Diapause of the Western cherry fruit fly, Rhagoletis indifferens (Diptera: Tephritidae): Metabolic rate and overwintering adaptations

Authors: Neven, Lisa

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2023
Publication Date: 4/29/2023
Citation: Neven, L.G. 2023. Diapause of the Western cherry fruit fly, Rhagoletis indifferens (Diptera: Tephritidae): Metabolic rate and overwintering adaptations. Environmental Entomology. 52(3):436-445. https://doi.org/10.1093/ee/nvad030.
DOI: https://doi.org/10.1093/ee/nvad030

Interpretive Summary: The western cherry fruit fly, Rhagoletis indifferens (Curran) is a pest of native and commercial cherries. This species occupies both temperate and alpine habitats throughout the Cascade Mountain range. This species enters into seasonal diapause and cold hardiness. Scientists at the USDA-ARS laboratory in Wapato, WA determined the metabolic heat rate and supercooling point of diapausing pupae. They found that this species has sufficient metabolic reserves and low metabolic heat rate to support diapause for more than one year. They also determined that this species effectively supercool to avoid lethal intracellular freezing in the winter months. They predicted that climate change will negatively impact the abundance and geographical distribution of this species. This information will be used to monitor the effects of climate change on native fruit flies as well as assisting in the control of this pest in commercial cherry production areas.

Technical Abstract: The Western cherry fruit fly, Rhagoletis indifferens (Currran), is a Tephritid fly in the Pacific Northwest that infests native bitter cherry, Prunus emarginata (Douglas ex Hooker) in the Cascade Mountain range of western United States. Rhagoletis indifferens exhibits overwintering adaptations of diapause and supercooling to survive in temperate to alpine climates. We used isothermal and differential scanning calorimetry to determine the effects of diapause chilling duration and post-chilling warm rearing on the metabolic heat rate and supercooling of R. indifferens. We used this information to calculate the ability for R. indifferens to remain in diapause for extended periods of time and to predict the potential effects of climate change on the future abundance and distribution of this pest. We determined that R. indifferens can diapause for more than one year based on the levels of metabolic reserves and metabolic heat rate. We also posit that the abundance and distribution of this species will greatly decline as a result of global climate change.