Date of this Version In the past 20 yr, populations of Cicindela
hirticollis Say (Coleoptera: Cicindelidae) that inhabit river
shorelines have declined dramatically. These habitats have
routinely flooded in winter and spring historically, but they
have been altered by damming and controlled water releases for
irrigation and power generation. We tested the ability of C.
hirticollis larvae from two river and one bayshore population to
survive immersion in severely hypoxic water. This is the first
report of population-level differences among insects in
immersion survival and likely relates to exposure to different
flooding regimes. The larvae from the Chesapeake Bay population
survived ≈3 d of immersion, and those from river populations
survived about a day longer. Despite survival differences
between riverine and seashore populations, recovery times after
exposure to severe hypoxia were comparable. Second and third
instars from the seashore population had similar survival at 9.0
and 16.5°C. Survival times of la