Alcidodes caviventris Lyal, 2000

Lyal, C. H. C. & Curran, L. M., 2000, Seed-feeding beetles of the weevil tribe Mecysolobini (Insecta: Coleoptera: Curculionidae) developing in seeds of trees in the Dipterocarpaceae, Journal of Natural History 34 (9), pp. 1743-1847 : 1831-1832

Alcidodes caviventris Lyal , n.sp.

Length 5.0± 7.94 mm (xÅ5 6.74 mm), PW 5 2.41±4.25 mm (xÅ5 3.57 mm), HW 5 3.00± 5.31 mm (xÅ5 4.53 mm) (n 5 95) (®gures 36, 69, 87).

Head. Rostrum evenly curved, longer and more curved in female ( RL 5 2.22±3.94 mm, xÅ5 3.37 mm; RL/ PW 5 0.83±1.01, xÅ5 0.92; RB/RD5 0.65±0.83, xÅ5 0.73; n 5 44) (®gure 213) than in male ( RL 1.94±2.84 mm, xÅ5 2.47 mm; RL/ PW 5 0.66±0.78, xÅ5 0.71; RB/RD 0.95±1.14, xÅ5 1.03; n 5 51) (®gure 214) .

Thorax. PL / PW 5 0.61±0.72 (xÅ5 0.66, n 5 95) (no signi®cant diOEerence between sexes); prothorax lacking tubercle posterior to coxa. Elytra with interstria wrinkled or with small granules, especially proximally; strial punctures narrower than interstriae, humeri with interstria 9 projecting beyond 8 in dorsal view (®gures 36, 46); EL/HW, m, 1.00±1.13 (xÅ5 1.07, n 5 44),, l1.04±1.13 (xÅ5 1.09 n 5 51). Elytra with darker pigmentation on humeri and as scattered markings elsewhere on interstriae, becoming completely dark with age, scales ®ne, hair-like. Fore femur with ventral tooth longer than high, proximal lobe inclined, acuminate, central lobe upright, with serrate distal margin sometimes developed into discrete lobe (®gures 143, 174, 175); proximal tooth may be more acuminate and inclined to the femur in female than in male. Fore tibia with ventral tooth, mid and hind tibiae lacking ventral tooth. Ventral margin of metasternum subparallel with or weakly converging towards elytral margin .

Abdomen. Male ventrite 5 with median depression occupying just less than onehalf maximum width of ventrite and three-®fths of length, with tuft of mediallydirected scales on either side, depression glabrous or with ®ne setiform scales (®gure 120). Female ventrite 5 with oval median depression approximately seventenths of length of ventrite, scales not in marked lateral tufts (®gure 121).

Male terminalia. Tergite 7 (®gure 411) with 3±5 plectral tubercles near posterior margin; posterior margin concave. Tergite 8 broad, with large posterior lip to genital opening (®gure 412). Hemisternites of sternum 8 narrow, lacking prominent setae (®gure 412). Genitalia as in ®gures 413±418. Tegmen with parameres separate, shorter than width of tegminal ring (®gure 414). Membrane between tegmen and aedeagus with pair of small membranous lobes (®gures 416, 418). Aedeagus longer than wide; sides weakly convex; apex abruptly downturned, truncate; endophallus with a pair of membranous lobes extending from ostium to beyond apex of aedeagus, ostiolar sclerites elongate, extending inside endophallus, not fused to aedeagal sclerotization (®gures 418±418).

Female terminalia. (®gures 419±421) Tergite 7 with 4±5 pairs of plectral tubercles (®gure 419). Tergite 8 with weakly concave posterior margin; disc and anterior margin more weakly sclerotized than rest of tergite (®gure 420). Spiculum ventrale (®gure 421) with broad apical part longer than wide, subequal in length to apodeme. Female genitalia as in ®gures 422±424; hemisternites short, styli long, with 2±4 subapical setae not on small projection; spermathecal duct arising on bursa away from its junction with oviduct; spermatheca with gland lobe tubular, bulbous medially (®gure 424).

Distinguishing features. A. caviventris belongs to the dipterocarpi subgroup with the proximal lobe of the fore femoral tooth inclined, rather than running along the axis of the femur, and meeting the central lobe approximately half-way between the femur and the apex of the lobe, rather than nearer the femur (®gures 143, 174). It can be distinguished from shoreaphilus , which shares these characteristics, by the less developed interstria 9 at the humerus, the somewhat smaller depression in ventrite 5 of the male, which occupies just less than half the width of the ventrite (®gure 120, cf. ®gure 118), and the more apparent depression in ventrite 5 of the female (®gure 121), which has weak scale tufts on either side in caviventris but not in shoreaphilus (®gure 119).

Comments. Specimens have been reared only from seeds of Shorea species. The single female from Shorea pinanga is the only individual to have been reared from this host in the study, and there must be a suspicion that the specimen was mislabelled.

Etymology. The species is so-called because of a marked depression in the metasternum.

Specimens examined

HOLOTYPE ,, l Brunei, with labels:`Holo- / type’ and`’ l and`C.L.1115 Reared / from seed of / Shorea isoptera ’ and` BRUNEI: / Temburong Distr. / Kuala Belalong / Sept.± Oct. 1992 ’ and`C. Lyal and J. Margerison Knight / B.M.1992-166’ and` HOLOTYPE / Alcidodes / caviventris Lyal / Lyal det 1997’ ( RBM).

PARATYPES: Brunei: 6 ll, 10mm, same data and host as holotype; same locality, reared from seeds of: Shorea amplexicaulis (2 ll, 1m), S. pinanga (1m), unidenti®ed host (5 ll, 5mm) ( RBM, BMNH).

Indonesia: Borneo: Kalimantan, Gunung Palung Nature Reserve, Cabang Panti Research Station, i-iv 1991 (Curran), reared from seeds of: Shorea atrinervosa (38 ll, 36mm); S. brunnescens (6 ll, 6mm); Shorea coriacea (5 ll, 4mm); Shorea crassa (57 ll, 54mm); S. hopeifolia (1, l 2mm); Shorea johorensis (1 l); Shorea kunstleri (2 ll); Shorea laevis (5 ll, 4mm); Shorea ovalis (1 l), Shorea parvifolia (2mm), Shorea parvistipulata (2 ll, 3mm); Shorea quadrinervis (6 ll, 7mm). ( MZB, BMNH, UMMZ).

Range. Borneo.

Hosts. Shorea amplexicaulis Ashton , S. atrinervosa Sym. , S. brunnescens Ashton , S. coriacea Burck , S. crassa Ashton , S. hopeifolia (Heim.) Sym. , S. isoptera