Astichus naiadis, Neser, Ottilie C., 2012

Neser, Ottilie C., 2012, The first record of Astichus Förster (Hymenoptera: Eulophidae: Entiinae), parasitoids of Ciidae (Coleoptera) in bracket fungi, from the Afrotropical Region and the description of four new species from South Africa, Zootaxa 3183, pp. 49-64 : 61-63

Astichus naiadis n. sp.

Figs 4 , 8, 15, 16 ; Map 1.

Etymology. naiadis (Latin) = belonging to the water nymphs, the Naiads.

Diagnosis. Both sexes: white crossband above scrobes only; scape slender, cylindrical, and not quite reaching median ocellus ( Figs 15, 16 ); angle between stigmal and postmarginal veins of forewing 30º and hyaline ( Fig. 8). Female: pattern of stripes on head and thorax as in Fig. 4 : four longitudinal dark bands on vertex, pronotum and mesoscutum, reaching hind margin of scutellum, very narrow median coppery band separating two median bands; antenna ( Fig. 15 ) black except scape base and F3 yellowy white; forewing ( Fig. 8) with two dark brown infuscated bands, proximal band narrow, distal band spindle shaped, disc with row of 8 setae below marginal vein on ventral surface; propodeum with anterior and posterior margins not meeting medially, a few weak, uneven longitudinal black ridges medially separating them; gaster with posterior margin of T1 incised medially, T2 only slightly; cercus with three short setae of equal length. Male: antenna ( Fig. 16 ) resembles that of A. micans , but peduncles placed ventrally on nodes, black, with base of cylindrical scape pale, F1 without peduncle, subquadrate, F2–4 calabash shaped, with short peduncles and whorls of curved rhinaria extending to apex of segments, club with spicule.

Female. Length: 1.3–1.6 mm (average 1.4 mm). Colour: Head and thorax ( Fig. 4 ) iridescent turquoise with dark bands with coppery sheen, setae inconspicuous; gaster black with blue sheen, especially at base; dark crossbands on face not well defined, giving the face a mottled appearance, indications of crossbands present at inner orbit; white crossband only above scrobes, four longitudinal dark bands on vertex, not crossing over ocelli; clypeus yellow-brown, mouth margin same colour as rest of head; eyes red; antenna ( Fig. 15 ) black except scape base and F3 yellowy white; rhinaria pale, setae on funicle and club pale; pronotum with dark marks, anterior margin of mesoscutum dark, four longitudinal dark bands on pronotum and mesoscutum reaching hind margin of scutellum, median coppery band very narrow (slightly wider in the specimens from Western Cape Province), side lobes of mesoscutum dark with round blue patch at centre; dorsellum dark, propodeum bright blue with purple reflections, black medially; wings hyaline, forewing ( Fig. 8) with small infuscated patch at parastigma, two complete dark brown infuscated bands, proximal band below base of marginal vein narrow, distal band wider and spindle shaped, the two dark bands faintly (more pronounced in the material from Western Cape Province) connected medially, often faint infuscation at apex of wing, angle between stigmal and postmarginal veins hyaline; disc setae dark, wing veins dark except white between parastigma and marginal vein, and apical two-thirds of marginal vein; hind wing hyaline; legs yellow-brown except coxae, fore femur dorsally, mid and hind femora, fore tibia base and apex, mid and hind tibia basal two-thirds and apical tip, tarsal segments two and four, dark brown.

Head. Head, mostly not collapsing, in dorsal view slightly wider than thorax (1.1 times), 1.9 times as wide as long, 1.8 times as wide as vertex; face in frontal view 1.3 times as wide as long; eye 1.7 times as long as malar space; eyes with very short hairs; IOL 4, OOL 3, POL 9; very fine complete malar sulcus present; sculpture fine, somewhat smoother and shinier than the other three species; clypeus inconspicuous; scrobes finely strigulate, shiny, lateral margins nearly parallel, slightly widening at base and apex, with rounded edges, slight low ridge between toruli; two shiny nodules on face each side at inner orbits, and on outer margin of scrobes one tiny, shiny elongated groove opposite the two nodules; antennae ( Fig. 15 ) inserted at lower eye level; scape slender, cylindrical, not quite reaching median ocellus, longer than club (1.3 times); pedicel slightly longer than funicle segments, F1–3 slightly longer than wide, without peduncles, F4 round with very short peduncle; rhinaria only slightly longer than segments; club one-segmented (no discernible septa at high magnification); flagellum about same length as head width.

Mesosoma. Pronotum fairly short, sloping anteriorly; mesoscutum as long as scutellum; sculpture as on head; mesoscutum with about 16 scattered setae; three or four pairs of setae on scutellum; axillae with two inward-facing setae; dorsellum reticulate, nearly as long as propodeum, which is fairly short, reticulate laterally, anterior and posterior margins not meeting medially, a few weak, uneven longitudinal ridges medially separating them, callus reticulate, with 3 or 4 setae; mesepimeron centrally smooth and shiny; forewing ( Fig. 8) just more than twice as long as wide, wing apex rounded, disc setae short and dense; short hairline at stigmal knob, submarginal vein slightly shorter than marginal vein [30:25], with 4 or 5 setae, parastigma with two setae, row of 8 setae on disc below proximal part of marginal vein, marginal vein about one third of wing length, stigmal vein forming angle of about 30˚ with postmarginal vein, longer than postmarginal vein, stigmal knob small, fringe setae half stigmal vein length.

Metasoma. Gaster ( Fig. 4 ) in lateral view 1.8 times as long as mesosoma, collapsing dorsally, smooth and shiny but T5 and T6 dorsally slightly reticulate; scattered setae ventrally; posterior margin of T1 incised, T2 only slightly; cercus with three short setae of equal length; epipygium bulging slightly, with slight texture, short, about half the length of T6; protruding portion of ovipositor as long as T6.

Male. Body less sculptured than female, black and shiny with purple and coppery reflections; wings and antennae quite similar to those of A. micans but antennal peduncles placed more ventrally on less-rounded nodes; antenna ( Fig. 16 ) somewhat compressed laterally, black with only base of scape pale, scape not expanded apically but somewhat wider near base, F1 without peduncle, subquadrate, F2–4 more or less calabash shaped, with short peduncles ventrally and distinctive whorls of curved short-based rhinaria, free ends extending to apex of segments, setae few and short, club three-segmented, with spicule; forewing with two poorly defined crossbands.

Remarks. The wing pattern of A. naiadis is rather similar to that of A. bachmaieri and A. longevittatus , but these three species differ in the colour of the female funicle segments: in A. naiadis only F3 is white, in A. longevittatus only F4, whereas in A. bachmaieri both F3 and F4 are white ( Doġanlar 1992, figs 2, 4).

Type material. SOUTH AFRICA. Mpumalanga Province: Holotype Ƥ ( HYMC 05755) Mooihoek Farm nr. Wakkerstroom, 27º13'S 30º32'E, 15.vii.2008, S & OC Neser, with Cis spp. P, Q & L from Stereum ostrea (Stereaceae) (BF138) on fallen tree trunk. Paratypes: 9Ƥ 23, same data as holotype (1Ƥ QM). Western Cape Province: 13 ( HYMC 05801) Montagu Pass N of George, 33º54'S 22º24'E, 4.xi.2009, S & OC Neser, ex Ceracis cucullatus from Coriolus hirsutus (Polyporaceae) (BF197) on fallen tree trunk; 23 ( HYMC 05802) same data except with Cis spp. E, J, N & Xylographus seychellensis from Coriolus hirsutus (Polyporaceae) (BF210) on Rapanea melanophloeos (Myrsinaceae) (13 QM); 2Ƥ 13 ( HYMC 05803) same data except with Ceracis cucullatus & Cis sp.E from Coriolopsis polyzona (Polyporaceae) (BF202); 3Ƥ ( HYMC 05804) same data except with Ceracis cucullatus , Cis spp.J & N from Ganoderma applanatum (Ganodermataceae) (BF201) (1Ƥ QM).

Figures

FIGURES 1 – 4. Dorsal habitus of female. 1. Astichus micans. 2. Astichus silvani. 3. Astichus gracilis. 4. Astichus naiadis. Scale bar = 1 mm.

FIGURES 9 – 16. Male and female antennae. 9. Astichus micans Ƥ. 10. A. micans 3. 11. A. silvani Ƥ. 12. A. silvani 3. 13. A. gracilis Ƥ. 14. A. gracilis 3. 15. A. naiadis Ƥ. 16. A. naiadis 3.