Apodrosus adustus Girón & Franz, 2010

Girón, Jennifer C. & Franz, Nico M., 2010, Revision, phylogeny and historical biogeography of the genus Apodrosus Marshall, 1922 (Coleoptera: Curculionidae: Entiminae), Insect Systematics & Evolution 41, pp. 339-414 : 392-395

Apodrosus adustus Girón & Franz sp.n.

( Fig. 16 )

Diagnosis

Apodrosus adustus is characterized by the combination of having a mesally constricted rostrum, an apically bifurcated median furrow on the head, uniformly colored legs, a slightly produced interval X along the second fifth of the elytra, and a uniform coverage of brown, iridescent (reddish) scales, except on the ventral surface where the scales are whitish. This species may be distinguished from A. empherefasciatus by its uniformly brown dorsal coloration, the lack of a constriction between the cornu and corpus of the spermatheca, and a less developed ramus of the spermatheca.

Specimens examined

Holotype ♀ “ GRAND BAHAMA ISLAND , Freeport , 20-27 June 1987, W. E. Steiner, M. J. & R. Molineaux ” ( NMNH, dissected); paratypes, same label information as holotype (NMNH: 1 dissected ♂, 1 dissected ♀).

Description

Body length 4–4.5 mm; in dorsal view ( Fig. 16A ) 2.1-times longer than greatest width which is at midpoint of elytra, shape subrectangular; dorsal outline in lateral view subplane. Integument surface smooth; vestiture uniformly composed of brown, iridescent (reddish) scales, and white scales on ventral surface, with recurvate, decumbent, brown setae. Eyes ( Fig. 16B ) 1.8-times longer than wide, projected, 0.3-times width and 0.6-times length of head in lateral view, separated from anterior margin of prothorax by 0.6-times greatest diameter of eye; line of anterior margin of eyes impressed; shortest distance between eyes (in dorsal view) 0.4-times greatest width of pronotum; median furrow ( Fig. 16B ) apically bifurcated, narrow, shallow, extending from anterior margin of eyes though not reaching their posterior margin. Rostrum ( Fig. 16B ) 1.2- times wider than long, with lateral margins slightly constricted at basal third; epistome apically with 3–4 setae situated on each side, extending posteriorly as a longitudinal, narrow keel to midpoint of rostrum, nasal plate defined, concave. Rostrum in lateral view slightly wider than long; antennal insertion near apical third of rostrum; scrobe curved downwards by 45°, directed ventrally at end, extending to midpoint of eye, separated from it by 2-times width of scrobe. Mandibles with 2–3 lateral setae. Antennae yellowish brown; antennal scape almost reaching posterior margin of eye; funicular antennomere I 1.8-times longer than II; antennal club 0.5-times length of funicle, 2.6-times longer than wide. Pronotum ( Fig. 16A ) subquadrate, 1.2-times wider than long, with greatest width at anterior third; dorsal surface shallowly puncturate, each puncture with a curved, brown seta; posterior margin slightly bisinuate, 1.2-times wider than anterior margin; prothorax in lateral view ( Fig. 16C ) with dorsal outline 1.5-times length of ventral outline; scutellum subcircular, with scales. Mesosternum ( Fig. 16D ) 0.6-times length of prosternum. Metasternum with lateral portions posteriorly produced (in lateral profile gradually ascending towards posterior third, thereafter descending roundly, posterior face covered with scales); distance between posterior margin of mesocoxae and anterior margin of metacoxae 0.7-times length of prosternum. Legs with profemora 1.2-times length of pronotum; claws subparallel. Elytra in dorsal view ( Fig. 16A ) 1.8-times their greatest width which is 1.6- times wider than pronotum; anterior margins straight; humeral region 1.5-times wider than posterior margin of pronotum; apex rounded; in lateral view ( Fig. 16C ) with dorsal outline subplane; posterior declivity rounded; striae IX and X fused along their second third; intervals completely covered with brown scales; interval X slightly produced along second fifth; with recurvate, decumbent setae. Venter ( Fig. 16D ) densely covered with whitish scales; VII with median posterior pit interrupting posterior margin, anterior margin 2.4-times wider than its length; ♂: IV 1.2-times longer than V and VI jointly, as long as VII, with VII posterior margin rounded; ♀: IV 2-times longer than V and VI jointly, 1.7-times longer than VII, VII with posterior margin mesally narrowed.

Terminalia. Male with tergum VII subpentagonal, nearly as long as wide; anterior margin subtriangular, mesally narrowly rounded, posterior margin mesally emarginate, laterally rounded. Tergum VIII transverse, 2.2-times wider than its mesal length; anterior margin roundly emarginate; posterior margin widely rounded. Sternum VIII with 2–3 apical setae. Spiculum gastrale with apodeme 1.3-times longer than aedeagus, each furcal arm suboval. Tegmen with tegminal apodeme nearly 0.6-times length of aedeagus, tegminal plate mesally slightly projected posteriorly. Aedeagus in dorsal view ( Fig. 16E ) 3.6-times longer than its greatest width, lateral margins parallel; apex widely rounded. Endophallus with a pair of opposed lightly sclerotized areas positioned near apex, and a median reticulate area. Aedeagus in lateral view ( Fig. 16F ) 7.4-times longer than its greatest width. Aedeagal apodemes 0.5-times as long as aedeagus.

Female. With tergum VII as long as wide, suboval, posterior margin acutely rounded. Tergum VIII subtriangular, as wide as long. Sternum VIII with lamina triangular, occupying posterior one fifth. Coxites+styli as long as lamina of sternum VIII, stylus 3.6-times longer than its greatest width, with 1 long and 3 shorter apical setae. Genital chamber 0.6-times length of sternum VIII. Spermatheca ( Fig. 16G ) 1.2-times longer than wide, J-shaped; cornu roundly curved towards ramus; margin between cornu and ramus nearly straight; ramus apically truncate; surface not particularly sculptured.

Variation

Th e examined specimens vary slightly in size. All examined specimens are apparently teneral.

Etymology

Named in reference to the uniform brown dorsal scale coloration, with the Latin term adustus meaning “brown, tanned, swarthy” ( Brown 1956).

Natural history

Apodrosus adustus is apparently restricted to Grand Bahama Island ( Fig. 18A ). The host plan associations remain unknown.

Figures

Fig. 16. Apodrosus adustus. (A) habitus, dorsal view; (B) head, frontal view; (C) habitus, lateral view; (D) habitus, ventral view; (E) and (F) aedeagus in dorsal and lateral view, respectively; (G) spermatheca. This figure is published in colour in the online version of this journal, which can be accessed via http:// www.brill/ise

Fig. 18. Occurrences of Apodrosus species in (A) the Bahamas (Grand Bahama and Andros Island) and (B) Hispaniola, Mona Island, and the Turks and Caicos Islands.