Controlled atmospheres for the postharvest disinfestation of Thrips obscuratus (Thysanoptera: Thripidae).
Potter, M.A., Carpenter, A., Stocker, A. and Wright, S.
Journal of economic entomology. Vol: 87 Issue: 5 Pages: 1251-1255
1994
บทคัดย่อ
New Zealand Thrips obscuratus (Crawford) adults were exposed to combi- nations of temperature (0, 7, 13, or 20 degrees C), gas (air, or 0, 9, or 18% carbon dioxide [CO2] in 2% oxygen [O2], with the balance nitrogen [N2]), and exposure time (2, 4, 6, or 8 d). Mortality vaned directly with temperature, gas, and time. Two-way interactions between temperature and gas, temperature and time, and gas and time were significant. The mortality of T. obscuratus held in the 0%-CO2 atmosphere did not differ significantly from the mortality of those held in air at 0, 7, or 13 degrees C. At 20 degrees C, T. obscuratus mortality was greater in the 0%-CO2 atmosphere than in air. Mortality was at a minimum in both of these gases at 13 degrees C. Multiple linear-regression analysis of the data excluding the air controls revealed significant three-way interactions between temperature, CO2 concentration, and time; this method was used to generate three-dimensional mortality response surfaces that predict a range of controlled-atmosphere treatments insecticidally effective against T. obscuratus. With CO2 concentrations less than or equal to 9%, T. obscuratus mortality tended to decrease as temperature increased from 0 degrees C to - 13 degrees C and then increase as the temperature approached 20 degrees C. The mortality response was the reverse of this in atmospheres > 9% CO2; in these atmospheres, mortality reached a maximum between 13 and 17 degrees C. Regardless of temperature, complete kill of T. obscuratus would be predicted to occur after 6 d of exposure to the 18%-CO2 atmosphere. We discuss how mortality-response surfaces can be used to help develop integrated controlled-atmosphere programs that are both effective against the pest and sensitive to the physiological tolerance of the produce.