Entomologia Experimentalis et Applicata (2005) 115, 333-340

Bertrand Soula and Frédéric Menu (2005)
Extended life cycle in the chestnut weevil: prolonged or repeated diapause?
Entomologia Experimentalis et Applicata 115 (2), 333-340
Abstract: Many insect species extend the life cycle of a part of their population over several years. The adaptive value of these long cycles is now well documented, but the physiological processes underlying them have been little studied. Long life cycles are usually viewed as resulting from prolonged diapause proceeding from a simple extension of the usual winter diapause. However, this hypothesis has not been greatly tested, and information is lacking for species with a larval diapause. The energetic cost of a prolonged larval diapause also needs to be measured, because the few published estimates of lipid consumption concern an imaginal diapause. It is not therefore clear whether the negligible lipid consumption observed during adult prolonged diapause can be extrapolated to larval diapause. From microrespirometry and lipid measures in the chestnut weevil, Curculio elephas Gyllenhal (Coleoptera: Curculionidae), we show that: (1) in contrast to the usual hypothesis, the long cycle does not result from an extension of larval winter diapause, but is due to a prolonged diapause occurring secondarily to a developmental phase, and (2) energy consumption during the prolonged diapause is not negligible, but is provided for by a higher initial lipid content in the long cycle individuals. The adaptive value of the observed cycle is discussed.
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Link to article at publishers website
Database assignments for author(s): Frédéric Menu

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Curculio elephas		France