Helotrephes, Stal, 1860

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 : 178

Key to the species of Helotrephes

1 Pronotum at hind margin without tubercles. Pronotal plate near eye with very deep, roundish incision ( Fig. 42 ). Subgenital plate of female with broad medial lobe ( Fig. 44 ). Apex of aedeagus narrow, hook-shaped ( Fig. 48 ). Helotrephes australis species group .................................................... Helotrephes australis

– Pronotum at hind margin with distinct tubercles ( Figs. 3, 9 ). Pronotal plate near eye with small incision ( Figs. 43 ). Subgenital plate of female with narrow medial process ( Figs. 45–47 ). Apex of aedeagus broad, not hook-shaped ( Figs. 51, 54, 57 ). Helotrephes otoeis species group .......................................... 2

2 Cephalonotum yellowish with numerous brown speckles. Medial process of subgenital plate of female large, with weakly narrowed “neck” ( Fig. 45 ). Aedeagus of male with broad apical lamella ( Fig. 51 ). Southern Thailand..... [ Helotrephes affinis ]

– Cephalonotum almost totally bright yellow. Medial process of subgenital plate of female narrow, with distinct “neck” ( Figs. 46, 47 ). Aedeagus of male with small, completely delimited apical plate ( Figs. 54, 57 ) ..................................................... 3

3 Subgenital plate of female moderately asymmetrical at base ( Figs. 46 ). Aedeagus of male with wide, posteriorly sharply delimited apex ( Fig. 54 ). ..................... Helotrephes flaviceps

– Subgenital plate of female strongly asymmetrical at base ( Figs. 47 ). Aedeagus of male with narrow, posteriorly curved apex ( Fig. 57 ) ......................................... Helotrephes rompinensis

Figures

Figs. 40–76. Key characters of species of Helotrephini. (40, 41) Pronotal plate (pnp) and genal plate (gp), ventrolateral aspect, (44–47, 60–63) Subgenital plate of female, ventral aspect, pilosity omitted in Figs. 44, 60–63) male genitalia in lateral (left) aspect: (48, 51, 54, 57, 64, 65, 68, 71, 74) aedeagus of male, (49, 52, 55, 58, 66, 69, 72, 75) left paramere of male, (50, 53, 56, 59, 67, 70, 73, 76) right paramere of male. 42, 44, 48 – 50, Helotrephes australis, 45, 51–53, Helotrephes affinis, 43, 46, 54–56, Helotrephes flaviceps, 47, 57–59, Helotrephes rompinensis, 60, 65–67, Hydrotrephes sitesi, 61, 68–70, Hydrotrephes maculatus (redrawn from Papá ek & Kovac, 2001a; slightly modified), 62, 74–76, Hydrotrephes benomensis, 63, 71–73, Hydrotrephes langkawicus, 64, Hydrotrephes mixtus.

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.