Depressed Supercooling Point and Increased Glycerol Concentration in Overwintering Adult Tiger Beetles (Cicindelida).
CRYO LETTERS 2020;
41:216-222. [PMID:
33988650]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
BACKGROUND
Tiger beetles are a widely distributed group including species that may be exposed to sub-freezing temperature overwinter. Despite being well studied, little is known about tiger beetle cold tolerance.
OBJECTIVE
We investigated seasonal changes in cold hardiness of two northerly distributed tiger beetle species (Cicindela repanda and Cicindela limbalis).
MATERIALS AND METHODS
We monitored the supercooling point (SCP), glycerol concentration, and hemolymph osmolality of adult tiger beetles during a 3.5-month acclimation to winter.
RESULTS
SCP decreased during winter acclimation for C. repanda, but not for C. limbalis. Both species modestly increased glycerol concentration, and C. repanda increased hemolymph osmolality by 38%.
CONCLUSION
This initial investigation into the cold-hardiness of adult tiger beetles suggests that they are capable of lowering their SCP as winter approaches, which may help them survive sub-freezing winter temperatures. Further assessment of their chill and freeze tolerance and of their overwintering conditions in the field is needed to better understand their winter physiology.
Collapse