Cotithene globulicollis Voss

Franz, Nico M., 2008, Revision, phylogeny and natural history of Cotithene Vo s s (Coleoptera: Curculionidae), Zootaxa 1782, pp. 1-33 : 21-24

Cotithene globulicollis Voss

Cotithene globulicollis Voss 1940: 4

Diagnosis. Length 4.5–6.1 mm; rostrum in male ( Fig. 8 A) in lateral view angulate and expanded near apical 2/5, slightly impressed along basal 1/5, head ( Fig. 8 A) with small, posterior, triangular projection and sparse, longer, recurvate setae, pronotum ( Fig. 1 B) expanded, light reddish-brown, prosternum with small obtuse elevation in front of each procoxal cavity, elytra dark-reddish-brown, aedeagus ( Fig. 11 ) apically evenly narrowed, internal sac without ventral, annulate structure; female with color pattern as that of male, procoxal cavities separated by about width of antennal club, spermatheca ( Fig. 11 ) constricted near apical 3/5; association with Asplundia Harling. Cotithene globulicollis may be distinguished from similarly sized members of the leptorhamphis-trigaea clade by the particular combination of modifications on the head and prosternum in males, and by the shorter and wider rostrum in females. This species furthermore differs from members of the anaphalanta-melanoptera clade by its color pattern and characteristics of the male and female terminalia.

Description. Male. Length 5.5–6.1 mm, width 2.4–2.8 mm, l/w = 2.2 (N = 3). Color light reddish-brown, rostrum and head slightly darker, legs yellowish-brown, elytra darker, brown. Rostrum ( Fig. 8 A) 1.5–1.7 mm, r/p = 0.6–0.8; dorsally slightly arcuate, angulate and tumescent near apical 2/5, ventrally straight; dorsally slightly impressed along basal 1/5 (cf. Voss 1940: 5, "muldenartig vertieft"); antennal insertion at apical 1/3 to 2/5. Head ( Fig. 8 A) with slight transverse elevation extending between posterodorsal edges of eyes, with small, posterior, triangular projection, setation sparse, short, recurvate; area adjacent to posterior margin of eye strongly projected, dorsally with row of short, recurvate setae. Pronotum ( Fig. 1 B) expanded (with apparent positive allometry), anterolaterally shallowly impressed. Prosternum with anterior margin tumescent, projected anteroventrad, anterior half transversely impressed, thereafter with shallow impression, anterolaterally of each procoxal cavity with obtuse tumescence; procoxal cavities separated by slightly more than width of antennal club. Legs light reddish-brown to yellow. Scutellum largely covered by elytra. Elytra ( Fig. 1 B) posteriorly slightly attenuate, widest at humeri, gradually narrowing in posterior two-thirds; slightly convex, anterior elevation present, extending along basal 1/5 of I–V; striae slightly narrower than intervals, VIII–X deeper. Spiculum gastrale shorter than aedeagus; furcal arms slightly arcuate, apically narrowed. Adeagus ( Fig. 11 ) l/ w = 3.1–3.3 (N = 3), widest near middle, strongly narrowing in apical 1/5, apex rounded, medially slightly projected; in lateral view apically gradually narrowed, dorsal and ventral margins straight; internally with a symmetrical, narrowly V-shaped pair of explanate sclerites; sclerites in lateral view triangular, slightly deflexed, margins undulate; apodemes shorter than body.

Female. Length 4.5–5.9 mm, width 2.1–2.6 mm, l/w = 2.1–2.3 (N = 3). Color more homogeneously reddish-brown than in male. Rostrum ( Fig. 8 B) 1.6–1.9 mm, r/p = 0.9–1.0; narrow, width similar throughout; antennal insertion at apical 2/5 to middle region. Pronotum less expanded. Prosternum without anterior impressions or tumescences; procoxal cavities separated by about width of antennal club. Elytra posteriorly rounded, widest near anterior third; anterior elevation less distinct; striae shallower than in male. Sternum VIII ( Fig. 11 ) with furcal arms slightly arcuate, subparallel, apices with 4–6 setae. Spermatheca ( Fig. 11 ) C-shaped, inner and outer margins constricted near apical 3/5, apex triangular, acuminate, deflected.

Material examined. Male syntype "coll. DEI Eberswalde / Cotithene globulicollis nv. / Syntypus [red label] / Cotithene globulicollis m. [green label] / Voss det. / Costa Rica, Turrialba, VI, 900 m [green label] /?" ( DEIC). Other specimens: " Costa Rica, Limón, P.N. Br. Carillo, Q. González, 50 m, N 10°09'78'', W 83°56'17'', on Asplundia sp. inflor., leg. N. Franz, VI-11-2003 " ( DEIC, 1 male); " Costa Rica, P. Her. [Heredia], Est. Biol. La Selva (OTS), 40 m, 27-IV-1997, #3, leg. N. Franz" ( CWOB, 1 male); " Costa Rica, Heredia, La Selva, 40 m, on Asplundia vagans , leg. N. Franz, IV-10-1999 " ( NMFC, 1 male); " Costa Rica, Alaj. [Alajuela], Est. Biol. San Ramon, xi– xii- 1999, 900 m, P. Hanson, malaise trap" ( CWOB, 1 male); " Costa Rica, Limón, P.N. Br. Carillo, Q. González, 50 m, N 10°09'78'', W 83°56'17'', on Asplundia sp. inflor., leg. N. Franz, VI-11-2003 " ( DEIC, 1 female; NMFC, 1 female); " Costa Rica: Alajuela, E.B. San Ramon, R.B. San Ramon, 27 km N & 8 km W San Ramon, 10°13'30'' N, 84°35'30'' W, 850–950 m, 29.VI-6.VII.1999, R. Anderson, wet premontane forest, 99-108/ on Asplundia vagans flowers" ( CMNC, 1 female); " Costa Rica: Alajuela, Los Lagos, Volcan Arenal, 600 m, 10°29' N, 84°43'30'' W, 26.III.2000, R. Anderson, on Asplundia (epiphytic)" ( CMNC, 1 female); " Panama, Bocas del Toro, Corriente Grande, Rio Changuinola/ 9°17'30 N, 82°32'41'' W, H. Wolda/ II-7-1980 " ( CWOB, 1 female).

Natural history. Cotithene globulicollis occurs at various localities in the Costa Rican Cordillera Central ( Fig. 13 A), including La Selva (OTS), Quebrada González (Braulio Carrillo), San Ramón (UCR), Turrialba (type locality) and Volcán Arenal, as well as on the Atlantic slope of Panama, Río Changuinola (Bocas del Toro). The reported host associations are with several species of Asplundia Harling , in addition to Asplundia vagans Harling as recorded. At La Selva, Costa Rica, 4–6 individuals were taken on inflorescences of Asplundia euryspatha and A. vagans ( Franz 2007b) . Typically only 1– 2 adults occur on an inflorescence, and their arrival and departure periods are not well synchronized with the anthesis of the inflorescence. Some individuals collected carried small quantities of pollen on different parts of their body. However, their low abundance, the absence of synchronized patterns of arrival and departure and their relatively large size preclude regular contacts with the plant's female flowers during receptivity. Therefore, C. globulicollis weevils are not pollinators of their hosts. Indeed, their behavior on the inflorescences is fairly destructive, as they feed on various floral parts including unopened anthers, bases of the male flowers and all structures of the female flowers. Following arrival, the females of C. globulicollis locate a suitable position on the surface of the inflorescence and then chew their way towards the central axis, into which they eventually oviposit. An entry hole is left after this activity. A single larva hatches and develops inside by feeding along the central axis and adjacent pulp and seeds, which may ultimately cause abortion of the infructescence. Large larvae were located in aborted infructescences, indicating that C. globulicollis larvae can consume living as well as rotting plant tissue during the final stages of development. Their destructive behavior has convergent similarities with Systenotelus Anderson & Gómez , a non-pollinating seed predator of Panama-hat palms in the genus Carludovica Ruíz & Pavón ( Franz 2004) .

Figures

FIGURE 1. Dorsal habitus of Cotithene, males. A, C. dicranopygia; B, C. globulicollis.

FIGURE 8. Rostrum and head of Cotithene globulicollis, lateral view. A, male; B, female.

FIGURE 11. Genital structures of Cotithene globulicollis, from left to right: aedeagus, ventral view; aedeagus, lateral view; posterior region of female sternum VIII, ventral view; spermatheca, lateral view; shaded areas depicting structures of the internal sac.

FIGURE 13. Reported localities of Cotithene in Costa Rica and Panama (A) and Venezuela (B). See text for further detail.