Idastes, Pascoe, 1881

Kuschel, Guillermo, 2008, Curculionoidea (weevils) of New Caledonia and Vanuatu: Basal families and some Curculionidae, Mémoires du Muséum national d'Histoire naturelle 197, pp. 99-250 : 215-216

Genus IDASTES Pascoe

Idastes Pascoe, 1881: 598 (type species I. elevatus Pascoe [= Orobitis gibbosa Montrouzier ]).

Conopsis Chevrolat, 1877b : CXVII (non Günther 1858). — Heller 1916: 326.

Conotypus Marshall, 1939: 583 (new name for Conopsis Chevrolat , type species Orobitis gibbosa Montrouzier ) n. syn.

DESCRIPTION. — Full-winged, moderately sized species with visible scutellum, conical or subconical prothorax, compressed conical elytra, eyes completely covered by ocular lobes, rostral canal bare, open or only slightly cavernous, metepisternum not fused with metasternum but suture partly or completely covered by elytra, femora sulcate, toothed or not, claws divaricate, stridulatory device present in both sexes, consisting of an elytral ridge and a double row of pegged granules on tergite 7. Wing: radial cell well-defined, having a broad anterior edge and an elongate window a little wider than edges; with two deeply pigmented radial sclerites apicad from cell, and a lightly pigmented area basad, r-m distinct throughout, evenly curved, attached to postero-basal angle of cell and end of mcu, A 4 well short of hind margin, A 5 closing or not anal cell, ending at junction with A 4; setae on anterior margin absent, cilia on hind margin indistinct; apical field 1.5 x (or half as long again) as wing from base to end of stigma. Tergites 1-6 weakly pigmented all across, darker at basal margin; tergite 7 more intensively pigmented.

Male: tergite 7 broadly emarginate at apex, densely punctate and pilose, dark except for pruinose areas and a pale stripe on either side of midline containing rather inconspicuous plectral pegs. Sternite 8 with two triangular, at base deeply emarginate bare plates; sternite 9 robust, straight (not upcurved), two-thirds of length of aedeagus inclusive of apodemes, with broad, nearly symmetrical arms. Tegmen with or without complete ring, with short, disjunct or fused parameral lobes. Aedeagus with deeply pigmented pedon but pale tectal area. Internal sac showing briefly between apodemes with a more or less forceps-shaped basal sclerite a little distance from membranous base; ejaculatory duct inserting dorsally into basal sclerite.

Female: tergite 7 converging from spiracle area to a rounded apex, densely punctate with piliferous puncta except for pruinose patches and two subparallel lines on basal half bearing plectral granules; tergite 8 similar, more rapidly converging to end with or without teeth. Sternite 8 a little longer than last three ventrites combined, blade a little longer than apodeme, punctation fine except on basal one-third. Hemisternites long and narrow, evenly pigmented, tapering apicad to width of styli, lacking setae and hairs but with very fine puncta; styli terminal, set-off from hemisternites by pale zone, about one-quarter as long as and darker than hemisternites. Vagina subcylindrical as far as end of apodeme of sternite 8, from here on gradually widening towards oviduct; bursa bulbous at end if turgid, pigmented or not ventrally at base; spermathecal duct inserted at ventral base of bursa, not quite as long as bursa, relatively stiff. Spermatheca with short subcylindrical or widening stem; gland sacciform or fusiform; duct emerging from middle of base of spermatheca.

DISTRIBUTION. — New Caledonia.

HOSTPLANTS. — Ferns, probably just tree-ferns, for I. gibbosus , host of other species unknown.

ETYMOLOGY. — None, a made-up name.

REMARKS. — Relationships not yet established but genus currently listed under Mecystostylina. Six species are present.

KEY TO SPECIES OF IDASTES

1. All femora with large tooth ............................................................................................................................ 2

— Femora lacking tooth, or with a rudimentary one on middle femora ................................................. 4

2 (1). Puncta on pronotum coarse, subcontiguous, larger than scales. 5.3-5.5 mm. New Caledonia. ....

.................................................................................................................................................................... paniensis

— Puncta on pronotum spaced, well apart, considerably smaller than scales ....................................... 3

3 (2). Rostral canal cavernous, having a pocket for reception of rostral apex. Scales large, relatively sparse, leaving most of integument exposed. Elytra separately rounded at apex, with two low tubercles on interstria 3. 6.0-11.0 mm. New Caledonia............................................................................ gibbosus — Rostral canal not cavernous, its hind wall not folded cephalad to form a pocket or receptacle. Scales minute, very dense, covering integument except for a few bare spots on pronotum and elytra. Elytra jointly rounded at apex, lacking tubercles. 13.5 mm. New Caledonia.............................. grandis

4 (2). Pronotum with six conspicuous tufts of squamiform setae: a pair at apex, four across middle. 4.3-8.0 mm. New Caledonia................................................................................................................ maculipes — Pronotum lacking tufts of setae ..................................................................................................................... 5

5 (4). Pronotum black, lacking ornamental patterns. Elytra without tubercles or tufts of setae. 6.5-7.5 mm. New Caledonia............................................................................................................................. montanus — Pronotum with dense, velvety brown scaling ornamented with sharply defined white lines. Elytra with six tufted tubercles on either elytron. 6.5 mm. New Caledonia......................................... graphicus