Trephotomasinae Papá

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 Trephotomasinae Papá ek, Štys & Tonner, 1988

At present, the subfamily Trephotomasinae is unknown from the study area. It is here included because the genus Platytrephes Zettel, 2005 (five described species) is widely distributed from southern China to Borneo ( Zettel, 2005), and possibly some species may be found in West Malaysia in the future. Two further monotypic genera are known in the subfamily, but their presence in the study area is unlikely: Trephotomas compactus Papá ek, Štys & Tonner, 1988 has been recorded from southern China, northern Vietnam, northern and central Thailand; and Papacekia microphthalma Zettel, 2005 from Borneo. Trephotomasinae possesses two unique characters, the pseudendocorium ( Fig. 12 ) and the tarsal formula 2–2–3. The genus Platytrephes can easily be recognized by its weakly convex and broad habitus ( Fig. 2 ) and wide, flattened medial areas on the metasternum and sternite 2. As far as their habitats are known, Trephotomasinae is benthic on gravelly bottoms of clean streams.

Figures

Figs. 12–24. Key characters of helotrephid genera. 12–14, Hemielytron in situ, dorsolateral aspect; cla = clavus, cls = claval suture, emb = embolium, pse = pseudendocorium, psm = pseudomembrane. (12) Platytrephes sitesi, hindwing-brachypterous morph, (13) Helotrephes australis, hindwing-brachypterous morph, and (14) Helotrephes australis, macropterous morph. 15–19, Cephalonotum (pnp = pronotal plate), lateral aspect, of (15) Helotrephes australis, (16) Distotrephes zetteli, hindwing-brachypterous morph, (17) Distotrephes pavelstysi Zettel, 1999, macropterous morph, (18) Tiphotrephes indicus, (19) Idiotrephes chinai. 20–23, Ventromedial carinae of thoracic and abdominal sternites, lateral aspect; prs – prosternum, mss – mesosternum, mts – metasternum, 2, 3, 4 etc. abdominal sternites 2, 3, 4 etc. (20) Helotrephes australis, (21) Ascetotrephes edmundsorum, (22) Hydrotrephes mixtus, (23) Hydrotrephes belomensis. 24, Metasternal carinae in Distotrephes zetteli, ventral aspect. Images not to scale.

Figs. 1–11. 1–8, Habitus, dorsal aspect; 9–11, frontal aspect.(1) Fischerotrephes jaechi; (2) Platytrephes sitesi; (3, 9) Helotrephes rompinensis; (4, 11) Hydrotrephes benomensis; (5, 10) Ascetotrephes edmundsorum; (6) Idiotrephes chinai; (7) Distotrephes zetteli; (8) Tiphotrephes indicus. (© NHMW Hemiptera Image Collection; published with permission). Images not to scale.