Abstract :
Gamma radiation and heat treatments are considered promising techniques for disinfestation treatments against stored product pests. This study aimed to evaluate the effects of thermal treatment with 40, 50, 70 and 90°C and different doses of gamma radiation from 40 to 350 Gy on Sitotroga cerealella stages. The result demonstrated that the LD50 of gamma-irradiation was 57.7, 61.9 and 74.0 Gy in irradiated eggs, pupae, and larvae, respectively. Concomitantly, the complete mortality (100 %) of heat treatment was recorded at 40°C, while the 90°C caused 100 % mortality to larva and egg stages. The results indicated that the egg stage is highly sensitive to irradiation doses than larvae and pupal stages, while the pupal stage is highly sensitive to the heat treatments than eggs and larval stages. Consequently, treatment with low doses 80 Gy and low heat condition 40°C was more effective than the other combination treatments. The results suggested that 80 Gy & 40°C was an effective treatment to prevent the reproduction of S. cerealella and could use for managing this pest with was the environment.
Keyword :
Stored product; disinfestation; lethal doses; combination treatments