Helobata Bergroth, 1888

Clarkson, Bruno, Santos, André Dias Dos & Ferreira-Jr, Nelson, 2016, On Brazilian Helobata Bergroth, 1888 (Coleoptera: Hydrophilidae): description of two new species, new records, and key to species, Zootaxa 4126 (4), pp. 548-562 : 549-550

Helobata Bergroth, 1888

Helopeltis Horn, 1873: 137 (nec Signoret, 1858).

Helobata Bergroth, 1888: 221 (replacement name for Helopeltis Horn ). Helopeltina Cockerell, 1906: 240 (replacement name for Helopeltis Horn ).

Type species. Helopeltis larvalis Horn, 1873 (by monotypy).

Diagnosis. Moderate-sized (ca. 4.3–7.7 mm in length), oval shaped in dorsal view (Figs. 1, 7, 12, 18 and 20); slightly convex in lateral view; outline not interrupted between pronotum and elytra. Labrum concealed by clypeus. Clypeus expanded sideward in front of eyes. Eyes deeply emarginated anteriorly. Antennae with eight antennomeres, pedicel ca.2/ 3x as long as scape, club loosely segmented, ca. 3x as long as wide. Maxillary palpi slightly longer than width of head, bending inwards (Figs. 2, 8, 13, 19 and 21). Without distinct systematic punctures on the head, pronotum and elytra. Elytra with 10 punctate striae; well-developed scutellary stria, restricted to the elytral basis; lateral portions of elytra very wide and expanded (Figs. 1, 2, 7, 8, 12, 13, 18, 19, 20 and 21). Prosternum well-developed, weakly convex, not carinate medially (Figs. 2, 8, 13, 19 and 21). Mesoventrite with posteromedial elevation delimited laterally by carinae. Metaventrite convex, finely carinate medially (metaventral medial carina), projected between mesocoxae (metaventral projection), posteromedial portion weakly raised (Figs. 2, 8, 13, 19 and 21). Femora without distinct tibial grooves; with hydrofuge pubescence, except apically. Tarsal formula 5-5-5; hind tarsi with 2nd tarsomere much longer than 1st. Abdomen with five exposed ventrites, with fine and dense pubescence (Figs. 2, 4, 6 and 8); posterior margin of ventrite 5 with a shallow apical notch. Median lobe divided into a broad and bifid dorsal lobule and a narrow ventral lobule (Figs. 3, 4, 9, 10, 14, 15, 16, 22, 23) (modified from Hansen 1991 and Fernández & Bachmann 1987).

Remarks. Since the external morphology of Helobata species are quite similar, Fernández & Bachmann (1987) described species based mainly on the shape of clypeus and general morphology of male genitalia. García (2000) proposed presence/absence of the frontoclypeal suture and aspects of mesoventral carinae, which laterally delimit posteromedial elevation on mesoventrite, as relevant for diagnosis and interspecific discernment. Although we’ve explored other features in this paper, differential diagnosis was also based on these characteristics in order to facilitate comparison and identification.