|Vreysen, Marc j.b.|
Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/5/2013
Publication Date: 6/1/2013
Citation: Hallman, G.J., Myers, S.W., Taret, G., Fontenot, E.A., Vreysen, M. 2013. Phytosanitary cold treatment for oranges infested with Bactrocera zonata (Diptera: Tephritidae). Journal of Economic Entomology. 106(6):2336-2340. DOI: http://dx.doi.org/10.1603/EC13221. Interpretive Summary: The peach fruit fly (PFF) attacks many fruits and occurs from Egypt to Vietnam. Occasionally it is trapped in subtropical US states and may result in costly quarantines until it is declared eradicated. Treatments are required to export fruit hosts of the pest out of quarantined areas to non-infested areas where it could become established. This research describes a cold treatment of 18 days at 1.7°C (35°F) that was developed for infested oranges. The PFF was not found to be less cold tolerant than the Mediterranean fruit fly; therefore, treatments for the latter could not be used for PFF. PFF was found to be more susceptible to cold than the Mexican fruit fly (Mexfly); therefore, treatment schedules for Mexfly could be used for PFF. However, the treatment for Mexfly requires 22 days. A shorter treatment was desired and verified for PFF when a total of 36,820 large larvae reared in oranges were treated at 1.7°C for 18 days with no larvae moving upon examination 24 hours after cold treatment. This information will be useful for developing treatments for fruits exported from quarantine areas.
Technical Abstract: The peach fruit fly, Bactrocera zonata (Saunders), attacks a wide range of tree fruits in countries from Egypt to Vietnam and is occasionally trapped in the US. Phytosanitary treatments are required to export fruit hosts of this insect from infested countries to non-infested countries where it might become established. This research describes a cold treatment of 18 d at 1.7°C that was developed for this pest infesting oranges. Fruit were infested by puncturing holes in oranges and allowing tephritids to oviposit in the holes. The treatments were initiated when the larvae reached late 3rd instar because previous research had shown that stage to be the most cold-tolerant. Bactrocera zonata was not found to be less cold tolerant that Ceratitis capitata (Wiedemann), the Mediterranean fruit fly; therefore, treatment schedules for the latter could not be used for the former. Bactrocera zonata was found to be more susceptible to 1.7°C than Anastrepha ludens (Loew); therefore, treatment schedules for A. ludens could be used for B. zonata. However, the treatment for A. ludens requires 22 d. A shorter treatment was verified for B. zonata when a total of 36,820 3rd instars reared from the egg in oranges were stored at 1.7°C for 18 d with no larvae moving upon examination 24 h after removal from the cold treatment chamber.