Quadrastichus ingens, Prinsloo & Kelly, 2009

Prinsloo, Rd. L. & Kelly, Ne. A., 2009, The tetrastichine wasps (Hymenoptera: Chalcidoidea: Eulophidae) associated with galls on Erythrina species (Fabaceae) in South Africa, with the description of five new species, Zootaxa 2083 (1), pp. 27-45 : 31-33

Quadrastichus ingens sp. n.

Figs 3–9 .

Eurytoma sp. : Van Staden, Davey & Noel, 1977: 283 (misidentification).

Female. Length: 3.7–4.4 mm. (including strongly protruding ovipositor). Colour: front aspect of head yellow, with brownish suffusions as follows: center of face below toruli, side of face below eyes, frontovertex from ocellar triangle to occipital margin, genae in some specimens; posterior aspect of head largely blackish above, the lower one-third or so yellowish; antenna ranging from yellowish-brown to blackish- brown, flagellum a little darker than scape in some specimens. Mesosoma black, with mesoscutal side lobes partly to entirely yellow in addition to the following areas that are also marked with yellow: hind margin of mesoscutal midlobe to a varying degree, hind margin of scutellum narrowly, prepectus and acropleuron. Metasoma black with uneven paler suffusions in some specimens, hind margin of second last tergite usually marked with yellow; protruding gonostyli blackish-brown. Forewing palely infuscated, venation brown. Legs whitish with following areas blackish- brown: all coxae basally, femora save basal and distal ends, the middle femur in some specimens almost entirely pallid, only the ventral margin narrowly darkened; distal tarsomere of all legs.

Head, in frontal view ( Fig. 5 ), about 1.2 X as wide as high, about 1.9 X as wide as frontovertex at its narrowest; malar space 0.7 X as long as an eye, the sulcus distinctly curved, without a triangular fovea beneath the eye; POL 1.6 X OOL, 3 X OD; mandible bidentate with a truncation; head finely setose as in Fig. 5 , the eyes naked; lower margins of toruli a little below lower eye margins; clypeus distinctly bilobed.

Antenna ( Fig. 7 ) with scape 4.1–4.3 X as long as wide, a little shorter than the length of an eye, almost reaching vertex; pedicel 3 X as long as wide, a little longer than basal funicle segment; one strongly transverse anellus present; funcile three-segmented, the segments progressively decreasing a little in size, segment I about 2.4 X as long as wide, III about twice as long as wide; club a little shorter that distal two funicle segments combined, 2.7–3.2 X as long as wide; basal club segment 1.1–1.4 X as long as wide, distinctly broader than apical funicle segment; apical club segment longer than wide; apical spine short, distinctly shorter than apical segment; sensilla fairly sparse, the flagellum densely covered with short setae, as in Fig. 7 .

Mesosoma ( Fig. 4 ) about 1.6 X as long as wide; mesoscutum in profile gently convex, in dorsal view gently rounded from side to side; mesoscutal midlobe about as long as wide, with traces of a midline visible in some specimens; midlobe with a row of 3–5 adnotaular setae at each side; mesoscutum with fine lineatereticulate sculpture; scutellum fairly strongly convex in profile, about 1.2 X as wide as long with distinct sublateral and submedian lines; sculpture much as in mesoscutum; scutellum with 2 or 3 setae at each side; dorsellum convex, smooth, medially about as long as propodeum; propodeum with a poorly defined median carina and no paraspiracular carinae, with fine reticulate sculpture; spiracles less than their own diameter from anterior propodeal margin; cali each with 4–5 setae. Middle leg with tibial spur about 0.5 X as long as basitarsus.

Forewing ( Fig. 3 ) 2.6 X as long as wide, the disc densely setose; costal cell about 20 X as long as broad, subequal in length to marginal vein, naked; submarginal vein with 1 dorsal seta; marginal vein 3 X as long as stigmal vein, the postmarginal vein subobsolete; subcubital line of setae extending basally as far as basal vein, closing speculum posteriorly; longest marginal cilia about 0.6–0.7 X as long as longest setae on marginal vein.

Metasoma with gaster (including strongly protruding ovipositor) long and slender, tapering strongly to an acute apex, about 2.5–2.9 X as long as mesosoma in dried specimens; epipygium distinctly longer than wide; hypopygium reaching to about two-thirds length of gaster; ovipositor, as seen in cleared slide-mounted specimens ( Fig. 8 ), 3.0–3.5 X as long as middle tibia, 2.3–2.6 X as long as gonostyli, the latter protruding strongly caudally by at least one-third gastral length, 14–16 X as long as middle tibial spur; 2 cercal setae.

Male. Length: 2.4–3. 0 mm. Colour: distinctly bicolorous: head and antenna whitish, with ocellar triangle and upper part of occiput dusky; mesosoma black with the following areas white: sides and venter of pronotum, posterolateral sides of mesoscutal midlobe in a pattern that leaves the black area V-shaped, mesoscutal side lobes, prepectus and acropleuron; metasoma blackish save basal two to three segments of gaster ventrally palely suffused; wings palely infuscated; legs whitish with distal tarsomere of all legs dark.

Differing structurally from the female mainly in the antenna ( Fig. 6 ): scape with a ventral plaque, placed in apical half and extending from near apex to about mid length of scape, as in Fig. 6 ; one anellus present; funicle four-segmented, basal segment 1.5–1.7 X as long as wide, distinctly shorter than segments II–IV which become progressively a little shorter, segment II about 3 X as long as wide, IV 2.2 X as long as wide; flagellum sparsely setose, the setae on funicle segments short, curved, distinctly shorter than the segments that bear them, not arranged in whorls; genitalia as in Fig. 9 .

Remarks. Quadrastichus ingens is a striking species that is readily separated from Q. gallicola , Q. bardus , Q. erythrinae and all the undescribed species of the genus known to be associated with Erythrina galls by its distinctive colour, large size, row of 3 – 5 adnotaular setae, long, slender, acutely pointed gaster and straight, strongly protruding ovipositor. Quadrastichus ingens does not fit any one of the two existing speciesgroups, namely anysis and brevinervis, which were established by Graham (1991) for the European fauna of the genus.

Type material examined. Female holotype, 21 female, 19 male paratypes as follows: SOUTH AFRICA. KwaZulu-Natal Province: Pietermartizburg , 29°36’S 30°22’E, B. Muller, vi.2008, ex leaf galls on Erythrina latissima (Female holotpye, 15 females, 14 males; HYMC05731 ); same data except D. J. Brothers, ix.2008 (5 females, 5 males; HYMC05732 ); 1 female, 1 male paratypes in each: ANIC, BMNH, MNHN .

Non type material examined. SOUTH AFRICA. KwaZulu-Natal Province: Pietermaritzburg , R . A. Noel, 1975, ex leaf galls on Erythrina latissima (7 females; HYMC00034 ) .

Figures

FIGURES 3– 9. Quadrastichus ingens sp. n.: 3, forewing, female; 4, mesosoma, female; 5, head, frontal view, female; 6, antenna, male; 7, antenna, female; 8, ovipositor and middle tibia, same scale, female; 9, male genitalia.