Distributional patterns of Chacoan water bugs (Heteroptera: Belostomatidae, Corixidae, Micronectidae, and Gerridae)

Abstract

( 2) southern Brazil, eastern Bolivia, Paraguay, and northeastern Argentina ( Belostoma bosqi, Heterocorixa brasiliensis, Tenagobia selecta tarahui, and T. schadei)

( 3) southeastern Brazil and northeastern Argentina ( Belostoma candidulum, B. testaceopallidum, Heterocorixa nigra, Sigara hungerfordi, Brachymetra furva, Halobatopsis spiniventris, Metrobates plaumanni plaumanni, and M. vigilis)

( 4) southeastern Brazil, Uruguay, and central western Argentina ( Belostoma cummingsi, B. martini, Sigara argentiniensis, Tenagobia fuscata, and T. carapachay)

and ( 5) southern ( Trichocorixa milicorum, Sigara santiagiensis, and S. forciceps). Three panbiogeographic nodes have been determined: ( 1) northeastern Argentina, in the intersection of generalized tracks 2 and 3

( 2) central Argentina, in the intersection of generalized tracks 1 and 4

and ( 3) central Argentina, in the intersection of generalized tracks 4 and 5. In spite of these complex patterns, these results show that the Chaco province appears to be a natural biogeographic area.

Distributional patterns of South American species of aquatic and semiaquatic Heteroptera freom the Chaco biogeographic province were analyzed. Based on a track analysis of 60 species of Belostomatidae, Corixidae, Micronectidae, and Gerridae, five generalized tracks were found: ( 1) Bolivia, and northwestern and central Argentina (Belostoma dallasi, Ectemnostega montana, E. quechua, E. stridulata, E. venturii, Sigara tucma, S. yala, Tenagobia pulchra, Eurygerris fuscinervis, and Trepobates taylori)