The Froggattimyia-Anagonia Genus Group (Diptera: Tachinidae)

Anagonia lasiophthalma (Malloch)

Figs 44–46, 84

Froggattimyia lasiophthalma Malloch, 1934:6. Synonymy by Crosskey (1973:138)

Type. Holotype female in ANIC, no. 5887, Canberra, Australian Capital Territory.

Male. Generally resembling the pale form of A. rufifacies in colour and chaetotaxy, differing principally as follows:

Head. Width 2.6–3.4 mm, mean 2.97 mm. Frons rather narrow, Frw/Hdw 0.2–0.3, mean 0.20. Gena rather wide, Gnw/Eyh 0.2–0.3, mean 0.26. Ivb/Vb-E 0.9–1.1, mean 1.1. Eye strongly and conspicuously haired. Postocellar setae 2–8, almost always more than 2, usually 4 or more.

Thorax. Median dark vitta well developed, extending postsuturally more than half way to scutellum. Presutural intra-alar bristle usually fine or absent on at least one side. Intrapostalars often finely differentiated on at least one side. Apical scutellars curved or directed upward and relatively stout. Scutellum distinctly narrow basally, ratio Sbs/Ssa 2.2–2.6, mean 2.40.

Legs. Tibiae all pale brown. Foretibia with preapical ad bristle distinct but usually very small, c. 0.2 length of d counterpart. Hindtibia with pd1 moderately long, ratio Pd1/ Sdd 0.8–1.1, mean 0.97.

Wing. Basicosta and tegula various shades of brown, sometimes concolorous, but tegula usually distinctly paler.

Abdomen. Tergite 3 with pair of stout submedian marginal bristles, a finer, finer pair often on syntergite 1+2 also. Also, tergite 4 and sometimes tergite 3 with 2 or more strongly differentiated bristles on disc.

Terminalia (Figs 44–46). Cerci with very distinctive, stout posterobasal lobes and conspicuous apical medial teeth; the lobes commonly visible in the dried specimen. Also, surstyli strongly pigmented and densely pilose on their inner surfaces.

Female. Differing from the male in the usual sexual characters, and as follows:

Head. Width 3.6–4.0 mm, mean 3.72 mm. Frw/Hdw mean 0.2 Postgular and sometimes subcranial setae pale.

Thorax. Median dark vitta poorly developed, presutural portion usually lacking. Presutural intra-alar bristle well developed. Intrapostalar bristles usually distinct. Pleuron with soft hairs mostly pale on all but anepisternum (more obviously so than in A. rufifacies).

Wing. Tegula and basicosta both pale brown.

Legs. Femora and tibiae concolorous, pale to mid-brown. Hindtibia with pd1 rather shorter, ratio Pd1/Sdd 0.6–0.8,

mean 0.76.

Abdomen. Sternite 1 with pale brown hairs.

Terminalia (Fig. 84). Tergite 6 more or less entire, slightly emarginate posteriorly; Sternite 6 in lateral view about as long as high, with stout, posteroventrally projecting, scooplike, median boss, lined apically with several fine setae; tergite 7 completely divided, with 2 more or less crescentshaped basal portions, the apical 2 ⁄ 3 represented by 2 narrow, parallel hemitergites; sternite 7 forming a conspicuous, sharp-pointed, thornlike “piercer”, curved anteroventrally, emarginate basally with a group of tiny setae on each angle; dorsal membrane of tergite 7, above the piercer and enclosing the hemitergites, with a conspicuous area of tiny dark toothlike spicules; these also extend posteriorly on to what is presumably the membranous tergite 8. More posterior parts so lightly sclerotized as to be hardly recognizable. In dried specimens, and presumably in life, the piercer is clearly visible, with its apex resting in the hollow of the median boss of sternite 6.

Distribution. Known from cooler climates in most southern states (NSW, ACT, Victoria, Tasmania, and southern Western Australia), and no doubt occurring in South Australia also. It is one of only three Anagonia species known from Tasmania.

Biology. Regularly taken in light traps; but a number were also reared from leaf-eating larvae of curculionid beetles —principally Gonipterus scutellatus (Gyllenhal), but one from Oxyops fasciatus Boisd. Two anomalous rearings—one from a “sawfly larva” and one from the chrysomelid Paropsis atomaria —are from reputable sources, but erroneous labelling cannot be excluded.

Notes. Malloch’s holotype and paratype, which seem to have been co-reared, both lack the usual, well differentiated discal bristles on abdominal tergite 4, and the submedian marginal pair on tergite 3 is very finely developed. This is a very rare variant in other material. There is no doubt, however, that they are conspecific with the material described above.

The development of the extraordinary piercer seems correlated with that of the median boss on sternite 6, in that one can envisage the former arising from extreme enlargement of a sclerite resembling the latter. It might also be noted that the shape of sternite 6 is highly reminiscent of that of sternite 7 in A. rufifacies.