Indomias decipiens ( Marshall )

Y, R A M A M U Rt H & Ayri, Shaloo, 2010, Revision of the genus Indomias Marshall (Coleoptera, Curculionidae, Entiminae, Tanymecini) from India, Zootaxa 2357, pp. 1-49 : 30-31

7. Indomias decipiens ( Marshall)

(figs. 1, 27, 54, 87, 88, 138, 153, 166, 192, 193 and 194)

Sympiezomias decipiens Marshall, 1916: 167 ; 1941: 350 [BMNH]

Description: Colour black, with dull brown to sand grey vestiture. Head 1.1x as long as rostrum, upper surface convex, with scattered deep punctations; frons 2x as broad as length of eye. Rostrum plain dorsally, as long as broad, anterior margin 0.83x as broad as posterior margin; median furrow club shaped, narrowed posteriorly; lateral carinae distinct; sides straight and narrowing towards the anterior margin; scrobes uniformly broad, oriented in a semicircular fashion up to the anterior margin of rostrum, then becoming parallel towards the eyes, space between scrobes 1.1x as that between the eyes. Eyes dorsolateral, moderately convex and circular, space between the eyes as much as the breadth of rostrum at posterior margin (figs. 1 and 27). Antennae dark brown; scape gradually broadened; funicle with first segment 1.1x as long as second, third and fourth subequal, fifth rounded; club broad, conical (fig. 54). Prothorax as long as broad in male, slightly broader than long in female (1:0.9), its breadth at middle 1.1x as that of posterior margin; sides rounded anteriorly but constricted behind, gradually narrowing towards the anterior margin which is only 0.7x as broad as breadth at middle; anterior margin 0.77x as broad as posterior margin, truncate dorsally and oblique laterally, posterior margin subtruncate; upper surface with coarse, confluent punctations, interspaces granulate. Legs with hind tibial apex without any dense, golden yellow hairs. Elytra narrowly ovate in male, broadly ovate in female, basal margin strongly raised, its external angle acute, with humeral fold slightly prominent, posterior declivity not impressed; apices in female each with a distinct, short mucro, but in males rounded; stria deeply punctate; upper surface less convex, almost flat, deepest near the base, then gradually sloping backwards and becoming abruptly steeper behind; ratio of length in elytra from basal margin to posterior declivity and from the posterior declivity to the apex 4:1; intervals less convex; second and third intervals 2x as broad as the first and fifth; elytral vestiture with predominant scales ovate to conical, flat, reddish brown, with 8–9 broken ridges (figs. 87–88). Venter with setae on the first two ventrites longer and finer when compared to those of I. cretaceus .

Male genitalia: Aedeagus with median lobe slender, slightly arcuate in profile, broadest at junction with apophyses, length: breadth 9:1; transfer apparatus massive, transparent, less sclerotized; apophyses 0.44x as long as median lobe; apex of median lobe bluntly rounded (figs. 192–193). Tegmen with dorsal piece 5x as broad as basal piece; parameres short, broad, apices smoothly rounded; manubrium short, uniformly thick, 0.33x as long as median lobe and bent towards apex in triangular fashion at 45˚ angle, with its apex, swollen and rounded (fig. 194). Spiculum gastrale with shaft moderately long, 0.66x as long as the median lobe, apex bent, narrowed and blunt (fig. 166).

Female genitalia: Spermatheca with proximal and distal arms subequal, proximal arm swollen, 2.5x as broad as distal arm; angle between proximal and distal arms acute; nodulus circular and smoothly rounded; ramus atleast 3x as nodulus, rectangular; cornu slightly bent inwards at apex and pointed (fig. 138). Spiculum ventrale with shaft broader at middle, narrowed at base, apex broadened and circular; basal plate laminate, longer than broad (3:2), apex bluntly rounded and bare; ratio of length of basal plate to that of shaft 1:4 (fig. 153).

Length: male, 7.35 mm; female, 7.55 mm. Breadth: male, 2.3 mm; female, 2.7 mm.

Specimens examined: 1 male, without locality, date and collector's name; 1 female: INDIA: Karnataka: Bangalore, 26.VIII.1913, Coll. T.B.F., on Mulberry; 1 female (paratype) Tamil Nadu: Nilgiris, without date, Coll. H.L. Andrewes; 1 male: Coimbatore, 18.VIII.1912, Coll. T.V.R.; Kerala: Pampadumpara, 22.I.1994, Coll. P.M. Mathew on Cardamom.

Distribution: India: Karnataka: Bangalore; Kerala: Pampadumpara; Tamil Nadu: Coimbatore; Nilgirii Hills.

Associated habitats: Mulberry, cardamom.

Taxonomic note: This species exhibits sexual dimorphism. Males are shorter than females. In females, prothorax slightly broader than long (1:0.9) compared to males, where prothotrax as long as broad; moreover apices of elytra in females with distinct, short mucro, while rounded in males.

Economic importance: Reported to be causing damage to young cinchona trees ( Marshall, 1916).