Trichillum (Trichillum) tishechkini, Vaz-De-Mello & Génier, 2005

Vaz-De-Mello, Fernando Z. & Génier, François, 2005, Lectotype designations, new synonymies, and new species in the genera Trichillum Harold and Pedaridium Harold (Coleoptera: Scarabaeidae: Scarabaeinae), Zootaxa 1038, pp. 41-52 : 47-49

Trichillum (Trichillum) tishechkini sp. nov.

(Figs. 7–8)

Holotype ɗ: BRASIL: Rio Grande do Sul: Glória, 7­IX­1925, P. Buck, #109a ( IBSP, ex­ FVMC).

Paratypes: ARGENTINA: Chaco: Río Bermejo, Pcia. Roca, II­1945, Martínez (1 CMNC); Córdoba: Do. Calamuchita, El Sauce, XII­1938, MJ Viana (2 CMNC); Do. Cruz del Eje, Los Leones, II­1967, Chichero (1 CMNC); Do. Santa María, Diquecito, XII­1965, Martínez (4 CMNC, 1 CNIC, 2 FVMC, 2 GHC); La Falda, I­1945, Martínez (1 CMNC); San Javier, I­1943, Martínez (1 CMNC); Formosa: Ciudad, Puerto, II­1949, Martínez (1 CMNC); Misiones: Loreto, Est. Experim., X­1966, Martínez (2 CMNC); Santa Fe: Rosario, Ciudad, I­1941, Martínez (1 CMNC); BRAZIL: Rio Grande do Sul: locality unreadable, 20­IX­1926, P. Buck, Ex.: Acromyrmex sp. nest. #168 (1 FVMC, 6 NMM); Glória, 7­IX­1925, P. Buck, #109a (4 FVMC, 1 BDGC); 26­VIII­1925: P. Buck, #98 (1 FVMC, 2 NMM); 3­IV­1925, #50 (1 NMM); Teresópolis, 6­IX­1925, P. Buck, coletado Ex.: Acromyrmex sp. nest. #103 (1 FVMC); Floresta, 20­IX­1925, P. Buck, Ex.: Acromyrmex sp. nest. #115 (1 NMM). All the specimens from Rio Grande do Sul from E.Wasmann's Coll'n Alcohol, mounted by A. Tishechkin, 2000.

Etymology: A patronym honoring Alexey Tishechkin, histeridologist, who diligently prepared Wasmannís material stored in alcohol at the NMM.

Diagnosis: 3.8–5.3 mm. The short triangular head and characteristic confluent large clypeal punctures ( Fig. 9 ), combined with size, shape of posterior tarsi (basitarsomere more than twice as long as the following tarsomere), and distribution (southern Brazil and Argentina) will be sufficient to separate this species from other Trichillum species.

Description: Holotype male. Head: (Fig. 7) wider than long, clypeus rounded, with a wide v­shaped emargination that originates on each side of a rounded, feebly conspicuous tooth. Clypeal surface with large irregular and coalescent punctures, with the larger ones bearing a seta. Punctures on the clypeo­frontal region feebly coalescent and of two sizes. On front and vertex, punctures feebly impressed and well separated. Clypeogenal suture straight from the border to near the eye tip and then curved inwards. Eye approximately twice as long as wide. Pronotum: covered with conspicuous punctures (when viewed with 10x magnification); punctures regularly spaced, smaller on disc, larger and more strongly impressed laterally. Lateral punctures often elongated and deeper with occasional lateral setae in both anterior and posterior angles. Pronotum with a transverse row of setae parallel to anterior margin, posteriorly deviated and interrupted medially. Elytra: elytral striae with feeble elongate punctures on the disc, discal interstriae with sparse, small punctures. Lateral and apical striae much deeper and with conspicuous punctures. Apical interstriae with one row of setae each, externally positioned on interstriae 1 and 2, internally on interstriae 3 to 7. Sterna : meso­metasternal sulcus in rounded straight angle, terminated by punctures at each side, just below the middle of the trocanter. Metasternum with large ocelated punctures laterally; with simple, small punctures in the disc. Discal concavity elongated, covering most of the disc except the anterior half of the anterior projection. Legs: anterior tibia with three external teeth in the apical two thirds, and one internal apical tooth; calcar spathuliform, somewhat larger than the first tarsomere. First tarsomere of median tarsi one and a half times longer than second. First tarsomere of hind tarsi about twice as long as the second. Abdomen: aedeagus with parameres slightly asymmetrical, the right paramere larger but similar in form to the left one (Fig. 8), external apical angle straight.

Variation: Paratypes vary in sexual features, size, color (teneral specimens are lighter in color), and in position of individual head punctures, not differing however of the general structure described for the holotype, apart of features related to abrasion of clypeal and fore tibial teeth. Females differ from males by protibial apical internal tooth absent, metasternal disc flat, not concave, and pygidium slightly more transverse.

Remarks: This species was treated as T. heydeni by Martínez (1968), who adequately diagnosed it in the key of his paper.

Figures

FIGURES 9 – 12. Head (7, 9, and 11) and parameres (8, 10, and 12), dorsal view. 7 – 8. Trichillum tishechkini n. sp. 9 – 10. Trichillum pseudoarrowi n. sp. 11 – 12. Trichillum cordobense n. sp.