A striking sexually dimorphic new species of Castolus (Hemiptera: Heteroptera Reduviidae) from Colombia, with new records from Neotropical countries and taxonomic notes on the genus Author Forero, Dimitri 0000-0002-6358-757X Laboratorio de Entomología, UNESIS, Departamento de Biología, Pontificia Universidad Javeriana, Bogotá, Colombia. forero-i @ javeriana. edu. co; https: // orcid. org / 0000 - 0002 - 6358 - 757 X forero-i@javeriana.edu.co Author Mejía-Soto, Andrés 0000-0001-7897-6183 Grupo de Entomología Universidad de Antioquia (GEUA), Universidad de Antioquia, Medellín, Colombia. andres. mejia 6 @ udea. edu. co; https: // orcid. org / 0000 - 0001 - 7897 - 6183 andres.mejia6@udea.edu.co text Zootaxa 2021 2021-10-08 5048 4 538 560 journal article 4046 10.11646/zootaxa.5048.4.4 a760312c-6096-4683-8365-49893b8853e0 1175-5326 5556768 CF8898E7-BCAF-42B9-986B-6C4CFD1A9519 Castolus plagiaticollis Stål, 1858 ( Fig. 9D , 10C ) Remarks. Castolus plagiaticollis is a conspicuous species with red head, red femora, dark tibiae, a large ovoid marking on the posterior lobe of the pronotum, mostly yellowish corium and clavus with the apex of the corium black, and a black membrane except its apex which is translucent ( Maldonado 1976 ). Nonetheless, it is variable regarding its hemelytral color pattern. Champion (1899) had already mentioned that some specimens from Mexico and Guatemala had a more darkened clavus and corium.Among the specimens examined and the observations from iNaturalist (https://www.inaturalist.org/observations?place_id=any&q=castolus%20plagiaticollis), several instead of a yellow corium have a whitish one; a few ones have a more extended dark area on the apex of the corium, reaching in some specimens almost half the corial length, or on the other hand have a completely yellow corium without dark areas. Very rarely, the specimens have a mostly black corium being yellow only the costal area and the base of clavus. Because color patterns are important to delimit species in Castolus ( Maldonado 1976 ) , the observed color variation in C. plagiaticollis highlights the importance of understanding the intraspecific color variation to adequately assess the specific limits for other species in Castolus . Quiroz & Carmona (2011) listed two specimens identified as C. plagiaticollis from MEFLG. We examined two additional specimens from MEFLG and corroborated their initial identification. The examined Colombian specimens all have a yellow corium and small apical dark area on the corium. Distribution . Originally described from Mexico ( Stål 1858 ), with subsequent records from Honduras ( Maldonado 1990 ), Guatemala , and Panama ( Champion 1899 ). It represents the first formal record of the species from South America, and a new country record from Colombia , extending the known distribution into South America ( Fig. 10C ). Material examined . COLOMBIA — Antioquia • 1 ♂ ; V . [alle] de Medellin ; [ 06.2416°N , 75.5775°W ]; Feb 1949 ; Gallego ( MEFLG ) • 1 ♂ ; same data; Aug 1945 ; Gallego ; en maleza; No. Catal. 6845 ( MEFLG ) • 2 ♀♀ ; Medellín; [ 06.2416°N , 75.5775°W ]; 1538m ; Mar 1937 ; F. Gallego ; en Zea mais (maiz); No. catal. 113 ( MEFLG ) .