Griburius ephippiatus
Creators: name: Sassi, Davide
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Griburius
Griburius ephippiatus

description: Griburius ephippiatus (Suffrian, 1866)
(Figs 2; 11b; 12a)
Scolochrus ephippiatus Suffrian, 1866: 148; Clavareau, 1913: 89 [Griburius] (catalogue); Blackwelder, 1946: 639 [Griburius] (catalogue).
Types. Suffrian (1866) did not mention the number of the studied specimens, but he reported that only females were available. After careful searching in the depositories listed by the author, three syntypes were found, two in BMNH and 1 in SDEI. The typification was made as follows, in order to stabilize the epithet. LECTOTYPE (by present designation): (BMNH) 1♀, pinned // “ Scolochrus ephippiatus Suff. Brazil ” [Green label, handwritten] // “ Scolochrus ephippiatus Suffr Brazil ” [White label, handwritten] // “Type Suffr coll Deyrolle” [White label, handwritten] // “Brasilia” [Green label, handwritten] // “Baly Coll.” [White label, printed] // “ Griburius ephippiatus (Suffrian, 1866) (Scolochrus ephippiatus) LECTOTYPUS D. Sassi des.” [red label, printed]. PARALECTOTYPES (2) were designated as follows. (BMNH) 1♀, pinned // “ Sc. ephippiatus.” [White label, handwritten] // “67-56” [White label, handwritten] // “9” [Blue label, handwritten] // “E. Coll. Laferté” [White label, printed] //; (SDEI) 1♀, pinned // “ephippiatus Suffr ” [White label, handwritten] // “ Brasil Kraatz” [White label, handwritten] // “coll. Haag” [White label, printed] // “DEI Müncheberg Col - 14396]” [Green label, printed] //. Both paralectotypes were labelled: // “ Griburius ephippiatus (Suffrian, 1866) (Scolochrus ephippiatus) PARALECTOTYPUS D. Sassi des.” [red label, printed] //.
Type locality. “ Brazil ”.
Additional material examined. BRAZIL: Rio de Janeiro: Rio de Janeiro Corcovado X.1957 (2, NHMB); São Paulo (1, NMPC); “Brasilien Alte Sammlung” (1, NHMB).
Distribution. Brazil (Rio de Janeiro)
Diagnosis. The dorsal coloration reminds of some chromatic forms of G. posticatus or G. consanguineus, which is why the species has been included in this group for revision, despite the lack of confirmation of some diagnostic characters of the species group (male unknown). The rather flattened shape on the dorsum, the wellimpressed elytral punctures, and the distinctly parallel elytral margins, however, are highly distinctive compared to the other species within the group, and they bear a resemblance to the genus Metallactus. It cannot be ruled out that the species may indeed belong to this genus. The shape of the spermatheca, as reiterated multiple times, while revealing some vague tendencies, does not provide reliable characters in Pachybrachina, even when comparing species that are externally quite dissimilar. However, the vasculum of the spermatheca of G. ephippiatus appears characteristically plump and corpulent (Fig 11b) compared to the Griburius and Metallactus species reviewed so far. The absence of males currently hinders clarification of this possibility.
Description of female (male unknown). Habitus in figs 2a–b (LT). BL = 6.2–6.3 mm, BW = 3.8–4.0 mm, PL = 1.8 mm, PW = 3.3–3.5 mm. Interocular distance 7.9–8.1 % of BL.
Head totally black. Labrum dark brownish. Vertex almost smooth. Head surface with sparse punctures and scattered, short setosity above all close to ocular lines and on clypeal area. Mid-cranial and frontoclypeal sutures not detectable. Upper lobes of eyes broadly separated from each other. Ocular line slender, marked by row of well impressed punctures, strictly adhering to ocular rim up to ocular canthus. Ocular canthus large, angular, with surface covered by short, appressed, dense setae. Antennae with first two antennomeres yellowish, reminders brownish. Antennomeres 3–5 bright subcylindrical; 6–11 dull, more flattened and more diffusedly setose.
Pronotum usually reddish brown with broad, subrectangular black band along the posterior half, reaching posterior margin but leaving free lateral ones. Pronotal shape elliptical, transverse and flattened. Lateral margins large, visible from above only along posterior half, regularly curved, with maximum width just behind middle. Surface moderately shiny with shallow, sparse punctures irregularly distributed across whole pronotal surface. Posterolateral impressions well impressed, obliquely arranged.
Scutellum dark brownish to black, triangular with rounded apex truncated in straight line. Surface shallowly micropunctured and sparsely setose.
Elytron reddish-brown with large black patch at center of disk, together with contralateral forming elliptical transversal band at center of disc. Such band not reaching lateral margins. Humeral callus, epipleuron and anterior fourth of lateral margin black as well. Elytral outline parallel-sided and visibly flattened on disc. Lateral margins large, simultaneously visible from above from behind humeral callus to posterior apex. Scutellar area not raised. Humeral callus moderately prominent, impunctate.Surface rather shiny with distinctly impressed punctures arranged in almost regular rows, visible up to elytral clivus. Intervals flat to slightly raised. Epipleuron smooth, impunctate, with flat to slightly concave surface.
Pygidium totally black. Surface bright, covered with shallow punctures and short, semi-erect dense setae.
Ventral parts of thorax black with hypomera, mesepimera, metepisterna and outer part of metasternum brownish. Abdominal ventrites totally black. Hypomera, mesepimera, mesepisterna and central part of metasternum shiny, almost devoid of punctation, covered with sparse, short setosity.Abdominal surface matt, with dense, short, regularly distributed whitish setae and fine, shallow, dense punctures. Prosternal process large, short, with sides almost straight between anterior coxae; apex broadly rounded; surface almost flat and closely but shallowly punctured, covered with long, semi-erect setae.Anterior legs black with yellowish tibiae. Mid and posterior legs yellow with tarsi partly darkened.
Fifth abdominal ventrite with quite large, subelliptical, rather shallow pit. Bottom of pit glabrous, matt, impunctate but covered by tiny wrinkles. Vasculum of spermatheca (Fig. 11b) fairly pigmented, short, plump, sickle shaped with swollen proximal lobe. Distal lobe short, terminated with blunt apex. Ampulla not pigmented, tiny, clearly bifurcated, with duct and sperm gland insertions perceptibly distinct. Duct uniform in size, slender, straight, arranged in few, loose turns. Insertion on bursa copulatrix simple, neither swollen nor pigmented.
Variability. One of the studied specimens has the dorsal surface, with the exception of the black scutellum, totally reddish brown (Fig. 2f). This fact leads to believe that the dorsal colour pattern of this species might be much more variable than the few available specimens could suggest.
description: Published as part of Sassi, Davide, 2024, Revision of the Griburius posticatus (Suffrian, 1866) species group (Coleoptera: Chrysomelidae: Cryptocephalinae), pp. 201-237 in Zootaxa 5406 (2) on pages 208-210, DOI: 10.11646/zootaxa.5406.2.1, http://zenodo.org/record/10618162