Trichocolletes Cockerell, 1912

Batley, Michael, 2012, Revision of the Australian Bee Genus Trichocolletes Cockerell (Hymenoptera: Colletidae: Paracolletini), Records of the Australian Museum (Rec. Aust. Mus.) 64 (1), pp. 1-50 : 3-4

Genus Trichocolletes Cockerell

Trichocolletes Cockerell, 1912, p. 176 ; Michener, 1965, pp. 78–80. Type-species Lamprocolletes venustus Smith, 1862 (original designation).

Diagnosis

Moderately large bees (length 10–18 mm) distinguished by the following combination of characters: fore wings with three submarginal cells; pterostigma short, parallel-sided, ending at, or slightly beyond, base of vein r; basitibial plate of female hidden by setae and incompletely defined; inner hind tibial spur of female almost palmate ( Michener, 2007, fig. 39–11b), of male, ciliate and broadened basally; labrum of both sexes at least 0.4× as long as wide, usually polished and smoothly convex, occasionally tectiform; mandibles bidentate, approximately parallel sided; compound eyes of some species covered with conspicuous, long setae; metasomal terga with apical, integumental bands usually metallic gold or silver but sometimes testaceous and inconspicuous.

Descriptions

Male. Face usually quadrate (eye length equal to interorbital distance at level of antennal bases), but sometimes wider than long; clypeus transversely convex, flat or weakly convex longitudinally; glossa broad, bifid: labial and maxillary palpi usually slender, almost reaching end of glossa; labrum uniformly convex (but with a tubercle in one species), length 0.5 to 0.8× width with apical fringe of bristles; mandible bidentate, straight or gently curved, often slightly twisted about longitudinal axis; scape occasionally swollen, but usually slender; gena c. half as wide as eye viewed laterally, rarely wider; flagellum 20% shorter than to 50% longer than head width, occasionally modified apically.

Legs usually slender, occasionally modified; tarsal claws deeply cleft; fore tibial calcar usually with strong apical spine, several long, fine teeth and rounded velum; hind basitibial area usually flattened with a posterior carina, but rarely forming a distinct plate; propodeum smoothly declivous; wings with three submarginal cells, stigma short, just reaching or slightly exceeding vein r.

Terminalia: genital capsule elongate with large gonoforceps, obliquely truncated with long, plumose apical hair, occasionally with simple hair or bare (Figs 29–40); volsellae of moderate size, not enlarged as in Anthoglossa ( Michener, 1965, figs 197, 192); S8 simple with spatulate apex, narrow neck and cordate base, with only minor interspecific variation ( Figs 41–43 ); S7 variable in form and diagnostically valuable (Figs 44–79), but retaining a combination of characters unique to this genus: partially hollow lateral lobes (arrowed b and e in Fig. 44), posterior margin usually with pair of blunt, hirsute projections (arrowed a in Fig. 44), surface extensively covered with long hair, anterior margin of lobes extended into ligulate processes (d in Fig. 44), frequently with a stout triangular tooth with serrated edges near base of each ligulate process (c in Fig. 44).

Scape, labrum, mandibles medially and legs usually orange-brown; apical part of clypeus sometimes orangebrown or cream; metasomal terga sometimes wholly or partly red or orange-brown; apical bands of T1–5 usually gold, silver or white; that of T6 translucent; sterna sometimes with narrow translucent margins.

Clypeus, except ventral rim, usually densely punctate; frons and vertex finely reticulate and closely punctate; mesosoma either with a dull sheen or matt due to fine pitreticulation that is sometimes strong enough to obscure the close punctures; metasomal terga dull or weakly shining, with weak, irregular, transverse lineolation or occasionally pit-reticulation (in which case the apical bands are lineolate), frequently surface is further roughened with broad, indistinct punctures or scrobiculi.

Eyes with either conspicuous cover of long setae or nearly bare with only scattered, minute setae; face usually densely covered with orange or white hair; mesosoma excluding propodeal triangle usually conspicuously hairy; scutum with finely-branched, moderately long hair; scutellum, metanotum, mesepisternum and sides of propodeum with somewhat longer and more plumose hair, often orangebrown, becoming paler ventrally; fore basitarsus frequently with a plume of long, sinuous hair; coxae, trochanters and femora with mid-length or long, finely-branched hair, usually open but sometimes close or dense; T1 sparsely covered with long, erect, pale hair; T2 usually with similar, shorter hair; remaining terga with sparse or open simple, short, semi-erect hair matching the colour of the underlying integument (inconspicuous when viewed perpendicular to the surface, but often reflective creating a sericeus appearance when illuminated obliquely); sterna with open covering of long, semi-erect, finely-branched pale hair, rarely with dense hair tufts.

Female. As for males, except clypeus often flattened sagittally; rarely labrum tectiform; scape always slender; flagellum between 0.55× and 0.72× as long as head width, never modified.

Tibiae and basitarsi broader and flatter than in males; hind basitibial area usually obscured by dense stiff, curved setae; tarsal claws simple or with an inner ramus; pygidial plate with or without a longitudinal elevation, apex rounded or truncate, emarginate or entire.

Clypeal punctures seldom dense, interspaces often reticulate, especially towards base. Facial hair usually paler than that of male and dense only in paraocular areas and on frons; scutal hair usually shorter and duller than in male; setae of hind basitibial area usually darker than those on surrounding areas; hair of hind femur and outer face of hind tibia plumose; T5 obscured by prepygidial fimbria.

Colour variation. Colours reported in the descriptions are those for specimens in collections. The colours of some species in vivo are noticeably brighter. The thoracic hair of foraging female T. hackeri (Cockerell) , for example, may appear to be mid- to light grey, but darkens considerably within hours post mortem. Similarly, T. maximus (Cockerell) looks to have brighter orange scutal hair when flying and the sericeus reflections from T. micans n.sp. when foraging in sunlight are so bright that the metasoma appears to be covered with pollen.

New combinations

Michener (1965) listed 21 names and Houston (1990) added two more. Of these names, four are synonymized and two are removed to other genera. T. rufus is removed to Leioproctus on the basis of (a) the pterostigma, which although short, is considerably longer and wider than in any Trichocolletes species, (b) the labrum which is short (0.2× as long as wide), (c) inner hind tibial spur, which is very long and uniform in width, not basally broadened as in Trichocolletes , (d) absence of translucent apical bands on metasomal terga, (e) polished area of propodeum and (f) very short first flagellomere. The hind basitibial plate is complete and carinate, albeit weakly pigmented, though this by itself would not be a reason to exclude the species from Trichocolletes .

Trichocolletes rufopilosus is removed to Anthoglossa . The type specimen has been dissected by the original describer and the genitalia are mounted with the specimen. The greatly enlarged volsellae are typical of those found in Anthoglossa species and the type specimen was indistinguishable from an undescribed species of Anthoglossa commonly found in the Avon wheatbelt area of Western Australia. Males of this undescribed species have been collected with females having tridentate mandibles and other characteristics of Anthoglossa species.

Figures

Figs 41–43. Eighth sternum of Trichocolletes males, ventral view: (41) T. dowerinensis, (42) T. sericeus, and (43) T. serotinus n.sp.