Survival of ground beetles (Coleoptera: Carabidae) submerged during floods: Field and laboratory studies

Abstract

Abstract. Field and laboratory experiments were conducted to assess the time ground beetles (Coleoptera: Carabidae) survive during actual and simulated flood conditions. The effects of three variants of potential flood conditions were tested: (1) beetles trapped on the surface of flood water; (2) beetles trapped in air pockets; (3) submersion of beetles in flood water without access to air. Ground beetles trapped on the surface of water survived more than two weeks (Carabus granulatus -up to 16 days; Oxypselaphus obscurus -up to 22 days). Carabus granulatus in simulated hibernation chambers that had air-pockets also survived for 15 days. The time for which ground beetles submerged without access to air survived differed significantly among species and was affected by season. They survived longest in mid-spring and late-autumn when water temperature is low. In mid-spring, survival times for C. granulatus and Platynus assimilis were 12 days and 9 days, respectively. During late summer and early autumn all species survived for a shorter period of time. In August, at least half of the individuals tested were dead after three days of immersion (water temperature 16-18°C). Removal of both of the elytra of adult of C. granulatus resulted in them surviving immersion for a shorter period, which indicates that air stored in the sub-elytral cavity is used to prolong the period they can survive immersion. The results of these experiments broaden the knowledge of how adult beetles survive seasonal flooding and are able to persist in floodplain habitats.

Metabolic recovery from drowning by insect pupae

“…Other species may use physical mechanisms to obtain oxygen. For example, adults of several species of floodplain ground beetles (Carabidae) can survive 10 days of immersion in cold water using air trapped under their elytra as a physical gill (Kolesnikov et al, 2012; see also Adis and Messner, 1997). We suggest that anaerobic processes are useful over short periods of time (days) but that survival for longer times requires either very cold temperatures or mechanisms for extracting oxygen from water.…”

“…For the pupa, an underground lifestyle raises the risk of flooding. The pupal chamber does not exclude water and therefore does not act as a physical gill (see Kolesnikov et al, 2012;Seymour and Matthews, 2013; J. C. Sprague and H.A.W., unpublished observations), nor do pupae trap air films on the cuticle as do many semi-aquatic insects (Hutchinson, 1981;Pedersen and Colmer, 2012). In nature, the risk of flooding may be high for pupae because larval host plants often occur in disturbed areas, such as along stream beds.…”

“…Distinguishing among these alternatives will require additional experiments. Kolesnikov et al, 2012;Topp and Ring, 1988). Pupae were immersed at 22°C, which is a typical nighttime soil temperature at 8 cm depth at our main field site in southeastern Arizona (Sprague and Woods, 2015).…”

“…Pupae were immersed at 22°C, which is a typical nighttime soil temperature at 8 cm depth at our main field site in southeastern Arizona (Sprague and Woods, 2015). By contrast, pupae in diapause over the winter have lower metabolic demand (Hahn and Denlinger, 2007) and experience lower temperatures, which likely extends survival times (Kolesnikov et al, 2012;Topp and Ring, 1988). Across life stages, differential tolerance of anoxia is common (Cavallaro and Hoback, 2014;Hoback and Stanley, 2001), and M. sexta is no exception.…”

Habitat Isolation Reduces the Temporal Stability of Island Ecosystems in the Face of Flood Disturbance

“…Indeed, the only post-flooding representatives of the previously ubiquitous predatory carabid beetles were Nebria brevicollis and Anchomenus (Platynus) assimile, both of which are highly resilient to the impacts of flooding. N. brevicollis is a common, winged beetle that has been shown to undergo irruptions following extreme floods (Gerisch et al, 2012), while A. assimile can survive being submerged for unusually long periods of time, for example, up to 9 days (Kolesnikov et al, 2012).…”