Lonchaea efate, MacGowan, 2021

Macgowan, Iain, 2021, The Lonchaeidae of Vanuatu (Diptera: Schizophora), Zootaxa 4926 (3), pp. 342-362 : 349-350

Lonchaea efate sp. nov. (Figures 20-22).

Description. MALE: Body length 2.6mm.

Head: Eyes bare. Frons sub-shining black, dulled by microsculpture, narrowing slightly towards antennal bases, ratio of width at anterior margin to eye width 0.35:1. Frontal and interfrontal setulae short, not more than 0.2x length of orbital seta, becoming longer near anterior margin. Orbital plate smooth, shining black, bare apart from orbital seta. Lunule and parafacials densely silver pollinose, face lightly silver pollinose. Antennae black, pedicel brown apically. Postpedicel broadly orange on medial base, length to depth ratio 2.6:1. Arista microscopically pubescent. Anterior genal setulae in single row of five along mouth margin.

Thorax: scutum shining blue-black, covered in setulae approximately 0.25x length of orbital seta. Anepisternum brightly shining blue-black, two long anterior setae, a long setula lying ventral to these, 3 posterior setae, remainder of sclerite with only a few short setulae. Katepisternum, one strong seta near dorsal margin. one seta on both proepimeron and proepisternum. Scutellum shining black, covered with slight greyish pollinosity, bare on disc, margin damaged with setae missing but at least one setula between apical and lateral setae. Calypteres; yellow-white with a brown fringe. Wings clear. Wing length 2.5mm. Legs black, t1 and t2 clear yellow.

Male terminalia: Epandrium spherical in shape, bearing a few scattered setulae along posterior and ventral margins. Cerci approximately same height as epandrium, a large hooded structure, covered externally with short setulae, attached to remainder of terminalia by a narrow curving basal section which has a row of five-seven strong setulae on ventral margin. Surstyli, simple elliptical lobes extending postero-ventrally from epandrium for approximately 0.3x their length, slightly truncated at posterior apex. Pregonites simple, blade-like without teeth or projections. Left pregonite 1.5x longer than right, narrowing gradually from base to a slightly blunt apex. Right pregonite shorter and narrower curving medially towards a bluntly pointed apex. Central plate (lying directly anterior to the base of the cerci) present, bearing a single medial tooth. Phallus, J-shaped, long and narrow with a slightly flared apex, basal arm 0.5x length of apical arm.

Type material. Holotype ♂: VANUATU: Efate , Vila, iii.1998 N. L. H. Krauss ( BMNH).

Paratypes: Efate, Port-Vila, 0-100m, iii.1981, N. L. H. Krauss, 2♂; Vila, 0-100m, xi.1978, N. L. H. Krauss, 1♂. Epi, Vaemali, 100-150m, 6-10 viii.1967, J. & M. Sedlacek, 3♂; Vaemali, 8. viii.1967, J. & M. Sedlacek, 2♂; Lowekewou, 0-100m, 31.viii.1979, W. C. Gagne & G. M. Nishida, 1♂. Espiritu Santo, Luganville, 20-30. viii.1958, B. Malkin, 1♂. Malekula, Lakatoro, 29.ix.1967, J. & M. Sedlacek, 1♂; Lakatoro, 0-200m, ii.1973, N. L. H. Krauss, 1♂ (all BPBM).

Etymology. The specific epithet is derived from the island of Efate on which the Holotype was captured.

Remarks. A typical member of the Lonchaea impressifrons Bezzi, 1920 species group as defined by McAlpine (1960). With long, stalked cerci and long, asymmetrical pregonites this species is perhaps most similar to Lonchaea minuta de Meijere, 1910 known from Java, the male terminalia of which are illustrated by McAlpine (1975: 991). However, L. efate is clearly distinctive in that the surstyli are longer and it is the left pregonite which is longer rather than the right.