Idioscopus clypealis (Lethierry)

VIRAKTAMATH, C. A. & YESHWANTH, H. M., 2024, Arboreal eurymeline leafhoppers (Hemiptera: Cicadellidae: Eurymelinae) of the Indian subcontinent with description of new genera and eight new species, Zootaxa 5462 (1), pp. 1-125 : 44-48

Idioscopus clypealis (Lethierry)

Figs 20A–L , 61F , 66A–D .

Idiocerus clypealis Lethierry 1889: 252 ; Distant 1908: 187, fig.122.

Idioscopus clypealis (Lethiery) : Baker 1915: 339; Maldonado-capriles 1964: 92–93, figs 6–9.

Idiocerus nigroclypeatus Melichar 1903: 48 ; Distant 1908: 187.

Idioscopus nigroclyoeatus (Melichar) : Viraktamath & Murphy 1980: 83–85, figs 1–9.

Idiocerus scutellatus Distant 1908: 187–188 ; Maldonado-Capriles 1964: 96, figs 23–27. Syn. nov.

Diagnosis. Ochraceous with black basal triangles on mesonotum and clypellus wholly black in both sexes. Male without black round spots on fore margin of head, male pygofer with a short ventral process almost at midlength of ventral margin; aedeagus compressed with two pairs of unequal thin long processes as long or longer than shaft (at least 0.75× as long as shaft).

Description. Female. Sternite VII slightly more than twice as wide as long medially, posterior margin slightly conex with median projection faintly bilobed ( Fig. 61F ). Valvula I almost straight in basal half then slightly dorsally curved, sculpturing stirgate, strigae cufrved and vertical, occypying distal half length ( Figs 66 AB). Valvula II slightly curved dorsally in distal half, toothed area occupying less than distal half and without teeth ( Figs 66 CD).

Material examined. INDIA: West Bengal: TYPE 1 ♂, Calcutta, Idioscopus clypealis Leth. (MNHN, Paris) . INDIA: West Bengal: LECTOTYPE ♂ (here designated), “ Atkison coll. 92- Calcutta, Idiocerus scutellatus Dist , type ( BMNH). Other material: Several male and female specimens collected on mango throughtout India and some parts of Sri Lanka.

Remarks. Letherirry (1898) described this species based on unspecified number of specimens collected from Calcutta. In NMNH, Paris there is a single male labeled as the type and was examined ( Fig. 20A–D ). This is an economically important species breeding on mango inflorescence and is considered as an important pest of mango (Viraktamath 1989). This species is often confused with I. nagpurensis which also breeds on mango inflorescence and both often occur together on the same plant. I. clypelis is sexually dimorphic whereas I. nagpurensis is not. The clypellus in I. clypealis is wholly black whereas in the case of I. nagpurensis it is variable from immaculate to 80 per cent of distal region of clypellus black. The aedeagal shaft processes are at least 0.75× as long as shaft and often much longer than aedeagus whereas in I. nagpurensis they are at most 0.60× as long as shaft and often much shorter. I. clypealis is much widely distributed. It is found in Iran in the west to Australia in the east, being invasive in Australia ( Day & Fletcher 1994). In India, I. clypealis is found mostly in areas receiving higher rain fall as in hilly regions and in northeast India, whereas I. nagpurensis is found in drier areas receiving less rainfall as in plains of penisnuslar India. Distant (1908) established Idiocerus scutelltus Distant based on three specimens with collection data “Calcutta (Atkinson Coll., Brit. Mus .)”. At present in the British Museum (BMNH) there are 27 specimens with the same collection data and one male is labeled in Distant’s hand as “ Idiocerus scutellatus Dist. , type” is here designated as lectotype. It is difficult to find out which of the remaining specimens were in front of Distant when he described the species and hence, no paralectotypes have been designated. Distant (1908) when describing this species commented “The British Museum possesses three examples of this species which is allied to I. clypealis, Leth. It remains to be proved whether it is only an extreme variety of that species,”. Examination of the lectotype and also one male specimen from the series studied by Maldonado-Capriles (1964:96, figs 23–27) paper and labeled as this species showed that this is a junior synonym of I. clypealis .

Figures

FIGURES 20A–L. Idioscopus clypealis (Lethierry): A–D type male: A–B, habitus, dorsal and lateral views; C, head anterior view; D, label data. E–G, non-type male: E–F, habitus, dorsal and lateral views; G, face; H, non-type female face; I, metabasitarsomere, ventral view; J, male genital capsule, lateral view; K, style, lateral view; L, connective and aedeagus, lateral view.

FIGURES 61A–R. Idiocerini of the Indian subcontinent, female sternite VII: A, Idiocerus cedarae; B, Metidioceus deodarae; C, M. gnezdilovai; D, Idiocerus sharmai; E, Idioscopus bimaculatus; F, I. clypealis. G, I. confuscous; H, I. irenae; I, I. nagpurensis; J, I. nitidulus; K, I. pretiosus; L, I. shillongensis; M, I. virescens; N, Jogocerus freytagi; O, Keralus webbi; P, Matangia capriliana; Q, M. inidca; R, M. thapai.

FIGURES 66A–P. Idiocerini of the Indian subcontinent, female valvula I, magnified view and valvula II, magnified view:A–D, Idioscopus clypealis; E–H, I. confuscous; I–L, I. irenae; M–P, I. nagpurensis.