Cryptic diversity in giant water bugs (Belostomatidae: Abedus herberti): what this means for desert stream management

Authors: David A. Lytle, Ivan C. Phillipsen, Emily E. Hartfield, Michael T. Bogan, Kate S. Boersma, Debra S. Finn

Year: 2012 (xliv)

Abstract

The giant water bug Abedus herberti is a large-bodied, flightless predator found in streams and rivers throughout deserts of Arizona, Sonora, and Chihuahua. A. herberti’s low dispersal and strict habitat requirements make it a useful indicator of perennial water in drainages too small to support fish. Analysis of microsatellites and mtDNA from > 600 individuals spanning 20 populations indicates strong among-population differentiation, and suggests that rare dispersal events occur across headwater boundaries rather than within major catchments. These genetic results support previous experiments that found evolved differences in flood escape behavior (the ability to use rainfall as a cue to escape flash floods) across populations separated by only a few km of terrestrial habitat. This pattern of population-level isolation and adaptation to local stream conditions has implications for stream management actions, such as post-renovation restocking of invertebrates from other streams or the introduction of fish into previously-fishless streams. Some of these findings likely apply to Abedus indentatus, a similar species found throughout southern California and northern Baja California.