Zinza grandis, Bradley, 1995

Sinclair, Bradley J. & McAlpine, David K., 1995, Zinza, a New Genus of Rhinotorine Flies from Northern Queensland, Australia (Diptera: Heleomyzidae), Records of the Australian Museum 47 (3), pp. 225-230 : 227-230

Zinza grandis n.sp.

Figs 1-4, 7, 8

Material examined. HOLOTYPE male. North Queensland: 4 km up Mount Edith Road , near Tinaroo Dam , 800 m, 17°05'S 145°38'E, fruit trap, 22-27 Apr. 1994, M.S. Moulds & B.l. Sinclair ( AMS) . PARATYPES: North Queensland: 1 male, same data as holotype ( ANIC) ; 1 female, Longlands Gap, Atherton district , 1150 m, 1r28'S 145°29'E, Malaise trap, Feb.-Mar. 1995, P. Zborowski ( AMS) .

Description. Coloration: head pale yellow; frons shiny gold, with 2 black spots at base of antennae; ocellar triangle dark; vertex with black spot on either side of postverticals; dark spot at base of vibrissa, larger and more distinct in female; scape, pedicel and basal half of first flagellomere brown; ventral surface of first flagellomere mostly pale yellow, less extensively so in female; palpus pale yellow with dark apical setae; proboscis brown. Thorax fulvous; mesoscutum with symmetrical patches of pale yellow, including postpronotal lobe; scutellum brown with median apical yellow marking; pleura with weak brown horizontal stripe on upper margin of proepisternum and anepisternum, brown mark above fore coxa, weak brown stripe across lower margin of anepisternum, upper half of katepisternum, anepimeron, meron, and katatergite. Fore and mid coxae yellow, hind coxa and trochanter brown; fore and mid femora yellow, hind femur brown; apices of femora with black band; tibiae with subbasal and apical black bands; tarsomeres 1-4 yellow, tarsomere 5 dull brown. Wing: membrane yellowish, more intensely so towards base; brown spot on crossvein r-m and Rs fork, crossing cell rl; small brown spot at apex of cell bm; smoky suffusion present around crossvein dm-cu and wing apex. Haltere pale yellowish. Abdomen bright golden yellow; lateral margins of tergites 1-2 with brown suffusion.

Head ( Fig. 1 ): ocellar and postocellar regions forming slight longitudinal convexity within broader frontal excavation; face concave in profile, with lower margin very prominent; postvertical bristle much longer than ocellar; fronto-orbital bristles 2, posterior one short but distinct, anterior one smaller, sometimes little differentiated from frontal setulae. First flagellomere subcircular, compressed. Clypeus shallow, but anteriorly prominent; proboscis elongate, with small apparently membranous labella.

Thorax somewhat elongate; scutellum without setulae, shape somewhat resembling that of Neorhinotora aristalis (Fischer) (Figs 6,7), with slight longitudinal ridge on each side of dorsal channel, concavity on each side between anterior and posterior bristles, and slightly bigibbous apex; prosternum narrow, weakly sclerotised. Chaetotaxy: 1 humeral, 2 notopleurals, 1 supra-alar, 1 postalar, 1 posteriorinter-alar, 1 posterior dorsocentral, 2 scutellars; acrostichal, proepisternal, and anepisternal bristles absent; katepisternum with 2 widely spaced bristles and long setulae. Males with mollisetae (see D. McAlpine [1991: 31] for definition) on ventral surface of katepisternum, metasternum, mid and hind coxae, and ventral surface of fore femur; hind trochanter simple (lacking brushed tubercle, present in males of Zentula species). Fore femur with several dorsal bristles; mid femur with several anterior bristles near and beyond middle; male mid femur with small socket-based ovoid anteroventral peg just beyond basal third; hind femur with few dorsal bristles and rather dense ventral setulae; male hind femur stout, apparently raptorial; female hind femur broad, longer than mid femur; fore and hind tibiae shorter than femora, slightly curved with subangular basal thickening; mid tibiae with several short, thick ventroapical spur-like bristles, among which one (female) or 2 (male) form longer spurs; all tibiae with large ventroapical bight (only slightly developed in other rhinotorines, presumably enabling tarsus to be sharply flexed ventrally against tibia); fore basitarsus slightly depressed; mid basitarsus subcylindrical; hind basitarsus obliquely compressed; tarsomeres 1-4 of mid leg with ventrolateral comb of stout black bristles. Wing: cell r1 without supernumerary crossveins.

Abdomen: tergites 2-5 with long, silky golden lateral setae; sternite 1 well sclerotised, quadrate, setulose laterally.

Male postabdomen (Figs 2,3): protandrial sclerites resembling those of Cairnsimyia uniseta D. McAlpine (see D. McAlpine, 1985, fig. 92); tergite 6 reduced, bare, separate from other sclerites; one large spiracle on either side of tergite 6, remaining spiracles absent; small sclerite present on right side of sternite 8; epandrium with long mollisetae; surstylus trilobed, apical lobe with short bristles; ventroapical lobes of hypandrium with dense patch of dark bristles;.gonostylus laterally compressed, apically expanded; ejaculatory apodeme slender with T-shaped base; basiphallus forming slender sclerotised rod; distiphallus with complex sclerotisation, anteriorly reflexed; cerci short, rounded, fused anteroventrally, with long dark undulating bristles.

Female postabdomen: sternite 6 divided by median desclerotisation; cerci short, slender, well separated and free distally. Two spermathecae on common duct plus slightly smaller spermatheca on separate duct, each with irregular outer envelope and subspherical, almost smooth black cuticular lining ( Fig. 8 ); black pigment decurrent for short distance on lining of duct; duct deeply inserted into vesicle (at least in single spermatheca, paired ones too intensely pigmented to enable interpretation of internal structure), with cellular (?muscular) envelope in part much thickened proximally to vesicle. Egg whitish, elongate-ovoid, roughly bilaterally and biterminally symmetrical, except for slight impression at one end from which a small cup-shaped structure protrudes; surface with numerous prominent longitudinal ridges, over 20 at mid-length, some of them not reaching ends, otherwise apparently without external processes; length 1.2 mm, width 0.44 mm.

Dimensions: total length, male (abdomen deflexed) 7.7-7.8 mm, female 9.7 mm; length of thorax, male 4.4 mm, female 4.7 mm; length of wing, male 9.7- 9.8 mm, female 10.0 mm.

Etymology. The specific epithet " grandis " refers to its much larger size compared to species of Cairnsimyia and Zentula .

Distribution

This species is known only from the Atherton Tableland, which rises more than 600 m above the coastal plain south-west of Cairns in northern Queensland. The Atherton Tableland is one of a series of temperate areas that represent a mesothermal "archipelago". Mesothermal refers to a plant group with optimum temperatures for growth of 19-22°C ( Nix, 1991). In northern Queensland, tropical and subtropical lowlands separate the tablelands (or mesothermal "islands") from similar mesothermal areas of montane New Guinea and southern Australia. These mesothermal environments of northern Queensland represent regions of high endemism in both vertebrates ( Nix, 1991) and invertebrates.

Of the five other heleomyzid species known from the Atherton Tableland (including the less elevated Kuranda district) only one, Diplogeomyza immaculata D. McAlpine , appears to be endemic (D. McAlpine, 1967). Three others, Diplogeomyza tridens D. McAlpine, D. signata D. McAlpine, and Cairnsimyia cavifrons Malloch , extend from the Atherton Tableland southwards into New South Wales. Pentachaeta sp. (undescribed "sp. E" in AMS) extends from Kuranda, at the northern edge of the Tableland, south to the Clarke Range-Eungella district (c. 2l01O'S), and is thus probably restricted to mesothermal areas of the tropics. Other Pentachaeta species are restricted to temperate Australia.

Biology

Specimens from Mount Edith Road were collected in a banana baited fly trap, suspended approximately 1.5-2 m above the ground in upland rainforest. The fly trap is similar to a lobster trap, consisting of a nylon mesh cylinder, with bait suspended near the bottom. The insects are caught alive and removed from the trap using an aspirator.

Comparative notes

Zinza conforms to the description of the tribe Rhinotorini (D. McAlpine, 1985) except that the arista is longplumose and inserted slightly closer to the base than to the apex of first flagellomere. Within this tribe, Zinza belongs in subtribe 1 as characterised by D. McAlpine (1985: 232-233), although the description must be extended to include forms without scutellar setulae ( Figs 5-7 ). This subtribe includes the two other Australian genera Cairnsimyia and Zentula , whereas subtribes 2 and 3 include only New World taxa.

The distinctive subtruncate, dorsally channelled scutellum resembles that of the Neotropical rhinotorine genus, Neorhinotora Lopes ( Fig. 6 ). In addition, M] is also strongly curved forward distally to meet R4+S in the Chilean genus Mayomyia Malloch ( Malloch, 1934, fig. 11). However, Zinza is only distantly related to these two genera, the latter genus belonging in a distinct tribe (Mayomyiini).

The small ventral peg on the mid femur of Zinza has not been observed in other rhinotorine taxa, and is malerestricted. As in many other schizophoran flies, mollisetae in this genus are much less developed in females.

Hennig (1958) recorded two spermathecae for Rhinotora pluricellulata Schiner (sic), and J. McAlpine (1987) described and figured two spermathecae for Neorhinotora diversa (Giglio-Tos) . As two and three are both frequent spermathecal counts in Heleomyzidae (four in some Suillia species), and as both numbers are present in the tribes Heleomyzini and Allophylopsini ( Hennig, 1958; Schneider, 1982; pers. obs. D. McAlpine), it is not surprising that this variation should be present in Rhinotorini . The egg of Zinza grandis differs greatly from those of Rhinotora and Neorhinotora as figured by Lopes (1935, figs 1-3).

Figures

Figs 1-7. 1, Zinza grandis head. 2, Z. grandis epandrium, sursty!us, cercus. 3, Z. grandis hypandrium, phallus, ejaculatory apodeme. 4, Z. grandis wing. 5, Cairnsimyia sydneiensis D. McAlpine scutellum. 6, Neorhinotora aristalis (Fischer) scutellum. 7, Z. grandis scutellum. Abbreviation: gst, gonostylus.

Fig. 8. Spermathecae of Zinza grandis. Scale TODO 0.1 mm.