Date of this Version
Evolutionary Systematics. 5 2021, 189–192
Chalepides pantanalensis Ratcliffe & Seidel is described as a new species from the Pantanal region in Brazil. A description, diagnosis for distinguishing the species, illustrations, and a distribution map are provided. The new species is morphologically compared with C. howdenorum Joly & Escalona and C. osunai Joly & Escalona.
The genus Chalepides Casey consists of 14 species distributed in South America with one species in the West Indies (Joly and Escalona 2002; Ratcliffe and Cave 2015). Chalepides species are recognized by a usually prolonged prepygidium with a concomitant shortening of the pygidium; presence of long, dense, tawny setae on the prepygidium that are exposed beyond the elytral apices; antenna with ten antennomeres and the club subequal in length to antennomeres 2–7; clypeus subtrapezoidal; frontoclypeal suture slender, arcuate; pronotum lacking a basal bead; and large claw of the male protarsus entire at its apex, not split.
The new species described here is from the Pantanal region of Brazil, and only Chalepides barbatus argentinus Prell has been reported from this area (Joly and Escalona 2002). Some Chalepides species are closely associated with submerged or partially submerged plants. Even their body shape is similar to that of many aquatic scavenger beetles (Hydrophilidae: Hydrophilinae). The Pantanal region (straddling Brazil’s border with Bolivia and Paraguay) is one of the world’s largest freshwater wetland ecosystem and prime habitat for Chalepides species with semi-aquatic habits. Silvera Guido (1965) suggested that C. barbatus argentinus may attack the water hyacinth, Eichhornia crassipes [Mart.] Solms [Pontederiaceae], in Uruguay. Valla and Cirini (1972) observed a Chalepides species in the water lily, Victoria cruziana D’Orbigny (Nymphaeaceae), in Corrientes Province, Argentina. Endrödi (1973) reported C. luridus (Burmeister) and C. alliaceus (Burmeister) collected on riverbanks. Martínez (1977) collected adults of C. barbatus argentinus Prell and C. luridus in the submerged axillae of Pistia striatiotes Linneaus (Araceae) and other submerged aquatic plants in the provinces of Chaco, Corrientes, Formosa, and Santa Fé in the Argentinian subtropical region.