Novochares atratus (Bruch, 1915)

Short, Andrew Edward Z. & Giron, Jennifer C., 2023, Revision of the Neotropical water scavenger beetle genus Novochares Giron & Short (Coleoptera, Hydrophilidae, Acidocerinae), ZooKeys 1171, pp. 1-112 : 1

Novochares atratus (Bruch, 1915)

Figs 20J-L , 22B

Helochares atratus Bruch, 1915: 451.

Helochares (s. str.) atratus Bruch, 1915; Knisch 1925: 4; Fernández 1989: 148 [in key]; Clarkson and Ferreira Jr 2014: 400.

Helochares (s. str.) parhedrus d’Orchymont, 1939: 259 (synonymy: Fernández 1982a: 35).

Novochares atratus (Bruch, 1915); Girón and Short 2021: 203.

Type material examined.

Holotype (male): We examined images of the holotype, including the dissected aedeagus. The specimen is from Buenos Aires Province, Argentina and deposited in MACN.

Additional material examined

(9 exs.): Argentina: Entre Ríos: Río Paraná Ibicuy, Pto. Ibicuy , 10.xii.1979, leg. C.M. & O.S. Flint, Jr. (2, USNM) . Brazil: Bahia: 5 km W. Ilheus, 4.vii.1969, leg. P. & P. Spangler (3, USNM) . Espírito Santo: Muniz Freire , 19.vi.1908 (1, CMNH) . Rio de Janeiro: Araruama , xi.1981, leg. Moacir Alvarenga (3, USNM) .

Differential diagnosis.

The dorsal plate of the median lobe of the aedeagus is very unusual and distinct in that each side of the fork is bilobed and projected dorsally (Fig. 20J, L ). The aedeagus is generally most similar to N. chaquensis , which may also be very dark brown to black.

Description.

Body length 6.0-7.2 mm. Coloration: Dorsal surfaces brown to dark brown, usually with slightly paler (orange) clypeus, margins of head, pronotum, and elytra. Head: Maxillary palps nearly 1.2 × width of head, uniformly orange in color. Thorax: Ground punctation on pronotum and elytra relatively dense and very shallowly impressed. Elytra without rows of serial punctures, each with very faint rows (one dorsal and two or three lateral) of scarce and weakly marked systematic punctures. Prosternum only very weakly medially convex. Posterior elevation of mesoventrite weakly, broadly, and somewhat triangularly elevated. Abdomen: Apical emargination of fifth ventrite shallow to deep, U-shaped. Aedeagus: (Fig. 20J-L ) Overall shape pear-like, 4.5 × longer than wide, with outer lateral margins of parameres weakly and evenly convex; apical region of each paramere rounded, with outer margin very weakly pointed; at closest point, dorsal inner margins of parameres separated by distance 0.6 × greatest width of a paramere; dorsal plate of median lobe with neck 0.65 × as broad as base; lateral margins of dorsal plate of median lobe strongly laterally projected at base of fork; arms of dorsal plate of median lobe diverging, dorsally concave, nearly 0.2 × length of dorsal plate of median lobe; each arm uniformly wide along basal 1/2, then narrowing to acute apex; notch between arms at base nearly as wide as base of an arm; gonopore placed at base of dorsal plate of median lobe; ventral plate of median lobe weakly sclerotized, triangular, acute at apex, apex extending to base of neck of dorsal plate; basal piece 0.3 × length of a paramere. In lateral view, aedeagus oblique at base, with ventral outline of parameres 3.4 × longer than greatest width near base; dorsal outline of aedeagus in lateral view nearly straight along second 1/3.

Distribution.

Argentina, Brazil (Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro) (Fig. 22B ). Colombia, Ecuador, Paraguay, and the Brazilian state of Mato Grosso do Sul are removed from the distribution, see remarks.

Habitat.

Little is known about the habitat of this species.

Remarks.

The Colombian specimens identified by Gonzalez-Rodriguez et al. (2017) as N. atratus are in fact N. chaquensis , as can be determined by their figure 24 of the aedeagus, which matches N. chaquensis perfectly. Colombia is thereby removed from the range of this species. Additionally, there is a historical record from Ecuador that was published by Knisch (1925). This Ecuador record was based on two specimens from “Gualaquiza” from "Dr. Festa". No sex is indicated, though in records of some other species in the same paper, the sex is sometimes indicated, suggesting that the specimens mentioned here may have been unsexed. Because this record is likely a misidentification and so far outside the known range of this species, which is otherwise not known from northern South America or anywhere in the Andean region, we remove Ecuador from the reported range of this species.

The records from Paraguay (Rio Alto Parana) and Mato Grosso do Sul (Corumba) in Brazil derive from specimens cited by d’Orchymont (1939) under H. parhedrus , which is now a synonym of N. atratus . However, all the specimens cited from these localities were females, so there is no way to confirm they are in fact this species and so we remove them from the currently known distribution.

Figures

Figure 20. Aedeagi of the Novochares sallaei species group A-E N. chaquensis F N. garciai G-I N. dicranospathus J-L N. atratus M-R N. sallaei A-C Argentina D Costa Rica E Trinidad M-P Guatemala Q, R Mexico A, D-G, J, M, Q dorsal view B, H, K, N, R ventral view C, I, L, O lateral view P oblique view.

Figure 22. Distribution of Novochares sallaei species group A N. cochlearis (red: circles, examined specimens; squares, literature / unconfirmed records), N. dicranospathus (yellow), N. pastinum (blue) B N. atratus (red: circles, examined specimens; squares, literature / unconfirmed records), N. clavieri (yellow), N. bisinuatus (blue), N. garciai (green) C N. chaquensis (red: circles, examined specimens; squares, literature / unconfirmed records), N. pichilingue (yellow) D N. fernandezae (red), N. tridentis (yellow), N. quadrispinus (blue), N. unguis (green).