The apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera:Tephritidae), was introduced from eastern North America into western North America via infested apples (Malus domestica Borkhausen) about 44 yr ago, where it subsequently adapted to 2 hawthorn species, Crataegus douglasii Lindley and C. monogyna Jacquin. Here, we test whether R. pomonella has also adapted to large-thorn hawthorn, Crataegus macracantha Loddiges ex Loudon, in Okanogan County, Washington State, USA. In 2020, 2021, and 2022, fruit of C. macracantha were shown to ripen in late September and were infested at rates from 0.7% to 3.0%. In laboratory rearing studies, large-thorn hawthorn flies from C. macracantha eclosed on average 9–19 days later than apple flies from earlier ripening apple (August–early September), consistent with large-thorn hawthorn flies having adapted to the later fruiting phenology of its host. In a laboratory no-choice test, significantly fewer (64.8%) large-thorn hawthorn than apple flies visited apples. In choice tests, greater percentages of large-thorn hawthorn than apple flies resided on and oviposited into C. macracantha versus apple fruit. Large-thorn hawthorn flies were also smaller in size than apple flies. Our results provide further support for the recursive adaptation hypothesis that R. pomonella has rapidly and independently specialized phenologically and behaviorally to different novel hawthorn hosts since its introduction into the Pacific Northwest of the USA, potentially leading to host race formation.
How to translate text using browser tools
8 April 2023
Evidence for adaptation of Rhagoletis pomonella (Diptera: Tephritidae) on large-thorn hawthorn, Crataegus macracantha, in Okanogan County, Washington State, USA
Wee L. Yee,
Joshua M. Milnes,
Robert B. Goughnour,
Michael R. Bush,
Glen Ray Hood,
Jeffrey L. Feder
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
Environmental Entomology
Vol. 52 • No. 3
June 2023
Vol. 52 • No. 3
June 2023
apple maggot fly
body size
eclosion time
host fruit choice
infestation rate