 ×) than pedicel; F1–F3 2.5–3.1, 2.1–2.35, and 1.8–2.1 × as long as broad, respectively. Clava threesegmented, compact, acute apically, slightly (1.05−1.1 ×) broader than F3, 3.05–3.7 × as long as broad, and 0.8– 0.96 × as long as F2 + F3; C1 1.3–1.55 × as long as broad and 0.4–0.45 × length of clava. Flagellum with sensilla placed in four or rarely three irregular rows on F1, in three or rarely two irregular rows on F2 and F3, and in two rows on C1–C2; with short, dense, decumbent setae.

Mesosoma in dorsal view ( Figs 17, 21 ) 1.6–1.8 × as long as broad, in lateral view ( Fig. 17 ) weakly convex dorsally, 1.8–1.93 × as long as high with propodeum sloping at about 40–45° with respect to plane of mesoscutum and scutellum. Pronotum 0.25–0.35 × as long as mesoscutum. Mesoscutum transverse, 1.4– 1.5 × as broad as long, and 1.3–1.4 × as long as scutellum; moderately strongly reticulate with isodiametric reticulations. Scutellum convex, 1–1.1 × as long as broad, with two pairs of strong, dark setae; sculpture of scutellum and axillae finer and not as strong as mesoscutum, the scutellum anteriorly with slightly elongate sculpture ( Fig. 21 ). Dorsellum reticulate ( Fig. 23 ). Propodeum ( Fig. 23 ) medially 1.7–1.9 × as long as dorsellum and 0.5 × as long as scutellum; uniformly reticulate, but not strongly so; median carina reaching less than half its length; plical carina indistinct; callus with setae long and white; spiracles of medium size, short-oval, separated from metanotum by 0.5–0.75 × its smallest diameter.

Fore wing ( Fig. 20 ) 2.35–2.4 × as long as broad. Costal cell 1.1–1.2 × as long as marginal vein and 9.5–11 × as long as broad; ventrally with a complete row of setae and another incomplete row in apical half, and dorsally a partial row of six to 13 setae apically. Submarginal vein dorsally with 13–18 setae. Marginal vein 3.35–4 × as long as stigmal vein. Stigmal vein at an angle of 42–46° to the costal wing margin, moderately thin basally; stigma elongate, hardly thickened. Postmarginal vein (1.65)1.85–2.15 × as long as stigmal vein and (0.4)0.5–0.57 × as long as marginal vein. Basal fold rarely glabrous, but usually with one to seven setae; basal cell open posteriorly, with zero to two setae at apex of mediocubital fold; bare dorsally and ventrally. Speculum of moderate size, reaching almost to base of marginal vein, rarely open posteriorly but usually closed by sparse to dense setae, without setae or hair bases at lower surface. Fore wing with moderately dense, dark pilosity beyond speculum; marginal fringe short. Hind wing rounded at apex.

Gaster ( Figs 17, 19 ) long-ovate, 1.9–2.4(3) × as long as broad, 1.35–1.55 × as long as mesosoma, 1.05– 1.2 × as long as head plus mesosoma, and (0.8)1– 1.1 × as broad as mesosoma; acute apically with syntergum transverse, 0.6–0.7 × as long as broad; T1 with posterior margin convex, reaching 0.15–0.2 × length of gaster. Ovipositor slightly protruding; cercal setae of similar length, not reaching apex of ovipositor. Hypopygium reaching 0.3–0.4 × length of gaster.

Male ( Fig. 18 )

Similar to female except in structure of antennae and gaster. Body length 1.7–2.25 mm. Antenna ( Fig. 25 ) with scape 3.7–4.4 × as long as broad, sensorial area ( Fig. 24 ) narrow, near margin, with 22–25 sensorial pores placed in one irregular row extending between basal 0.3 and apical 0.71–0.8 length of scape, and densely placed with interspaces narrower than pore size. Pedicel + flagellum 1.55–1.65 × as long as breadth of head and 1.9– 2.05 × as long as breadth of mesoscutum. Flagellum with one laminar anellus, four funicular segments, and three-segmented clava; F4 1.5–1.7 × as long as F3 and 0.9–1 × as long as clava. Funicle with three long, thin, subcylindrical rami on F1–F3, the rami with long, hairlike setae; funicular segments and all three rami with mps, but denser on R2 and R3, and sparsely on frontal surface of R1. Fore wing with marginal vein 3.3– 3.45 × as long as stigmal vein; stigmal vein at an angle of 45° to costal wing margin; postmarginal vein 1.9– 2 × as long as stigmal vein and 0.58–0.6 × as long as marginal vein. Costal cell dorsally with a marginal row of 11 or 12 setae apically. Legs ( Fig. 18 ) with mesotibia darkened in apical 0.6–0.85 and metatibia darkened in apical 0.6–0.75, with the dark portions dark brown to black; tarsi with basitarsi or rarely basal two tarsomeres pale. Gaster 2.3–2.5 × as long as broad, 1.05– 1.1 × as long as mesosoma, and 0.85–0.87 × as long as head plus mesosoma.

Variation

The fore wing usually has the speculum closed by rows of sparse setae basally and posteriorly ( Fig. 20 ), but sometimes it is entirely open with the basal and mediocubital folds bare; this variability is seen also in N. tutae . Specimens always have hyaline wings and most have dark tibiae. However, several specimens reared from Cos. pulchrimella under lab conditions, at different temperatures, vary in having the tibiae dark, with the basal third pale, or the tibiae even wholly pale yellow, and with the two basal tarsomeres pale. This variation can be attributed to phenotypic plasticity, as reported also in other Eulophidae by Bernardo, Pedata & Viggiani (2007). Although it has not been seen in specimens collected from the wild, such variation presumably also exists to some degree. Specimens reared under lab conditions from T. absoluta always have the tibiae dark. Pale specimens reared from Cos. pulchrimella also have some differences in morphological features, having a less elongate (1.65– 1.9 ×) postmarginal vein relative to the stigmal vein, pale yellow venation, and finer and paler wing setation, the gaster relatively more elongate (2.8–3.05 ×) and differing values of ocellar ratios (POL 2.2–2.3 × OOL, OOL 1.25–1.4 × OD).

Hosts

Cosmopterix pulchrimella on Parietaria judaica L. ( Urticaceae ), T. absoluta on Solanum lycopersicum , and Se. capparidana (Zeller) , based on sequenced specimens. The records published as N. sp. nr tidius or N. tidius in previous surveys of Tuta parasitoids ( Ferracini et al., 2012; Zappalà et al., 2012, 2013) belong to N. cosmopterix . The record listed in Noyes (2013) as N. artynes from Cos. pulchrimella also belongs to N. cosmopterix .

Discussion

Because of their hyaline wings and dark legs, in general appearance females of N. cosmopterix are most similar to N. tidius and related species of the N. tidius group. However, the elongate antennae, host preferences, and molecular analyses place N. cosmopterix in the N. artynes group, even though the wings lack an infuscate pattern. This condition is found also in atypical pale specimens of some other N. artynes -group species, and a few extralimital species. Females of N. cosmopterix differ from those of N. tidius in having the pedicel + flagellum 1.2–1.35 × as long as the breadth of head, the combined length of F1 + anelli 1.9–2.4 × as long as the pedicel and 2.8–3.4 × as long as broad ( Fig. 22 ). In N. tidius the pedicel + flagellum is 1.1 × as long as the breadth of the head, and the combined length of F1 + anelli is 1.25–1.6 × as long as the pedicel and 2.1– 2.8 × as long as broad ( Fig. 167 ). Furthermore, the gaster is slightly longer in female N. artynes , 1.05–1.2 × as long as the head plus mesosoma compared with as long as the mesosoma in N. tidius (cf. Figs 19 , 165 ). Because of the dark legs and reticulate propodeum females also resemble specimens of N. metalarus that have very faint or that lack infuscation from the wings, but females of the latter species always have a more strongly sculptured propodeum, with more distinct plical carinae and a longer median carina ( Fig. 37 ). Furthermore, females of N. metalarus have a shorter postmarginal vein (1.25– 1.5 × as long as stigmal vein), shorter marginal vein (2.8–3.4 × as long as stigmal vein), and shorter antenna with the pedicel + flagellum 1.25–1.35 × as long as the breadth of the mesoscutum. Females also resemble atypical specimens of N. tutae that have subhyaline fore wings, and atypical N. artynes that have pale wings, but these usually have at least some trace of infuscation behind the stigmal vein. Females of N. cosmopterix also differ in having the propodeum uniformly reticulate ( Fig. 23 ) compared with weakly, superficially reticulate or coriaceous to partly smooth in N. tutae and N. artynes , and usually dark although rarely pale tibiae compared with the tibiae always being partly pale in N. tutae ( Fig. 53 ) and N. artynes ( Figs 6, 7 ). Females of N. cosmopterix usually also have a longer antenna (pedicel + flagellum 1.2–1.35 × vs. 1.15–1.27 × as long as breadth of head in N. tutae ), the marginal vein (3.35)3.55–4 × as long as the stigmal vein vs. 2.8– 3.6 × in N. tutae and N. artynes , and the postmarginal vein (1.65)1.85–2.15 × as long as the stigmal vein vs. 1.4–1.7 × in N. tutae and N. artynes . Males of N. cosmopterix differ from those of N. tidius in the presence of mps on the basal ramus, even though these are restricted to the anterior face. Males of N. cosmopterix differ from those of N. artynes , N. tutae , and N. navonei by having a longer postmarginal vein, 1.9–2 × vs. 1.3–1.75 × as long as the stigmal vein, longer marginal vein, 3.3–3.45 × vs. 2.4–3.25 × as long as the stigmal vein, and the costal cell being more setose dorsally, with a marginal row of 11 or 12 vs. three to six setae in the latter species, and the propodeum being more strongly reticulate and the legs usually dark in the apical 0.65–0.85.

Figures

Figures 17–25. Necremnus cosmopterix sp. nov. 17–19, habitus: ♀ lateral (2012-7); 18, ♂ lateral (2013-68); 19, ♀ dorsal (2012-7). 20–23, ♀ (2012-7): 20, fore wing; 21, dorsal mesosoma; 22, antennae; 23, metanotum and propodeum. 24, ♂ pedicel and scape. 25, ♂ antenna (2013-67).

Figures 165–171. Necremnus tidius. 165, 166, ♀ habitus: 165, dorsal (2012-25); 166, lateral (2012-26). 167, ♀ antenna (2012-25). 168, ♀ fore wing base (arrow points to subcubital setal line). 169, ♂ antennae (Nec-125/NT135). 170, ♂ antennae (2012-22). 171, ♂ scape (arrows point to basal- and apical-most sensillum). Arrows point to multiporous plate sensilla in 169 and 170.

Figures 32–39. Necremnus metalarus. 32–34, habitus: 32, ♀ lateral (2012-9); 33, ♂ lateral (2012-12); 34, ♀ dorsal (2012- 8). 35, ♀ dorsal mesosoma (2012-8). 36, ♀ fore wings (2012-9). 37, ♀ metanotum and propodeum (2012-8). 38, ♀ antenna (2012-9). 39, ♂ antenna (2012-10).

Figures 48–56. Necremnus tutae sp. nov. 48–50, habitus: 48, ♀ dorsal; 49, ♀ lateral; 50, ♂ lateral. 51, ♀ dorsal mesosoma. 52, ♀ fore wing. 53, ♀ metanotum and propodeum. 54, ♀ antenna. 55, ♂ pedicel and scape. 56, ♂ antenna.

Figures 2–7. Necremnus artynes. 2–6, lectotype ♀: 2, dorsal habitus; 3, lateral habitus; 4, head and antenna; 5, dorsal mesosoma; 6, metanotum and propodeum. 7, paralectotype ♀: metanotum and propodeum.