Astichus gracilis, 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 : 59-61

Astichus gracilis n. sp.

Figs 3 , 7, 13, 14 ; Map 2

Etymology. gracilis (Latin) = slender, graceful

Diagnosis. Both sexes: white crossband above scrobes full width of face; scape expanded, widest at apex, reaching just past median ocellus; forewing with intricately mottled hyaline and dark areas, angle between stigmal and postmarginal veins 60º and hyaline ( Fig. 7). Female: pattern of stripes on head and thorax as follows: vertex green with six dark diagonal bands converging toward occiput, four longitudinal dark bands on green background extending from pronotum to scutellum ( Fig. 3 ); funicle segments spindle-shaped, F1 and F3 pale ( Fig. 13 );, disc without setae on ventral surface below marginal vein; propodeum smooth and shiny with median carina, and small shiny nodule on either side; gaster with hind margin of T1 incised medially, cercus with three very delicate setae of different lengths, one very long. Male: antenna with scape expanded as widely as in female, all funicle segments with long peduncles and setae longer than segments, club with long setae, without spicule ( Fig. 14 ).

Description. Female. Length: 1.3–1.6 mm (average 1.4 mm). Colour. Head, thorax and propodeum with iridescent colours and various dark bands with coppery sheen as follows ( Fig. 3 ): face green with four dark crossbands, the dorsal two between apex of scrobes and median ocellus full width of face, with white crossband between them; vertex green with six dark diagonal bands converging towards occiput, but not reaching it, the two central bands crossing lateral ocelli; four longitudinal bands extending from pronotum to scutellum, ventro-laterally a narrow band from front margin of pronotum to tegulae; lower face shiny yellow-green, yellow-brown line at mouth margin including ventral half of inconspicuous clypeus and malar space; eyes red; antenna ( Fig. 13 ) black except F1, peduncle of F3 and whole F4 whitish; mesoscutum turquoise, scutellum turquoise with purple reflections; dorsellum and propodeum laterally shiny turquoise, centre of propodeum, mesopleuron and gaster black with blue and purple sheen; wings hyaline; forewing with characteristic dark brown mottled pattern as in Fig. 7 (white spots in Western Cape Province material smaller or missing, giving the wings a darker look—see discussion), angle between stigmal and postmarginal veins hyaline; wing veins brown; wing disc setae dark, darkest on infuscated areas, setal fringe longer than stigmal vein; hind wing with small infuscated areas at base and apex of marginal vein (hind wing of Western Cape Province material more extensively infuscated below marginal vein); legs yellowbrown, except darker brown at apex of fore, mid and hind coxae, basal two-thirds of mid femur, hind femur except apex, apical tips of all tibiae and tarsal segments two and four.

Head. Wider than thorax (1.3 times); head in dorsal view about twice as wide as long, 1.7 times as long as vertex; face in frontal view 1.4 times as wide as high, mostly collapsing; eyes with short pale setae, bulging somewhat, eye about two and a half times longer than malar space, fine malar sulcus present; sculpture finely rugulose, smoother at mouth, scrobes short, wide, smooth, narrow at centre, only reaching halfway to median ocellus, IOL 2, OOL 6, POL 5, ocelli small; antenna inserted at lower eye level, small shiny oval ridge between toruli, with a tiny nodule between ridge and apex of scrobes, two shiny nodules at inner orbit between lower and mid dark bands, two small shiny depressions on either side of scrobes, between mid and upper dark bands, setae sparse, dark, two conspicuous setae at either end of white crossband; antenna ( Fig. 13 ) with scape expanded, widest at apex, as wide as pedicel length, reaching just past median ocellus, as long as club, pedicel as long as funicle segments, funicle segments spindle-shaped, nearly twice as long as wide, F1 without, F2–4 with short peduncles; club one-segmented (no discernible septa at high magnification); rhinaria on F1 diagonal, rhinaria longer than segments, with bases about half rhinaria length, setae about as long as rhinaria bases; flagellum longer than head width.

Mesosoma. Sculpture as on head; pronotum very short, sloping anteriorly; notauli deep and complete, mesoscutum and scutellum same length, each with two pairs of conspicuous dark setae, posterior pair on scutellum long and strong; axillae sculptured, each with one inward facing seta; upper mesepimeron shiny and smooth; dorsellum just shorter than propodeum, central one-third smooth and shiny; propodeum of medium length, smooth, shiny, with two small, very shiny nodules each side of median carina, callus smooth and shiny with two setae; forewing ( Fig. 7) more than two and a half times as long as wide, submarginal vein with three setae, centre one long, conspicuous, parastigma with two setae, no setae on ventral side of disc below marginal vein, marginal vein twice as long as submarginal, postmarginal longer than stigmal (7:5); angle of stigmal and postmarginal veins about 60˚, stigmal knob small, round; no hairlines in distal part of wing, apex slightly asymmetrically rounded, fringe setae longer than stigmal vein.

Metasoma. Gaster ( Fig. 3 ) smooth and shiny, posterior margin of only T1 medially incised; gaster collapsing dorsally, about twice as long as mesosoma in lateral view, scattered inconspicuous setae ventrally; cercus with three delicate setae of different lengths, one very long; epipygium bulging conspicuously upwards, shiny and smooth; ovipositor shiny, protruding portion as long as T6 and epipygium combined.

Male. Smaller than female but structure and colour of body and wings similar, except for antenna ( Fig. 14 ): scape expanded as in female (in figure scape is turned sideways, full expansion not visible), funicle segments brown, small and round, with white peduncles longer than nodes, very long dark setae, club three-segmented with similar setae, without spicule.

Remarks. Although the complex wing pattern of A. gracilis resembles some undescribed Australian species, each species has other characters like antennal shape and colour that differ significantly from the diagnostic characters given for A. gracilis .

The wing pattern of A. gracilis also resembles that of A. miyatakei Tachikawa and A. sakaii Tachikawa , but the species differ in the antennae: female funicle segments of A. miyatakei subquadrate and only F1 pale, male F1 without peduncle (similar to that of A. silvani ), whereas A. sakaii has female scape cylindrical, funicle F3 and F4 pale, all segments somewhat elongated but not spindle-shaped as A. gracilis ( Tachikawa 1977, fig. 2 A & D; fig. 3 A & C).

Type material. SOUTH AFRICA. Mpumalanga Province: Holotype Ƥ ( HYMC 05724) Alkmaar, W of Nelspruit, 25º27'S 30º50'E, 10.ii.2008, OC Neser, with Ceracis cucullatus & Cis sp.L from Trametes sp. ( Polyporaceae ) (BF47); paratypes: 12Ƥ 33, same data as holotype; 2Ƥ 13 ( HYMC 04907) Blouberg, NW of Polokwane, 23º04'S 28º59'E, 27.iv.2007 OC Neser, with Ceracis cucullatus & Cis sp.Q from Trametes sp. ( Polyporaceae ) (BF34) (1Ƥ QM). KwaZulu-Natal Province: 1Ƥ 13 ( HYMC 05752) Mpisini Nature Reserve, Umkomaas, 30º12'S 30º48'E, 9.vii.2008 S & OC Neser, with Ceracis cucullatus , Cis spp. M & N from Funalia sp. ( Polyporaceae ) (BF110); 1Ƥ 23 ( HYMC 05754) Twinstreams Nursery forest, nr Mtunzini, 28º57'S 31º46'E, 13.vii.2008, RP Urban, ex Ceracis cucullatus from unidentifiable bracket fungus (BF167). Limpopo Province: 1Ƥ ( HYMC 05753) Wonderwoud, Wolkberg Wilderness Area, 24º01'S 30º04'E, 31.viii.2008, S Neser, ex Ciidae from Coriolopsis sp. ( Polyporaceae ) (BF157). Western Cape Province: 4Ƥ ( HYMC 05797) Montagu Pass, N of George, 33º54'S 22º24'E, 4.xi.2009, S & OC Neser, with Ceracis cucullatus , Cis sp.J & Xylographus seychellensis from Coriolus hirsutus (Polyporaceae) (BF211) on Brachylaena neriifolia ; 1Ƥ ( HYMC 05799) same data except with Ceracis cucullatus & Cis sp.E from Coriolopsis polyzona (Polyporaceae) (BF202); 7Ƥ ( HYMC 05800) same data except with Ceracis cucullatus , Cis spp. J & N from Ganoderma applanatum (Ganodermataceae) (BF201) on fallen tree trunk; 5Ƥ 73 ( HYMC 05798) Prince Alfred’s Pass, N of Knysna, 33º58'S 23º09'E, 5.xi.2009, S & OC Neser, with Ceracis cucullatus & Cis sp.E from Lenzites elegans (Polyporaceae) (BF214) on fallen tree trunk (2Ƥ 13 QM).

MAP 2. Collecting sites of Astichus silvani and A. gracilis in South Africa.

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.