Batochares Hansen, 1991

Giron, Jennifer C. & Short, Andrew Edward Z., 2021, The Acidocerinae (Coleoptera, Hydrophilidae): taxonomy, classification, and catalog of species, ZooKeys 1045, pp. 1-236 : 1

Genus Batochares Hansen, 1991 Figs 1I , 2 , 4 , 9D, E , 22D , 23

Batochares d’Orchymont, 1939b: 293 [Described as subgenus; unavailable, ICZN (1999) Art. 13.3: no type species designated].

Helochares Fixed as subgenus of Helochares by Hansen (1991: 292) [available, granting authorship to Hansen under ICZN (1999) Art. 50.1.].

Helochares Elevated to genus by Short et al. (2021).

Gender.

Masculine.

Type species.

Helochares (Batochares) burgeoni d’Orchymont, 1939b: 294; by original designation ( Hansen 1991: 292).

Diagnosis.

Body length between 3-4 mm. Body shape oval in dorsal view, moderately convex in lateral view, with dorsal outline nearly straight along basal 2/3 (Fig. 23 ). Dorsal surfaces smooth, uniformly covered by short setae, brown to pale brown in coloration, either uniform or with yellowish patches along margins of pronotum and elytra, or scattered throughout surface giving spotted appearance (Fig. 23A, B ); ground punctation fine and shallow; ventral surfaces rather densely covered by rather long and fine golden setae. Head rather oval in dorsal view, clearly constricted at anterior margin of eyes (Fig. 11E ). Eyes not emarginate, moderate in size, separated by nearly 3.8 × width of eye, strongly projected from outline of head (Fig. 11E ). Clypeus with anterior margin broadly emarginate, with medial region of emargination nearly straight; anterior corners round. Labrum fully exposed, with apical region anteriorly flattened, thus forming fine transverse carina across anterior region (Fig. 11D ). Mentum rather flat, surface laterally punctate, mesally and anteriorly striate, with anteromedial region depressed. Submentum finely and shallowly punctate. Antennae with nine antennomeres, with strongly asymmetric and round cupule. Maxillary palps nearly 1.5 × longer than maximum width of head, with palpomere 4 0.8 × as long as palpomere 3 (Fig. 23C ); inner margin of maxillary palpomere 2 nearly straight, outer margin apically slightly curved. Pronotum medially evenly convex, explanate and somewhat bending upwards along antero-lateral areas; posterior margin of pronotum clearly narrower than anterior margin of elytra combined. Elytra without sutural striae, with outer margins explanate, especially along anterior third; serial punctures well developed, forming longitudinal rows, at least well defined along outer areas, or visible along entire length of elytra; seta bearing systematic punctures irregularly distributed. Surface of prosternum slightly elevated along midline, with anterior margin acutely triangular and slightly projected anteriorly. Posterior elevation of mesoventrite rather flat; intercoxal process of mesoventrite broad (nearly as wide as antennal club), apically truncate; anapleural sutures sinuate, separated at anterior margin by distance slightly shorter than anterior margin of mesepisternum. Metaventrite with medial surface elevated as platform, densely covered with hydrofuge pubescence, except for posterolateral patches (Fig. 23C ). Protibiae with spines of anterior row very fine and erect; apical spurs of protibiae small (larger spur similar in size and shape to tarsal claws). Metafemora without tibial grooves; metafemora with hydrofuge pubescence covering at least basal 2/3 of anterior surface (Fig. 23C ). Metatarsomere 5 1.5 × longer than metatarsomere 2, metatarsomere 2 nearly as long as metatarsomeres 3 and 4 combined; tarsomeres 1 to 4 with sparse long setae on dorsal surface, and spiniform dense setae on ventral surface; tarsomere 5 with few setae along apical margin. Abdomen with five pubescent ventrites. Fifth abdominal ventrite with apex broadly truncate, without stout setae. Aedeagus trilobed, with basal piece nearly as long as parameres (Fig. 22D ); parameres somewhat triangular, slender and apically narrowing; median lobe tapering to round apex; gonopore well-developed.

Differential diagnosis.

Batochares differs from all other known acidocerines by its unique labrum (with apical region anteriorly flattened, forming a transverse carina across anterior region; Fig. 11D ), combined with oval head which is constricted at the anterior margins of the eyes, anterolaterally explanate pronotum, explanate elytra, rows of serial punctures visible at least along outer margins, broadly truncate posterior margin of fifth abdominal ventrite, and unusually large basal piece of the aedeagus (longer than parameres). These features, especially the configuration of the labrum, pronotum and elytra, along with the yellow spots along the surface of the elytra distinguish Batochares from all other known acidocerines.

Distribution.

Afrotropical: Burundi/Rwanda, Central African Republic, Democratic Republic of the Congo, Gabon, Guinea, Kenya, Republic of the Congo, Uganda; Fig. 4 .

Natural history.

Little natural history information is available for the genus. Recent collecting data for a few series suggests it may be associated with the margins of streams and small rivers.

Larvae.

Immature stages for Batochares remain unknown.

Taxonomic history.

Batochares was described as a subgenus of Helochares by d’Orchymont (1939b) who did not explicitly designate a type species; therefore, the subgenus name was unavailable according to article 13.3 of the ICZN (1999). In 1991, Hansen validated Batochares as a subgenus of Helochares by fixing the type species for it; therefore, under article 50.1 of the Code (ICZN 1999), Hansen is granted authorship of the subgenus name. d’Orchymont considered Batochares as a subgenus of Helochares based for the most part in the number of antennomeres, relatively long maxillary palps, characters of the mentum and pubescent femora, even though the author recognized the distinctiveness of the shape of the head and the explanate elytra. Batochares was elevated to full generic status based on the phylogenetic analysis in Short et al. (2021), in which it was resolved as an early-diverging, isolated lineage within the Helochares group.

Remarks.

There are three species of Batochares described to date. In his description of Batochares corrugatus Balfour-Browne (1958a: 183), the author pointed out that his record of B. burgeoni from Mutsora, Parc National Albert (currently Virunga National Park, Democratic Republic of the Congo; Balfour-Browne 1950b) was not actually B. burgeoni , but a larger and likely different species. The author also indicated the existence of a different species from Angola.

Species examined.

Batochares burgeoni ( d’Orchymont) and B. byrrhus ( d’Orchymont).

Selected references.

d’Orchymont 1939b: 293: original description; Balfour-Browne 1958a: 183: description of one additional species; Hansen 1991: 292: type species designated, subgenus validated; Short et al. 2021: generic status, phylogenetic position and affinities discussed.

Figures

Figure 1. Variation across Acidocerinae, dorsal and lateral views A Colossochares ellipticus B Peltochares sp. C Peltochares conspicuus D Aulonochares tubulus E Helochares sp. F Helochares tristis G Novochares sp. H Helopeltarium ferrugineum I Batochares sp. J Helobata larvalis K Radicitus sp. L Nanosaphes tricolor M Agraphydrus cf. attenuatus N Tobochares luteomargo O Tobochares sulcatus P Quadriops similaris Q Crucisternum ouboteri R Primocerus neutrum S Agraphydrus coomani T Agraphydrus sp. U Globulosis flavus V Crephelochares nitescens.

Figure 2. Phylogeny of the Acidocerinae simplified from Short et al. (2021), indicating the distribution, preferred habitat, and currently described number of species for each genus. For habitat, filled black circles indicate that at least some species of the genus are commonly found in this habitat; light grey circles indicate the genus has been found in this habitat, but is rare or not typical for the group; white circles indicate no species have been recorded for the genus in this habitat.

Figure 4. Known distribution of genera of Acidocerinae: Acidocerus, Agraphydrus, Aulonochares, Batochares, Chasmogenus, Colossochares, and Crephelochares.

Figure 9. Examples of seepage habitat for Acidocerinae A, B marginal seepage along river (Guyana: GY 14 - 0312 - 01 B) C, D isolated seep on granite inselberg (Venezuela: VZ 10 - 0710 - 01 A) E, F hygropetric zone next to waterfall (Venezuela: VZ 12 - 0122 - 03 A).

Figure 11. Head of miscellaneous Acidocerinae A-D anterolateral view: A Tobochares luteomargo with white arrow pointing to straight anterior margin of eye B Tobochares emarginatus with white arrow pointing to Tobochares canthus emarginating anterior margin of eye C Quadriops politus with white arrow pointing to Tobochares canthus fully dividing the eye in dorsal and ventral faces D Batochares sp. black arrow pointing to transverse carina on labrum E-L dorsal view of head: E Batochares sp. F Helochares tristis G Crephelochares nitescens, H Chasmogenus australis with black arrow pointing to preclypeal membrane I Colossochares ellipticus J Aulonochares tubulus K Peltochares conspicuus L Helobata larvalis.

Figure 22. Aedeagi of Aulonochares and Batochares spp. A A. tubulus B A. novoairensis C A. lingulatus D B. sp. Scale bars: 0.5 mm.

Figure 23. Habitus of Batochares sp. A dorsal habitus B lateral habitus C ventral habitus. Scale bar: 1 mm.