Helotrephinae, Esaki & China, 1927

Zettel, Herbert, ek, Miroslav Papá & Kovac, Damir, 2011, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia: Vii. Family Helotrephidae, Raffles Bulletin of Zoology 59 (2), pp. 171-179 : 177

Subfamily Helotrephinae – Tribe Limnotrephini

According to present classification (Papá ek & Zettel, 2005), this tribe contains seven genera including four from Southeast Asia and three from the study area. Distotrephes and Tiphotrephes each are represented by single species on the Malay Peninsula: Distotrephes zetteli is known from Central Thailand to West Malaysia (Selangor). Tiphotrephes indicus is widely distributed from India to Borneo; it has been collected in Selangor and Perak and it is the only helotrephid so far recorded from Singapore. The distributions of two extremely similar species of Idiotrephes overlap in Malaysia (Papá ek & Zettel, 2000): the chiefly Southeast Asian I. asiaticus and the West Malesian I. chinai . They can only be distinguished by discrete differences in the structures of the males’ genitalia and the apices of the females’ first valvulae (compare Figs. 34–41 ; main differences marked by arrows).

These three genera differ distinctly in their preferred habitats. Distotrephes is benthic and prefers clean streams. Idiotrephes is usually found in lithotelms, but also in other small, stagnant water bodies. Tiphotrephes can be found in various kinds of stagnant waters and is probably the most euryoecious helotrephid species worldwide.

Mixotrephes thermophilus is so far recorded from northern Myanmar (Sagaing Division, Shan States) and northern Thailand (Chiang Mai, Kampaeng Phet) (Papá ek & Kovac, 2001b; Papá ek & Zettel, 2006); its tolerance for warm water (Papá ek & Kovac, 2001b) suggests that this cryptic species also might occur further south .

Figures

Figs. 25–41. Key characters of species of Limnotrephini. Female terminalia in ventral, male genitalia in lateral (left) aspect. (25, 29, 33) Subgenital plate of female, (34, 38) first valvulae of female, (26, 30, 35, 39) aedeagus of male, (27, 31, 36, 40) left paramere of male, (28, 32, 37, 41) right paramere of male. 25–28, Distotrephes zetteli, 29–32, Tiphotrephes indicus, 33–37, Idiotrephes chinai, 38–41, Idiotrephes asiaticus. Redrawn from Papá ek & Zettel, 2000, 2003 and Papá ek & Kovac, 2001b, respectively; some parts slightly modified.