Kernegaster diminutus Schmitz, 2025

Kernegaster diminutus Schmitz sp. nov.

( Fig. 1 G; Fig. 5 A – C; Fig. 7 D; Fig. 8 D; Fig. 9 D; Fig. 10 D; Fig. 12 D, M; Fig. 13 H and I)

Tetyra sp. Brugnera et al., 2023:614 ( Fig. 4t).

Type Material (29): Holotype. (1M) BRAZIL, Rio Grande do Sul: Palmares do Sul, Ilha Grande , 10.IV.2003, Equipe Probio ( MCNZ 53720 ) ;

Paratypes. PARAGUAY, Caaguazú: Pastoreo , (2M), 23.I.2023, Donald Wees ( AMNH) ; Iguazu River , (2M), 10.III.2002, Donald Wees ( AMNH) ; BRAZIL, Bahia: Remanso, Santo Antˆonio , (2M), 25.II.1964, no collector ( CIBM) ; Santa Catarina: Nova Teutˆonia, (1F, 2M), 1.XI.1944, Plaumann F. ( USNM) ; ibid., J.C. Lutz Collection 1961, (1M), 22.II.1956 ( USNM) ; Rio Grande do Sul: S˜ao Francisco de Paula ( FLONA ), (1F), 13. I.2007, Schwertner C.F. ( UFRG) ; Porto Alegre , (1F), 17.II.1950, no collector ( MCNZ 15119 ) ; Viam˜ao, (1M), IX–1956, Palcya M. ( MCNZ 2248 ) ; ibid., (3F) 11.IV.1983, Becker C.J. ( MCNZ 47928 , MCNZ 47926 , MCNZ 47927 ) ; ibid., (1M), 13.II.1983, Becker C.J. ( MCNZ 47966 ) ; ibid. ( Fazenda B. Caldas ), (1F), 4–6.X.1979, Becker C.J. ( MCNZ 13295 ) ; Guaíba ( Arroio Petim ), (2F), 19.I.1981, Gastal H.A. ( MCNZ 45006 , MCNZ 45029 ) ; Barra do Ribeiro ( Fazenda Boa Vista ) (1F), 16.XII.2003, Equipe Probio ( MCNZ 176235 ) ; Palmares do Sul ( Fazenda Rinc˜ao do Anast´acio ), (1F), 12.XI.2003, Equipe Probio ( MCNZ 175277 ) ; ibid. ( Ilha Grande ), (1F, 1M), 10.IV.2003, Equipe Probio ( MCNZ 53718 , MCNZ 53720 , MCNZ 53719 ) ; Tapes, (1F, 2M), XI.1963, Buck P. ( MCNZ 1935 ; MCNZ 1625 , MCNZ 1931 ) ; ibid., (1M), XI.1979, Buck P. ( MCNZ 1934 ) .

Color pattern. Highly polychromatic, brownish to ferrugineus, usually with large clusters of punctations ( Fig. 5 A – C). Head. Clypeus with basal and median spots, 1 + 1 longitudinal dark stripes between the eyes. mandibular plates with 1 + 1 dark blotches located anteriorly and laterally above antennal insertion ( Fig. 7 D). Antennomeres I bicolored (proximal half yellow and distally dark). Rostrum with segment III bicolored, segment IV mostly dark. Thorax. Pronotum with at least 3 + 3 distinct inner maculate rows. Scutellum with many enlarged dark macules irregularly distributed. Femora with proximal and distal dark blotches about the same size, tibiae with medial and distal dark blotches. Tarsomeres dark. Abdomen. Connexiva yellow, with anterior and posterior larger dark macule. Ventral pattern. Lateral rows with one solid spot in each sternite. Median rows with a large cluster of spots on each sternite. Inner row with a solid blotch on each sternite, culminating into a larger solid blotch on sternite VII. Stridulatory areas with blotches. Spiracles concolorous with adjacent area ( Fig. 5 C).

Head. Wider than long. Clypeus slightly surpassing mandibular plates ( Fig. 7 D). Maxillary plates slightly surpassing mandibular plates. Rostrum reaching the middle of sternite III. Thorax. Pronotum, anterolateral margins slightly convex, humeral angles round and slightly produced, less than a quarter the width of the eye ( Fig. 5 A – C). Peritreme spout-like reduced, about as wide as long ( Fig. 8 D). Abdomen. Posterior margin of sternite VII uniformly concave ( Fig. 9 D).

Genital plates. Valvifers VIII subtriangular, anterior margin convex, sutural margins truncate posteriorly, posterior margin sinuous. Laterotergites IX subrectangular, anterior margin markedly convex, angles slightly produced ( Fig. 9 D). Gynatrium. Ring sclerites with almost the entire inner margin with thick "leaf-like" sclerotized process. Posteromedian gynatrial pouch with a poorly sclerotized median sclerite and 1 + 1 oval sclerites larger than the median sclerite ( Fig. 10 D).

Genital capsule. Posterior margin sub-rectilinear ( Fig. 12 D). Ventral rim also sub-rectilinear in posterior view. Parameres. Crown clearly surpassing width of the stem, apex acute ( Fig. 12 M). Phallus. Aedeagus sensu stricto tapering, sinuous in lateral view; apex strongly curved dorsally, with a curved dorsal process. Conjunctival processes II with a small robust sclerotized process, cpIII distal half sclerotized, elongated and cylindrical ( Fig. 13 H and I).

Measures. Body length (7.6–9.9) and width (5.1–6.8). Head length (1.6–2.1) and width (2.6–3.3).

Distribution: The species is present mainly in southern Brazil, except for two individuals from Bahia and Paraguay. The species probably occurs throughout the Atlantic Forest biome.

Biological notes: Collected with an entomological umbrella and also found in a nest of Tyrannus melancholicus Vieillot ( Aves: Tyrannidae ).

Etymology and comments. The epithet “diminutus” refers to the size of the species, which is about half the length and width of its congeners, with the exception of K. chapadanus . Beyond size, the species resembles K. poecilus , except for the genitalia of both sexes, which are unique.