Griburius febriculosus, Sassi, 2023

Sassi, Davide, 2023, Five new species of the genus Griburius Haldeman from Central America (Coleoptera: Chrysomelidae, Cryptocephalinae), Fragmenta entomologica (Deerfield Beach, Fla.) 55 (1), pp. 117-138 : 119-123

Griburius febriculosus sp. nov.

( Figs 1 , 8a )

Types. HOLOTYPE: m#, body, aedeagus and detached abdomen glued on the same card, “ MEXICO, Veracruz Est. Biol. de Los Tuxtlas 18°35’N 95°05’W ” [white label, printed] // “ 4.V.1991 H.A. Hespenheide ” [white label, printed, partly handwritten] // “ Griburius febriculosus sp. nov . HOLOTYPUS D. Sassi des.” [red label, printed] // ( TAMU) . PARATYPES (8 specimens): MEXICO, CHIAPAS: Hwy 199 10 km S Palenque San Manuel Rd 30.V.1987 at mercury vapor & blacklight (2m #. ERPC, DSPC); Comitán de Domínguez (2f#, MNHUB) . MEXICO, VERACRUZ: same data of the HT but 28.IV.1991 (2f#, TAMU, DSPC); ca 15 km N Catemaco 1000 m N 18°32’ W 95° 08’ 26.IV.1991 (1f#, TAMU). “Mexico…” [remainder of the label is unreadable] (1f#, MNHUB). All paratypes are labelled: // “ Griburius febriculosus sp. nov . PARATYPUS D. Sassi des.” [red label, printed] //.

Type locality. Estación de Biología Tropical Los Tuxtlas (Veracruz, Mexico) .

Etymology. Latin adjective meaning feverish. No specific reference to the taxon, but the evening I was working on it, it turned out that my daughter had just got the COVID-19 disease.

Distribution. Mexico.

Diagnosis. A species of Griburius characterized by unusually strong and dense punctation on the elytra and pronotum. On the latter the punctation tends to become wrinkled. The species seems to show an evident chromatic dimorphism, the males being dorsally yellow with a pattern of black lateral bands, while the females available for the study have entirely black elytra and pronotum. In terms of dorsal colouration, the species vaguely recalls Pachybrachis forreri Jacoby 1889 (see http://www.chrysomelidae.it/amer-pachy/p.-forreri.html), which however is well distinguished by the shape of the pronotum, much less transverse, by the elytra slimmer and not converging towards the apex, and by the finer punctation.

Description of male. Habitus in Fig. 1 a-c (PT). BL = 3.7–4.0 mm, BW = 2.4–2.7 mm, PL = 1.4–1.6 mm, PW = 2.2–2.3 mm. Interocular distance = 0.0 % (inner eyes margins are in contact along median line).

Head yellow with vertex and, at times, part of clypeus black. Labrum yellow. Head surface basically devoid of setosity. Surface of frontoclypeal area with few, scattered, shallow-impressed punctation. Upper lobes of eyes in contact along midline, so neither interspace nor mid-cranial suture visible in between. Ocular lines strictly adhering to ocular rim, marked with a line of fine punctures along lower part of upper lobes. Ocular canthus large, angular. Antennae ( Fig. 1h ) with first six antennomeres yellow, reminders brownish. Antennomeres 3-5 bright, subcylindrical; antennomeres 6-11, dull, flattened and more diffusedly setose.

Pronotum black with lateral margins yellow. Two trapezoidal spots in posterior part of disc, close to midline, touching posterior margin and median line raising from anterior margin and reaching middle of disc yellow as well. At times, discal spots fused together giving single trilobate marking. Pronotal shape elliptical, scarcely transverse, regularly convex. Lateral margins narrow, visible from above only along posterior half, angularly curved at middle, with maximum width at about middle. Surface dull, covered with coarse strongly impressed punctation evenly distributed across whole pronotal surface. Punctures deep, lengthened, partly coalescent at middle of disc to form longitudinal ridges. Posterolateral impressions well marked just up to midline, so that pronotal outline looks slightly raised in lateral view.

Scutellum yellow, triangular with apex truncated in straight line. Surface sparsely micropunctured.

Elytron black with large yellow patch along suture, broadened to reach fifth row of punctures on anterior half, at about middle and on apical clivus. In holotype yellow patch on apical clivus separated from anterior one to form independent spot. Epipleuron yellow along anterior half. Elytral outline with sides almost straight and posteriorly convergent. Lateral margin rather large, simultaneously visible from above from apex to humeral callus. Elytral surface slightly flattened on disc, dull with strong, coarse, deeply impressed punctuation, partly coalescent to give rugulose appearance to disc surface. Punctures arranged in almost regular rows above all along inner part of disc. Intervals raised. Postscutellar area perceptibly raised. Humeral callus prominent, impunctate. Epipleuron flat, slightly rugulose.

Pygidium totally yellow; surface bright, covered with shallow punctures and short, semi-erect pale setae.

Ventral parts of thorax black, with prosternal process and most of metasternum yellow. Inner part of metaepisterna bordered with yellow as well. Abdominal ventrites yellow with central part of ventrites 1-4 light brown. Medial projection of ventrite 1 yellow. Hypomera almost bare, shiny, covered with dense, strong punctures; mesoepimera and mesoepisterna shiny, with fine, scattered punctation. Remainder of ventral surface matt, covered with thick, short, regularly distributed setae and fine, shallow punctures. Prosternal process large with sides almost straight between anterior coxae; surface almost flat, closely but shallowly punctured, covered with sparse semi-erect setae. Legs totally yellow.

Median depression on fifth abdominal ventrite distinct, narrow. Ventrite posterior margin shallowly but perceptibly notched. Median lobe of aedeagus ( Fig. 1 m-o) dorsoventrally flattened, terminated by median, long, pointed, apical process, delimited by mildly concave sides. In lateral view apex perfectly straight. Ventral surface marked by median low, linear carina. Setose depressions very shallowly impressed, with few, scattered, very small punctures and long arcuate setae. In dorsal view, in all examined specimens, membranes of endophallus always protruding from apical foramen. Among them, two apical lobes, extending sideways, always well distinguishable.

Female. Habitus in Fig. 1 d-f (PT). BL = 3.6–4.5 mm, BW = 2.3–2.9 mm, PL = 1.2–1.6 mm, PW = 2.1–2.6 mm. Interocular distance = 8.3–8.9 % of BL.

In females the head surface is black with the lower margin of clypeus and labrum yellow. The eyes are smaller and more separated along midline, and the head surface is evenly covered with coarse punctation. Additionally, upper parts are totally black, while yellow pattern on ventral parts is more extended, being the abdominal tergites and ventrites totally yellow.

The fifth abdominal ventrite in females has a quite large, subelliptical, and deep pit. The bottom of the pit is glabrous, matt, slightly darkened in respect to the surrounding surface, impunctate but covered by tiny wrinkles. The vasculum of the spermatheca ( Fig. 1i ) is not pigmented, slender, sickle shaped with slightly curved, not swollen proximal lobe. The distal lobe is slender, almost straight in the first trait and then abruptly curved at apex. The ampulla is not pigmented, short. The duct insertion on the ampulla is short, neither thickened nor pigmented. The sperm gland insertion is rather long and slightly curved. The duct is uniform in size, slender, short, quite rigid, forming a single turn near the vasculum, then straight, devoid of further coils and turns. The insertion on the bursa copulatrix is simple, neither swollen nor pigmented.

Remarks. The single male from Comitán de Domínguez is dorsally totally black apart from two triangular yellow spots on the anterior angles of the pronotum, and the scutellum, which is yellow as well. The single female from the same locality also differs from the others in the yellow lateral sides of pronotum and lower part of frontoclypeal surface, up to ocular lobes, yellow as well. Besides, the proximal lobe of the vasculum is fairly swollen at base. However, because of the small number of the available specimens, it is impossible to give any taxonomic significance to this variability.

Figures

Fig. 1 – Griburius febriculosus sp. nov. a–b, habitus, dorsal and lateral view (PT, male); c, frontal view, male; d, frontal view, female; e–f, colour variation, female; m–o, median lobe of aedeagus in ventral (m), dorsal (n) and lateral (o) view [0.7 mm]; h, antenna [1.7 mm]; c spermatheca [0.3 mm]. sd, setose depressions. Square brackets: length of scale segment.

Fig. 8 – Distribution maps. a, Griburius febriculosus; b, G. gracilis; c, G. mokaya; d, G. puncturatus; e, G. textus.