Novochares Giron & Short, 2021

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 Novochares Giron & Short gen. nov. Figs 1G , 2 , 6 , 42 , 43

Helochares "Clade D", Short et al. (2021)

Gender.

Masculine.

Type species.

Helochares tectiformis Fernández, 1982b; by present designation.

Etymology.

From the Latin word novus, meaning new, in reference to the genus being restricted to the New World, combined with the ending chares, expressing affinity with Helochares . Masculine.

Diagnosis.

Medium sized beetles, body length 4.5-9.0 mm. Body shape oval in dorsal view; slightly to moderately convex in lateral view, with dorsal outline nearly flat along anterior half of elytra, or somewhat evenly curved (Fig. 42 ). Coloration usually uniformly dark brown, sometimes orange or pale brown; ground punctation shallow to moderately marked (Fig. 42 ). Shape of head trapezoid. Eyes relatively large, not emarginated anteriorly, usually projected from outline of head. Clypeus trapezoid, with anterior margin broadly and roundly emarginate. Labrum fully exposed. Mentum with lateral longitudinal crenulations, lateral oblique ridges, and transverse crenulations along antero-medial area (Fig. 42C, F ). Antennae with nine antennomeres; cupule strongly asymmetric, with rounded outline; antennomere 9 slightly to 2 × longer than antennomere 7. Maxillary palps slender, moderately long, 1.1-1.5 × the width of head; inner margin of maxillary palpomere 2 weakly and evenly curved to nearly straight, outer margin evenly curved or curved along apical half; maxillary palpomere 3 slightly longer than 4 (Fig. 42C, F ). Prosternum flat to weakly convex. Elytra without sutural striae, with ground punctures usually shallowly marked; usually at least one row of systematic punctures visible along midline of each elytron; serial punctures sometimes visible along posterior half of elytra (e.g., Fig. 42D ). Posterior elevation of mesoventrite, usually simply bulging, sometimes bulge impressed posteriorly, sometimes bulge extends anteriorly as low, shiny, and glabrous longitudinal ridge; anapleural sutures concave, separated at anterior margin by distance 0.6-0.9 × the width of anterior margin of mesepisternum. Metaventrite with medial glabrous patch, sometimes very narrow and extending along entire length of metaventrite (e.g., Fig. 42C, F ). Protibiae with spines of anterior row extremely reduced to tiny appressed denticles. Metafemora with tibial grooves well developed; hydrofuge pubescence covering basal 6/7 of anterior surface. Tarsomeres 1-4 with long, thick, and rather dense setae on ventral face, sometimes with only rows of short spines on metatarsomeres 2-4; metatarsomere 2 as long or slightly longer than 5 and as 3 and 4 combined. Fifth abdominal ventrite apically emarginate, with fringe of stout setae. Aedeagus divided (Fig. 43 ); parameres separated from each other for most of their lengths; median lobe divided in dorsal and ventral plates; dorsal plate usually strongly sclerotized and elongated, often bifurcated or otherwise shaped along apical region; ventral plate sometimes reduced, usually simple and of variable length; basal piece 0.3 × or less than length of parameres, usually clearly noticeable; gonopore usually clearly visible.

Differential diagnosis.

Novochares includes medium sized, pale to dark brown species that are somewhat dorsoventrally compressed and highly polished (smooth, and often shiny) to the naked eye. In the New World the most similar genus is Aulonochares , from which it can be differentiated by the shape of the head [trapezoid in Novochares , subquadrate in Aulonochares (Fig. 11J )], and the sculpture of the mentum (variously striate in Novochares , punctate in Aulonochares ). Some members of the New World Helochares may resemble Novochares in their external features, but the aedeagal form is completely different (tubular in Helochares , Figs 16E, F , 37 ; divided in Novochares , Figs 16G, H , 43 ).

From the rest of acidocerines, Novochares externally is strikingly similar to the dark and highly polished members of the Old World genus Peltochares (compare Fig. 1B vs 1G), from which Novochares can be distinguished by the shape of the posterior elevation of the mesoventrite (simply and broadly bulging, often with additional anterior low longitudinal ridge in Novochares , longitudinally elevated in Peltochares ), in addition to characteristics of the male genitalia (divided aedeagus in Novochares (Figs 16G, H , 43 ), spiked aedeagus in Peltochares (Figs 16C, D , 45 ); see also explanation under the aedeagus section of Morphological variation in Acidocerinae and its taxonomic importance).

To differentiate Novochares from dark brown, relatively flattened, highly polished, and 4-5 mm long species of Helochares , the most reliable feature for identification would be the male genitalia: Novochares always exhibit divided aedeagi (Figs 16G, H , 43 ; parameres separated from each other for most of their lengths, dorsal plate of the median lobe usually strongly sclerotized, elongated, often bifurcated or otherwise shaped along its apical region), whereas in Helochares the aedeagi are always tubular (Figs 16E, F , 37A-H ; parameres fused to each other for most of their lengths, median lobe with very long basal apodemes; see also explanation under the aedeagus section of Morphological variation in Acidocerinae and its taxonomic importance).

Distribution.

Nearctic: U.S.A. (Florida; thought to be introduced). Neotropical: Argentina, Belize, Bolivia, Brazil (Amazonas, Espírito Santo, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pernambuco, Piauí, Rio de Janeiro, São Paulo), Colombia, Costa Rica, Cuba, Ecuador, French Guiana, Guatemala, Lesser Antilles (Grenada, Guadeloupe, St. Vincent), Mexico, Panama, Paraguay, Suriname, Uruguay, Venezuela; Fig. 6 .

Natural history.

Species of Novochares occur in a broad range of both lentic and lotic habitats; we are not aware of any seepage specialists in this lineage. Some species such as the widespread N. abbreviatus (Fabricius) are found in lentic habitats including marshes, swamps, and pond margins ( Short 2005). Forest pools with abundant leaf litter detritus are often very productive for a variety of species. Novochares atlanticus (Clarkson and Ferreira-Jr.) was collected at temporary ponds with leaf litter and aquatic vegetation, either covered and shaded in the border of the forest (Clarkson and Ferreira-Jr. 2014), or in open areas. Some species come to lights. Fernández (1983), in describing the immature stages of N. pallipes ( Brullé), indicated that the species was found on coastal zones, associated with swamp plants ( Spirodela intermedia ; Araceae ).

Larvae.

The immature stages are only known for Novochares pallipes ( Brullé) (described as Helochares (s. str.) Helochares pallipes Brullé in Fernández 1983: 444); egg sac, first, second and third instar larvae, and pupa are described and illustrated. From each egg sac, 80-103 larvae emerged ( Fernández 1983).

Taxonomic history.

Species of Novochares have been described since as early as 1801, but it was only with the investigations by Fernández in the 1980's ( Fernández 1981, 1982a, 1982b, 1983, 1989) that the group was studied in a comparative taxonomic framework beyond the description of single species.

Remarks.

There are 15 species of Novochares described to date. Species of Novochares tend to have moderate to shallow punctation and serial punctures are usually absent. There is a group of species with serial punctures visible along the posterior half to third of the elytra (Clade D1 in Short et al. 2021).

Species examined.

Novochares abbreviatus (Fabricius), N. carmona (Short), N. chaquensis ( Fernández), N. cochlearis ( Fernández), N. coya ( Fernández), N. guadelupensis ( d’Orchymont), N. pallipes ( Brullé), N. sallaei (Sharp), N. tectiformis ( Fernández). Paratypes of N. carmona were examined for this study.

Selected references.

Fernández 1982a: notes on the taxonomic status of some of the previously described species; Fernández 1982b: description of four new species; Fernández 1983: description of immature stages for Novochares pallipes ( Brullé); Fernández 1989: one new species and identification key; Short 2005: one new species with review of Central American species; Clarkson and Ferreira-Jr 2014: one new species and new records from southern Brazil; Short et al. 2021: phylogenetic placement.

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 6. Known distribution of genera of Acidocerinae: Novochares, Peltochares, Primocerus, Quadriops, Radicitus, Sindolus, Tobochares, and Troglochares.

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 16. Aedeagi A-E trilobed: A schematic B Chasmogenus schmits C, D spiked: C schematic D Peltochares foveicollis E, F tubular: E schematic F Helochares politus G, H divided: G schematic H Novochares pallipes.

Figure 37. Aedeagi A-H Helochares spp.: A H. sp. (Guinea) B H. tristis C H. nr. cresphontes D H. nr. tatei E H. sp. (India, Goa) F H. sp. (Vietnam) G H. politus H H. songi (from Jia and Tang 2018, fig. 48) I Helopeltarium ferrugineum. Scale bars: 0.5 mm.

Figure 42. Habitus of Novochares spp. A-C N. sallaei: A dorsal habitus B lateral habitus C ventral habitus D-F N. sp. (Peru): D dorsal habitus E lateral habitus F ventral habitus. Scale bars: 1 mm.

Figure 43. Aedeagi of Novochares spp. A N. sp. (Ecuador) B N. abbreviatus C N. pallipes D N. chaquensis E N. atratus F N. pichilingue G N. cf. tectiformis H N. cf. coya I N. cf. guadelupensis J N. cf. cochlearis. Scale bars: 0.5 mm.

Figure 45. Aedeagi of Peltochares spp. A P. conspicuus B P. foveicollis C P. sp. (Australia) D P. sp. (Tanzania;). Scale bars: 1 mm.