Quadrastichus gallicola, 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 : 33-36

Quadrastichus gallicola sp. n.

Figs. 10–16 .

Female. Length: 0.7–1.3 mm. Colour: front aspect of head yellowish, genae and temples with dusky suffusions; posterior aspect of head dusky above, the lower one-third or so yellowish; antenna dominantly white to yellow, flagellum a little darker than pedicel and scape in some specimens. Mesosoma almost entirely dark brown to blackish-brown or with side lobes and posterior half of mesoscutum, scutellum, prepectus and acropleuron variably suffused with yellowish-brown to pale brown in some specimens. Metasoma blackishbrown, the base of gaster dorsally broadly suffused with yellowish-brown. Forewing disc entirely hyaline, venation brownish. Legs white to yellowish-white save basal half or more of hind coxa, and apical tarsomere of all legs, dusky, the base of fore coxa also somewhat darkened in some specimens.

Head, in frontal view ( Fig. 12 ), 1.1–1.3 X as wide as high, 1.7–1.8 X as wide as frontovertex at its narrowest; malar space 0.6–0.8 X as long as an eye, the sulcus slightly curved, without a triangular fovea beneath the eye; POL 1.4 – 1.6 X OOL, 3.1–3.6 X OD; mandible bidentate with a truncation; head finely setose as in Fig. 12 , eyes naked; lower margins of toruli a little below lower eye margins; clypeus distinctly bilobed.

Antenna ( Fig. 14 ) with scape 2.8–3.3 X as long as wide, a little shorter than the length of an eye, almost reaching vertex; pedicel approximately 2.5 X as long as wide, 1.5 X as long as basal funicle segment; one strongly transverse anellus present; funicle three-segmented, segments about equal in size or progressively decreasing a little in size, each 1.5–2.1 X as long as wide; club about equal in length to distal two funicle segments combined, 2.6–3.2 X as long as wide; basal club segment about as long as wide, a little broader than apical funicle segment; apical club segment as long as wide to a little wider than long; apical spine short, distinctly shorter than apical segment; sensilla sparse, flagellum rather sparsely setose, as in Fig. 14 .

Mesosoma ( Fig. 10 ) 1.2–1.5 X as long as wide; mesoscutum in profile gently convex dorsally, in dorsal view gently rounded from side to side; mesoscutal midlobe slightly wider than long, without a median line, with 1 adnotaular seta at each side, in posterior half; mesoscutum with fine lineate-reticulate sculpture; scutellum fairly strongly convex in profile, 1.2–1.5 X wider than long with distinct sublateral and submedian lines; sculpture much as in mesoscutum; scutellum with 2 pairs of setae; dorsellum convex, smooth, medially about as long as propodeum; propodeum with median carina, without paraspiracular carinae, with very fine reticulate sculpture; spiracles less than their own diameter from anterior propodeal margin; cali each with 2–3 setae. Middle leg with tibial spur slightly shorter than basitarsus.

Forewing ( Fig. 11 ) 2.3–2.4 X as long as wide; costal cell 16–21 X as long as broad, subequal in length to marginal vein, naked or with a variable number of ventral setae; submarginal vein with 1 dorsal seta; marginal vein 3.3 – 3.7 X as long as stigmal vein, the postmarginal vein less than 0.25 X length of stigmal vein; subcubital line of setae extending basally as far as basal vein, closing speculum posteriorly; longest marginal cilia about 1.4–1.7 X as long as longest setae on marginal vein.

Metasoma short, about as long as mesosoma in dried specimens, somewhat circular in outline, hardly longer than broad, broadly rounded apically; epipygium wider than long; hypopygium reaching to about half the length of gaster; ovipositor, as seen in cleared slide-mounted specimens ( Fig. 15 ), about half as long as gaster, slightly shorter than middle tibia, 6.0–7.3 X as long as gonostyli, the latter short and broad, not or hardly protruding caudally, 1.1–1.5 X as long as middle tibial spur; 2–3 cercal setae.

Male. Length: 0.7–1.2 mm. Colour: much as in female except head more extensively yellow in some specimens, leaving only the posterior aspect partly dusky; hind coxa almost entirely pale, only the base slightly darkened.

Differing structurally from the female mainly in the antenna ( Fig. 13 ): scape with a ventral plaque, placed in apical half and extending from near apex to beyond mid length of scape, as in Fig. 13 ; a single anellus present; funicle four-segmented, the basal segment quadrate to 1.3 X as wide as long, distinctly shorter than segments II-III which are subequal in size or progressively decreasing a little in size, each about 1.5–2.1X as long as wide; flagellum sparsely setose, the setae on funicle segments fairly long, slightly curved, not arranged in whorls; genitalia as in Fig. 16 .

Remarks. Quadrastichus gallicola can be easily distinguished from Q. ingens , Q.bardus and Q. erythrinae by a combination of characters that include colour, the presence of 1 pair of adnotaular setae and the short, broadly rounded gaster with ovipositor hardly protruding. Quadrastichus gallicola most closely resembles the undescribed Quadrastichus species known from Togo and Benin, which can be separated from the former species in the female by its distinctive colour in which the head and basal half or so of the gaster are yellow in contrast to the remainder of the body which is blackish. Both these species fit the anysis - species group, as defined by Graham (1991), to a large extent.

Type material examined. Female holotype, 33 female, 20 male paratypes as follows: SOUTH AFRICA. Western Cape Province: Stellenbosch , 33°56’S 18°51’E, xii.1975, ex leaf galls on Erythrina caffra (Female holotype, 12 females, 8 males; HYMC00065 ); same data except xi.1975 (1 female, 5 males; HYMC00036 ); Stellenbosch, vii.1980, ex leaf galls on E. lysistemon (7 females, 3 males; HYMC02282 ); Cape Town, 33°55’S 18°22’E, iii.1978, ex galls on Erythrina sp. (5 females, 2 males; HYMC02947 ); Gauteng Province: Pretoria, Rietondale experiment farm, 25°44’S 28°13’E, xi.2004, ex leaf galls on Erythrina lysistemon (8 females, 2 males; HYMC03772 ). All series collected by S. Neser. 2 female, 2 male paratypes each: ANIC, BMNH, MNHN .

Non type material examined. SOUTH AFRICA. Western Cape Province: Stellenbosch , 33°56’S 18°51’E, xi.1975, ex leaf galls on Erythrina ? caffra (2 females, 2 males; HYMC00064 ) ; same data except xii.1975 (4 females, 1 male; HYMC00067 ) ; Wynberg , xii.1975, ex E.? caffra (4 females, 2 males; HYMC00066 ) ; Gauteng Province: Pretoria, Rietondale experiment farm, 25°44’S 28°13’E, iii.1993, ex leaf galls on Erythrina lysistemon (9 females, 4 males; HYMC02935 ) ; ii.2006 (4 females, 3 males; HYMC03792 ) ; ii. 2006 (5 females, 5 males; HYMC0580 ) ; Pretoria, Brummeria , ii.1993, ex leaf galls on E. zeyheri (2 females, 2 males; HYMC02976 ) ; Limpopo Province: Blouberg , NW of Polokwane, 23°04’S 28°59’E, v.2006, ex leaf galls on E. lysistemon (1 female; HYMC 03795 ) ; Mpumalanga Province: Pongola , v.1996, from Erythrina sp. (5 females, 3 males; HYMC02270 ) ; KwaZulu-Natal Province: Richards Bay , 28°44’S 32°05’E, xi.2003. M. Clark, ex leaf galls on Erythrina sp. (3 females, 3 males; HYMC05077 ) . All series collected by S. Neser except HYMC05077 .

Figures

FIGURES 10–16. Quadrastichus gallicola sp. n.: 10, mesosoma, female; 11, forewing, female; 12, head, frontal view, female; 13, antenna, male; 14, antenna, female; 15, ovipositor and middle tibia, same scale, female; 16, male genitalia.