Beltia Jacoby 1881
Creators: name: Flowers, R. Wills
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Beltia

description: Beltia Jacoby, 1881
Beltia nicaraguensis Jacoby 1881: 128; Blackwelder 1946: 656; Flowers 1996: 8, 24.
Figures 1–3, 5, 7–81
Type species. Beltia nicaraguensis Jacoby (1881: 128), by original description. Holotype deposited in MCZ.
Redescription. Body ovate, dorsally convex (Fig. 1); color dark to bright metallic blue, green, or copper; antennae, legs, and underside testaceous to dark metallic.
Head. Clypeus densely punctate, apex of clypeus emarginate. Frons strongly punctate, vertex finely to coarsely punctate, surface between punctures smooth to finely wrinkled, a median impressed line present or absent, antennal calli smooth, weakly swollen. Eyes oval, shallowly and broadly emarginate at antennal insertion. Antenna: Scape elongate oval, pedicel shorter than scape, distinctly shorter than flagellomere 1; antennomeres of male slender, each slightly wider at apex; antennomeres 3–6 slender, with scattered appressed setae; antennomeres 7–11 widened, densely pubescent, with whorl of long erect setae at apex of antennomeres 3–10; antennomere 11 spindle-shaped. Antennomeres 7–11 of females shorter and more cylindrical. Mouthparts: Apex of labrum emarginate or truncate, with two dorsal setae and paired long lateral setae at outer angles. Mandibles piceous, outer margin with sharp bend, lateral surface smooth and setose, a prominent seta on dorsal surface, apical teeth broad, pointed. Maxillary palp with apical segment spindle-shaped.
Thorax. Prothorax distinctly wider than long, pronotum convex, with posterior margin wider than anterior margin; anterior angles acute, directed anteriorly and downward, posterior angles acute; all angles with seta-bearing puncture; basal marginal bead present; lateral margins narrow, rounded; disc regularly punctate, with punctures separated by distance greater to less than their diameters; surface between punctures shining, with numerous punctulae. Undersurface of thorax smooth to finely wrinkled. Prosternum excavated for reception of gular area of head, subquadrate, sparsely punctate; intercoxal process truncate to markedly concave (Fig. 15). Lateral arms of prosternum with anterior margin convex or sinuate, surface setose in anterior half (Fig. 2). Proepimeron weakly concave, sparsely punctate, with punctures separated by distance greater than puncture diameter. Mesosternum subequal in width to prosternum, flat or convex between coxae. Metasternum punctate or alutaceous, with prostrate short setae; metepisternum broad, gradually narrowed posteriorly. Metendosternite (Fig. 7) with a small triangular base and long, narrow lateral branches. Hind wing (Fig. 8) with medio-cubital patch (Jolivet 1957, 1959) distinct.
Legs. Sparsely covered with short prostrate setae; all surfaces alutaceous. Femur strongly swollen in middle. Tibiae widened apically, protibia curved, mesotibia with broad, shallow subapical notch; tibiae multicarinate, deeply sulcate between apical dorsal carinae, metatibia with dorsal carinae forming a pair of high flanges above tarsal insertion (Fig. 5); with setae increasing in length and density toward apex of tibiae. Tarsi densely and uniformly pilose beneath; basal tarsomere of fore- and middle legs triangular, slightly expanded in male, second tarsomere broadly triangular, with acute apicolateral angles; third tarsomere longer than second, deeply bilobed; terminal tarsomere distinctly surpassing apex of third tarsomere; claws divergent, appendiculate.
Elytra. Evenly punctate, punctures larger than those of pronotum; surface between punctures smooth, with small punctulae; humeri prominent, subquadrate; basal calli weakly developed; postbasal depression shallow to obsolete. Sides of elytra subparallel in basal half, convergent in apical third; apices conjointly rounded; a low posthumeral callus present behind humeral callus, followed by a small depression. Epipleuron narrow, slanted downward, tapering evenly from base to apex. Each elytron with three internal flanges at base and apex of sutural margin, and laterally at midlength; a field of tiny spicules present just anterior of lateral flange. Scutellum U-shaped, with base subequal to length; surface smooth, with few punctulae.
Abdomen. Segments subequal in length. Sterna with numerous short setae; male with pairs of submedian setae or submedian patches of longer setae on sterna III–V and a central patch on sternum VI; surface of segments smooth or alutaceous. Male sternum VII with lateral margins smooth, one or two weak depressions in center, long setae along posterior margin. Female sternum VII with lateral margins smooth or crenulate. Terga with row of spicules along basal margin of tergites II and III, and in some species laterally along base of tergum IV; upper surface of terga V and VI shagreened. Pygidium (Fig. 3) with longitudinal median groove broad, shallow, extending almost to apical margin, low median carina present on floor of median groove; pygidial surface smooth basally, shagreened lateral to median groove; lateral margins smooth, with long setae apically.
Male genitalia. Median lobe flattened in cross section, strongly sclerotized along sides but weakly sclerotized in center on ventral side; in en-face view completely membranous except for lateral margins and a narrow apical area; in lateral view bent sharply downward anterior to basal spurs, length of median lobe subequal to one-half length of basal hood (Fig. 42–59, a), apex of median lobe with small to pronounced projection that is often asymmetrical; sub-basal fenestra present; basal spurs prominent; basal hood lightly sclerotized, with apodemes indistinct at lateral margins; tegmen triangular. Endophallus with membranous to partially sclerotized basal and endophallic lobes; apical sclerites small to large, sometimes in conjunction with spicule patches on adjacent membranes (Fig. 42–59, b).
Female genitalia. Segments VIII–XI forming a short and broad, to elongate ovipositor. Sternum VIII with basal apodeme short and Y-shaped (Fig. 69a, 70a, 73a) or long and narrow, often widened apically (Fig. 60–68, a; 71a; 72a; 74a); only several inconspicuous setae remain of apicolateral arms; dorsum of segment VIII weakly sclerotized. Segment IX covered with minute setae along all or part of its length; hemisternites with short to long sclerotized basal rods; paraprocts separated into pair of slender dorsal rods, apically forming hood-like projection above genital orifice; baculum distinct, apical, shorter or subequal to gonocoxae. Gonocoxae of variable length, with long setae at apex; coxostyli very small, with several long apical setae. Spermatheca with receptacle relatively small, bulbous to conical, weakly or not differentiated from pump, spermathecal gland located in apical third; spermathecal duct thin, sclerotized, not coiled (Fig. 60–74, b).
Diagnosis. Beltia can be distinguished from all other Neotropical Eumolpinae by the following combination of characters: 1) pygidium with wing-locking groove; 2) prosternum broadly excavated at anterior margin; 3) lateral arms of prosternum with convex or sinuate anterior margins and with ventral surface concave with appressed whitish setae (Fig. 2); 4) median lobe strongly bent, forming a flattened tube with thin to membranous upper and lower surfaces; 5) apex of metatibia strongly expanded, with a deep channel on the upper surface. Beltia most closely resembles Sterneurus Lefèvre, as noted by Jacoby (1881) in his description of Beltia, but Sterneurus differs in having a low triangular projection on the ventral edge of the profemora, while Beltia has the profemora unarmed, or with distinct tooth in the apical third. Beltia closely resembles Colaspoides in overall form and color (as noted in the Introduction), as well as some large species of Antitypona Weise, e.g. Antitypona gigas (Jacoby). Colaspoides is distinguished from Beltia and Antitypona by its lack of a wing-locking groove on the pygidium, having the entire surface of the prosternal lateral arms convex and glabrous (Fig. 4), and the metatibia with a relatively weak dorsal channel (Fig. 6). Beltia differs from Antitypona in having a sinuate anterior edge of the prosternal lateral arms; in Antitypona this margin forms a continuous even curve with the anterior central margin of the prosternum.
Beltia will key to couplet 10 in Flowers (1996); the separation based on toothed vs. non-toothed profemora is no longer relevant at the generic level.
description: Published as part of Flowers, R. Wills, 2018, A review of the genus Beltia Jacoby (Chrysomelidae: Eumolpinae: Eumolpini), with descriptions of fourteen new species from Costa Rica, Panama, and northwestern South America, pp. 1-43 in Insecta Mundi 672 on pages 3-4, DOI: 10.5281/zenodo.3713503