Omolabus quadratus (Sharp)

HAMILTON, ROBERT W., 2005, Omolabus Jekel in north and central America (Coleoptera: Attelabidae), Zootaxa 986 (1), pp. 1-60 : 11-13

Omolabus quadratus (Sharp)

( Figs. 2 , 10 , 29, 30, 31 & 32) Attelabus quadratus Sharp 1889: 11

Type locality. Chontales, Nicaragua

Type data. Two card mounted female syntypes with the following labels were examined: 1) Attelabus quadratus , Type, D. S., Chontales, Janson (on card with specimen); Type [circular label with red margin]; Chontales, Nicaragua, Janson; BCA Col. IV.3., Attelabus quadratus Sharp. 2) Attelabus quadratus D. S., Chontales, Janson [on card with specimen]; Chontales Nicaragua, Janson; BCA Col. IV.3., Attelabus quadratus Sharp. The first mentioned female is here designated as the lectotype.

Type holder. British Museum of Natural History ( BMNH)

Size range. Male: 3.7 x 2.0 mm (minor male) to 6.0 x 3.0 mm (major male); Female: 3.8 x 2.0 mm (minor female) to 5.4 x 2.8 mm (major female).

Description. Body reddish­brown or blackish­brown throughout. (Major male): Head distinctly elongate,with two raised areas at dorsal base separated by median sulcus, strongly narrowed from base to just behind eyes, transversely strigate through middle, with some postocular punctures, with prominent bluntly rounded subocular denticle; with shallow smooth rounded genal concavity; frons and vertex bisulcate with smooth wide median channel; eyes nearly round, strongly protuberant. Rostrum longer than head, bisulcate at dorsal base, lateral base coarsely punctured, moderately punctured beyond antennal insertions, less punctured at dorsal apex; apex about twice as wide as width of frons; postlabial area with elongate chin­like process; process weakly bilobate at apex.

Antennae inserted near basal 1/3; club elongate­compact, distinctly shorter than funicle; basal segment longest; middle segment distinctly shorter than basal segment; terminal segment slightly shorter than middle segment; funicular segment 1 ovo­globose, slightly shorter than scape; 2–4 clavate, subequal; 3 like 2–4 but slightly shorter; 5 and 6 subequal, short, clavate; 7 like 5 and 6 but more robust. Pronotum strongly robust, with small triangular postocular projection, with distinct cup­like dorso­basal depression; posterior rim of depression broadly U­shaped, carinate; carina broken at middle; laterally with oblique linear groove on each side; anterior collar distinct, band­like. Scutellum twice as wide as long; 4­sided; posterior margin broadly rounded. Elytra short, as wide as long, in dorsal view narrowed posteriorly, with weak transverse depression behind scutellum, widest at humeri; humeri simple, rounded, moderately protuberant; with distinct dorsal posthumeral hump­like protuberance; striae more distinct at base, forming linear grooves, becoming smaller posteriorly, more shallow and less distinct from middle of elytra to apex; intervals convex basally; beyond elytral base becoming wide, smooth, flat. Profemora strongly stalked, ventrally angulate with angle minutely strigate. (Minor male): Head not elongate, without raised basal areas; subocular denticle weakly developed; rostrum subequal in length to head; postlabial process small, bluntly denticulate; pronotum only with oblique lateral grooves; profemora evenly swollen, weakly stalked. (Female): Head not elongate, without doro­basal raised areas, without subocular denticle; eyes oval; rostrum subequal to head in length, without postlabial armature; antennae inserted near basal ¼ of rostrum; pronotum only with oblique lateral grooves; profemora evenly swollen, not stalked.

Distribution ( Fig. 2 ). All specimens examined are from Costa Rica and Panama.

Comments. The species can be recognized by the dark reddish­brown color and hump­like posthumeral protuberances (Figs. 29–32). Major and minor males have confused the taxonomy of this species. The single elongate postlabial projection, unique head characters and pronotal sculpture of the major males are diagnostic. The aedeagus, including the TA, of this species is very similar to that of O. ligulatus (compare Figs. 10 & 14 ) and reveals a close relationship between these two species. I refer to this species and O. ligulatus as “chin” weevils due to the distinct singular chin­like postlabial projection (Figs. 29 & 41). Several species from South America also exhibit this chin­like projection.

Host plants. Specimens have been taken on Spondias sp. ( Anacardiaceae ) and G. Vogt specimen labels record this species as feeding on and rolling the leaves of S. mombin (L.). F. Odegaard (personal communication) has observed O. quadratus feeding on leaves of Tapirira guianensis and Spondias mombin (Anacardiaceae) in Panama. The Oedegaard specimens were collected from canopy cranes at 15–25 m above ground.

Specimen data. 133 specimens were examined. The sexes and label data are as follows:

COSTA RICA: 1 male, Punt.[Puntarenas], Ricon de la Osa, 26­vii­1966, D Veirs; 1 male, Ala.[Alajuela], 20 km S Upala, 24­i­1991, FD Parker; 2 females (same except 15–18 iii­1991); 1 female (same except 12­ii­1991); 1 female (same except 21 –30 iv­1991); 1 male, [Cartago], Turrialba, 11­vii­1971, G Ekis; 1 male, Guanacaste, Area de Conservacion Guanacaste, Corridor Biologico, 25­v­00, RW Flowers; 1 male, S. Jose [San Jose], 5 km SW Escazu, 24­v­1995, 1200 m, J Rifkind (CWOB); 1 female, Heredia Prov. La Selva

biol. sta. 3 km S Pto.Viejo [Puerto Viejo], 19­iv­1988, 10° 26' N 84° 01' W, HA Hespenheide; 1 female (same except 17­vi­1982, young lvs. of Spondias ) (CHAH); 1 male, Turrialba, iv[?]­1984, Spondias mombin, G Vogt (USNM); 1 male, Sta. Clara pr. [Santa Clara Province], Hamburg Farm, 21­viii­1925, Nevermann; 1 female, Turrialba, 28­v­1951, OL Cartwright; 1 female (same except 6­vi­1951) (USNM).

PANAMA: 22 males & 26 females, Pina, vii­1983, feeding & nidifying small leaf Spondias, G Vogt ; 2 males, clearing en route to Pina, R. de Panama [Republic de Panama], vii­1983, feeding & nidifying small leaf Spondias, G Vogt ; 3 males & 7 females, El Valle, mesic pass, north of El Valle, R. de Panama, viii­1983, feeding & nidifying small leaf Spondias, G Vogt ; 4 females, Canal Zone, P. N. [Parque Nacional] Soberania, vii­1989 [?], feeding & nidifying Spondias , small leaf also being nidified by A. corvinus, G Vogt ; 1 male & 4 females, Canal Zone P. N. Soberania, vii­viii­1983, P. N. Soberania, small leaf Spondias G Vogt ; 2 females, Madden Forest, 1971, G Vogt; 1 female (same except Madden Forest near Paraiso); 1 male, Madden Dam, 1971, nidifying large leaf Spondias, G Vogt ; 1 male, 1971, G Vogt; 2 males & 1 female, [Canal Zone] Gamboa Pipeline, 1971, G. Vogt; 1 female, Panama [?], Rio near Kolibe [?], 19­ii­1971, G Vogt; 1 male, Circito, Canal Zone, 3­iii­1930, Blackwelder; 1 male, Canal Zone, Barro Colorado Island, 6­vii­ 1961, at light, JM Campbell & JM Kingsolver; 1 female, Canal Zone Barro, Colorado, 11–17 xii­1964, KW Cooper; 1 female, Canal Zone, Lion Hill, 18­vi­1907, A Busek (USNM); 1 male, Chiriqui, La Fortuna area, Finca La Suiza, 10­vi­1995, 1,250 m, wet montane forest, RS Anderson; 1 female, Chiriqui Prv. [Province], vic [vicinity] Hornito, 14–18­v­1996, 4,200', Wappes, Huether & Morris (CMNC); 1 male, Canal Zone, Pipeline Rd, 7 km NW Gamboa, HA Hespenheide; 2 males & 1 female, Canal Zone 3.5 km WNW Paraiso, 13­viii­1971, 9° 2' N, 79° 40' W, H A Hespenheide; 1 male, Canal Zone, 5 mi SW Gatan, 22­ix­1969, 9° 14' N, 79° 58' W, HA Hespenheide; 1 female, Canal Zone, Madden Forest 2.5 mi, 15­vii­1970, 9° 05' N, 79° 37' W, HA Hespenheide (CHAH); 1 male, C. Z. [Canal Zone] Summit, xii­1953, NLH Krauss (AMNH); 1 female, Chiriqui, Alto Lino, 22­ vi­1965, 3,800 m, HG Real (CASC); 1 male, Las Cumbres, 15­viii­1974, 9° 06' N, 79° 32' W, at light, H Wolda; 1 male & 1 female, Canal Zone, 3.5 km WNW Paraiso, 27­vii­1974, 9° 02; N, 79° 40' W, H Stockwell (HPSC); 1 male & 1 female, Canal Zone, Ft. Sherman, 2­viii­1974, CW & O’Brien & Marshall; 1 female, Canal Zone, Achiote rd, 10 km SW Gatun, 12­vi­1976, EG Riley; 1 female, Canal Zone, Barra Colorado Is, 10­vi­1978, uv trap 26 m high, H Wolda; 1 female, Canal Zone, Fort Gulick, iii­1979, at light, HJ Harlan (CWOB); 2 males, Colon Pr., Fort Sherman, 2­iii­2001, on Tapirira guianensis , F. Oede­

gaard; 3 females, Colon Pr., Fort Sherman, 16­iii­2001, 9° 17'N 79° 49'W, on Tapirira guianensis, F. Oedegaard ; 4 females (same except 10­iii­2001); 3 females (same except 10­ii­2002); 1 female, Canal Zone, Pr. [Parque] Nat. [Natural] Metropolitano, 15­iv­1995, on Spondias mombin, F. Oedegaard ; 1 male, (same except Panama, 17­vi­1995); 1 male, (same except Canal Zone, 30­iv­1995); 1 female, (same except 20­v­1995); 1 female (same except 2­vii­1995); 1 male, Canal Zone, Parque Natural Metropolitano, 28­iii­1995, on Anacardium exelsum (FODC).

Figures

FIGURES 1 – 8. Distribution of Omolabus species: 1) Omolabus veracruensis (square), Omolabus spinipectus (circle), Omolabus megalomus (triangle), Omolabus fasciventris (open triangle) 2) Omolabus ligulatus (circle), Omolabus quadratus (open triangle) 3) Omolabus heterocerus (triangle), Omolabus angulipennis (circle) 4) Omolabus laesicollis 5) Omolabus corvinus 6) Omolabus sedatus (circle), Omolabus longiclava (triangle) 7) Omolabus callosus 8) Omolabus conicollis.

FIGURES 9 – 14. Male genitalia of Omolabus species, 64 X: a) tegmen, dorsal view b) median lobe with endophallic sac and transfer apparatus in repose, ventral view 9) Omolabus spinipectus, Costa Rica, Puntarenas 10) Omolabus quadratus, Panama, Pina 11) Omolabus laesicollis Mexico, Guerrero 12) Omolabus angulipennis, Costa Rica, Puntarenas 13) Omolabus corvinus, Mexico, Quintana Roo 14) Omolabus ligulatus, Honduras, Tela.