Aprostocetus tritus, 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 : 38-41

Aprostocetus tritus sp. n.

Figs. 24–30 .

Female. Length: 1.1–1.7 mm. Colour: head and body entirely blackish-brown to almost black save basal one and a half segments of gaster yellowish; antenna with the scape and pedicel yellowish, flagellum brown to blackish-brown; legs white to yellowish, coxae partly to almost completely dusky, tarsal tips dark, hind femur with dusky suffusions in the middle in some specimens. Forewing disc entirely hyaline, venation pale brown. Head in frontal view ( Fig. 26 ) about 1.2 X as wide as high, 1.6 X as wide as frontovertex at its narrowest; malar space about 0.6 X as long as an eye, the sulcus slightly curved, without a triangular fovea beneath the eye; POL 1.6 X OOL, 2.6 X OD; mandible bidentate with a truncation; head finely and rather densely setose as in Fig 26 , eyes naked; lower margin of the toruli about level with lower eye margins; clypeus distinctly bilobed.

Antenna ( Fig. 27 ) with scape about 4 X as long as wide, 0.8 X the length of an eye, not reaching vertex; pedicel twice as long as wide, about equal in length to basal funicle segment; four strongly transverse anelli; funicle three-segmented; basal two segments subequal in size, each not quite twice as long as wide, a little longer than the distal segment, the latter 1.5 X as long as wide; or segment II intermediate in size between I and III; club about equal in length to the distal two funicle segments combined, 2.5 X as long as wide; basal club segment a little longer than wide, distinctly wider than apical funicle segment; apical segment wider than long; apical spine shorter than length of apical club segment; sensilla sparse, the flagellum sparsely setose, as in Fig. 27 .

Mesosoma ( Fig. 25 ) about 1.5 X as long as broad; mesoscutum in profile slightly convex dorsally, in dorsal view gently rounded from side to side; mesoscutal midlobe more or less as long as wide, with a median line which is barely discernible in some specimens, with 6–8 adnotaular setae at each side, roughly arranged in one or two rows; mesoscutum with clearly discernible lineate-reticulate sculpture; scutellum moderately convex, 1.2 – 1.4 X as wide as long with distinct submedian and sublateral lines; sculpture much as in mesoscutum; scutellum with 2 pairs of setae, anterior pair placed slightly behind mid-length of scutellum; dorsellum convex, smooth, medially subequal in length to propodeum; propodeum with a median carina, without paraspiracular carinae, with distinct reticulate sculpture; propodeal spiracles less than their own diameter from anterior margin of propodeum; cali each with 2 setae. Middle leg with tibal spur slightly shorter than basitarsus.

Forewing ( Fig. 24 ) 2.2–2.3 X as long as wide; costal cell 12–15 X as long as broad, almost as long as marginal vein, with a short row of 3–5 ventral setae at distal end; submarginal vein with 4 dorsal setae; marginal vein 3.2–3.7 X as long as stigmal; postmarginal vein subobsolute; subcubital line of setae extending basally as far as basal vein, closing speculum posteriorly; longest marginal cilia about 0.7–0.9 X as long as longest setae on marginal vein.

Metasoma with gaster long and slender, tapering to an acute apex, 2.4–2.6 X as long as wide, 1.6–2.0 X as long as mesosoma; epipygium about as long as wide; hypopygium reaching to about half way the length of gaster; ovipositor, as seen in cleared slide mounted specimens ( Fig. 29 ), as long as gaster, 2.2–2.5 X as long as middle tibia, 3.6–3.8 X as long as gonostyli, the later long, slender, protruding prominently caudally, 2.4–3.0 X as long as middle tibial spur.

Male. Length: 0.9–1.3 mm. Colour: entirely blackish-brown save gaster near base with a large yellowishbrown patch. Antenna sordid white, setation dark brown, lending the flagellum a dark appearance. Legs whitish with all coxae largely blackish-brown, the hind femur with a dusky suffusion in the middle in some specimens; tarsal tips dark. Forewing disc entirely hyaline.

Differing structurally from female mainly in the antenna ( Fig. 28 ): scape about 4.4 X as long as wide, with a bold ventral plaque in apical half as in Fig. 28 ; three strongly transverse anelli present; funicle foursegmented, the basal segment subquadrate, distinctly shorter than each of segments II–IV, which are subequal in length, each approximately twice as long as broad; flagellum with whorls of very long setae as in Fig. 28 . Genitalia as in Fig. 30 .

Remarks. Aprostocetus tritus , which is best placed in the subgenus Aprostocetus , can be distinguished from A. nitens , A. exertus and the known undescribed species of Aprostocetus associated with Erythrina galls by a number of characters, which include: non-metallic body; long row of 6–8 adnotaular setae; 4 dorsal setae on the submarginal vein; long, slender, strongly tapering gaster with shortly protruding ovipositor; male flagellar segments with whorls of long setae.

Type material examined. Material examined. SOUTH AFRICA. Female holotype, 23 female, 18 male paratypes as follows: Western Cape Province: Stellenbosch , vii.1980, ex leaf galls on Erythrina lysistemon (female holotype, 10 females, 11 males; HYMC02280 ); Cape Town , iii.1978, ex galls on Erythrina sp. (2 females, 1 male; HYMC00551 ); Gauteng Province: Pretoria , Rietondale experiment farm, 25°44’S 28°13’E, ii. 2004, ex leaf galls of E. lysistemon (1 female, 2 males; HYMC03773 ); same data except ii.2006 (2 females; HYMC0583 ); Pretoria , Botanic Gardens , 25°44’S 28°16’E, ii.2006, ex leaf galls on Erythrina acanthocarpa (4 females, 2 males; HYMC03799 ); Pretoria , Botanic Gardens , iv.2003, with leaf galls on E. zeyheri (2 females; HYMC03779 ); North-West Province: Hartbeespoort Dam, 25°44’S 27°51’E, ii.1976, G. L. Prinsloo & R . P. Brown, ex galls on Erythrina sp. (3 females, 2 males; HYMC00054 ). All series collected by S. Neser except HYMC00054 . 2 females, 1 male each: ANIC, BMNH, MNHN .

Non type material examined. KwaZulu-Natal Province: Midmar Dam, nr. Howick , ii.1985, ex galls in petioles of E. humeana (1 female, 1male; HYMC02277 ) ; Limpopo Province: Blouberg NW of Polokwane, 23°04’S 28°59’E, v.2006, ex leaf galls on E. lysistemon , (1 female; HYMC03794 ) ; Gauteng Province: Pretoria, Rietondale experiment farm, 25°44’S 28°23’E, ii.1997, ex inflorescens of Erythrina humeana (2 females, 4 males; HYMC02274 ) . All series collected by S. Neser.

Figures

FIGURES 24–30. Aprostocetus tritus sp. n.: 24, forewing, female; 25, mesosoma, female; 26, head, frontal view, female; 27 antenna, female; 28, antenna, male; 29, ovipositor and middle tibia, same scale, female; 30, male genitalia.