Deleterious effects of repeated cold exposure in a freeze-tolerant sub-Antarctic caterpillar

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dc.contributor.authorSinclair B.J.
dc.contributor.authorChown S.L.
dc.date.accessioned2011-05-15T16:05:03Z
dc.date.available2011-05-15T16:05:03Z
dc.date.issued2005
dc.description.abstractMultiple freeze-thaw cycles are common in alpine, polar and temperate habitats. We investigated the effects of five consecutive cycles of approx. -5°C on the freeze-tolerant larvae of Pringleophaga marioni Viette (Lepidoptera: Tineidae) on sub-Antarctic Marion Island. The likelihood of freezing was positively correlated with body mass, and decreased from 70% of caterpillars that froze on initial exposure to 55% of caterpillars that froze on subsequent exposures; however, caterpillars retained their freeze tolerance and did not appear to switch to a freeze-avoiding strategy. Apart from an increase in gut water, there was no difference in body composition of caterpillars frozen 0 to 5 times, suggesting that the observed effects were not due to freezing, but rather to exposure to cold per se. Repeated cold exposure did not result in mortality, but led to decreased mass, largely accounted for by a decreased gut mass caused by cessation of feeding by caterpillars. Treatment caterpillars had fragile guts with increased lipid content, suggesting damage to the gut epithelium. These effects persisted for 5 days after the final exposure to cold, and after 30 days, treatment caterpillars had regained their pre-exposure mass, whereas their control counterparts had significantly gained mass. We show that repeated cold exposure does occur in the field, and suggest that this may be responsible for the long life cycle in P. marioni. Although mean temperatures are increasing on Marion Island, several climate change scenarios predict an increase in exposures to sub-zero temperatures, which would result in an increased generation time for P. marioni. Coupled with increased predation from introduced house mice on Marion Island, this could have severe consequences for the P. marioni population.
dc.description.versionArticle
dc.identifier.citationJournal of Experimental Biology
dc.identifier.citation208
dc.identifier.citation5
dc.identifier.issn220949
dc.identifier.other10.1242/jeb.01455
dc.identifier.urihttp://hdl.handle.net/10019.1/12950
dc.subjectacclimatization
dc.subjectanalysis of variance
dc.subjectanimal
dc.subjectarticle
dc.subjectbody composition
dc.subjectbody weight
dc.subjectclimate
dc.subjectcomparative study
dc.subjectcrystallization
dc.subjectdigestive system
dc.subjectfeeding behavior
dc.subjectfreezing
dc.subjectIndian Ocean
dc.subjectlarva
dc.subjectmoth
dc.subjectpathology
dc.subjectphysiology
dc.subjectAcclimatization
dc.subjectAnalysis of Variance
dc.subjectAnimals
dc.subjectBody Composition
dc.subjectBody Weight
dc.subjectClimate
dc.subjectCrystallization
dc.subjectDigestive System
dc.subjectFeeding Behavior
dc.subjectFreezing
dc.subjectIndian Ocean Islands
dc.subjectLarva
dc.subjectMoths
dc.subjectLepidoptera
dc.subjectMus musculus
dc.subjectPhacelia congesta
dc.subjectPringleophaga
dc.subjectPringleophaga marioni
dc.subjectTineidae
dc.titleDeleterious effects of repeated cold exposure in a freeze-tolerant sub-Antarctic caterpillar
dc.typeArticle
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