Effects of short-term exposure to low temperature on survival, development and reproduction of banana-associated Oulenziella bakeri (Acari: Winterschmidtiidae)

Abstract

Abstract Oulenziella bakeri (Acari: Winterschmidtiidae) is a fungus feeder, commonly found in tropical regions and frequently intercepted on bananas imported from Ecuador and the Philippines at the New Zealand border. To assess its potential to establish in New Zealand, this study tested the effects of short-term exposure to low temperatures (3, 0, -3, -5, and -18.5°C) on the survival, development, and reproduction of O. bakeri. With the exception of very low survival rates of eggs at -5°C, no stages of O. bakeri survived after 24 hr exposure at -5°C and -18.5°C. Cold exposure at 0°C for 24 hours not only increased egg mortality, but the negative effects also transmitted to the larvae and nymphs developed from these eggs, e.g. only 40% of the eggs treated for 24 hr at 0°C survived but only <1/3 of these developed to adults. Increasing the duration of cold exposure further reduced survival rates, e.g. about 40% of the eggs survived after 24 hr exposure at 0°C, but <10% of them survived after 48 hr treatmen...