|JOHNSON, S - University Of Stellenbosch|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/23/2010
Publication Date: 4/1/2011
Citation: Johnson, S.A., Neven, L.G. 2011. Heated controlled atmosphere postharvest treatments for Macchiademus diplopterus (Distant)(Hemiptera: Lygaeidae) and Phlyctinus callosus (Schoenherr)(Coleoptera: Curculionidae). Journal of Economic Entomology. 104(2): 398-404.
Interpretive Summary: Macchiademus diplopterus (Distant) (Hemiptera: Lygaeidae), commonly known as the grain chinch bug, and Phlyctinus callosus (Schöenherr) (Coleoptera: Curculionidae), commonly known as the banded fruit weevil, are two key quarantine pests of South African export fruits. Non-chemical, environmentally-friendly quarantine treatments are preferred for use in postharvest control of insect pests. Controlled Atmosphere/Temperature Treatment System (CATTS) is an environmentally-friendly postharvest 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. In order to streamline these treatments, the controlled atmosphere water bath (CAWB) system can be used to determine the most tolerant stage of a pest without the additional cost of infesting and treating the commodity. Scientists from the University of Stellenbosch in South Africa and the USDA-ARS in Wapato, WA collaborated to use the CAWB system to test the tolerance of these two pests to CATTS treatments. They found that M. diplopterus was more resistant to CATTS treatments of 12°C/h and 24°C/h under a 1% oxygen and 15% carbon dioxide environment than P. callosus, which was attributed to summer dormancy of M. diplopterus. Results indicate that the potential for the development of CATTS treatments for these phytosanitary pests, particularly P. callosus, is promising.
Technical Abstract: Non-chemical, environmentally-friendly quarantine treatments are preferred for use in postharvest control of insect pests. Combined high temperature and controlled atmosphere quarantine treatments for phytosanitary fruit pests, Macchiademus diplopterus (Hemiptera: Lygaeidae) and Phlyctinus callosus (Coleoptera: Curculionidae) were investigated to determine the potential of such treatments for quarantine security. Field-collected, aestivating M. diplopterus adults and P. callosus adults were treated using a controlled atmosphere waterbath system. This system simulates the controlled atmosphere temperature treatment system (CATTS) used to control a number of phytosanitary pests in the United States, and allows for a rapid assessment of pest response to treatment. Insects were treated under regular air conditions and a controlled atmosphere of 1% oxygen, 15% carbon dioxide in nitrogen, at two ramping heat rates, 12°C/h and 24°C/h. Treatment of both species was more effective under both heating rates when the controlled atmosphere condition was applied. Under these conditions of controlled atmospheres, mortality of P. callosus was greater when the faster heating rate was used, but the opposite was true for M. diplopterus. This could be due to the physiological condition of aestivation contributing to metabolic arrest in response to the stresses being applied during treatment. Results indicate that the potential for the development of CATTS treatments for these phytosanitary pests, particularly P. callosus, is promising.