Response of Ceratitis capitata, Bactrocera dorsalis, and Bactrocera cucurbitae (Diptera:Tephritidae) to metabolic stress disinfection and disinfestation treatment

Authors: GALARZA, LOURDES AREVALO - University Of Mexico; Follett, Peter

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2010
Publication Date: 4/1/2011
Citation: Galarza, L., Follett, P.A. 2011. Response of Ceratitis capitata, Bactrocera dorsalis, and Bactrocera cucurbitae (Diptera:Tephritidae) to metabolic stress disinfection and disinfestation treatment. Journal of Economic Entomology. 104:75-80.

Interpretive Summary: Quarantine pests must be controlled in fresh commodities before they can be exported from Hawaii. This often means applying a quarantine treatment after harvest, such as heat or irradiation, to control the pest in the commodity. MSDD is a new type of postharvest treatment that combines short periods of low pressure (vacuum) and high CO2 with ethanol vapor to control pathogens and arthropod pests on commodities. MSDD was tested against white peach scale, a serious pest of papaya in Hawaii. Experiments were conducted to evaluate the effect of MSDD treatment on various life stages of Mediterranean fruit fly, oriental fruit fly, and melon fly. Mortality was generally high when various life stages were treated in Petri dishes. When papaya fruit infested with fruit fly eggs or larvae were treated by MSDD, they produced fewer pupae than untreated control fruit, but a substantial number of individuals developed nonetheless. This suggests that internal-feeding insects in fruit may be partially protected from the toxic effects of the ethanol because the vapor does not easily penetrate the fruit pericarp and pulp. MSDD treatment using the atmospheric conditions tested has limited potential as a disinfestation treatment for internal-feeding quarantine pests such as fruit flies infesting perishable commodities.

Technical Abstract: Metabolic stress disinfection and disinfestation (MSDD) is a postharvest treatment designed to control pathogens and arthropod pests on commodities that combines short cycles of low pressure/vacuum and high CO2 with ethanol vapor. Experiments were conducted to evaluate the effect of MSDD treatment on various life stages of Mediterranean fruit fly, oriental fruit fly, and melon fly, in Petri dishes and in papaya fruit. In some experiments, the ethanol vapor phase was withheld to separate the effects of the physical (low pressure) and chemical (ethanol vapor) phases of treatment. In the experiments with tephritid fruit fly larvae and adults in Petri dishes, mortality was generally high when insects were exposed to ethanol and low when ethanol was withheld during MSDD treatment, suggesting that ethanol vapor is highly lethal but that fruit flies are quite tolerant of short periods of low pressure treatment alone. When papaya fruit infested with fruit fly eggs or larvae were treated by MSDD, they produced fewer pupae than untreated control fruit, but a substantial number of individuals developed nonetheless. This suggests that internal-feeding insects in fruit may be partially protected from the toxic effects of the ethanol because the vapor does not easily penetrate the fruit pericarp and pulp. MSDD treatment using the atmospheric conditions tested has limited potential as a disinfestation treatment for internal-feeding quarantine pests such as fruit flies infesting perishable commodities.