Tetrameringia

Introduction

Tetrameringia McAlpine is a pale clusiine genus known from four species in Australia (T. pubescens McAlpine and T. ustulata McAlpine), South African (T. aethiopica Stuckenberg) and Madagascar (T. distoma (Verbeke)). Species are often collected around creeks and small streams in shady areas (McAlpine 1960).

Characteristics

As indicated by the generic name, Tetrameringia is defined (in part) by four pairs of fronto-orbital bristles, although some aberrant specimens of T. ustulata have only three pairs. The female abdomen is somewhat bulbous basally (or before its midpoint) and strongly narrowed distally, there are two dorsocentral bristles, there are no dorsal preapical tibial bristles, the bristles are black, and there is no subnotal stripe (Lonsdale & Marshall in manuscript).

Like other Clusiinae, Tetrameringia can also be characterized by an inclinate anterior fronto-orbital bristle, a small ratio of the length of the ultimate section of vein M to the penultimate, a presutural intra-alar bristle, outstanding bristles on the posterodorsal surface of the fore femur, a jointed distiphallus (entire and bent in some genera), and a posteromedial truncated notch on the vertex (Lonsdale & Marshall in press).

Phylogenetics

Tetrameringia is the sister-group to the monotypic Phylloclusia Hendel within the Clusiinae, defined (in part) by dorsocentral bristles that are closely spaced near the posterior margin of the scutum, an absence of the subnotal stripe, one row of short ctenidial bristles along posteroventral margins of fore and mid femora, and very characteristic genitalia.

A revision of this genus is currently being prepared (Lonsdale & Marshall, in manuscript).

References

Lonsdale, O & Marshall, S.A. In press, a. Redefinition of the Clusiinae and Clusiodinae, description of the new subfamily Sobarocephalinae, revision of the genus Chaetoclusia and a description of Procerosoma gen. nov. (Diptera: Clusiidae). European Journal of Entomology.

McAlpine, D.K. 1960. A review of the Australian species of Clusiidae (Diptera: Acalyptrata). Rec. Aust. Mus. 25: 63-94.