Low pressure treatments for codling moth on fresh fruits

Authors: Johnson, Judy; JIAO, SHUNSHAN - Washington State University; DAVENPORT, T - Vivafresh Division Of Atlas Technologies; WANG, SHAOJIN - Washington State University

Submitted to: Proceedings of International Research Conference on Methyl Bromide Alternatives
Publication Type: Proceedings
Publication Acceptance Date: 9/2/2011
Publication Date: 10/30/2011
Citation: Johnson, J.A., Jiao, S., Davenport, T., Wang, S. 2011. Low pressure treatments for codling moth on fresh fruits. Proceedings of International Research Conference on Methyl Bromide Alternatives, October 31 - November 2, 2011. 65:1-4.

Interpretive Summary: Codling moth is an important quarantine pest of fresh fruits such as apples, pears and cherries. The primary phytosanitary treatment used for exports to markets requiring quarantine protocols is fumigation with methyl bromide. While Quarantine and Pre-Shipment (QPS) treatments are currently allowable under the Montreal Protocol, there is growing concern that the QPS exemption will eventually be lost. Consequently, alternative treatment protocols are being considered. Low pressure treatments, coupled with low temperatures and carefully regulated humidity, has been shown to prevent product deterioration caused by bacterial and fungal decay, and prevent wilting and fruit ripening during storage. This project looks at using these treatments to disinfest stone fruits of the various life stages of the codling moth. The laboratory low pressure system was shown to hold treatment parameters to the necessary limits. Preliminary studies with test insects indicate that large larvae and pupae may be the most tolerant stage, but more replicates are needed. Tests at 4C show that treatments in excess of 20 days would be needed, and that to reduce the treatment time, increasing the temperature to 10C may be necessary.

Technical Abstract: The primary phytosanitary treatment used for fresh fruits exported to markets requiring quarantine protocols is fumigation with methyl bromide. Quarantine and pre-shipment (QPS) treatments are currently allowable under the Montreal Protocol, but there is growing concern that the QPS exemption will eventually be lost. Low pressure treatments, coupled with low temperatures and carefully regulated humidity, has been shown to prevent product deterioration caused by bacterial and fungal decay, and prevent wilting and fruit ripening during storage. This project looks at using these treatments to disinfest fresh fruits of the various life stages of the codling moth (Cydia pomonella), a quarantine pest of stone fruits. The laboratory low pressure system was shown to hold treatment parameters to the necessary limits. By adding 1.3 cm of foam insulation to the outside chamber walls, variation in chamber air temperature was reduced to +/-0.04C, which prevented condensation on the inner surface of chamber walls. Average relative humidity varied from 98.4-99.35%. The pressure regulators operated well with the air exchange system, providing a means to maintain high humidity levels and prevent ethylene build up while keeping pressure variations to a minimum. Preliminary studies with test insects indicate that large larvae and pupae may be the most tolerant stage, with eggs the most susceptible, but more replicates are needed. Tests at 4C show that treatments in excess of 20 days would be needed, and that to reduce the treatment time, increasing the temperature to 10C may be necessary.