Canadian Forest Service Publications

Shedding new light upon circadian emergence rhythmicity in the mountain pine beetle (Coleoptera: Curculionidae: Scolytinae). 2019. Wertman, D.L., Bleiker, K.P. Can. Entomol. 151: 273–277.

Year: 2019

Available from: Pacific Forestry Centre

Catalog ID: 40129

Language: English

CFS Availability: PDF (request by e-mail)

Available from the Journal's Web site.
DOI: 10.4039/tce.2019.18

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Abstract

The phenological behaviours of temperate insects can be highly controlled by photoperiod. Some foundational studies of the mountain pine beetle, Dendroctonus ponderosae (Hopkins) (Coleoptera: Curculionidae), documented a diurnal emergence rhythm that was asynchronous with maximum daily temperatures in the field and persisted under constant temperature and light conditions. In the 1970s, researchers hypothesised that this emergence rhythm was regulated by an endogenous circadian mechanism. Reflecting upon these historical data, we consider that a diurnal pattern of D. ponderosae emergence may result from photoperiodic entrainment of the circadian clock during the immature stages. Mechanistically, we suggest that the long-wavelength-sensitive opsin that we previously found to be expressed across D. ponderosae life stages could mediate, from beneath the bark, the input of light–dark cycle cues that are usually required for entrainment of the insect circadian clock.

Plain Language Summary

The phenological behaviours of temperate insects can be highly controlled by photoperiod. Some foundational studies of the mountain pine beetle, Dendroctonus ponderosae, documented a diurnal emergence rhythm that was asynchronous with maximum daily temperatures in the field and persisted under constant temperature and light conditions (Watson 1970, Gray et al. 1972, Billings and Gara 1975). In the 1970s researchers hypothesized that this emergence rhythm was regulated by an endogenous circadian mechanism. Reflecting upon these historical data, we consider that a diurnal pattern of D. ponderosae emergence may result from photoperiodic entrainment of the circadian clock during the immature stages. Mechanistically, we suggest that the long-wavelength sensitive opsin that we previously found to be expressed across D. ponderosae life stages (Wertman et al. 2018) could mediate, from beneath the bark, the input of light-dark cycle cues that are usually required for entrainment of the insect circadian clock.