Author
Hollingsworth, Robert | |
Armstrong, John |
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/7/2004 Publication Date: 4/20/2005 Citation: Hollingsworth, R.G., Armstrong, J.W. 2005. Potential of temperature, controlled atmospheres and ozone fumigation to control thrips and mealybugs on ornamental plants for export. Journal of Economic Entomology. 98(2):289-298. Interpretive Summary: Fumigation with ozone gas is a potential quarantine treatment for control of insect pests on stored-product and fresh agricultural commodities. In this research, we exposed western flower thrips, Frankliniella occidentalis (Pergande), and longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti, to ozone in treatments using different temperatures, treatment times, atmospheres, and vacuum levels. These insects are important pests of ornamental crops. The effectiveness of treatments was enhanced by higher ozone concentrations, higher temperatures, lower oxygen levels, and longer treatment times. Reduced pressure was not an important factor. A one-hour treatment of ozone at ~400 ppm in carbon dioxide at 32.2ºC killed 98.4% of adult female thrips. A similar level of control (98.8%) was obtained with mealybugs using the same treatment except with a temperature of 37.8ºC. All of the ornamentals tested were damaged to some degree by the ozone treatment. However, crops with thick leaves such as orchids exhibited little damage, and the waxy portions of certain flowers were not damaged. The results suggest that ozone has potential as a quarantine treatment to control thrips and mealybugs on selected commodities. Technical Abstract: Ozone fumigation is a potential quarantine treatment alternative for controlling stored-product pests and surface insect pests on fresh agricultural commodities. We explored the effects of temperature, treatment time, controlled atmospheres, and vacuum in combination with ozone to control two important pests of ornamental crops: western flower thrips, Frankliniella occidentalis (Pergande) and longtailed mealybug, Pseudococcus longispinus Targioni-Tozzetti. Treatment parameters tested were ozone concentrations from 0 to 3800 ppm, treatment durations from 30-120 minutes, vacuums from 0 to 0.41 bar below ambient, temperatures from 32.2 to 40.6ºC, and controlled atmospheres composed primarily of nitrogen, carbon dioxide, or breathing air. Treatment efficacy was enhanced by higher ozone concentration and temperature, lower oxygen, and longer treatment times. Reduced pressure was not an important factor. A one-hour treatment of ozone at ~400 ppm in carbon dioxide at 32.2ºC killed 98.4% of adult female thrips. A similar level of control (98.8%) was obtained with mealybugs using the same treatment except with a temperature of 37.8ºC. All of the ornamentals tested were damaged to some degree by the ozone treatment. However, crops with thick leaves such as orchids exhibited little damage, and the waxy portions of certain flowers were not damaged. The results suggest that ozone has potential as a quarantine treatment to control thrips and mealybugs on selected commodities. |