Tryella crassa, Moulds, 2003

Moulds, M. S., 2003, An Appraisal of the Cicadas of the Genus Abricta Stål and Allied Genera (Hemiptera: Auchenorrhyncha: Cicadidae), Records of the Australian Museum 55, pp. 245-304 : 283-284

Tryella crassa n.sp.

Figs. 23, 61a–e, 78, 81, 82

Types. Holotype 3, K179830, 16 km E of Cloncurry , N Queensland, 19.i.1984, M.S. & B.J. Moulds; in AM . Paratypes as follows: NORTHERN TERRITORY —2 33, K179831 and K179833, 1♀, K179832, Kalkaringi , 17°26'54"S 130°50'05"E (gps), 10.i.2001, MBM ; all in AM. 1♀, Kalkaringi , 17°26'54"S 130°50'05"E (gps), 10.i.2001, MBM , in BMNH. 1633, 10♀♀, Kalkaringi , 17°26'54"S 130°50'05"E ( GPS), 10.i.2001, MBM ; 13, 123 km SW of Kalkaringi , 17°45'48"S 129°52'10"E (gps), 10.i.2001, MBM ; 13 (genitalic preparation no. AB45), 80 km SW of Katherine , 6.ii.1977, MBM ; 333 (one male genitalic preparation no. AB89), 2♀♀, Mataranka Hstd , 11.i.1992, MBM ; all in MSM. QUEENSLAND —1 3, same data as holotype and allotype, ANIC . 13, same data as holotype and allotype, in BMNH . 833, 15 km E of Mt Surprise, 2.iii.1998, J. Olive and J. Thompson; all in JO. 633 (one male genitalic preparation no. AB46), 3♀♀, Lawn Hill Ck, Adels Grove, W of Gregory Downs , 19.xii.1986, 18.xii.1991, MBM ; 233, 1♀, Normanton , 15.i.1986, MBM ; 1833 (one male genitalic preparation no. AB25); 4♀♀, same data as holotype; 633, 3♀♀, 20 km W of Cloncurry , 20.i.1984, MBM ; 333, Selwyn Mine , 160 km SE of Mt Isa, 21.ii.1991, 26.i.1995, 30.i.1997, T . Woodger; 1233, 3♀♀, 40 km W of Georgetown , 16.i.1992, MBM ; 1133 (one male genitalic preparation no. AB9), 4♀♀, Bruce Hwy, nr Salt Water Ck , 20 km S of Home Hill, 22.xii.1987, MBM ; all in MSM. 13, 1♀, same data as holotype and allotype, both in QM .

Etymology. From the Latin crassus meaning thick, fat or stout and pertaining to the stocky build of this species.

Description

Male ( Figs. 23, 61a,c, 81, 82). Head. Dark ferruginous usually partly tending black and usually a little darker than thorax, occasionally almost entirely black except for postclypeus; postclypeus always ferruginous brown and usually lighter in tone than thorax; anteclypeus ferruginous brown to nearly black but usually with midline entirely or partly of a lighter tone. Rostrum brown and black to varying degrees but usually brown basally becoming black towards apex and often with extreme apex brown; not quite reaching bases of hind coxae. Eyes of live specimens light grey with no distinct pseudopupil. Antennal plates well developed and when viewed from directly in front covers most of antennal segment 1. Antennae usually black but sometimes partly brown. Often bearing some silver pubescence most obvious below. Thorax. Pronotum dark reddish brown to dark ferruginous, usually unicolorous but on some individuals midline marginally darker or paler; pronotal collar usually a little darker than remainder, sometimes tending blackish. Mesonotum similar in colour to pronotum; virtually concolorous but some individuals with a very faint obconical marking each side of midline against anterior margin. Thorax above often bearing a little silver pubescence. Thorax below similar in colour to above and nearly always with an obvious covering of silver pubescence. Wings. Hyaline but usually with a faint brown suffusion. Fore wings infuscated at bases of apical cells 2 and 3, usually appearing as a continuous zigzag but sometimes as two spots confined to crossveins; some individuals also infuscated at apical cell 1 partly or entirely along length of vein R1b; venation brown, costa light yellowish brown; basal cell tinted brown, usually darker than tint on remainder of the wing; basal membrane light yellowish brown; lacking silver pubescence obvious to naked eye. Hind wings with a distinct infuscation at distal end of vein 2A which sometimes extends partially around margin of anal lobe; often a small infuscation near centre of wing at base of apical cell 4; basal half or so of anal lobe weakly tinted brown similar to the tint of fore wing basal cell; plaga off-white; venation from light brownish yellow to brown. Legs. Dark reddish brown to dark ferruginous, similar in tone to that of thorax; without noticeable markings. Opercula. Pale muddy yellow to dark brown tending black; often bearing some fine silver pubescence usually discernible to the naked eye; clearly separated exposing apex of sternite I and barely concealing tympanal cavities. Abdomen. Tergites dark reddish brown to dark ferruginous, similar in tone to that of thorax; tergite 8 usually with its posterior margin narrowly edged black at least across dorsal half. Sternites variable between individuals, sometimes entirely brown, sometimes with pale posterior margins and sometimes with black posterior margins, the distal half or so of sternite VII nearly always dark.Abdomen above and below often with some fine golden pubescence. Tymbals ( Fig. 23). Usually 10 long tymbal ribs, otherwise as for generic description. Genitalia ( Figs. 81, 82). Pygofer dark reddish brown to dark ferruginous; upper pygofer lobes in lateral view clearly subdivided with a large, broad, rounded basal section behind which continues an apical section that tapers to a blunt rounded point, in ventral view tilted slightly inwards with the subdivision of terminal sections clearly visible externally as a stepped profile; basal lobes without webbing fusing inner and outer lobes, outer lobe in lateral view like a very long thin finger, gently curved, nearly equal in length to upper pygofer lobe. Uncal lobes scooplike and gently upturned at their distal ends; lateral processes of uncus in lateral view nearly equal in length to upper pygofer lobes, nearly straight, broadly rounded at apex. Conjunctival claws directed laterally, the distal end of each bearing three sharply-pointed teeth, the central tooth longest. Flabellum absent. Palearis absent.

Female ( Figs. 61b,d,e). Colour and markings similar to male. Abdominal segment 9 similar in colour to abdomen and thorax; dorsal beak usually darker and sometimes black. Ovipositor sheath dark brown to black and clearly extending beyond dorsal beak.

Measurements. n = 1033, 10♀♀ (includes smallest and largest of available specimens). Length of body: male 15.5– 23.8 (19.9); female 17.7–24.8 (20.6). Length of fore wing: male 20.2–29.2 (24.7); female 21.6–30.5 (25.2). Width of head: male 5.1–7.3 (6.3); female 5.4–7.5 (6.5). Width of pronotum: male 6.0–8.8 (7.6); female 6.5–9.0 (7.8).

There are notable differences in size, both within and between populations. Of the limited material available those specimens taken near Cloncurry in January 1984 are largest and very much larger than specimens taken near Georgetown in January 1992. Specimens from Mataranka, Northern Territory, and near Home Hill, northeastern Queensland, are also smallish while those from Adels Grove, northwestern Queensland, are intermediate in size. Size, therefore, shows no geographic trend and is very likely a consequence of availability of nymphal food.

Distinguishing features. The uniform body colouration of this species, combined with its lightly tinted wings, makes confusion with any other Tryella species unlikely. It is most similar to occidens, noctua and some individuals of stalkeri , but none of these species occurs sympatrically with crassa . Tryella crassa is immediately distinguished from occidens, noctua and stalkeri by the lack of fore wing infuscation anywhere across the base of apical cell 4; the infuscation on crassa never passes beyond the base of apical cell 3.

Distribution ( Fig. 78). Inland regions of monsoonal Northern Territory, where it is known from 80 km SW of Katherine, Mataranka Homestead and the headwaters of the Victoria River, and drier regions of monsoonal Queensland south of the Gulf of Carpentaria to Selwyn mine (160 km SE of Mt Isa) and east almost to Georgetown and far eastern Queensland at Salt Water Creek, 20 km south of Home Hill. Adults emerge after the first heavy summer rains and tend to be very local. There are records from mid December to late February.

Habitat. Adults appear to favour shrubs and low eucalypt saplings where they are usually found on the smaller branches or amongst foliage. However, the populations from 20 km south of Home Hill, Queensland, and from Kalkaringi, NT, were almost exclusively confined to grass in areas where there was a total or substantial absence of trees and shrubs. The species may in fact breed upon grass and males may seek higher advantage points when available from which to call.

Song. Singing occurs both during the day and at dusk. Day calling, however, may be restricted to overcast or partly overcast conditions as I have never heard singing on hot sunny days except at dusk. The dusk call is always vigorous. An analysis of the song is under study (Moulds, in prep.).

Biology. Mature nymphs are golden brown and glossy except for abdomen below; wing pads light yellowish brown; a dark brown area each side of midline on pronotum; brown patch each side of midline on abdominal segment 8; legs golden brown with fore leg claws dark brown; eyes grey.