Revision of the Belostoma triangulum group (Insecta: Heteroptera: Belostomatidae) Author Stefanello, Fabiano Laboratório de Biologia Comparada e Abelhas (LBCA), Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP), Universidade de São Paulo, Avenida Bandeirantes, 3900, 14040 - 901, Ribeirão Preto, SP, Brazil. Author Ribeiro, José Ricardo Inacio 0000-0001-5035-2766 Laboratório de Estudos da Biodiversidade do Pampa (LEBIP), Universidade Federal do Pampa, Campus São Gabriel, Avenida Antônio Trilha 1847, 97300 - 162, São Gabriel, RS, Brazil. jozecaricardo @ gmail. com; https: // orcid. org / 0000 - 0001 - 5035 - 2766 Museo de La Plata, División Científica de Entomología, Paseo Del Bosque s / nº, B 1900 FWA La Plata, Buenos Aires, Argentina. jozecaricardo@gmail.com Author Estévez, Ana Lia text Zootaxa 2021 2021-04-14 4958 1 95 102 journal article 7178 10.11646/zootaxa.4958.1.8 5a347ee5-0d8e-4851-9b8e-f00f37173214 1175-5326 4693159 D9A893E4-4685-44EF-9250-43E3A48A12E1 Belostoma triangulum Lauck ( Figure 2D ) Belostoma triangulum Lauck, 1964: 105–107 . Size and shape. Length: male (n=4) = 19.5–23.0 mm, female (n=4) = 19.5–22.5 mm ; width: male = 10.0–12.0 mm, female = 10.5–11.5 mm . Body broad. External morphology . Head : clypeogenal cleft longer than clypeoloral cleft; anteoculus as long as interoculus; eyes globose, longer than wide; interocular space 1.7 to 1.9 times the width of an eye ( Fig. 1D ); vertex without mesal carina; article II of labium as long as III. Thorax : prosternal keel triangular, prominent, not projecting forward ( Fig. 1A ); pronotum quadrate, without carina; the mesal portion of metaxiphus elevated anteriorly and swollen posteriorly, and distal portion concave; membrane of hemelytra reduced, as wide as the maximum width of clavus ( Fig. 2D ). Abdomen . pilosity covering about half of connexivum, constricted between spiracles; pilosity not developed on segment VII segment and not covering sternites. Male genitalia . Dorsal arms of phallosoma as long as phallobase, width at the base and apex subequal, welldeveloped, meeting at tip of the diverticulum, covering lateral margins of the diverticulum; diverticulum without ventroapical protuberance in lateral and ventral views ( Figs. 3D–F ). Diagnosis . The prominent triangular prosternal keel is diagnostic for this species ( Fig. 1A ). Type material examined . Holotype ( ♂ ), allotype ( ♀ ) pinned ( SEMC ), PERU , Huánuco Department [ Pasco Region ], Leon Pampa locality, 14.XII.1937 , F. Woytkowski coll., designated by D. R. Lauck, 1961 ; Paratype ( ♂ ) pinned ( USNM ), PERU , Huánuco Department [Region], [Leoncio Prado Province, José Crespo y Castillo District] Aucayacu , designated by D. R. Lauck, 1961 ; Paratypes ( 2 ♂ and 3 ♀ ) pinned ( SEMC ), PERU , Huánuco department, [Leoncio Prado Province] Shapajilla jungle?, 29.VII.1938 , F. Woytkowski coll., designated by D. R. Lauck, 1961 . FIGURE 3. (A–C) Dorsal, ventral, and lateral views of phallosoma of Belostoma bachmanni , respectively. (D–F) dorsal, ventral, and lateral views of the phallosoma of Belostoma triangulum , respectively. da = dorsal arms of phallosoma, div = diverticulum of phallosoma, pb = phallobase. Distribution . This species is known only from the type series from Huánuco , Peru , and from a male and a female from Cáceres, Mato Grosso , Brazil (specimens not examined, deposited in the collection of Dr. Arnold S. Menke, University of California, Davis ( Fig. 4 ).