Author
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Hallman, Guy |
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Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/15/2004 Publication Date: 8/1/2004 Citation: Hallman, G.J. 2004. Irradiation disinfestation of apple maggot (Diptera: Tephritidae) in hypoxic and low temperature storage. Journal of Economic Entomology. 97:1245-1248. Interpretive Summary: Apple maggot, Rhagoletis pomonella, is a pest of apples and pears in much of the U.S. and Canada. As such, apples and pears shipped from infested areas to uninfested parts of the world might need to be subjected to a treatment that prevents the shipment of viable insects. Available treatments are methyl bromide fumigation and cold storage for 40 days. Methyl bromide is being restricted because it is a stratospheric ozone-depleting substance, and alternatives are sought. The objective of this research was to develop irradiation quarantine treatments against apple maggot that would work even under low oxygen and cold storage. Irradiation under low oxygen conditions increased from 30.5 to 35.7 Gy , the estimated dose to achieve 99% prevention of the pupal stage from irradiated third instar larvae in apples compared with normal atmospheric conditions. In any case, 50 Gy completely prevented the pupal stage in 22,360 and 15,530 third instar larvae, respectively, irradiated in apples under normal and low oxygen conditions. Cold storage at 1 degree C did not increase tolerance of apple maggot to irradiation. Technical Abstract: Apple maggot, Rhagoletis pomonella (Walsh), is a quarantine pest of apples and pears shipped from much of the U.S. and Canada. Current quarantine treatments include methyl bromide fumigation and cold storage for 40 days. Methyl bromide is being restricted because it is a stratospheric ozone-depleting substance, and alternatives are sought. The objective of this research was to develop irradiation quarantine treatments against apple maggot considering the fact that fruit hosts may be stored under hypoxic and cold conditions when they are irradiated. Hypoxia increased from 30.5 to 35.7, the estimated dose to achieve 99% prevention of the phanerocephalic pupal stage from irradiated third instars in apples compared with ambient atmospheres. However, 50 Gy completely prevented the phanerocephalic pupa in 22,360 and 15,530 third instars, respectively, irradiated in apples in ambient and hypoxic atmospheres. There was no difference in development to the phanerocephalic stage in apple maggot third instars held at 1 or 24 degrees C when irradiated with 20 Gy. |
