Zalea ohauorae, 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 : 51-52

Zalea ohauorae n.sp.

Figs 56, 57

Material examined. HOLOTYPE?, New Zealand: Ohauora (or Rocky Point), White Island, North Island vicinity, 6.xii.1966, K.A.W. ( AMNZ). “Swept shore landing”. Drymounted on subtriangular card, genitalia in microvial.

Other material. 1!, same data as holotype ( AMNZ) .

Description (based on?, except where indicated). Very similar to Z. johnsi , agreeing with description of that species, except where indicated.

Coloration. Anterior part of postfrons tending to yellowish brown, but not on a defined zone. Palpus tawny.

Head (slightly collapsed in holotype) probably essentially similar to that of Z. lithax ; vibrissa longer than Z. lithax and Z. johnsi (see comments below); postvertical bristles probably convergent (displaced in holotype, strongly convergent in associated female).

Thorax. Wing: cell-4 index = 0.55 (0.53 in associated female).

Abdomen. Epandrium with pair of distinct bristles near anterior margin; anterior surstylus slender, rod-like, its apex rounded, slightly expanded, compressed, and curved posteriorly, with some moderately large setulae on inner surface, those near base relatively stout, distal ones slender and quite long, with short microtrichia confined to roughened area at apex; posterior surstylus relatively broad basally with posterior gibbosity, distally slender and scarcely compressed, basal part with irregular group of very large setulae, particularly on posterior part of inner surface, distal part with smaller scattered setulae, with microtrichia concentrated near middle of outer surface; cercus small, with few setulae.

Dimensions. Total length,? c. 1.4 mm (! 1.6 mm); length of thorax,? 0.62 mm (! 0.68 mm); length of wing,? c. 1.3 mm (! c. 1.5 mm); length of vibrissa,? 0.10 mm (! 0.11 mm).

Distribution. New Zealand: North Island vicinity. There has been little collecting on White Island, an active volcano, c. 50 km from the shore of North Island in the Bay of Plenty and difficult of access (see Parham, 1973: 19, 119). The habitat of Z. ohauorae may have been altered recently by ash clouds (K.A.W. in litt.). There is at present no reason to assume that Z. ohauorae is endemic to White Island.

Notes

As with other New Zealand species having convergent postvertical bristles, this species can only be recognized reliably by male genitalia characters. The holotype and one of the two females from the same locality have longer vibrissae than most specimens I assign to Z. lithax (measurements given above), but this measurement is not consistent in other species.As indicated above, female abdominal characters are useful for separating Z. johnsi , Z. lithax and Z. horningi , but good fresh material with abdominal segments extended has not been available for this and some other species.

The specific epithet refers to the type locality and is treated as a Latin noun in the genitive case.