Effect of rearing temperatures on mortality of Anastrepha suspensa exposed to hot-water immersion or cold storage
In quarantine treatments against Anastrepha suspensa (EPPO A1 quarantine pest) cold temperatures of 0-5 °C or hot temperatures of 43-48 °C can be used. The author has studied the effects of rearing temperatures (20, 25 or 3 °C) on the mortality of third instars exposed to such treatments. A. suspensa was reared from egg to third instar in a semi-artificial diet, carambolas and guavas and then submitted to hot-water immersion (43-
46 °C) or cold storage (1 °C). The results showed that rearing temperatures did not affect tolerance to 1 °C cold storage. However, for hot-water immersion treatments the rearing temperature has an effect on mortality. For example, third instars reared on semi-artificial diet at 30 °C showed significantly less mortality (49.0 %) than those at 20 °C (94.2 %) when exposed to a hot-water immersion (43 °C for 21 min). The same results were observed for hot-water treatments at 46 °C and for insects reared on carambolas or guavas. The author concluded that immature stages of A. suspensa are more tolerant to hot temperatures (43-46 °C) when reared at higher temperatures between 20-30 °C. Therefore, it might be more difficult to eliminate A. suspensa in fruit harvested during the warmest seasons and this aspect should be taken into account when designing quarantine treatments against A. suspensa.
46 °C) or cold storage (1 °C). The results showed that rearing temperatures did not affect tolerance to 1 °C cold storage. However, for hot-water immersion treatments the rearing temperature has an effect on mortality. For example, third instars reared on semi-artificial diet at 30 °C showed significantly less mortality (49.0 %) than those at 20 °C (94.2 %) when exposed to a hot-water immersion (43 °C for 21 min). The same results were observed for hot-water treatments at 46 °C and for insects reared on carambolas or guavas. The author concluded that immature stages of A. suspensa are more tolerant to hot temperatures (43-46 °C) when reared at higher temperatures between 20-30 °C. Therefore, it might be more difficult to eliminate A. suspensa in fruit harvested during the warmest seasons and this aspect should be taken into account when designing quarantine treatments against A. suspensa.
Sources
Hallman, G. (1994) Mortality of third-instar Caribbean fruit fly (Diptera: Tephritidae) reared at three temperatures and exposed to hot water immersion or cold storage.
Journal of Economic Entomology, 87 (2), 405-408.