Alcidodes humeralis ( Heller, 1940 )

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 : 1800-1804

Alcidodes humeralis ( Heller, 1940)

Alcides humeralis Heller, 1940: 97 , ®g. 2; Haaf, 1961d: 399; 1964a: 37.

Robust species, characterized by very pronounced humeri. Length,, l 5.75±9.5 mm, (xÅ5 7.75), m, 5.81±10.13 mm, (xÅ5 8).27; PW,, l 2.75±4.63 mm, (xÅ5

3.70), m, 2.88 ±4.94 mm, (xÅ5 4.01); HW,, l 3.50±6.13 mm, (xÅ5 4.96), m,

3.63±6.56 mm, (xÅ5 5.33) (n l 5 52, n m 5 49); (®gures 33, 65, 84).

Head. Rostrum weakly curved, slightly longer, more slender and less strongly punctate in female ( RL 5 2.31±4.50 mm; RL/ PW5 0.80±0.93; RB/RD 5 0.77±1.00; n 5 49) (®gure 195) than in male ( RL 5 2.19±3.63 mm; RL/ PW 5 0.76± 0.87; RB/RD5 0.95± 1.30; n 5 52) (®gure 196) .

Thorax. PL/PW 5 0.67±0.80 (xÅ5 0.73, n 5 101); prothorax without tubercle posterior to each coxa, although very weak prominence sometimes present. Elytra with interstriae wrinkled proximally, strial punctures deep, as wide as or wider than interstriae except on disc, where narrower; humeri with interstria 9 projecting strongly beyond 8 in dorsal view (®gures 33, 43); EL/HW, m, 0.98±1.24 (xÅ5 1.11, n 5 49),, l1.08±1.22 (xÅ5 1.13, n 5 52). Elytra with pigmentation uniform, scales ®ne and hair-like over most of elytra, broader in patches. Fore femur with ventral tooth subtriangular, lacking proximal lobe, proximal margin at c.90ss to long axis of femur and at least as long as length of tooth, with proximal and distal margins meeting femur at approximately the same level and distal margin with a relatively steep slope, distal margin dentate or serrate (®gures 134, 158, 159); all tibiae with small ventral tooth. Metasternum strongly produced posteroventrally before hind coxae, its ventral margin strongly diverging from elytral margin.

Abdomen. Ventrite 5 with two caudal setal tufts on prominences on posterior margin in both sexes, smaller in female than male; disc with rounded depression medially, stronger and more de®ned in female than male (®gures 102, 103).

Male terminalia. Tergite 7 as in ®gure 293; short diagonal row of plectral tubercles on each side. Segment 8 as ®gure 294. Genitalia as in ®gures 295±300. Tegmen with parameres fused at base (®gure 296). Aedeagal body curved in lateral view, in dorsal view aedeagus with apex broadly rounded with median point (®gures 298±299), sides sinuate with apical third much narrower than basal two-thirds, sclerotization extending onto dorsal surface much more in apical third than basally (®gure 298), distance from ostium to apex much less than width of ostium. Ostiolar sclerites extending into endophallus; endophallus lacking spines or scales.

Female terminalia. (®gures 301±303) Tergite 7 with a short diagonal line of plectral tubercles on either side of midline (®gure 301). Tergite 8 with weakly rounded or truncate posterior margin, (®gure 302). Spiculum ventrale (®gure 303) with broad part not at an angle to apodeme; sclerotized arms of broad part separate for approximately half total length of sternite. Female genitalia as in ®gures 304±305; spermathecal duct arising on bursa anterior to junction of bursa and common oviduct; spermatheca with gland lobe simple, tubular, ¯exed; hemisternites subequal in length to broad part of spiculum ventrale, styli elongate, approximately onequarter length of hemisternites.

Distinguishing features. A. humeralis belongs to the crassus group sub-group having the distal margin of the fore femoral tooth relatively steeply sloping (®gure 158) although very occasionally this character is not distinct. Of all members of this sub group (and, with the possible exception of some ramezei specimens) the whole crassus group, it has the most prominent humeral angles to the elytra. The aedeagus, as with other species, is characteristic in shape.

Comments. Heller (1940) recorded the type as a male, but there is no doubt that the specimen in the Dresden Museum labelled as`Typus’ by Heller and`Holotype’ by Haaf is a female. Precise measurements (not ranges) were given in the original description and these match this specimen. There is a male specimen of the same series in the USNM (also with the number`14668’), but the insect is smaller than that described by Heller. Continued recognition of the Dresden specimen as holotype seems justi®ed. The habitus drawing of the specimen in Heller (1940: ®gure 2) has the strial punctures square, whereas in fact they are more elongate.

Four specimens in the BMNH are recorded as from`Malay; Ligor’. In the records of the Fry Collection, to which they originally belonged, this is ampli®ed to the Malay Peninsula. The specimens are probably from what is now Thailand.

The species has been recorded from Shorea macroptera Dyer ( Daljeet-Singh, 1974) (specimens from this host seen); S. curtisii Dyer ex King ( Daljeet-Singh, 1974) ; S. laevis Ridley ( Daljeet-Singh, 1974) ; S. platyclados V. Sl. ex Foxw. (Daljeet- Singh, 1974). Records given in Toy (1988) are all based on specimens used in this study, and are correct identi®cations.

A single male is recorded as reared from Vatica umbonata . This is the only record from a dipterocarp other than Shorea species , and is most likely to be a mislabelling. Specimens examined

HOLOTYPE, m: Malaysia: Sabah, with labels:`Sandakan / Borneo / Baker’ and`14668’ and` humeralis Hlr / 1939 / Typus’ and`m’ and` HOLOTYPE / Alcidodes / humeralis Heller / det Dr E. HAAF 1958’ and`Staatl. Museum fuÈr / Tierkunde Dresden’ ( SMTD).

Other material. Thailand: 3 ll, 1m,`Ligor’ (Castelman) ( BMNH) .

Singapore: 3 ll, 1m, (no further data) ( BMNH) .

Malaysia: Peninsular Malaysia, 1, l 2mm, Malacca ( USNM, IRNSB); Negri Sembilan, Pasoh (Toy), 1986, reared from seeds of: Shorea lepidota (1m), Shorea leprosula (3 ll, 2mm), Shorea macroptera (3mm), Shorea acuminata (2 ll, 2mm), Shorea ovalis (1m), Shorea parvifolia (1 l); same locality and collector, trap in canopy of Shorea leprosula (1 l); same locality and collector, trap in canopy of Shorea parvifolia (3 ll); Selangor: FRIM Arboretum, Kepong (Toy) 1986, water trap in canopy of Shorea longisperma (1 l) ( BMNH).

Indonesia: Java, 1, l(no further data) ( MNHN) .

Indonesia: Sumatra, 1, l(no further data) ( MNHN); 1 lN . Sumatra; Madan, Bukit Lawang 11-12 October 1990 (Riedel) ( ARC) .

Brunei: 1, l 2mm, Temburong Distr. Kuala Belalong, September ±October. 1992 (Lyal and Margerison Knight), reared from dipterocarp seeds; 1m, same locality, 20 October 1992, collected on palm (Martin). ( RBM, BMNH) .

Malaysia: Borneo: Sabah, 1, l Sandakan ( USNM); 1m, Lahad Dadu; Sungai Tabin, 15 February 1990 (Lantoh), reared from seed of Shorea johorensis (FRCS) .

Indonesia: Borneo: Kalimantan, Gunung Palung National Park, Cabang Panti Research Station January± April 1991 (Curran), reared from seeds of: Shorea atrinervosa (3 ll, 4mm), Shorea brunnescens (1 l), Shorea crassa (3 ll, 1m), Shorea gibbosa (1 l), Shorea johorensis (123 ll, 126mm), Shorea kunstleri (8 ll, 7mm), Shorea ovalis (62 ll, 61mm), Shorea ovalis sericea (1m), Shorea parvifolia (4 ll, 1m), Shorea parvistipulata (7 ll, 10mm), Shorea parvistipulata x albifolia (1, l 5mm), Shorea pauci- X ora (2 ll, 3mm), Shorea platycarpa (1 l), Shorea quadrinervis (13 ll, 15mm), Shorea rubra (11 ll, 11mm),`Vatica umbonata ’ (1 l). ( BMNH, MZB, UMMZ).

Range. Thailand, Peninsular Malaysia, Singapore, Java, Sumatra, Borneo.

Hosts. Shorea acuminata Dyer , S. atrinervosa Sym. , S. brunnescens Ashton , S. crassa Ashton , S. gibbosa Brandis , S. johorensis Foxw. , S. kunstleri King , S. lepidota (Korth.) Bl. , S. leprosula Miq. , S. macroptera Dyer , S. ovalis (Korth.) Bl. , S. ovalis sericea (Dyer) Ashton , S. parvifolia Dyer , S. parvistipulata Heim , S. pauci X ora King, S. platycarpa Heim. , S. quadrinervis Sloot. , S. rubra Ashton.