Apodrosus alternatus Anderson

Anderson, Robert S. & Zhang, Guanyang, 2017, The genus Apodrosus Marshall, 1922 in Cuba (Coleoptera, Curculionidae, Entiminae, Polydrusini), ZooKeys 679, pp. 77-105 : 81-84

Apodrosus alternatus Anderson sp. n. Figures 4-6

Specimens examined.

5 males, 8 females. Holotype male (CMNC), labelled CUBA: Province Guantanamo, El Yunque, 360 m, 20.34501, -74.56642, IV.2014, CarBio Team, CU-15. Paratypes. Same data as holotype (1 male, 2 females; CMNC). El Yunque, 20-150 m, 20.317, -74.571, 31.I.2012, R. Anderson, wet rainforest (1 male; CMNC). El Yunque, along trail to peak, 20.35060, -74.57497, 550 m, beating shrubs and trees, leg. N. Franz, 1.II.2012 (4 females; ASUHIC). El Yunque, Finca La Delicia, 4 km SW Flora y Fauna Station, 20.32085, -74.57014, 150 m, F. Cala, 1.II.2012 (1 female; ASUHIC). El Yunque, along road near Flora y Fauna Station, 20.32775, -74.56941, 100 m, N. Franz, 31.I.2012 (2 males; ASUHIC). Nibujón, Parque Nacional Humboldt, Sendero Mirador, 3 km N. Nibujón, 20.52036, -74.69018, 100 m, on plants, N. Franz, 2.II.2012 (1 female; ASUHIC).

Diagnosis.

This species is distinguished from other Cuban species by larger eyes, elytra with intervals 3 (subbasally and discally), 5 (subbasally) and 7 (at humerus) elevated above adjacent intervals (moreso in female than in male), and distinctive male genitalia with the aedeagus length about 4.5 times maximum width.

Description.

Male. Body length 3.0-3.4 mm; in dorsal view 2.1-2.3 times longer than greatest width which is between midlength and second third of elytra; dorsal outline in lateral view slightly convex. Vestiture composed of pink, pinkish-white to brown scales, with very small recurved, fine brown setae. Eyes 1.6 times longer than wide, projected, separated from anterior margin of prothorax by 0.25 times greatest diameter of eye; line of anterior margin of eyes slightly impressed; shortest distance between eyes (dorsal view) 0.3-0.4 times greatest width of pronotum; median furrow linear, narrow and deep, extending from anterior margin of eye but not reaching anterior margin of pronotum. Rostrum slightly longer than wide; epistoma apically with a single seta situated on each side; nasal plate well defined, tumid, steeply declivious. Antennal insertion apicad of midpoint of rostrum; scrobe curved downwards by 45°, directed posteriorly at end, barely reaching anterior margin of eye, separated from it by 1.5 times width of scrobe. Mandibles with 2 lateral setae. Antennae reddish brown; antennal scape extending to just slightly before posterior margin of eyes; desmomere I about same length as II. Pronotum cylindrical, about as long as wide, greatest width near base; dorsal surface shallowly punctate, each puncture with a curved, fine brown seta; posterior margin slightly bisinuate, slightly wider than anterior margin; scutellum subcircular, rugose and glabrous. Mesocoxal cavities about 3 times width of intercoxal process. Metasternum with lateral portions posteriorly produced. Elytra in dorsal view 1.5 times their greatest width; anterior margin slightly sinuate; humeral region of elytra 1.5 times width of posterior margin of pronotum; lateral margins slightly divergent until second third, thereafter convergent; apex acutely rounded; in lateral view with dorsal outline slightly convex; posterior declivity gradually descending; striae 9 and 10 separate along entire length; intervals completely covered with scales, with dark and light areas forming an irregular pattern; interval 3 slightly produced at base and again at middle on disc, interval 4 tumid at base, interval 5 produced at base, then less so, then pronounced again throughout most of length, humerus distinctly angled; interval 9 slightly tumid above metacoxa; all intervals with recurved, fine brown setae. Venter with scales denser, larger on ventrites 1 and 2, small and fine, some seta-like, on ventrites 3-5; ventrite 2 about as long as ventrite 1 (medially), ventrites 3 and 4 subequal in length, their combined length slightly shorter than ventrite 5; posterior margin of ventrite 5 widely rounded, finely narrowly emarginate at middle, apex at middle narrowly impressed. Tegmen with tegminal apodeme 0.6 times length of aedeagus; tegminal plate simple. Aedeagus in dorsal view about 4.5 times longer than its greatest width; apex rounded. Endophallus with a pair of large asymmetrical hook-like sclerites positioned near midlength, two elongate fields of microtrichiae extended between aedeagal apodemes, and a faint apical sclerite complex. Aedeagus in lateral view slightly evenly convex. Aedeagal apodemes about 0.5 times length of aedeagus.

Female. Body length 3.3-3.8 mm. Differing from male as follows: elytra with interval 3 produced at base and again more strongly so at middle on disc, interval 4 tumid at base, interval 5 strongly produced at base, then less so, then moderately pronounced again throughout most of length, humerus distinctly angled, humeral interval somewhat produced a short distance beyond humerus.

Etymology.

This species is named after the Latin adjective " alternatus ", referring to the alternating elevation of the elytral intervals.

Natural history.

Adults were collected beating vegetation along trails in tropical wet forest.

Comments.

During the initial phase of this study, this species and A. pseudoalternatus were considered as conspecific. Males can be separated by the form of the aedeagus but females at present are not separable using external features.