Zalea clava, McAlpine, 2007

McAlpine, D. K., 2007, The Surge Flies (Diptera: Canacidae: Zaleinae) of Australasia and Notes on Tethinid-Canacid Morphology and Relationships, Records of the Australian Museum 59 (1), pp. 27-64 : 56-57

Zalea clava n.sp.

Figs 72–75

Material examined. HOLOTYPE!, Western Australia: Cable Beach (foot of cliffs W of beach), S of Albany (35°07'02"S 117°53'51"E), 29–30.xi.1998, B.J. D., D.K.M. ( WAM) . PARATYPES. Western Australia: 4??, 3!!, same data as holotype ( AM, USNM) ; 1?, 2!!, Canal Rocks, near Yallingup , 33°39'42"S 115°00'35"E, 23.xi.1998, B.J. D., D.K.M. ( AM) ; 1?, Ellensbrook Beach, near Margaret River , 33°54'17"S 114°59'16"E, B.J. D., D.K.M. ( AM) .

Description (?,!). General characters as given for subfamily and for genus Zalea .

Coloration generally as given for Z. dayi . Thoracic pleura greyer than in Z. dayi ; mesopleuron with little or no brown suffusion. Legs, especially femora, greyer than in Z. dayi ; tarsi brown to tawny-brown.?: anterior surstylus tawny, more shining on outer surface than in Z. minor and Z. dayi , through more restricted pruinescence.!: paired sclerites of sternite 7 predominantly black, grey-pruinescent only at posterior extremities; tergite 7 pruinescent, brownish grey; sternite 7 largely shining black; cercus brownish, usually darker both apically and near base.

Head. Height of cheek c. 0.26–0.32 of height of eye; postvertical bristles subparallel to slightly divergent.Antenna similar to that of Z. minor and Z. dayi in proportions. Palpus clavate, much more thickened distally than in other Zalea spp. , and usually distinctly more than half as deep as cheek or antennal segment 3 (though depth of both these rather variable).

Thorax. Chaetotaxy and most leg characters as for genus. Mid femur of male with loose distal comb of variably short, thick posteroventral bristles, either all quite blunt or some pointed; mid femur of female without differentiated posteroventral bristles. Fore tibia with one long dorsal bristle slightly beyond mid-length; mid tibia with one long dorsal bristle near mid-length; hind tibia often with few irregular long setulae or fine bristles. Vein 2 usually more strongly arched than in Z. minor ; cell-4 index = 0.58–0.65.

Abdomen. Male: anterior surstylus very elongate, pruinescent, but extensively smooth and shining on outer surface; posterior surstylus not pruinescent, narrowly obtuse at apex, with long-setulose anterior gibbosity beyond base; hypandrium and aedeagus resembling those of Z. minor ; posterior papilla of aedeagus smaller; distiphallus with denticles finer and less dense, and without distinctly pigmented longitudinal strips. Female: sternites 3 to 6 broader than in Z. minor and Z. major , but much less so than in Z. dayi , all undivided; tergite 7 undivided, somewhat sclerotized and pigmented across whole width, but weakly sclerotized centrally and on posterior margin, with broad, strongly sclerotized plate on each side, and with lateral arms of anterior apodeme short; paired sclerites of sternite 7 much broader than in Z. minor and Z. major , quite narrowly separated medially.

Dimensions. Total length,? 1.8–1.9 mm,! 2.1–2.4 mm; length of thorax,? 0.77–0.90 mm,! 0.86–0.96 mm; length of wing,? 1.8–2.0 mm,! 2.0– 2.2 mm.

Distribution. Western Australia: southern coast, S of 33°30'S.

Notes

Zalea clava is distinguishable from all other Zalea spp. by its very strongly clavate palpus. It is the only known Australian species with a long dorsal bristle on the fore and mid tibia, and, unlike the New Zealand, species this is an isolated bristle near or slightly beyond mid-length.

The specific epithet is a Latin noun referring to the clavate palpus.