Selitrichodes casuarinae Fisher & La Salle, 2014

Fisher, Nicole, Moore, Aubrey, Brown, Bradley, Purcell, Matthew, Taylor, Gary S. & Salle, John La, 2014, Two new species of Selitrichodes (Hymenoptera: Eulophidae: Tetrastichinae) inducing galls on Casuarina (Casuarinaceae), Zootaxa 3790 (4), pp. 534-542 : 537-539

Selitrichodes casuarinae Fisher & La Salle , sp. n.

( Figs 8–13 )

Female. Length 0.7–1.2 mm. Head generally yellow, with the area bordering eye margin posteriorly light brown to dark brown, covering the ocellar triangle, and back of head. Clypeus light brown ventrally. Antenna with scape yellow, dorsal margin light brown; flagellum light brown to yellow. Mesosoma dark brown (may have metallic reflections), with yellow markings as follows: dorsellum (may range to light brown in some specimen), tegula, and small patch on mesopleuron just ventral to tegula. Gaster dark brown, with transverse yellow to light brown stripes of varying strength along posterior margin of each tergite. Fore and middle coxae yellow, hind coxa dark brown to lighter yellow apically; trochanters light yellow; femora light yellow, fore tibia light brown to yellow; middle and hind tibiae yellow, tarsi light yellow, dark brown apically.

Fore wing ( Fig. 9 ) hyaline. Submarginal vein usually with 3 dorsal setae. Relative length of wing veins: CC: MV: STV: PMV = 0.2–0.22: 0.24–0.25: 0.065 –0.075: 0.03–0.035. PMV one-third to one-half length of stigmal vein. Speculum small, partially closed posteriorly with cubital line of setae extending almost to basal vein. Basal vein with 3 or 4 setae. Wing disk beyond speculum densely pilose.

Antenna ( Fig. 14 ) with 3 funicular segments and a 3 segmented club. F1–F3 quadrate, each successive funicle segment increasingly broader than the last. Length/width ratio of F1 0.35–0.4; F2 0.4–0.45; F3 0.5–0.55. Clava 2.0× longer than wide, wider than funicle, without distinct terminal spine; C3 very short and its end broad, not tapering apically. Scape slightly flattened ventrally.

Head ( Fig. 12 ). Ocellar triangle not surrounded by grooves. POL about 1.5× as long as OOL. Scrobal area without distinct median carina. Torulus located at middle of face, above level of lower margin of eye. Face with a broad depression (supraclypeal area) below torulus extending to clypeus and with some pilosity. Gena only slightly swollen and with malar sulcus somewhat curved near mouth margin. Mandible bidentate. Clypeal margin bilobed. Pronotum very short medially in dorsal view. Midlobe of mesoscutum without median groove and with one row of 3 or 4 adnotaular setae on each side; notauli quite deep. Mesosternum convex just in front of the trochantinal lobes and without precoxal suture. Scutellum with 2 pair of setae. Dorsellum rounded posteriorly and slightly overhanging propodeum. Propodeum medially shorter than dorsellum in dorsal view; with median carina. Propodeal spiracle with entire rim exposed and separated from anterior margin of propodeum by less than half its longest diameter. Paraspiracular carina absent. Propodeal callus with 2 setae.

Metasoma. Gaster slightly shorter than mesosoma in dried specimens. Hypopygium reaching more than half the length of the gaster. Cercus with 4 slightly curved setae; longest 2 cercal setae subequal in length, relatively short and similar to surrounding setae. Epipygium wider than long. Ovipositor sheaths not protruding beyond apex of gaster.

Male. Length 0.75–1.25 mm. Body color pattern similar to female, but with more dark brown markings on mesosoma and gaster. Dorsellum light brown to yellow. Antenna ( Fig.11 ) with a ventral plaque on scape, the plaque less than one-third length of scape, and situated near apex of scape.

Type material. Holotype ♀: USA: Guam, Polaris Pt., 6 Jan. 2009, Aubrey Moore, ex Casuarina equisetifolia, Database no. 32-022423 ( ANIC).

11♀, 29♂ Paratypes. 8♀, 26♂: same data as holotype (4♀, 17♂ ANIC; 1♀, 3♂ QMB; 1♀, 3♂ USNM; 2♀, 3♂ ESUG) . 6♀, 3♂: Palau, Koror, 12 Mar. 2009, J.Miles, ex Casuarina (3♀, 3♂ ANIC; 1♀ QMB; 1♀ USNM; 1♀ ESUG) .

Distribution. Micronesia: Guam, Rota and Palau. This species is presumed to be Australian in origin, although its distribution in Australia is still unknown.

Etymology. Named for the host plant.

Pest status. A damage survey on Guam showed that C. equisetifolia branchlets with galled tips were noticeably stunted in comparison to those that were not attacked. Dry biomass of branchlets with galled tips was reduced by 35% (t-test; t = 3.06, df = 13, p-value = 0.009).

Figures

FIGURES 8–13. Selitrichodes casuarinae. 8. Holotype ♀, habitus, lateral view. 9. Fore wing, ♀. 10. Antenna, ♀. 11. Antenna, ♂. 12. Head, frontal view, ♀. 13. Mesosoma, dorsal view, ♀.

FIGURES 14–19. Selitrichodes utilis, ♀. 14. Holotype, habitus, lateral view. 15. Fore wing. 16. Antenna. 17. Head, frontal view. 18. Mesosoma, dorsal view. 19. Mesosoma, lateral view.