Virtually all temperate insects overwinter in diapause, a pre-emptive response to adverse environmental conditions and for many species a pre-requisite of winter survival. Increased global temperatures have the potential to disrupt the induction and maintenance of diapause. In the first part of this thesis, a four year phenological study of the blow fly, \(Calliphora\) \(vicina\), identifies that diapause is already being delayed due to high temperatures experienced by larvae within the soil layer. Laboratory studies identified that non-diapause life stages are capable of heightening cold tolerance through a rapid cold hardening ability, and winter acclimated adults maintain locomotion at lower temperatures than summer acclimated adults. A previously unrecognised threat, however, is that higher adult temperatures have the transgenerational effect of reducing the cold tolerance of diapausing progeny. In the second part of this thesis, the relationship between diapause and cold hardiness was investigated. The amino acid, alanine, was up-regulated as part of the diapause programme. Non-diapause larvae developed on an alanine augmented-diet expressed cold tolerance phenotypes similar to those of their diapausing counterparts. This adds to a growing body of evidence to suggest that amino acids have a direct role in insect cold tolerance.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:607313 |
| Date | January 2014 |
| Creators | Coleman, Paul C. |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/5191/ |
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