Griburius gamma
Creators: name: Sassi, Davide
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Griburius
Griburius gamma

description: Griburius gamma (Jacoby, 1889)
(Figs 7, 9b)
Scolochrus gamma Jacoby, 1889: 132; Clavareau, 1913: 89 [Griburius] (catalogue); Blackwelder, 1946: 640 [Griburius] (catalogue).
Types. Jacoby (1889) reported that nine specimens were available for the study, and he unambiguously identified one of them as type of the species (“I have taken for the type the specimen with the darkest markings”. For this reason, this specimen, kept in BMNH, was here identified as the holotype of the species. HOLOTYPE: m#, glued, // “Acapulco, Guerrero. Höge.” [white label, printed] // “ Scolochrus gamma Jac. ” [blue label, handwritten] // “B.C.A., Col. VI,1. Suppl. Scolochrus gamma, Jac. ” [white label, printed] // “Sp. figured” [white label, printed] // “Type H. T.” [white label with red margin, printed] // “ Syntype ” [white label with blue margin, printed] // “ Griburius gamma (Jacoby, 1889) (Scolochrus gamma) HOLOTYPUS D. Sassi des.” [red label, printed] // (BMNH). PARATYPES: Four further specimens belonging to the same series are housed in BMNH and therefore they must be considered paratypes: 4 specimens, glued, same data of the holotype (BMNH). In addition, one male specimen belonging to the same series is kept in MCZ and labelled: // “Acapulco, Guerrero. Höge.” [white label, printed] // “ S. gamma Jac ” [blue label, handwritten] // “1 st Jacoby coll.” [white label, printed] // “Type 8648” [red label, partly handwritten] // (MCZ). For the same reasons pointed out before, it must as well be considered a paratype of the species. All paratypes are labelled: // “ Griburius gamma (Jacoby, 1889) (Scolochrus gamma) PARATYPUS D. Sassi des.” [red label, printed] //.
Type locality. Acapulco (Guerrero, Mexico).
Additional material examined. EL SALVADOR, Cuscatlán: El Rosario 4.VII.1953 & 17-20.VII.1955 (5, USNMNH). Cabañas: Tejutepeque 23.VII.2021 (1, GBIF). MEXICO, CHIAPAS: 16 km W Ocozocoautla El Aguacero 10.VI.2009 (1, BYU). COLIMA: 6 mi w Colima 6.VIII.1978 (1, TAMU); 9.7 km S Colima 335m 4.VIII.1988 (2, TAMU). GUERRERO: Acapulco coll. Flohr (3, MNHUB); 38 km W Iguala 18à 31’ N 99° 44’ W 16 VII.1995 (6, USNMNH); 10.3 mi S Iguala 23.VII.1981 (1, TAMU); 8 km S Mazatlan 1130m 29.VI.1992 (1, ERPC); 4 mi W Chilpancingo 15.VII.1984 (3, TAMU); 12 mi S Chilpancingo 12.VII.1966 (1, TAMU); 3.3 km Cacahuamilpa 1495 m 2.VII.1992 (2, ERPC); Grutas de Cacahuamilpa 30 km N Taxco 27.VIII.1993 (1, MNHUB); 6 km W Teloloapan 20.IX.1989 (1, TAMU); Tierra Colorada 12 mi N Guerrero 2600’ 5.VIII.1954 (1, CNCI). JALISCO: 4 mi S El Tuito 1200’ hwy 20010. VIII.1982 (2, ERPC); Chamela Vic. ESTC UANM 9-19.VII.1993 (3, TAMU); Chamela Res. Sta. 13.VII.1986 (1, BYU); 18 mi N Barra de Navidad 23.VIII.1976 (1, BYU). MORELOS: Xochicalco Ruins 18° 48’ N 99° 16’ W 14.VII.1995 (5, USNMNH); Cuernavaca 15.VIII.1954 (1, USNMNH). OAXACA: 4.4 mi NE San Pedro Mixtepec 16.VII.1985 (1, TAMU); 2.7 mi NW El Camarón 21-22.VII.1974 (1, TAMU). NAYARIT: 2 km E Punta de Mita 30.VII-2.VIII.1991 (4, TAMU). PUEBLA: Izúcar de Matamoros-Cautla Rd. Route 160 km 129 24.VII.1997 (1, USNMHN).
Distribution. El Salvador, Mexico. New from El Salvador.
Diagnosis. The species looks very similar to G. puncturatus. It can be distinguished from the latter by the different (more transverse and more flattened) pronotal shape. Besides, punctures on pronotum are usually denser and finer and the “gamma-shaped” dark marking is always visible while in G. puncturatus the pronotum is uniformly yellow. Finally, the aedeagal median lobe looks rather different, above all on its apical section.
Description of male. Habitus in Fig. 7 a-b (HT), 7c, 7e. BL = 3.8– 3.9 mm, BW = 2.3–2.4 mm, PL = 1.3–1.4 mm, PW = 2.1–2.2 mm. Interocular distance = 0.0–2.6 % of BL.
Head totally yellow. Labrum yellow as well. Vertex very shallowly, minutely punctured. Head surface with sparse punctures and scattered, short setosity above all between antennal insertions. Mid-cranial suture shallow, but clearly detectable between upper lobes of eyes. Upper lobes of eyes close to each other along midline but usually not really in contact. Ocular lines usually clearly visible above all along lower part of upper lobes, strictly adhering to ocular rim. marked by row of fine, shallowly impressed punctures. Ocular canthus large, angular, with surface not differentiated by remainder of frontoclypeus. Antennae (Fig. 7h) long, yellow with last two antennomeres slightly darkened. Antennomeres 3-5 slender, bright, subcylindrical; 6-11 slender as well, dull, slightly more flattened and more diffusedly setose.
Pronotum yellow with large, M-shaped brown marking extended across pronotal disc, leaving free only anterior and lateral margins. Pronotal shape elliptical, transverse, slightly flattened on disc. Lateral margins narrow, only basal half visible when seen from above, regularly curved, with maximum width at about middle. Surface rather matt, covered with fine punctures rather regularly distributed. Posterolateral impressions well impressed, narrow, obliquely arranged.
Scutellum yellow, triangular with apex truncated in straight line. Surface sparsely micropunctured.
Elytron yellow with brown markings of variable appearance: “typical” pattern consists of six brown spots, two of them, usually almost coalescent, forming a curved marking around scutellar area; three spots sitting on oblique line from humeral callus to beginning of apical clivus; one spot, further back than previous ones, close to lateral margin. All spots often coalescing in different ways giving transversal, more or less discontinued bands. Sometimes part of dark spots missing. Apical margin and suture narrowly darkened as well. Bottom of punctures brownish. Epipleuron yellow. Elytral outline with sides almost straight and slightly convergent posteriorly. Lateral margins narrow, simultaneously visible from above only along posterior half. Elytral surface moderately shiny with fine but well-impressed punctation, distinct up to posterior clivus, arranged in almost regular rows. At about one third of length usually one shallow but well-visible transverse impression, extended from first to fifth rows of punctures. Intervals flat. Postscutellar area slightly raised. Humeral callus prominent, impunctate. Epipleuron impunctate, slightly rugulose with slightly convex surface.
Pygidium totally yellow Surface bright, covered with shallow punctures and short, semi-erect pale setae.
Ventral parts of thorax and abdomen brown. Abdominal ventrites brown with large yellow band along margins; median projection of abdominal ventrite 1 sometimes yellow as well. Hypomera, mesoepimera and mesoepisterna shiny, almost devoid of punctures and setosity. Remainder of ventral surface of thorax and abdomen covered with rather sparse, regularly distributed setae and fine, shallow punctures. Prosternal process large, with sides slightly salient, almost straight between anterior coxae, terminated with rounded apex; surface almost flat and closely punctured, covered with long, semi-erect setae. Legs totally yellow.
Median depression on fifth abdominal ventrite indistinct, hardly detectable. Ventrite posterior margin straight. Median lobe of aedeagus (Fig. 7 m-o) dorsoventrally flattened, almost parallel-sided, terminated by triangular apex with slightly concave sides, devoid of true terminal denticle. Apex slightly bent dorsally in lateral view. Ventral surface smooth, slightly convex. Setose depressions very shallowly impressed, with few, minute punctures and almost straight setae.
Female. Habitus in Fig. 7d, 7 f-g. BL = 4.0– 4.7 mm, BW = 2.6–2.9 mm, PL = 1.4–1.5 mm, PW = 2.3–2.6 mm. Interocular distance = 7.5–8.5 % of BL.
In females the eyes are smaller and more separated along midline and antennae are shorter and less distinctive than in males. Additionally, the elytral pattern is darker in some specimens, being blackish instead of brown.
The fifth abdominal ventrite in females has a large, rounded, 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. 7i) is scarcely to fairly pigmented along the base of the proximal lobe, sickle shaped with straight, slightly swollen proximal lobe. The distal lobe is slender, regularly curved and terminated with an acute apex. The ampulla is not pigmented, almost square. The duct insertion is short. The sperm gland insertion is rather long and curved. The duct is uniform in size, quite robust and rigid, straight, with a single turn close to the vasculum, then straight up to the bursa copulatrix. The insertion on the bursa copulatrix is simple, neither swollen nor pigmented.
Acknowledgments – I would like to gratefully acknowledge Lee H. Herman (American Museum of Natural History, New York), Max Barclay and Michael Geiser (The Natural History Museum, London), Shawn Clark (Arthropod Collection, Monte L. Bean Life Science Museum, Brigham Young University, Provo, UT), Patrice Bouchard (Canadian National Collection of Insects, Ottawa), James H. Boone (Field Museum of Natural History, Chicago), Edward G. Riley (Texas A&M University, College Station), Kyle E. Schnepp (Florida State Collection of Arthropods, Gainesville), Mauro Daccordi (Verona), Karla Schneider and Joachim Händel (Suffrian’s Collection, Martin Luther University, Halle), Antoine Mantilleri (Muséum national d’Histoire Naturelle, Paris), Johannes Frisch, Bernd Jäger and Joachim Willers (Stiftung Museum für Naturkunde, Leibniz-Institut fur Evolutions und Biodiversitätsforschung, Berlin), Maurizio Rigato e Michele Zilioli (Museo civico di Storia Naturale, Milano), Alexander Konstantinov and Maria Lourdes Chamorro (National Museum of Natural History, Smithsonian Institution, Washington, D.C.), Katja Neven (Zoologische Staatssammlung, München) for the loan of material and, in many cases, for the kind and friendly support during my visits in their institutions.
This work was supported by the Synthesys Project (http://www. synthesys.info/) financed by the European Community Research Infrastructure Action, under GB-TAF-3383, DE-TAF-4995 and the Systematics Research Fund 2014/15 administered by the Linnean Society of London and the Systematics Association.
description: Published as part of Sassi, Davide, 2023, Five new species of the genus Griburius Haldeman from Central America (Coleoptera: Chrysomelidae, Cryptocephalinae), pp. 117-138 in Fragmenta entomologica (Deerfield Beach, Fla.) (Deerfield Beach, Fla.) 55 (1) on pages 135-137, DOI: 10.13133/2284-4880/1465, http://zenodo.org/record/8148247