Chidaea sidnicus ( Stål, 1859 ) Löcker & Holzinger, 2019

Löcker, Birgit & Holzinger, Werner E., 2019, Revision of the Australian planthopper genus Chidaea Emeljanov with a redescription of Cixius sidnicus Stål, 1859 (Hemiptera: Auchenorrhyncha: Fulgoromorpha: Cixiidae), Zootaxa 4691 (5), pp. 401-443 : 431-433

Chidaea sidnicus ( Stål, 1859) comb. nov.

( Fig. 15 , 31B )

Cixius sidnicus Stål, 1859: 273 .

Types. Holotype, ♀ (examined), AUSTRALIA, NSW: Sydney , Kinb. ( NHRS NHRS-GULI 000038154).

Colour. Vertex and pronotum light to mid brown with slightly paler carinae. Face mid brown with paler carinae. Mesonotum mid brown, central area (in between carinae) light brown. Forewings light brown, veins light brown, concolorous with cells, tubercles dark, in distinct contrast with lighter coloured veins. Pterostigma, crossveins and apical parts of veins slightly darker. Body mid brown, legs light to mid brown.

Morphology. Body length: ♀ 6.4 mm.

Head: Vertex 2.0 x wider than long; median carina covering about half of length of basal compartment of vertex; absent in apical compartment. Frons 1.2 x longer than wide; position of maximum width distinctly dorsad of frontoclypeal suture; lateral carinae of frons in facial view convex, rectilinear apically. Frontoclypeal suture strongly semicircular, bent upwards, median part just reaching lower margin of antennal scape. Median carina of post- and anteclypeus well developed. Rostrum reaching hind coxae.

Thorax: Hind margin of pronotum acutely angled. Mesonotum with weakly developed median and lateral carinae. Forewing 3.3 x longer than wide; concavity at costal border absent; costal margin with 20–22 tubercles; fork of ScP+RA and RP at same level or slightly basad of fork CuA1 and CuA2; tubercles of forewing dark, distinctly contrasted to paler coloured veins; ScP+RA apically bifid; RP trifid; additional subapical cell between branches of MP1 and MP2 absent; MP1+2 trifid; MP3+4 trifid; 12 apical cells; 6 subapical cells. Hind leg: tibia with 6 apical spines; 1 st tarsomere with 11 apical teeth and 6 platellae; 2 nd tarsomere with 10 apical teeth and 8 platellae.

Diagnosis and Remarks. Several characters prove that the female holotype of Cixius sidnicus is not congeneric with Cixius nervosus . The most striking are: A median ocellus is missing in Ch. sidnicus , but always present in true Cixius . All Cixius species have 2–3 large lateral spines on the hind tibia, whereas Ch. sidnicus only has 2 minute lateral spines.

The characters given above as diagnostic for Chidaea fit with the female type of C. sidnicus , thus we conclude that the specimen belongs to the genus Chidaea . In several Chidaea taxa, we are—on a morphological basis—at the moment unable to identify females to species level. Thus, we are also unable to decide if the female holotype of C. sidnicus is conspecific with males of a species described above or represents another species where males are as yet unknown.

The examination of the female holotype revealed the presence of dark tubercles on the forewing in distinct contrast to lighter coloured veins. Four species of Chidaea are known to have dark tubercles. Based on the locality (the specimen was collected in Sydney), two of these species can be excluded ( Ch. kimbaensis only occurs in South Aus- tralia and Ch. etelis is restricted to Western Australia). Therefore Ch. sidnicus Stål is likely to be conspecific with one of the two remaining species, either Ch. crassa or Ch. bobadeenensis , which have an overlapping distribution in New South Wales and Queensland, both occurring in the Sydney region. With the present state of knowledge it is impossible to associate the female holotype with certainty with one of these two species as differentiation between these species is entirely based on males. If an assignation will be possible in future—either by new characters or methods—one of the names given here might become a junior subjective synonym of Ch. sidnicus ( Stål, 1859) .

Distribution: NSW.

Figures

FIGURE 15. Chidaea sidnicus: A habitus and labels; B–D head; E forewing.

FIGURE 31. Known distribution of Chidaea species.