Helochares

Short, Andrew Edward Z. & Girón, Jennifer C., 2018, Review of the Helochares (Hydrobaticus) MacLeay of the New World (Coleoptera: Hydrophilidae: Acidocerinae), Zootaxa 4407 (1), pp. 29-50 : 48-49

publication ID	https://doi.org/ 10.11646/zootaxa.4407.1.2
publication LSID	lsid:zoobank.org:pub:B45E9ABD-CB52-4EE7-91D6-783E8E958AC5
DOI	https://doi.org/10.5281/zenodo.3803384
persistent identifier	https://treatment.plazi.org/id/676A87E0-FFB7-B15E-2392-FB2D47900F17
treatment provided by	Plazi
scientific name	Helochares
status

Treatment

Key to the New World species of the Helochares View in CoL subgenus Hydrobaticus

1. Elytra with distinct rows of serial punctures, sometimes deeply impressed into grooves (e.g., Fig. 2A View FIGURE 2 , C–E). Size variable (4.2– 6.6 mm). Widely distributed............................................................................. 2

- Elytra without rows of serial punctures ( Figs. 2B View FIGURE 2 , 4 View FIGURE 4 ). Size larger than 5.5 mm. Mexico and Central America.............. 8

2. Abdominal pubescence sparse and not uniformly distributed on each ventrite ( Fig. 6A View FIGURE 6 ). Abdominal ventrites uniformly very dark brown to almost black in coloration. Elytra with rows of serial punctures not impressed into striae............................................................................................ H. normatus (LeConte) View in CoL (in part)

- Abdominal pubescence dense and uniform, not appearing sparse or absent on anterior half of each ventrite (e.g. Fig. 6 View FIGURE 6 B–D). Abdominal ventrites variously colored. Elytra with rows of serial punctures impressed into striae or not................. 3

3 Size larger (> 5.8 mm). Elytral serial punctures not impressed into striae or only very weakly so; absent or almost appearing absent anteromedially ( Fig. 2A View FIGURE 2 ).............................................................. H. trujillo View in CoL n. sp.

- Size variable (4.2–6.0 mm). Elytra with rows of serial punctures impressed into striae or not; rows distinctly present anteromedially............................................................................................... 4

4 Abdominal ventrites pale in color, either uniformly yellowish brown or yellowish brown on lateral thirds with median third darker brown......................................................................................... 5

- Abdominal ventrites uniformly dark brown to almost black in color..............................................6

5 Parameres of aedeagus truncate at apex, with outer corners widely rounded ( Fig. 7 View FIGURE 7 F–H). More southern distribution ( Panama, Ecuador, Venezuela)....................................................................... H. nexus View in CoL n. sp.

- Parameres of aedeagus with apex oblique to truncate, with outer corners widely rounded ( Fig. 8 View FIGURE 8 ). More northern distribution (this rarer form known from Mexico)............................................ H. normatus (LeConte) View in CoL (in part)

6 Clypeus pale in coloration, not darkened medially ( Fig. 5A View FIGURE 5 ). Eastern North America............. H. maculicollis Mulsant View in CoL

- Clypeus distinctly darkened medially ( Fig. 5E, H View FIGURE 5 ). South America............................................... 7

7 Pronotum almost entirely darkly colored ( Fig. 2D View FIGURE 2 ). Size smaller (4.7–4.8 mm). Ecuador................ H. zamora View in CoL n. sp.

- Pronotum only darkened on central disc ( Fig. 2E View FIGURE 2 ). Size larger (5.2–5.5 mm). Peru............................ H. sp. A

8 Clypeus pale in coloration, not darkened medially ( Fig. 5G View FIGURE 5 ). Aedeagus with median lobe broadly rounded, with only a small “pinched” apex ( Fig. 7K View FIGURE 7 )............................................................... H. championi Sharp View in CoL

- Clypeus distinctly darkened medially ( Fig. 5I View FIGURE 5 ). Aedeagus with median lobe tapered to a point at apex ( Fig. 7 View FIGURE 7 I– J)......... 9

9 Aedeagus with apex of parameres rounded ( Fig. 6I View FIGURE 6 ); lateral outer margins of parameres parallel, slightly constricted near midlength; maximum width of aedeagus at basal half, nearly as wide as maximum width of aedeagus at apical half................................................................................................... H. politus View in CoL n. sp.

- Aedeagus with apex of parameres truncate ( Fig. 6J View FIGURE 6 ); lateral outer margins of parameres parallel along basal two thirds, slightly constricted at two thirds, diverging along apical third; maximum width of aedeagus at basal half, clearly narrower than maximum width of aedeagus at apical half........................................................... H. laevis View in CoL n. sp.