Hydrometridae, Billberg, 1820

Yang, Chang Man & Zettel, Herbert, 2005, Guide To The Aquatic Heteroptera Of Singapore And Peninsular Malaysia. V. Hydrometridae, Raffles Bulletin of Zoology 53 (1), pp. 79-97 : 82

Key to genera of Hydrometridae

(modified from Andersen, 1982a)

1. First antennal segment much longer than second segment. Eyes located about middle of head, AO subequal in length to PO ( Fig.1 ). Length 3.0-5.0 mm .............. [ Heterocleptes Villiers ] (species spinosus Andersen , subfamily Heterocleptinae, Borneo only)

– First antennal segment subequal to or shorter than the second segment. Eyes located far behind middle of head, AO distinctly longer than length of PO ( Figs. 2 , 3 , 4). Length 7.0-18.0 mm ............................................................... Hydrometra Latreille (subfamily Hydrometrinae , widespread)

Figures

Fig.1. Heterocleptes spinosus Andersen, macropterous female (from Andersen, 1982).

Fig. 2. Head of Hydrometra (from Polhemus & Polhemus, 1995). Abbreviations: AC, anteclypeus; AO, anteocular distance; GL, gular lobe; MXP, maxillary plate; MDP, mandibular plate; PO, postocular distance.

Fig. 3. Hydrometra longicapitis Torre-Bueno, brachypterous male with appendages removed, dorsal view. Abbreviations: L, laterotergite; PT8, posterior process of segment 8 (Sg8); T, tergite; W, wing.