Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. X. Infraorder Nepomorpha-Famlies Belostomatidae And Nepidae Author Polhemus, Dan A. Author Polhemus, John T. text Raffles Bulletin of Zoology 2013 2013-02-28 61 1 25 45 journal article 10.5281/zenodo.5351508 2345-7600 5351508 KEY TO SPECIES OF LACCOTREPHES OCCURRING IN SINGAPORE AND MALAYSIA 1. Very large species, body length (excluding siphon) exceeding 35 mm , usually 40 mm or greater; prosternal keel with an angular projection set back slightly from anterior margin when viewed laterally ( Fig. 31 ); male paramere with apex massive, hooked, acute ( Fig. 38 ) ........................................ L . pfeiferiae (Ferrari) – Moderate to small sized species with body lengths (excluding siphon) 32 mm or less.............................................................2 2. Moderate sized species, body length (excluding siphon) 30–32 mm ; prosternal keel with a broad, rounded projection anteriorly when viewed laterally ( Fig. 32 ); male paramere with apex massive, hooked, apex blunt ( Fig. 37 )...................................... ............................................................. L . archipelagi (Ferrari) – Smaller species, body length (excluding siphon) less than 20 mm ...........................................................................................3 3. Prosternal keel flat when viewed laterally, lacking an angular anterior projection ( Fig. 33 ); length of respiratory siphon less than or equal to that of the body; male paramere with a broad, blunt process distally ( Fig. 36 ) ......... L . simulatus Montandon – Prosternal keel with an angular projection anteriorly when viewed laterally ( Fig. 34 ); length of respiratory siphon 1.5X that of the body; male paramere with a slender, acute process distally ( Fig. 35 ) ........ L . longicaudatus Nieser, Zettel & Chen