Zalea lithax, 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 : 52

Zalea lithax n.sp.

Figs 58, 59

Material examined. HOLOTYPE?, New Zealand: Whangaparapara Harbour , Great Barrier Island, North Island vicinity, 21.iii.1973, K.A.W. ( AMNZ). “Swept stony beach W. side.” Dry-mounted on subtriangular card, genitalia in micro-vial . PARATYPES. North Island vicinity: 2??, 1!, same data as holotype ( AM, AMNZ) ; 3??, 5!!, Medlands Beach , Great Barrier Island, 4.xi.2001, J.W.E ( AM, AMNZ) , in alcohol; 3??, 3!!, Awana Bay , Great Barrier Island, 19.ii.2002, J.W.E. ( AM, AMNZ) , in alcohol; 1?, Takou Bay (35°6.3'S 173°56.7'E), 7.x.2002, D.M., W.N.M. ( NZAC) ; 5??, Whananaki South (35°31.1'S 174°27.2'E), 6–8.x.2002, D.M., W.N.M. ( NZAC, USNM, AM) ; 1?, Sandy Bay (35°33.4'S 174°28.5'E), 6.x.2002, D.M., W.N.M. ( USNM) .

Other material. South Island: 4??, Cable Bay , Nelson district (41°09.6'S 173°24.9'E), 13.ii.1998, W.N.M. ( NZAC, USNM, AM) .

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

Coloration. Hypofacial only indistinctly darkened. Palpus dull yellow. Thorax and abdomen as described for Z. johnsi . Female: tergite 7 lightly pigmented, with only the narrow apodeme dark.

Head. Height of cheek 0.15–0.22 of height of eye; postvertical bristles rather small, strongly convergent; vibrissa rather short, but not much shorter than anterior peristomial bristles.

Thorax. Wing: cell-4 index = 0.52–0.56.

Abdomen. Male: epandrium with pair of moderately distinct, widely spaced bristles near anterior margin; anterior surstylus slender, rod-like, curved, rounded and compressed at apex, not as long nor as markedly posteriorly directed on distal part as in Z. johnsi , with only very fine scattered setulae, except for one or two longer ones on inner surface near base, with microtrichia restricted to inner surface near apex; posterior surstylus extensively microtrichose, more elongate than in Z. johnsi and Z. horningi , about as long as anterior surstylus (though appearing shorter in Fig. 58), very obtuse at apex, with posterior sub-basal gibbosity, with very few fine setulae anteriorly, and coarser setulae posteriorly, including some on and near posterior gibbosity; cercus short. Female: sternite 1 vestigial; sternites 4 to 6 medially little sclerotized and more or less divided in two; tergite 7 with relatively small anterior apodeme, spreading into broad rami posteriorly, each of which is confluent with a rather broad posterolateral plate; sternite 7 forming pair of plates, each separated from tergite by narrow pleural membrane.

Dimensions. Total length,? 1.3–1.5 mm,! 1.5 mm; length of thorax,? 0.55–0.61 mm,! 0.57–0.68 mm, length of wing,? 1.2–1.5 mm,! 1.5–1.6 mm.

Distribution. New Zealand: North Island vicinity—Great Barrier Island and Northland. South Island—far north.

Notes

Recognition of this species depends largely on postabdominal characters in both sexes, but there is no evidence of such closely related species as Z. mathisi and Z. ohauorae inhabiting Great Barrier Island or the vicinity.

The specific epithet is a Greek adjective meaning stony, in reference to the habitat.