|JOHNSON, S - UNIVERSITY OF STELLENBOSCH|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2009
Publication Date: 12/20/2010
Citation: Johnson, S.A., Neven, L.G. 2010. The Potential of Heated Controlled Atmosphere Postharvest Treatments for the Control of False Codling Moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae). Journal of Economic Entomology. 102:265-271..
Interpretive Summary: Fruits and vegetables exported from South Africa to the United States must undergo quarantine treatments to kill a pest called the false codling moth. Quarantine treatments in use are either harmful to the environment or damage the produce. A promising approach to this problem is to use a combination of high temperatures together with increased carbon dioxide and reduced oxygen. This type of treatment kills the insect without damaging the fruit if the proper combination of temperature, carbon dioxide and oxygen is used. These types of treatments are expensive to develop however. Researchers at the University of Stellenbosch in South Africa and USDA, ARS, Wapato, Washington developed an alternative testing system involving a water bath that determines mortality and survival of insects under treatment conditions without the cost of infesting and treating the produce. They determined the best concentrations of carbon dioxide and oxygen, and the best temperature, to use to kill the insect stages. This technique permits faster determination of treatment conditions to use. The specific information on the false codling moth will be used to design quarantine treatments of fruits and vegetables, reduce use of hazardous chemical treatments, and facilitate international trade.
Technical Abstract: Controlled Atmosphere/Temperature Treatment System (CATTS) is an environmentally-friendly postharvest mitigation treatment that uses high temperature forced-air combined with a low oxygen and high carbon dioxide atmosphere to control quarantine pests. The development of CATTS treatments is expensive and time-consuming. For a more rapid assessment of different species and life stages’ tolerances to heated controlled atmospheres, the controlled atmosphere water bath (CAWB) system can be used to help advance the development of CATTS treatments for pests. The CAWB system was used to test the response of eggs and larval stages of the false codling moth, Thaumatotibia leucotreta (Meyrick). Eggs and larvae at different developmental stages were treated under regular air and a modified controlled atmosphere of 1% O2 and 15% CO2, at two ramping heat rates: 12°C/h and 24°C/h. Typically the faster heat rate and modified atmosphere reduced treatment times required to control the different life stages. Thaumatotibia leucotreta larvae were more tolerant of the treatments than eggs. The most tolerant life stage was the fourth instar. Effective treatments against the most tolerant life stage determined by the CAWB system can now be used to develop CATTS technology against T. leucotreta. Further research will focus on developing CATTS treatments using infested fruit to determine effective treatments that maintain fruit quality.