Buerelius Clay & Tandan 1967

Buerelius Clay & Tandan, 1967

Docophorus Nitzsch, 1818: 289 (in partim). Buerelius Clay & Tandan, 1967: 34.

Type species. Docophorus longiceps Piaget, 1880: 663, by original designation.

Diagnosis. In the phylogeny of Bush et al. (2016), Buerelius was placed as a sister to Couala n. gen. Both of these genera share the following characters: female subgenital plate (Figs 511, 517, 523) broad, trapezoidal, not reaching vulval margin, cross-pieces absent; vos much longer than vms (Figs 511, 517, 523); mesosome at least partially fused to basal apodeme (Figs 516, 522). However, the two genera are separated by the following characters: marginal carina interrupted medianly in Buerelius (Fig. 509) but not in Couala (Figs 514, 520); dorsal preantennal suture and ventral anterior plate present in Buerelius (Fig. 509) but absent in Couala (Figs 514, 520); mst2 ventral, thorn-like or curved in Couala (Figs 514, 520), but lateral microseta in Buerelius (Fig. 509); parameres fused to mesosome in Couala (Figs 516, 522) but not in Buerelius (Clay & Tandan 1967: figs 5–7). The shape of the dorsal preantennal suture of Buerelius (Fig. 509), the presence of a clearly delimited ventral anterior plate combined with the absence of a dorsal anterior plate are unique within the Brueelia -complex. The male genitalia of Buerelius (not illustrated) are also dissimilar to those of any other genus treated here.

Description. Both sexes . Head bulb-shaped (Fig. 509). Marginal carina completely interrupted medianly. Hyaline margin continuous with broad dorsal preantennal suture that reaches to lateral margin of head, but not ads. Pattern of suture unique within the Brueelia -complex. Premarginal carina plates present. Ventral anterior plate present, crescent-shaped. Ventral carinae diffuse anterior to pulvinus, not clearly continuous with marginal carina. Head setae as in Fig. 509; as3 absent. Coni large, pointed. Antennae monomorphic. Temporal carinae diffuse but present; mts 3 only macrosetae. Gular plate spade-shaped, not prominent.

Prothorax rectangular (Fig. 510); ppss on postero-lateral corners. Proepimera broad, median ends blunt. Pterothorax pentagonal; lateral margins divergent; posterior margin convergent to median point; mms moderately separated medianly. Meso- and metasterna not fused; 1 seta on postero-lateral corner of mesosternum on each side; 2–3 setae on postero-lateral corner of metasternum on each side. Metepisterna broad, median ends blunt. Leg chaetotaxy as in Fig. 25, except fI-p2–4, fI-v4, fII-v2, fIII-v2, fIII-a4 absent.

Abdomen broadly oval (Fig. 510). Abdominal chaetotaxy as in Table 2. Tergopleurites rectangular; tergopleurites II–X+X in male and tergopleurites II–VIII in female moderately separated medianly. Sternal plates small, crescent-shaped, not approaching pleurites. Pleural incrassations slender. Ventral sections of tergo-pleurites moderate. Re-entrant heads small, blunt. Male subgenital plate long, rectangular, reaching terminal margin of abdomen. Female subgenital plate slender, triangular, approaching vulval margin. Vulval margin (Fig. 511) with short, slender vms, long, slender vss; vos follow lateral margins of subgenital plate; distal vos median to vss.

Basal apodeme (not illustrated, see Clay & Tandan, 1967) rectangular, anterior margin rounded. Proximal mesosome small, quadratic, often indistinct, may be partially fused to basal apodeme. Gonopore terminal, open distally. Mesosomal lobes small, with wide marginal thickenings; 2–3 ames microsetae antero-lateral to gonopore; 2 pmes microsetae on postero-lateral margins of mesosome. Parameral heads bluntly cup-shaped. Parameral blades broad, finger-like; pst1–2 sensilla, both central.

Host distribution. Known only from Brachypteracias leptosomus (Lesson, 1833), which is host to both species of Buerelius. Species of this louse genus may also occur on other members of the Brachypteraciidae, but more collections are needed to test that hypothesis.

Geographical range. Madagascar.

Remarks. Buerelius was well described and illustrated by Clay & Tandan (1967) and the species are not redescribed or fully illustrated here. Clay & Tandan (1967: 39) described the second species “with some hesitation”, owing the unusual peculiarity of having two closely related louse species from the same host species. The two species are very similar except for the preantennal area (see photos in Clay & Tandan 1967). We illustrate only the female of Bu. longiceps (Figs 509–511), as the male of this species was well illustrated by Clay & Tandan (1967).

Included species

* Buerelius longiceps (Piaget, 1880: 663) [in Docophorus] * Buerelius subsimus Clay & Tandan, 1967: 38