Agricultural and Forest Entomology (2000) 2, 49-55

Mark D. Hunter and Jeremy N. McNeil (2000)
Geographic and parental influences on diapause by a polyphagous insect herbivore
Agricultural and Forest Entomology 2 (1), 49-55
Abstract: 1 Facultative diapause permits insects to initiate an additional generation when conditions are favourable, or to enter diapause when they are not. Although the principle environmental cues for diapause induction are often temperature and photoperiod, we demonstrated recently that the quality of host plant consumed by the larvae of Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) influences the proportion of larvae that enter diapause and therefore voltinism.
2 Previous work has also suggested that non-Mendelian parental effects influence diapause by C. rosaceana larvae, but the mechanism was not established. Here, we report further evidence for parental effects on diapause and examine whether parental diet influences diapause induction.
3 We collected larvae of C. rosaceana from six sites at three latitudes in the Province of Québec. There was an increase in the proportion of larvae entering diapause with increasing latitude. Rearing larvae under identical conditions on artificial diet for two generations significantly reduced variation in diapause among populations within a given latitude, and supported the existence of parental effects that influence offspring diapause.
4 Experiments with different host plants and high- vs. low-quality artificial diets provided no evidence that the parental effects on offspring diapause were based on the quality of food consumed by parents. Diapause in C. rosaceana appears influenced by a hierarchy of cues, including temperature, photoperiod, current larval diet and parental environment.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Mark Hunter, Jeremy N. McNeil

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Choristoneura rosaceana