Genus Idioscopus Baker

Idioscopus Baker 1915; 320; Maldonado-Capriles 1964: 90, 92. Type species: Idiocerus clypealis Lethierry, by original designation.

Diagnosis. Aedeagus compressed, with well-developed dorsal apodeme, shaft narrowing distally with one or two pairs of often long apical or subapical processes. Style blade-like with apophysis ventral margin serrated and with dorsal marginal thin short to moderately long setae and a group of setae basally. The genus differs from Idiocerus in having 2+1 metafemoral distal macrosetae (2+0 in Idiocerus); aedeagal shaft with one or two pairs of apical or subapical long processes

Description. Lemon green, ochraceous, brown to dark brown with or without dark brown to black markings on head and mesonotum,

Crown slightly longer medially than next to eyes, face dorsad of ocelli either transversely rugose (as in most species) or shagreen (as in I. bimaculatus, I. confuscous and I. shillongensis), 3.8–4.3 × as wide as long medially. Face including eyes wider than long. Ocelli closer to adjacent eye than to each other, frontolateral suures reaching ocelli. Lora slightly raised from general surface, either reaching or short of ventral genal margin. Clypellus parallel sided in basal 0.5–0.75 length then expanded. Labium in male thin in both sexes (except in I. nitidulus group of species, see remarks below), at most reaching the posterior margin of metacoxae. Male antennae often with terminal disc. Pronotum. 2.1–2.8× as wide as long medially, shagreen, posterior margin slightly concave medially. Mesonotum eiher longer than combined length of crown and pronotum or more or less equal, mesoscutellum rough sculptured. Meta femur with 2+1 distal macrosetae. Meta tibial chaetotaxy on row AD 5–7 PD 5–7 and AV 15–18. Metabasitarsomere with 3 platellae on distal transverse row flanked on either side by one seta (Fig. 20I). Male abdomen with basal tergal and sternal apodemes well developed. Female sternite VII wider than long, more or less convex posterior margin with or without median concavity.

Male genitalia. Pygofer anterior margin with well-developed dorsal apodemes, with basal fracture, height more than width, with short or long ventral process (as in I. bimaculatus, I. clypealis, I. confuscous, I. irenae, I. nagpurensis, I. shillongensis, I. virescens) or without (as in I. pretiosus). Subgenital plate with basal short segment, rest more or less of same width or slightly widened distally with marginal thin hair-like setae, either as long as or slightly shorter or longer than pygofer. Style blade-like, with anterior part short compared to portion beyond articulation with connective, apophysis curved, narrowed distally often pointed at apex, ventral margin serrated for a short distance, dorsal margin with thin moderately long hair-like setae often present only in distal 0.25–0.33 length. Connective either T-shaped with broad stem or papilionaceous, with posteromedian ridge or keel. Aedeagus slightly compressed, preatrium when present short, dorsal apodeme always well-developed shaft curved or straight, distally narrowed, with apical or subapical single or paired shafts of various lengths, gonopore subapical on ventral surface. Anal collar well-developed with either bifid or hooked or slender long posterior process.

Female genitalia. Ovipositor extending well beyond pygofer. Valvula I more or less straight or slightly curved, tapered distally, apex pointed, with strigate sculpture occupying about 0.5 or more distal length and less than 0.5 dorsal width of valvula. Valvula II more or less straight, teeth either absent (as in I. clypealis and I. nagpurensis, Figs 66 CD, MP) or small widely spaced (as in I. bimaculatus, I, pretiosus (Figs 65 OP, 67GH) or well-developed (rest of the species, for example Figs 67 CD, KL), toothed area occupying 0.33–0.5 distal length.

Remarks. The genus at present contains 9 species from the Indian subcontinent. The genus as redefined here is still heterogenous and further grouping of the species may be necessary once most of the species of the genus from the Oriental region become known. At present four species groups based on the forewing venation, the structure of the male genitalia and the female ovipositor are recognised as follows:

Idioscopus clypealis species group. Upper part of face dorsad of ocelli and crown rugose. Male antenna with apical platella. Labium in male slender. Forewing with two subapical cells. Style without a rectangular lobe adjacent to articulation with connective. Aedeagus with two pairs of unequal subapical processes, each process serrated on at least one margin, shaft narrowed distally in lateral view. Female valvula II without teeth on dorsal surface; breed exclusively on mango inflorescence. This group contains two very closely related species, I. clypealis and I. nagpurensis .

Idioscopus confuscous species group. Upper part of face dorsad of ocelli and crown shagreen. Male antenna without platella. Labium in male slender. Forewing with two ( I. bimaculatus and I. shillongensis) or 3 ( I. confuscous) subapical cells. Style without rectangular lobe adjacent to articulation with connective. Aedeagus with one (in I. bimaculatus) or two pairs (in I. confuscous and I. shillongensis) of fairly long subapical processes, shaft narrowed distally in lateral view. Female valvula II with well-developed teeth. This group includes three species, I. bimaculatus, I. confuscous and I. shillongensis .

Idioscopus irenae species group. Upper part of face dorsad of ocelli and crown rugose. Labium in male slender. Forewing with two subapical cells. Style without rectangular lobe adjacent to articulation with connective. Aedeagus with one pair of short apical processes, shaft narrowed distally in lateral view. Female valvula II with well-developed teeth. This group includes three species, I. irenae, I. pretiosus and I. virescens .

Idioscopus nitidulus species group. Upper part of face dorsad of ocelli and crown rugose. Labium in male with distal segment expanded (Fig. 24E). Forewing with three subapical cells, the outer cell very small and triangular (Fig. 59H). Style with a rectangular region adjacent to articulation with connective (Fig. 24G). Aedeagus with two pairs of long thin processes, shaft in lateral view, not narrowed distally. It includes one species from the Indian subcontinent, I. nitidulus . However, I. chumphoni Hongsaprug (from Thailand) and I. clavostignatus Maldonado-Capriles (from Thailand, Indonesia, Malaysia) also belong to this group.

Key to species of Idioscopus Baker from the Indian subcontinent

1. Crown and face dorsad of ocelli shagreen.................................................................. 2

- Crown and face dorsad of ocelli striate.................................................................... 4

2. Uniformly lemon green, head and pronotum immaculate (Fig. 19A); aedeagal shaft with one pair of subapical processes bent at midlength (Fig. 19F)................................................................ I. bimaculatus (Pruthi)

- Ochraceous or yellowish with black markings on head and pronotum (Figs 21 AB, 26AB); aedeagal shaft with two pairs of processes directed basad (Fig. 21F)....................................................................... 3

3. Forewing with 3 subapical cells (Fig.59H); pygofer with ventral process (Fig. 21D)................. I. confuscous (Pruthi)

- Forewing with 2 subapical cells (Fig. 59G); pygofer without ventral process (Fig. 26F)......... I. shillongensis Viraktamath

4. Forewing with three subapical cells (Fig. 59H) and with transverse ivory markings slightly distad of base and also at end of clavus (Fig. 24 AB); male style in lateral view rectangularly extended ventrally proximad of mid-length and apophysis with ventral tooth at mid-length (Fig. 24G)...................................................... I. nitidulus (Walker)

- Forewing with two subapical cells, not marked with ivory; male style without such structures (Fig. 20K)................. 5

5. Aedeagus with one pair of processes (Fig. 22G)............................................................. 6

- Aedeagus with two pairs of processes (Fig. 20L)............................................................ 8

6. Forewing third apical cell with a round black spot (Fig. 25B); pygofer without ventral process (Fig. 25E)................................................................................................. I. pretiosus Viraktamath

- Forewing third apical cell without black spot; pygofer with ventral process (Fig. 27E)................................7

7. Aedeagal shaft with lateral lamellate expansion at mid-length, processes thin with smooth margin (Figs 27 GH)............................................................................................. I. virescens Viraktamath

- Aedeagal shaft without lamellate expansion, processes broader and with serrated lateral margin (Figs 22 GH)................................................................................................ I. irenae Viraktamath

8. Clypellus entirely black in both sexes (Fig. 20 GH); aedeagal processes 0.75× as long as or longer than shaft (Fig. 20L); male usually without black spot on head fore margin (Fig. 20 CE–G)................................ I. clypealis (Lethierry)

- Clypellus not entirely black maybe ochraceous (Figs 23E–I); aedeagal process at most 0.66 as long as shaft or shorter (Fig. 23L); male always with a pair of round black spots on fore margin of head (Figs 23 AB)............. I. nagpurensis (Pruthi)