The light at the end of the tunnel: photosensitivity in larvae of the mountain pine beetle (Coleoptera: Curculionidae: Scolytinae)

2018 ◽  
Vol 150 (5) ◽  
pp. 622-631 ◽  
Author(s):  
Debra L. Wertman ◽  
Katherine P. Bleiker ◽  
Steve J. Perlman
Keyword(s):  
Mountain Pine Beetle ◽  
Light Sensitivity ◽  
Opsin Gene ◽  
Physiological Effects ◽  
Life Stages ◽  
Forest Insect ◽  
Long Wavelength ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Eggs And Larvae

AbstractInvestigations of light sensitivity and its physiological effects on insects developing within subcortical tree tissues are limited, presumably due to the assumption that cryptic microhabitats are completely devoid of light. In this study, we documented light-mediated behaviour and opsin gene expression in larvae of the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), an extremely important forest insect that is well adapted for development beneath the bark of pine (Pinus Linnaeus; Pinaceae) trees and is eyeless in the larval stage. Larvae were negatively phototactic, as they selected dark over light microhabitats in phototaxis assays. We recovered long-wavelength opsin transcripts from all life stages, including eggs and larvae, suggesting that D. ponderosae is photosensitive throughout its entire life cycle. Our results imply that photosensitivity contributes to immature D. ponderosae survival and that extraocular photoreception could be common among bark beetle larvae.

Shedding new light upon circadian emergence rhythmicity in the mountain pine beetle (Coleoptera: Curculionidae: Scolytinae)

2019 ◽  
Vol 151 (3) ◽  
pp. 273-277 ◽  
Author(s):  
Debra L. Wertman ◽  
Katherine P. Bleiker
Keyword(s):  
Circadian Clock ◽  
Mountain Pine Beetle ◽  
Historical Data ◽  
Life Stages ◽  
Light Conditions ◽  
Dark Cycle ◽  
Long Wavelength ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Emergence Rhythm

AbstractThe 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.

The contribution of genetics and genomics to understanding the ecology of the mountain pine beetle system

2019 ◽  
Vol 49 (7) ◽  
pp. 721-730 ◽  
Author(s):  
Catherine I. Cullingham ◽  
Jasmine K. Janes ◽  
Richard C. Hamelin ◽  
Patrick M.A. James ◽  
Brent W. Murray ◽  
...  
Keyword(s):  
Mountain Pine Beetle ◽  
Management Strategies ◽  
Dutch Elm Disease ◽  
Native Forest ◽  
Forest Insect ◽  
Genetic Studies ◽  
Long Term Study ◽  
Mountain Pine ◽  
Pine Beetle

Environmental change is altering forest insect dynamics worldwide. As these systems change, they pose significant ecological, social, and economic risk through, for example, the loss of valuable habitat, green space, and timber. Our understanding of such systems is often limited by the complexity of multiple interacting taxa. As a consequence, studies assessing the ecology, physiology, and genomics of each key organism in such systems are increasingly important for developing appropriate management strategies. Here we summarize the genetic and genomic contributions made by the TRIA project — a long-term study of the mountain pine beetle (Dendroctonus ponderosae Hopkins) system encompassing beetle, fungi, and pine. Contributions include genetic and genomic resources for species identification, sex determination, detection of selection, functional genetic analysis, mating system confirmation, hybrid stability tests, and integrated genetic studies of multiple taxa. These resources and subsequent findings have accelerated our understanding of the mountain pine beetle system, facilitating improved management strategies (e.g., enhancements to stand susceptibility indices and predictive models) and highlighting mechanisms for promoting resilient forests. Further, work from the TRIA project serves as a model for the increasing number and severity of invasive and native forest insect outbreaks globally (e.g., Dutch elm disease and thousand cankers disease).

scholarly journals TEMPERATURE-DEPENDENT DEVELOPMENT OF THE MOUNTAIN PINE BEETLE (COLEOPTERA: SCOLYTIDAE) AND SIMULATION OF ITS PHENOLOGY

1991 ◽  
Vol 123 (5) ◽  
pp. 1083-1094 ◽  
Author(s):  
Barbara J. Bentz ◽  
Jesse A. Logan ◽  
Gene D. Amman
Keyword(s):  
Mountain Pine Beetle ◽  
Lodgepole Pine ◽  
Life Stage ◽  
Temporal Distribution ◽  
Effect Of Temperature ◽  
Life Stages ◽  
Temperature Dependent ◽  
Dependent Development ◽  
Mountain Pine ◽  
Pine Beetle

AbstractTemperature-dependent development of the egg, larval, and pupal life-stages of the mountain pine beetle (Dendroctonus ponderosae Hopkins) was described using data from constant-temperature laboratory experiments. A phenology model describing the effect of temperature on the temporal distribution of the life-stages was developed using these data. Phloem temperatures recorded in a beetle-infested lodgepole pine (Pinus contorta Douglas) were used as input to run the model. Results from model simulations suggest that inherent temperature thresholds in each life-stage help to synchronize population dynamics with seasonal climatic changes. This basic phenological information and the developed model will facilitate both research and management endeavors aimed at reducing losses in lodgepole pine stands caused by mountain pine beetle infestations.

TRIA-Net: 10 years of collaborative research on turning risk into action for the mountain pine beetle epidemic

2019 ◽  
Vol 49 (12) ◽  
pp. iii-v ◽  
Author(s):  
Patrick M.A. James ◽  
Dezene P.W. Huber
Keyword(s):  
Collaborative Research ◽  
Mountain Pine Beetle ◽  
Management Strategies ◽  
Detailed Examination ◽  
Forest Insect ◽  
Complex Interactions ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Blue Stain Fungi ◽  
Blue Stain

Forest insects are showing increasing intensity of outbreaks and expanded ranges, and this has become a major challenge for forest managers. An understanding of these systems often depends upon detailed examination of complex interactions involving multiple organisms. In 2013, a team of researchers formed TRIA-Net, an NSERC support Strategic Network, with the explicit goal of exploring such interactions in the mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins, 1902) – pine (Pinus sp.) – blue stain fungi (Ophiostomatales) system. Contributions of this network include novel genetic and genomic resources and insights, as well as exploration of how landscape structure affects MPB movements. This review highlights the unique contributions of TRIA-Net to our understanding of the MPB outbreak system. We also highlight how the insights we generated can be used to inform management strategies — including assessing stand susceptibility, predicting spread, and developing better monitoring approaches — and how the approach taken by the TRIA project can be used as a model for tackling other challenging forest insect outbreaks.

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