Belostomatidae Leach, 1815 (Insecta: Hemiptera: Heteroptera: Nepomorpha) of northeastern Brazil Author Franco, Cleilton Lima 741AEAC5-6076-4F49-BBBE-46B68F535214 Universidade Federal Rural do Rio de Janeiro, Programa de Programa de Pós-graduação em Biologia Animal, Seropédica, Rio de Janeiro, Brazil. & Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Entomologia, Rio de Janeiro, Rio de Janeiro, Brazil. cleiltonubc@hotmail.com Author Stefanello, Fabiano 22ABA44E-2F9C-4298-A5E3-CE606939AF20 Universidade Estadual do Maranhão, Departamento de Química e Biologia, Laboratório de Entomologia Aquática, Caxias, Maranhão, Brazil. stefanellof@gmail.com Author Azevêdo, Carlos Augusto Silva de 6EA23A73-0473-4559-BCF3-6DC1D1297F06 Universidade Estadual do Maranhão, Departamento de Química e Biologia, Laboratório de Entomologia Aquática, Caxias, Maranhão, Brazil. casazevedo08@gmail.com Author Moreira, Felipe Ferraz Figueiredo 7B880394-839B-42A2-AF4D-B8E564160CE2 Fundação Oswaldo Cruz, Instituto Oswaldo Cruz, Laboratório de Entomologia, Rio de Janeiro, Rio de Janeiro, Brazil. ppmeiameiameia@gmail.com text European Journal of Taxonomy 2024 2024-05-13 932 271 304 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2537/11431 journal article 10.5852/ejt.2024.932.2537 2118-9773 11190467 93508BDE-BCC6-4C54-A276-D1FA94F252CC Key to the species of Belostomatidae from northeastern Brazil The key includes characters previously used to recognized species of Lethocerus from Perez-Goodwyn (2006) and Belostoma from Lauck (1964) , Estévez & Polhemus (2007) , Ribeiro (2007) , Ribeiro & Alecrim (2008) , Ribeiro et al. (2017) , and Stefanello et al. (2021). 1. Sternites IV–VI subdivided laterally by a suture-like fold ( Perez-Goodwyn 2006 : figs 30–31); labium short, with second article thicker than long.....................................2 Lethocerus Mayr, 1853 – Sternites IV–VI not subdivided; labium long, with second article longer than thick (Stefanello et al. 2021: fig. 1A)...........................................................................................4 Belostoma Latreille, 1807 2. Ventromesal projection of hind tibia pointed ( Perez-Goodwyn 2006 : fig. 4); body length 90 mm or more ......................................................................................... Lethocerus maximus De Carlo, 1938 – Ventromesal projection of hind tibia rounded ( Perez-Goodwyn 2006 : fig. 3); body length less than 70 mm ................................................................................................................................................ 3 3. Parasternites III–VII with longitudinal dark stripe ( Fig. 14 ); prosternal keel pointed at the apex ( Perez-Goodwyn 2006 : fig. 38) .............................................. L. annulipes (Herrich-Schäffer, 1845) – Parasternites III–VII without longitudinal dark stripe; prosternal keel rounded at the apex ( Perez-Goodwyn 2006 : fig. 37).......................................................................... L. delpontei De Carlo, 1930 4. Eye triangular, lateral margins straight or slightly rounded (Stefanello 2021: fig. 1C–D)................ 5 – Eye globose, lateral margins rounded................................................................................................ 9 5. Anteoculus longer than interoculus; body length 40–52 mm ............................................................ 6 – Anteoculus as long as interoculus (Stefanello 2021: fig. 1C); body length 21–28 mm .................... 7 6. Ventral abdominal pilosity covering entirety of connexivum ( Fig. 7 )................................................. .................................................................................................. Belostoma dilatatum ( Dufour, 1863 ) – Ventral abdominal pilosity covering only half of connexivum ( Fig. 8 ) .............................................. ................................................................................................................ B. gestroi Montandon, 1900 7. Ventral abdominal pilosity covering entirety of connexivum and part of sternites ( Ribeiro 2007 : fig. 2E) .................................................................................................. B. costalimai De Carlo, 1938 – Ventral abdominal pilosity not covering entirety of connexivum and not covering sternites (e.g., Figs 3, 5 and Ribeiro 2007 : fig. 2A) .................................................................................................. 8 8. Metaxiphus with a carina-like structure developed along mesal part; lateral folding of the pronotum broad, extending up to the posterior part ....................................................... B. bosqi De Carlo, 1932 – Metaxiphus with proximal part elevated and distal part swollen; lateral folding of the pronotum narrow, not extending up to the posterior part................................... B. discretum Montandon, 1903 9. Vertex, pronotum, and posterior part of scutellum with distinct carina; vertex straight below the ocular line; eye small, interocular space> 1.7× eye width ............................................................. 10 – Vertex, pronotum, and posterior part of scutellum without distinct carina; vertex prominent above the ocular line; eye large, interocular space <1.6× eye width .........................................................11 10. Body narrow, ratio length/width about 2.3×; lateral margins of body almost parallel; length of anteoculus 0.88–1.13 × length of interoculus ........................... B. aurivillianum ( Montandon, 1899 ) – Body broad, ratio length/width about 2.0×; lateral margins of body slightly convex; length of anteoculus 1.15–1.59 × length of interoculus .............................. B. stollii ( Amyot & Serville, 1843 ) 11. Body 10–20 mm in length; prosternal keel not elevated ( Ribeiro 2007 : fig. 12A–B); anteoculus shorter than interoculus.................................................................................................................... 12 – Body 28–52 mm in length; prosternal keel prominent, with apex rounded ( Ribeiro 2007 : fig. 7A–C); anteoculus longer than interoculus .................................................................................................. 16 12. Ventral diverticulum straight distally, in lateral view ( Ribeiro 2007 : fig. 11G–I); diverticulum broad ................................................................................................................................................ 13 – Ventral diverticulum curved downward, in lateral view (as in Figs 35, 37 ); diverticulum elliptical .. ......................................................................................................................................................... 14 13. Body 13–16 mm in length; ratio length/width about 2.35, narrow species; dorsal arms of phallosoma straight, covering lateral margins of diverticulum............ B. amazonum Estévez & Polhemus, 2001 – Body 17–19 mm in length, ratio length/width about 2.15, elliptical species; dorsal arms of phallosoma slightly convergent, not covering lateral margins of diverticulum ...... B. horvathi Montandon, 1903 14. Body more than 13 mm in length; prosternal keel prominent...................... B. plebejum ( Stål, 1860 ) – Body 10.5–13 mm in length; prosternal keel not prominent........................................................... 15 15. Diverticulum of phallosoma with strong, median dorsal depression, dorsal arms of phallosoma divergent ( Ribeiro 2007 : fig. 12C–E) ...................................................... B. micantulum ( Stål, 1860 ) – Diverticulum of phallosoma with slight, median dorsal depression, dorsal arms of phallosoma abruptly convergent ( Ribeiro & Alecrim 2008 : fig. 4) ......... B. nessimiani Ribeiro & Alecrim, 2008 16. Body narrow, elongate; diverticulum of phallosoma with lateral margins sinuous, broader basally than apically ( Ribeiro et al. 2017 : figs 32, 52) ................................................................................ 17 – Body elliptical; diverticulum of phallosoma evenly elliptical......................................................... 18 17. Ratio basal/apical width of ventral diverticulum about 2.3× (ventral view), dorsal arms divergent ( Figs 32–33 )...................................................................................... B. elongatum Montandon, 1908 – Ratio basal/apical width of ventral diverticulum about 2.0 × (ventral view), dorsal arms more parallel .................................................................................................... B. foveolatum ( Mayr, 1863 ) 18. Clypeogenal cleft longer than clypeoloral cleft............................................... B. harrisi Lauck, 1964 – Clypeogenal cleft as long as clypeoloral cleft (Stefanello et al. 2021: fig. 1D).............................. 19 19. Prosternal keel narrowly rounded to acute ( Fig. 24 ); dorsal arms of phallosoma broad ( Fig. 30 ) ( Ribeiro et al. 2017 : figs 39–43); body length about 42–50 mm ............... B. dentatum ( Mayr, 1863 ) – Prosternal keel rounded; dorsal arms moderately slender; body length about 29–35 mm .............. 20 20. Ventral diverticulum of phallosoma twice as wide as long (ventral view), ventroapical protuberance poorly developed ( Fig. 29 ) ........................................................ B. anurum ( Herrich-Schäffer, 1848 ) – Ventral diverticulum of phallosoma 1.3× as wide as long (ventral view); ventroapical protuberance well developed............................................................................................ B. dallasi De Carlo, 1930