Chidaea dayi Emeljanov

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 : 418-420

Chidaea dayi Emeljanov

( Figs 8 , 23 , 31D )

Chidaea dayi Emeljanov, 2000: 14 .

Types (not examined). Holotype, ♂, AUSTRALIA, ACT: Canberra , Black Mt., 25.ix.1979 (V. Zaitzev) ( ANIC) . Paratypes, 2 ♂, 3 ♀, same data as holotype ( ZIN) .

Other material examined. AUSTRALIA, NSW: 4 ♂, 4 ♀, Mt Kosciuszko , Wilsons Valley, i.1965 (J.W. &

F. Evans) ( ASCU). Tas : 2 ♂, Hartz Mtns, 24.xii.1974 (F. McDonald) ( ASCU) ; 1 ♂, Ellendale , ex E[ucalyptus] regnans / E. nitens , 24.ii.2004 (V. Patel) ( ASCU) ; 2 ♂, 3 ♀, 4km S Gt. Oakleigh , 41.51S, 146.03E, 800m, closed forest, malaise trap, 8.i.–12.ii.1991 (A. Calder & W. Dressler) ( ANIC) ; 1 ♂, 2 ♀, Mt Field NP, Lake Dobson Rd, 42.41S, 146.40E, 710m, 31.i.1980 (Lawrence & Weir) ( ANIC) . Vic : 1 ♂, Otway Ra [nge]s, 7–9.i.1966 (T. Weir) ( QM, formerly UQIC) .

Notes. The females listed under ‘Other material examined’ have been associated with this species because they have been collected in the same collecting event as males of that species. However, because there are no diagnostic external features to differentiate between Ch. dayi and Ch. armidalensis , which is also known from New South Wales and Tasmania, there remains the possibility that some of these females may be Ch. armidalensis . One male listed in the ‘Other material examined’ as having been collected on Mt Kosciuszko does not have a locality label, but because it was mounted in the same style as the other specimens from that area and it is assumed to have been collected there.

Colour. Vertex mid or dark brown (rarely light brown) with paler carinae. Frons mid to dark brown with paler carina (lateral carinae palest near frontoclypeal suture). Post- and anteclypeus darker than frons with slightly paler carinae. Pronotum light brown, sometimes with darker patches. Mesonotum midbrown (rarely dark brown) with concolorous or slightly paler carinae. Forewings light brown, tubercles and veins light or mid brown, concolorous with cells. Pterostigma, crossveins and apical parts of veins often slightly darker. Body and legs mid brown, rarely light brown.

Morphology. Body length: ♂ 4.9–6.7 mm; ♀ 6.1–7.4 mm.

Head: Vertex 2.0–2.7 x wider than long; median carina of vertex covering ¼–

¾ of basal compartment of vertex; absent in apical compartment. Frons 1.0–1.2 x longer than wide; position of maximum width distinctly dorsad of centre of frontoclypeal suture; lateral carinae of frons in facial view convex, rectilinear apically or convex, evenly rounded. Frontoclypeal suture strongly semicircular, bent upwards, median part just or just not reaching lower margin of antennal scape. Postclypeus with median carina well developed, but sometimes evanescent near frontoclypeal suture. Anteclypeus with median carina moderately developed, evanescent or absent. Rostrum reaching hind coxae.

Thorax: Hind margin of pronotum obtusely angled or rectangular. Mesonotum with median carina evanescent or moderately developed and lateral carinae weakly developed to evanescent. Forewing 3.1–3.4 x longer than wide; concavity at costal border absent; costal margin with 17–25 tubercles; fork of ScP+RA and RP slightly basad, slightly distad or at same level as fork CuA1 and CuA2; tubercles of forewing dark or pale, concolorous with veins; ScP+RA apically bifid or unforked; RP trifid; additional subapical cell between branches of MP1 and MP2 absent or present; MP1+2 and MP3+4 bifid (rarely trifid); 9–11 apical cells; 6 (rarely 7) subapical cells. Hind leg: tibia with 6 (rarely 5) apical spines; 1 st tarsomere with 7–9 apical teeth and no (rarely 1) platellae; 2 nd tarsomere with 9–11 apical teeth and 7–9 platellae.

Male genitalia: Anal tube as in Figs 23 D–E. Pygofer and genital styles as in Figs 23 F–G. Aedeagus ( Figs 23 A– C): Phallotheca narrow; dorsally with a short, moderately bent spine (a) with its curvature best seen in left lateral view; spine (a) only partly visible in ventral view; phallotheca ventrally with a very long, prominent spine (b) with a large triangular base, tip of spine (b) directed left laterad; phallotheca near base with a bifurcate ventral process. Aedeagal spines not reaching bifurcate ventral process.

Diagnosis. Many species in Chidaea have very similar male genitalia but this species stands out in having a very large, prominent spine (b) which arises on the ventral side of the phallotheca and which has a very large base that covers more than half of the width of the phallotheca and which has the tip directed left laterad. There is a slight resemblance in genitalia with Ch. wilarra , however in Ch. wilarra spine (b) is not as prominent, it only has a slightly enlarged base and it arises more ventro-laterally, whereas in Ch. dayi spine (b) arises in the centre of the phallotheca in ventral view. In most cases the two species can easily be distinguished by the length of spine (a) versus spine (b). In Ch. wilarra spine (b) reaches only slightly further down the aedeagus shaft than spine (a). In most specimens of Ch. dayi spine (b) reaches down about twice as far as spine (a). Chidaea dayi shares the presence of a ventral spine with a large base with Ch. armidalensis . In Ch. armidalensis the tip of this spine is directed right laterad, in Ch. dayi it is directed left laterad. Ch. dayi resembles Ch. dickinsonorum , Ch. armidalensis and Ch. pulyonna in certain external characters, see diagnosis section of Ch. pulyonna for details on how to distinguish these four species.

Distribution: ACT, NSW, Tas, Vic.

Associated plant records: Eucalyptus sp.

Remarks. During this research project ten specimens from Tasmania, Victoria and NSW have been studied, that match the original description of Ch. dayi in all aspects, apart from the length of aedeagal spine (b). In those specimens spine (b) was slightly longer than it appears to be in the drawings of the original description, resulting in spine (b) reaching about twice as far down the aedeagus shaft than spine (a). Since the types, despite several attempts to get hold of them, were unavailable for comparison, it is for the moment assumed that these specimens are conspecific with Ch. dayi . Similar configurations with short- and long-spine-‘morphotypes’ are also known in other Cixiini-taxa, e.g. Cixius nervosus and Cixius beieri Wagner, 1939 (see Holzinger et al. 2003).

Figures

FIGURE 8. Chidaea dayi: A habitus; B–D head.

FIGURE 23. Chidaea dayi: A aedeagus left lateral; B aedeagus ventral; C aedeagus right lateral; D–E anal tube; F–G genital styles.

FIGURE 31. Known distribution of Chidaea species.