Thraxan misatulus Yeates & Lambkin, 1998

Li, Xuankun, Yuan, David, Rodriguez, Juanita & Yeates, David K., 2019, Sand wasp (Hymenoptera: Crabronidae) parasites emerging from mud wasp nests (Hymenoptera: Sphecidae) - a reliable host record of Thraxan Yeates & Lambkin (Diptera: Bombyliidae: Anthracinae) with description of the pupal exuviae of three Thraxan species, Zootaxa 4609 (1), pp. 149-159 : 152-156

Thraxan misatulus Yeates & Lambkin, 1998

( Fig. 3 )

Thraxan misatulus Yeates & Lambkin, 1998 . Type-locality: Australia (Qld); Holotype ♂, ANIC.

Specimens examined. Australia, Qld., ♂ Pupal exuvia, bat cave. Boonah, October 1957, P.R. Wilkinson .

Description. Pupal exuvia. Length: 17.9 mm. Head width: 3.0 mm. Thorax width: 4.1 mm. Abdominal width: 4.5 mm, tapering to 0.7 mm at width of anal segment. Coloration. Predominantly pale yellow, spines dark brown to black. Head. Armed with 3 pairs of cephalic spines. One anterior antennal process (aap) present, base area with one dorsal long hair and one lateral long hair ( Figs 3g, h ). Two posterior antennal processes (pap) present, two pap slightly shorter than aap ( Figs 3g, h ). One median facial hair (mfha) present, one frontal spine (fsp) present. Labral sheath (lsh) with a small ventral subapical process. Proboscidal sheath (prsh) short, about 0.5 length of lsh, slightly rugose laterally. Maxillary sheath (msh) smooth, extending and connecting well after prsh. Palpal sheath (pash) rugose, extending slightly over lsh ( Figs 3c, d ). One posterolateral facial hair (plfha) present. Thorax. Mostly smooth, one small posterior mesothoracic callosity (pmc) present. Thorax with one long hair located anterior of pmc, one long hair located above pmc, and two pairs of dorsal hairs. Wing sheath (wsh) and base half of leg sheaths (lesh) smooth, apex half of lesh rugose ( Fig. 3d ). Wsh reaching abdominal segment 3. Fore leg sheath (lesh 1) exceeding apex of wing sheath, reaching abdominal segments 3, mid leg heath (lesh 2) reaching abdominal segment 4, hind leg sheath (lesh 3) reaching abdominal segment 5. Abdomen. Eight abdominal segments visible, segments 8 and 9 fused ( Fig. 3b ). Abdominal tergite 1 with a row of sparse long hairs. Abdominal tergites 2 to 6 with well-developed chitinous rods with both apexes raised as spines on tergites 2 to 5, and posterior apex raised as spines on tergite 6, and with short spines on tergite 7; long hairs present laterally and between two chitinous rods or spines on tergites 2 to 7 ( Fig. 3e ). Tergite 8+9 with one dorsal spine, one lateral spine, and one posterolateral callosity. Abdominal pleuras 2 to 7 each with a cambered row of long hairs, pleura 8+9 with four long hairs. Sternites 2 to 7 and 8+9 with a transverse row of hairs on posterior half. Anal segment smooth, some ventral small callosities present ( Fig. 3j ). Dorsal posterolateral process (dpp) small and fused, ventral posterolateral process (vpp) elongate, acute with one inboard spine, dorsal area with one dorsal spine and two ventral spines ( Figs 3i, j ).

Host. Based on the label: "ex mud cocoon of large psammocharid, with pupal case" ( Hymenoptera : Pompilidae ).

Remarks. Because of the “mud” provenance of the host record, this pompilid species probably belongs to the tribe Ageniellini , which are the only Australian pompilids known to use pre-existing or build mud-nests ( Elliot 2007). Currently the tribe includes three genera, Macromeris , Phanagenia and Auplopus . Macromeris includes a single species with large individuals (> 25mm) and the remaining two genera together include more than 20 species with smaller individuals (<10mm). Given the size recorded in the label data, presumably this record corresponds to a Macromeris violacea (Lepeletier) mud nest.

Figures

FIGURE 3 Thraxan misatulus Yeates & Lambkin. Male Pupal exuvia: (a) dorsal; (b) lateral; (c) head, ventral; (d); head and thorax, ventral; (e) abdominal segments 2 to 4, dorsal; (f) cephalic spines, dorsal; (g) cephalic spines, frontal; (h) cephalic spines, lateral; (i) anal segment, dorsal; (j) anal segment, ventral. Scale bars = 1 mm (c, e–j); = 0.1 mm (a, b, d).