Review of the Helochares (Hydrobaticus) MacLeay of the New World (Coleoptera: Hydrophilidae: Acidocerinae) Author Short, Andrew Edward Z. Author Girón, Jennifer C. text Zootaxa 2018 2018-04-09 4407 1 29 50 journal article 22806 10.11646/zootaxa.4407.1.2 8e0aac3a-6556-4b96-a67e-fce9f0db0ba9 1175-5326 3766290 B45E9ABD-CB52-4EE7-91D6-783E8E958AC5 Helochares (Hydrobaticus) championi Sharp, 1882 Figs. 2B , 5G , 7K , 10B . Helochares championi Sharp, 1882: 75 . Helochares ( Hydrobaticus ) championi Sharp ; Balfour-Browne 1939: 293 . Type material examined. Lectotype male: “ Helochares / championi/ D. S./ S. Geronimo / Guatemala ” [on same card as specimen], “Co-Type” [yellow disc], “San Geronimo/ Vera Paz./ Champion”, “Sharp Coll./ 1905.-313.”, “ B. C. A. Col. I. 2./ Helochares / championi,/ Sharp”, “ LECTOTYPE / Helochares / championi/ Sharp, 1882 / des. A. Short 2004” ( BMNH ) . Paralectotypes (16): GUATEMALA : same locality as lectotype (4, BMNH ) ; Guatemala City (10, BMNH ) ; Duenas (1, BMNH ) . NICARAGUA : Chontales (1, BMNH ) . Additional material examined (79): COSTA RICA : Cartago Province : Tapanti National Park , 9°45'55.2594"N , 83°47'37.7376"W , 1237m , side pools of Rio Orosi , 1237 m , 17.iii.2010 , leg. Short & Gustafson, CR 10-0317-SG2 (5, SEMC , INBio ; includes DNA voucher SLE1174) ; Tapanti National Park , oropendola trail, trail head, 1250 m , 17.vii.2011 , in ditch, leg. A.E.Z. Short , CR11-0717-02C (2, SEMC , INBio ) . Puntarenas Province : Las Cruces Biological Station , 3800’ elev. (= 1158 m ), 19.vi.2003 , A.E.Z. Short (1, INBio ) . GUATEMALA : 10 mi. E Guatemala City , 8.viii.1965 , leg. P.J. Spangler (30, USNM , SEMC ) ; 20 mi. NW Chimaltenango , 20.viii.2965 , leg. P.J. Spangler (6: USNM ) ; Vista Hermosa , 24.vi.1966 , leg. Flint & Ortiz (29: USNM , SEMC ) ; Totonicapan , San. Christobal T. , 13.vi.1966 , leg. Flint (1, USNM ) . Differential diagnosis. Body size 5.8–6.4 mm . Clypeus entirely pale yellow ( Fig. 5G ). Ground punctation on head and elytra fine. Elytra without any detectable serial punctures or striae ( Fig. 2B ). Abdominal ventrites uniformly dark brown; pubescence dense and evenly distributed, the longest hairs shorter than those on the metaventrite. Aedeagus ( Fig. 7K ) 2.8-times longer than its greatest width; apex of parameres narrow and oblique, with outer corners weakly rounded; inner corners of apex of parameres forming a nearly right angle; lateral outer margins of parameres nearly parallel, weakly rounded along apical half; median lobe with apex broadly rounded. The complete lack of elytral serial punctures or striae easily separate this species from all other New World Hydrobaticus except H. laevis and H. politus . It can be distinguished from those species by its uniformly pale colored clypeus (darkened medially in H. politus ) and its distinctive aedeagus ( Fig. 7K ). FIGURE 2. Dorsal habitus images of Helochares ( Hydrobaticus ) spp. (A) H. trujillo n. sp. , (B) H. championi Sharp , (C) H. nexus n. sp. , (D) H. zamora n. sp. , (E) H. sp. A. Distribution. Currently known from scattered localities as far south as Costa Rica and as far north as Guatemala ( Fig. 10B ). Biology. In Costa Rica , most series have been collected from muddy pools with abundant vegetation in the floodplain of a river and also in a nearby roadside ditch. The specimen from Las Cruces Costa Rica was collected in an open, forested stock water tank on the grounds of Las Cruces Biological Station. All recent collections of this species have been at a relatively high elevation of ~ 1150–2200 m . This species has been observed to carry its egg case. Remarks. In assigning this species to the subgenus Hydrobaticus , Balfour-Browne (1939 : p. 293) commented that H. championi possesses “ten longitudinal series of punctures on the elytra, which are not mentioned by Sharp”, and that “These longitudinal series are very weakly impressed and composed of punctures scarcely larger than the interstitial punctation.” Examination of the type series as well as dozens of additional specimens show that the species lacks any distinct elytral series, in agreement with Sharp’s original description.