Lethocerus, Mayr, 1853

Polhemus, Dan A. & Polhemus, John T., 2013, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. X. Infraorder Nepomorpha-Famlies Belostomatidae And Nepidae, Raffles Bulletin of Zoology 61 (1), pp. 25-45 : 26

Genus LETHOCERUS Mayr, 1853

Diagnosis. — Body elongate elliptical ( Fig. 1 ), length 64.0– 80.0 mm; maximum width 23.5–29.7 mm. Colouration light chestnut brown with darker markings at muscle attachment scars; pronotum bearing two wide, pale, anteriorly diverging stripes ( Fig. 1 ). Head with eyes parallel, interoculus carinate. Legs with fore femur 20% wider than hind femur, outer margin of hind tibia arcuate.

Distribution. — Originally described from “indes orientales”, with subsequent records from China, Korea, Hong Kong, the Ryukyu Islands, Burma, Thailand, Vietnam, the Philippines, Java, Sumatra, Borneo, Sulawesi, Singapore, and Peninsular Malaysia (Fernando & Cheng, 1974; Nieser & Chen,1999).

Discussion. — With a body length exceeding 60 mm, L. indicus is by far the largest species of aquatic Heteroptera known to occur in Singapore and adjacent Peninsular Malaysia. In addition to the Singapore specimen listed above, which may have been introduced by air transport, we have seen two Peninsular Malaysian specimens of L. indicus with minimal data from the states of Kedah and Selangor. Fernando & Cheng (1974) also reported light trap captures from Selangor, Perak and Kedah, although we have not examined these specimens. Overall, collections of this species in Singapore and Peninsular Malaysia are strikingly limited Diagnosis. — Very large belostomatids, body length exceeding 60 mm. Head width more than twice the maximum interocular width ( Fig. 1 ); clypeal suture only slightly indicated, nearly absent. Pronotum with lateral expansions, anterior margin relatively straight. Fore trochanter bearing a pit; fore femur bearing three pads, the outer pair symmetrical and wider than the single inner; tarsomere II of foreleg shorter than tarsomere III; anterior tarsi bearing single claw. Abdomen with parasternites II and III narrower than IV, their external margins nearly straight.

Figures

Fig. 1. Lethocerus indicus (Lepeletier & Serville), male, specimen from Laos, Vientiane Prov.