Antargidium nigrum, Schmidt, Stefan, 2012

Schmidt, Stefan, 2012, Revision of the Australian sawfly genus Antargidium (Hymenoptera, Symphyta, Argidae) with description of two new species, Zootaxa 3180, pp. 47-56 : 55-56

Antargidium nigrum new species

( Figs 5 , 15, 16)

Description. Female. Length 6–7 mm. Head and thorax black, abdomen dark brown to black, tegula, tibiae of fore- and middle leg, and hind tibia at base whitish, tarsi brown. Wings hyaline, veins and stigma dark brown.

Supraclypeal area without median longitudinal carina, sparsely but distinctly punctured and, as the whole head, with pale grey setation contrasting to black colour of head. Antenna shorter than width of head (0.9); pedicel transverse, 0.4 × as long as broad. POL slightly shorter than OOL (0.9); postocellar area about 2.0 × as broad as long. Eyes about 1.5 × as long as broad, converging below, interocular distance 0.8 × eye height. Sheath narrow, almost parallel sided in dorsal view, without dorsal projections, in lateral view obliquely truncate. Lancet narrow and pointed at apex, with 20 serrulae, basal 2 serrulae rounded, other serrulae distinctly serrate, proximal margin of annuli with distinct, but slender and almost seta-like ctenidia.

Male. Apart from sex related differences, similar to female in structure and colour.

Host. Labichea lanceolata Benth. (Leguminosae) .

Distribution. Western Australia.

Types. Holotype: Female, labelled “Tent. 7, H. 4 Dec. [19]71, N. McFarland Larval Collection – see notes”, “ Holotype, Antargidium nigrum sp. nov., det. S. Schmidt 2011” [red label]. Paratypes: WESTERN AUSTRALIA. Red bluff Caravan Park, 2 miles south of Kalbarri, 2 ƤƤ, 17.xi.1971, reared from larvae on Labichea lanceolata , and 1 Ƥ, 15.xi.1971, collected as adult on L. lanceolata (ANIC, ZSM); Bushmead, 1847 (1 3, WAM, Reg. Nr. 71285).

Etymology. The species is named after the predominantly black colour.

Biology. The specimens collected by Noel McFarland are associated with handwritten notes and include descriptions of larvae, cocoons and life history traits. Larvae feed on leaves of Labichea lanceolata Benth. The leaf margins and midrib usually remain untouched. They cling tightly and do not let go or drop unless pulled off. Usually there is only one per leaf. The cocoon consists of several layers of coarse, pure white, woolly-looking silk. Half and full grown larvae were collected in mid-November and by late November, and early December adults were hatching.

Figures

FIGURES 1 – 7. Antargidium spp., 1 – 2 face, 3 – 4: vertex, 5: apex of abdomen, 6: female hypopygium, 6: sawsheath. (1, 6) A. allucente; (2) A. atriceps; (3, 7) A. flavescens holotype; (4, 5) A. dentivalve. Abbreviations: S: supraclypeal area, K: carina, P: dorsal projections.