Apotomoderes Dejean (1834: 253)

Franz, Nico, 2010, Revision and phylogeny of the Caribbean weevil genus Apotomoderes Dejean, 1834 (Coleoptera, Curculionidae, Entiminae), ZooKeys 49 (49), pp. 33-75 : 36-45

Apotomoderes Dejean (1834: 253)

= Apotomus Schoenherr (1834: 44) [non Illiger 1807; junior synonym]

= Apotomoderes Schoenherr (1840: 402) [non Dejean 1834; unnecessary replacement name]

= Eurilia Laporte (1840: 308) [unnecessary replacement name]

Type species: Apotomoderes lateralis ( Gyllenhal, 1834: 45) , by monotypy (originally as Apotomus lateralis ).

Diagnosis. Apotomoderes keys to Artipus Sahlberg in Anderson (2002) , by virtue of the absence of a postocular lobe and vibrissae, the laterally positioned scrobe, the long median sulcus on the rostrum, laterally positioned eyes, and the conspicuous epistoma. However, Apotomoderes can be distinguished from this and other genera of Caribbean entimine weevils (cf. O’Brien and Wibmer 1982) by a unique combination of synapomorphic and/or diagnostic features; viz. scale coverage complete; labial palps 2-segmented ( Fig. 3B ); rostrum dorsally with a transverse depression (e.g. Fig. 13B); antennal scape only moderately stout; head with a postocular constriction (e.g. Fig. 9B ); eyes protruded, globular; pronotum sexually dimorphic, larger and more globular in males (e.g. Fig. 11A); metatibial apex simple, without a bevel or flange (“corbel open”), margins lined with spiniform setae, surface surrounding condyle partially covered with scales; presence of setae in the dorsal subapical region of the aedeagus (e.g. Fig. 5D ); aedeagus with a pair of weakly sclerotized rami along ostium; and spermatheca with collum and ramus subcontiguous (e.g. Fig. 17C). In addition, nearly all species of Apotomoderes have a large, knife-like cuticular tooth only on the profemur and a conspicuously toothed ridge along the anteromesal margin of the protibia (in idealized orientation of legs) in both males and females (e.g. Fig. 13C). The genera and species most closely related to Apotomoderes are likely still undescribed (NMF, personal observation), but differ from this taxon minimally by the shape of the head and pronotum.

Redescription – male. Length 4.32–10.70 mm, width 1.65–4.95 mm; shape elongate to oval, length/width ratio 2.16–2.80; widest at humeri (to anterior third). Integument dark reddish brown. Linear, piliform scales (“setae”) sparse throughout, short, recurved, transparent white to yellow. Scales densely and homogeneously arranged throughout, partially overlapping and covering most of integument, mostly subcircular to subquadrate to irregular (pronotum), colors variously interspersed creamy white to beige/tan to (light rusty to dark) brown, or locally “transparent”, scales arranged in complex regional to irregular patters, often locally (rostrum, pronotum, legs, elytral punctures) also with yellowish, greenish, pinkish, turquoise or (pale) blue iridescent metallic scales creating secondary underlying patterns.

Mouthparts. Mandibles with 4–6 longer setae, and several shorter setae and piliform scales adjacent to projected, apicolaterally positioned scar. Maxillae ( Fig. 3A ) with cardo elongate, basically widely bifurcate, with sparse setae; stipes elongate, not mesally projected, with lateral setae; galeo-lacinial complex not extending to apex of maxillary palpomere I, apically rounded, covered with setae throughout, with 6–8 apicomesal “lacinial teeth” ( Ting 1936), thereafter (along mesal margin) with a tuft of very long setae; palpiger with transverse row of setae; maxillary palps 3-segmented; I longer than II, with 2 apical setae; II slightly shorter than III, with 2 apical setae; III elongate, with parallel sulci, apically papillate. Labium ( Fig. 3B ) with prementum entirely covering maxillary palps; escudate or pentagonal, ventrally evenly concave; apical margin medially projected (ligula), angulate; each lateral region with 3–5 long setae; labial palps 2-segmented, II reaching apical margin of prementum; I shorter than II, with 1 apical seta; II elongate, apically papillate.

Figure |. Habitus of A. lateralis : A male, dorsal view B male, lateral view C male, ventral view D female, venter, ventral view.

Rostrum. Length 0.45–1.28 mm, rostrum/pronotum length ratio 0.28–0.42, rostrum length/width ratio 0.60–0.82; shape in cross-section subrectangular. Dorsal outline of rostrum subrectangular; dorsolateral margins anteriorly slightly diverging; apical margin emarginate-triangular, profoundly incised. Nasal plate ( Vaurie 1963) well defined, inversely V-shaped, concave, posteriorly carinate; epistoma forming a narrow line basad of carina, without scales yet with a row of long, mesally directed setae; region basad of epistoma distinctly depressed, covered with variously colored, iridescent metallic scales. Dorsal surface of rostrum with a subcircular to transverse concavity near midpoint, and with 1 median sulcus extending from posterior margin of epistoma to imaginary midpoint between (or slightly beyond) dorsal margins of eyes, ending in a narrow fovea; each dorsolateral margin with (or without) a poorly defined, short and irregular sulcus anteriad of eye; ventrolateral margins subparallel. Rostrum in lateral view nearly straight, apically slightly expanded; ventrolateral sulci well defined, extending parallel to and ventrad of scrobe; margins of mandibular incision with evenly spaced, linear scales. Rostrum ventrally with 2 paramedian sulci. Antennal insertion near anterior 2/5 of rostrum. Scrobe lateral, strongly curved and posteriorly widened (subtriangular), initiating at apicodorsal apex, region, terminating in ventrolateral region, anteriad of eye, dorsal margin angulate, ventral margin (typically) curved, covered with scales.

Antennae 11-segmented. Scape moderately stout, nearly straight, clavate; extending to region between posterior margin of eye and anterolateral margin of pronotum, directed ventrad of eye in idealized position; covered with linear scales. Funicle 7-segmented, slightly longer than scape; funicular antennomeres progressing from elongate to equilateral, clavate, covered with appressed and suberect, linear scales; I and II (usually) similar in length. Club 3-segmented, similar in length to funicular antennomeres III–VI, nearly 3× longer than wide, dark brown, pubescent; I and II similar in length; III slightly longer, conical, transversely sutured.

Head. Eyes laterally positioned, variously globular, strongly protruded, in some species posteriorly abruptly curved and “tilted” posteriad, anterodorsal margin of each eye impressed, posterior margin nearly straight, elevated (set off) in relation to head; eyes (usually) separated (in dorsal view) by distance nearly 2× as long as anterior-toposterior length of each eye. Head with apparent postocular constriction extending along entire circumference, rostrum and head in lateral view angulate.

Thorax. Pronotum variously equilateral, length/width relation 0.80–1.20, pronotum/elytra ratio 0.42–0.55, slightly to strongly globular (convex); widest near midpoint, anteriorly constricted; surface punctate, with equilateral to irregularly shaped, variously colored scales; median sulcus absent. Anterior margin of pronotum slightly curved, lateral margins strongly curved, posterior margin bisinuate, posterior side with plumose scales. Pronotum in lateral view globular, anteriorly constricted; anterior margin nearly straight, postocular lobe and vibrissae absent.

Scutellum exposed, semi-circular, slightly wider than long, anterior margin straight, posterior margin rounded, covered with creamy white scales.

Epipleura with mesepisternum triangular; mesepimeron dorsally obliquely narrowed; metepisternum linear, anteriorly abruptly widened; metepimeron entirely covered by elytron.

Prosternum (Figs. 1C, 14B) longer than mesosternum, with a transverse sulcus on each side anteriorly and posteriorly of procoxal cavities; procoxal cavities positioned at midpoint, contiguous, prosternal process short, elevated. Mesosternum slightly shorter than metasternum, strongly angulate, mesocoxal process slightly elevated; anterior half coved with plumose scales, posterior half with longer, suberect, linear scales; mesocoxal cavities separated by distance nearly half as long as width of each mesocoxal cavity. Metasternum with median sulcus present as a large, transverse fovea positioned anteriad of posterior margin, surface slightly undulate, posterolateral regions set off (with small posterior “face”), and with linear scales (see above); metacoxal cavities separated by distance slightly shorter than width of each mesocoxal cavity.

Metendosternite ( Fig. 4A ) with stalk slightly shorter than furcal arms, ventral margin 2–3× wider than dorsal width of stalk; hemiducts wide, truncate; dorsal margin of sheath undulate; anterior tendons positioned near midpoint between median keel and base of furcal arms; furcal arms diverging at 30–45° in relation to medial keel.

Legs. Prothoracic legs longer than mesothoracic legs; scale colors variously interspersed, though forming a more uniform light/dark/light pattern on femora, metallic scales often present on anterior sides of profemora and near tibial apices; ventral sides of tibiae with rows of longer, whitish or yellowish, suberect setae. Profemur/pronotum length ratio 0.80–1.08; profemur moderately stout, in cross-section subcircular; (usually) with 1 very large, knife-like cuticular tooth inserted at apical 2/5 on anteromesal margin, tooth ventrally directed (absent in one examined species). Protibia/profemur length ratio 0.84–1.02; protibia moderately stout, nearly straight, in cross-section elliptical, apically slightly expanded; anteromesal margin with a distinct, laminate, rounded or triangular projection near basal 2/5 (absent in one examined species), from thereon to apex with row of 10–15 smaller, apically rounded or (oblique) truncate cuticular teeth (teeth larger along laminate projection), each tooth distally with an aurate, spiniform seta; protibial apex with anterior margin truncate, setal comb absent; mucro similar in length to tarsal claw, surpassed by tufts of aurate setae. Protarsus with tarsomere I nearly 2× as long as II, elongate, clavate; II and III similar in length, equilateral to transverse; and jointly similar in length to V; claw paired, separate, simple. Meso- and metathoracic legs slighter shorter and longer than prothoracic legs, respectively; meso- and metafemora unarmed; meso- and metatibiae lacking laminate projec- tions, teeth along anteromesal margin less pronounced; metatibial apex simple, with anterior margin curved (on side opposed to mucro), projected, margins with a comb of spiniform setae of increasing length, yet without a bevel or flange (“corbel open”), surface surrounding metatarsal condyle glabrous to partially covered with (metallic) scales “invading” surface from dorsal side.

Elytra. Length/width ratio 1.52–1.90; widest at humeri (to anterior third); anterior margins jointly wider than posterior margin of pronotum, sinuate; humeri obliquely rounded; lateral margins posteriorly slightly converging in anterior half, thereafter more strongly converging, rounded, posteriorly attenuate; posterior margins narrowly truncate. Elytra in lateral view slightly convex; posterior declivity apparent though not strongly angulate, nearly straight. Elytra with 9 complete striae and 1 incomplete stria; striae similar in width to intervals; stria X indistinct (“merging with stria IX”) in second third of entire length; punctures separated by distance similar to, or slightly longer than, width of each puncture; intervals slightly elevated; scales covering entire integument, arranged in mostly irregular micro-patterns of creamy white to dark brown hues, though often locally also with iridescent metallic scales, including (in most species) a single colored or metallic scale in each strial puncture.

coxites

Wings. Wings ( Fig. 4B ) fully developed (absent in one examined species), elongate (linear), wing/body length ratio 1.15–1.35, wing length/width ratio 3.30–3.78; anterior margin slightly angulate near midpoint; posterior margin nearly straight, undulate in anal area; anal lobe absent. Alar veins well defined: C, Sc, R, Rr and rs distinct, radial cell present; M r and Cu 1 short, r-m reduced; 2A distinct, 3A and 4A weaker; R 3 distinct, M 1 reduced, only apparent distally.

Abdomen. Venter (Figs. 1C, 1D, 14B) with segments III and IV narrowly connected (jointed), slightly elevated, V-VII separate; appressed, subcircular scales less abundant in mesal region of venter, “replaced” with longer, suberect linear scales, particularly on III and posterior half of VII; III longer than IV, mesally plane, posterior margin slightly emarginate; IV longer than V and VI together; V and VI similar in the length, anterior and posterior margins nearly straight; VII similar in length to IV, (widely) subtrapezoidal, with 2 subcircular, slightly impressed anterolateral regions with abundant scales, lateral margins gradually rounded, posterior margin very slightly emarginate. Tergum VII on each side with a subcircular, transversely strigulate region. Pygidium (tergum VIII) entirely covered by elytra, convex, lateral margins posteriorly roundly converging, posterior margin plicate, medially roundly emarginate.

Terminalia . Sternum VIII ( Fig. 5A ) consisting of 2 transversely oriented, subtriangular sclerites (connected via membrane); each sclerite laterally acuminate, posterior margin strongly angulate, with 4–6 setae; spiculum relictum minute. Spiculum gastrale ( Fig. 5B ) slightly longer than median lobe; anteriorly expanded into an alate, irregular lamina; stylus slightly sinuate; posteriorly bifurcate, furcal arms weakly sclerotized, wide and explanate, arms apically slightly diverging, gradually narrowed, apices more sclerotized, slightly curved outwards, lacking setae. Tegmen ( Fig. 5C ) slightly shorter to slightly longer than median lobe; tegminal apodeme slender, sinuate; basal piece apically with 2 narrowly triangular projections (parameres), each arm apically increasingly finely denticulate. Aedeagus (e.g. Fig. 5D ) with median lobe (aedeagal pedon) length/width ratio 6.12–9.50; basiventral margin strongly emarginate, with 2 lobe-like (to triangular), sclerotized projections; lateral margins mostly subparallel throughout, outline minimally expanded in region of ostium, thereafter gradually converging, rounded or straight, apex variously rounded to narrowly projected. Median lobe in lateral view homogeneously curved; width similar throughout basal three fourths of entire length, in apical fourth dorsal margins converging towards apex in a straight line; dorsal subapical region with a small region of short, recurved setae; apex narrowed or with a terminal, knob- or lobe-like projection. Internal sac with variously plicate membranes though lacking sclerites or denticles, in most species with 2 weakly sclerotized, angulate-uncinate rami (apices directed laterally or mesally); ostium large, elliptical, basal and apical edge of ostium each with a recurved invagination. Aedeagal apodemes nearly half as long as median lobe, proximally embedded in a membranous evagination of median lobe, not sclerotized; distally sclerotized, slender.

Female. Overall very similar to male. Length 4.76–11.88, width 1.95–4.60 mm, length/width ratio 2.40–2.92, widest at humeri to midpoint. Rostrum length 0.46– 1.32 mm, rostrum/pronotum length ratio 0.30–0.46, rostrum length/width ratio 0.60–0.82. Eyes slightly less protruded and/or posteriorly “tilted”. Pronotum length/ width ratio 0.92–1.04, pronotum/elytra length ratio 0.36–0.48, typically slightly smaller, less globular, and anteriorly less constricted than in male. Metasternum mesally subplane. Profemur/pronotum length ratio 0.80–1.10, profemur slightly less stout, tooth slightly smaller, protibia/profemur length ratio 0.95–1.03. Elytra length/width ratio 1.66–2.08, widest at humeri to midpoint, lateral margins subparallel in anterior half, posteriorly less attenuate, declivity in lateral view more distinct, very slightly concave. Venter with segment VII slightly shorter than IV, subtriangular, lateral margins posteriorly more strongly converging, posterior margin narrowly rounded. Pygidium larger and more triangular than in male, lateral margins posteriorly more strongly converging, posterior margin not plicate, medially with triangular emargination.

Terminalia . Sternum VIII (e.g. Fig. 6A ) with anterior two thirds (spiculum ventrale) narrowly stylate, anterior end knob-like; posterior third (lamina) variously triangular, entire (arms jointed); anterior edges rounded or (slightly) projected, lateral margins nearly straight, continuously converging, posterior margin rounded to truncate; lamina separated in to anterior region (2/5 of entire length) without setae, thereafter laterally with 2 semi-circular, transparent (less sclerotized) regions, and posterior region (3/5 of entire length) with pores, increasingly dense short setae, and several longer setae along posterior margin. Coxites ( Fig. 6B ) similar in length to sternum VIII, elongate, slender, posteriorly slightly narrowed, with 2–3 longer setae; styli relatively small, digitate, apically obliquely truncate, with 2–3 long setae. Genital chamber slightly shorter than sternum VIII. Spermatheca (e.g. Fig. 6C ) variously C-, U-, V-, or?-shaped; collum short to reduced, apex of spermathecal duct truncate; collum subcontiguous with, and variously angled (45–150°) in relation to, (very) short to moderately long ramus; corpus very short, though widest overall (“swollen”); cornu much longer, variously curved to angled, apically gradually narrowed, apex with or without additional deflection.

Variation. Variation in size, shape (relative expansion) of the pronotum, “armature” of the profemur and protibia, and particularly in scale patterns is considerable within and among species of Apotomoderes . In spite of the remarkable palette of scale colors – ranging from creamy white to dark brown and including several hues of iridescent scales that can occur on many parts of the rostrum, pronotum, elytra and legs – these patterns are often too variable to clearly separate species. In older, worn specimens, large portions or nearly all of the scales are lost, or have turned transparent, exposing the underlying, dark reddish brown integument. Some minor intraspecific variation is apparent in the shape of the male aedeagus and female spermatheca.

Natural history. Apotomoderes is restricted to Hispaniola – with two apparently disjunct regions of occurrence in the southwestern and eastern parts of the island – and to Mona Island, Puerto Rico (Fig. 18). The sampled species tend to inhabit lower elevation coastal dry forests. No specific host plant associations are known. It is likely that the species have fairly broad host ranges within their particular habitats, as observed generally in many entimine lineages (e.g. Woodruff 1985; Oberprieler et al. 2007; Franz and Girón 2009).

Etymology. The name Apotomoderes is derived from the name Apotomus (see above), based on the Greek term apo-tomós = abruptly, curtly; and the Greek term deire = neck, throat. Thus the name likely refers to the postocular head constriction. The gender is masculine.

Figures

Figure 3. Mouthparts of A. lateralis: A right maxilla, ventral view B labial prementum, ventral view.

Figure 4. Metendosternite and hind wing of A. lateralis: A metendosternite, posterior view B right hind wing.

Figure 5. Terminalia of A. lateralis, male: A sternum VIII B spiculum gastrale C tegmen D aeadeagus, ventral and lateral view.

Figure 6. Terminalia of A. lateralis, female: A sternum VIII B coxites and styli C spermatheca.

Figure 9. Habitus of A. menocrater: A female, dorsal view B female, lateral view C male, head and pronotum, dorsal view, showing subfoveate punctures D female, declivity with patch of suberect setae, lateral view.