Canadian Forest Service Publications
Factors affecting larval diapause in Dendroctonus rufipennis (Coleoptera: Scolytidae) 1977. Dyer, E.D.A.; Hall, P.M. The Canadian Entomologist 109(11): 1485-1490.
Year: 1977
Issued by: Pacific Forestry Centre
Catalog ID: 1603
Language: English
Availability: Not available through the CFS (click for more information).
Available from the Journal's Web site. †
DOI: 10.4039/Ent1091485-11
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Abstract
The effect of daily day-degrees C in relation to brood age was investigated to determine its influence on the induction of larval (prepupal) diapause in Dendroctonus rufipennis (Kirby). Daily day-degrees of less than about 9° above the development threshold (6.1 °C) induced diapause in most of the broods while diapause was averted by daily day-degrees C of 10 or more above the threshold. Induction of diapause occurred no later than third larval instar; temperature changes during the fourth instar produced no change in aversion or induction of diapause. Laboratory results reveal that field temperatures during larval development determine whether most beetles have a 1- or 2-year life cycle.