Howickia Richards 1951

Marshall, S. A., Luk, S. P. L. & Dong, H., 2014, A revision of the New Zealand species of Howickia Richards, Zootaxa 3887 (1), pp. 1-36 : 2-3

Howickia Richards 1951

Howickia Richards 1951: 844 . Type species Apterina trilineata Hutton, 1901: 93 .

Biroina Richards1973: 330 . Type species Limosina myrmecophila Knab and Malloch, 1912: 236 . NEW SYNONYM

Definition. The most convincing synapomorphy for Howickia is the structure of the hypandrium, which consists of three distinct parts: the usual Y-shaped main part with arms entirely but asymmetrically fused to the anterolateral corners of the epandrium; a broad, bilobed posteroventral portion (ventral hypandrial lobe); and a dorsal longitudinal rod (posterodorsal hypandrial apodeme) running above and parallel to the hypandrium, extending to a point (fulcrum) just beyond the base of the distiphallus. The posterodorsal hypandrial apodeme was recognized as a synapomorphy of Biroina by Papp (1995), who also stated that the hypandrium was "without robust bifurcate ventral appendage but with a slipper-shaped cranioventral process, its ventral surface with or without small teeth". Other probable apomorphies include the extremely long, delicate and narrow telescoping female terminalia normally retracted into a broad, heavily sclerotized abdomen; basiphallus small but strongly prolonged posteriorly beyond the distiphallus base; distiphallus simple and tubular at least in basal half; male sternite 5 posteromedially concave; R2+3 strongly sinuate in winged forms; mid tibia with strong paired anterodorsal-posterodorsal bristles distally and proximally; mid tibia with only an apical bristle ventrally and palpus petiolate, gradually to abruptly expanded distally.

Relationships. Winged Howickia are generally superficially similar to Paralimosina species, which also have posteroventral hypandrial lobes. Paralimosina species, however, have short female terminalia, R4+5 sinuate but R2+3 straight, mid tibia without strong paired bristles, and very different distiphallus structure.

The New Zealand species of Howickia cluster into two groups. The trilineata group, including the winged species as well as the wingless type of the genus, is diagnosed by three narrow, parallel-sided, silver frontal strips. The myersi group is less distinctive, with a relatively dark head and complete or almost complete loss of wings.

Australian species in the genus seem to fall into both groups. Assessment of phylogenetic relationships within and between these groups requires a revision of the genus as a whole, including the Australian species.

Generic diagnosis. Howickia oliveri and H. lepidostylus , the only winged species of Howickia known from New Zealand, differ from all other New Zealand Sphaeroceridae in having a short, sinuate R2+3. All other New Zealand Howickia are wingless or effectively wingless, and all wingless Sphaeroceridae in New Zealand belong in Howickia . Orbital and interfrontal bristles are variously reduced, often absent, in wingless forms. Ocelli are present but often minute and indistinct in wingless forms. The eyes are large and distinctly notched along the anterodorsal margin (at level of antennae). Wings are usually completely absent but are sometimes retained as a short, darkened, veinless flap of tissue. Halteres are usually present, but are lost in most of the wingless species in the H. trilineata group. New Zealand species in the genus have a single pair of dorsocentral bristles but Australian species (including the type) often have two pairs. The mid tibia always has proximal and distal pairs of anterodorsalposterodorsal bristles, often with additional smaller bristles above the anterodorsals. All species lack a midventral mid tibial bristle and all New Zealand species have an apical ventral mid tibial bristle, although it is usually smaller in the male and is greatly reduced in males of some Australian species. The first two tarsomeres of the hind tarsus are strongly swollen, together longer than the distal three tarsomeres.

Male terminalia: Hypandrium with Y-shaped main part with main posterior lobes asymmetrical and fused with the anteroventral epandrial corners; a generally broad and U-shaped posteroventral lobe; a narrow but distinct and well sclerotized posterodorsal apodeme extending from the top of the main stem of the hypandrium to the anterobasal part of the distiphallus. Sternite 5 variable, usually posteromedially concave but sometimes with posteromedial lobes, combs or bristles. Surstylus variable, with or without short, stout bristles. Cercus small, usually divided into flat inner parts forming a partial or complete subanal plate and convex, rounded outer ventral parts. Basiphallus always projecting posteriorly into a characteristic broadly rounded epiphallus. Distiphallus relatively narrow and simple. postgonite simple, narrow, differing in detail between species.

Female terminalia (segments posterior to segment 5) narrow, elongate, largely desclerotized and telescoping into the preabdomen. Tergite 8 tripartite, divided or almost divided into three parts with setulosity usually restricted to the posterior margin. Epiproct and cerci small and tightly integrated, epiproct usually desclerotized medially. Spermathecae (3) small, spherical to elongate oval with transverse striations. Ring-like vaginal sclerites ("spectacles-shaped sclerites") usually present. Sternite 8 usually distinct, posteriorly setulose. Hypoproct relatively large, microtrichose and setulose along posterior margin, anterior part often projecting into the abdomen as a bare plate or bare lateral arms.