Efficiency of gamma radiation and ozonation against Sitotroga cerealella stages (Gelechiidae:Lepidoptera) infesting stored wheat grains and their effect on wheat quality

Abstract

The present studies were carried out to determine the efficacy of gamma radiation and ozone technology as management tools to control and kill all life stages of S. cerealella (eggs, larvae and pupae) infesting stored wheat grains and their effect on viability and backing characters. The obtained results revealed that S. cerealella eggs were slightly tolerant to gamma radiation followed by pupae and larvae stages. It was showed that, the complete reduction in adult emergence (100 %) required 1500 Gy dose for all tested stages. Our results appeared that dose of 1000 Gy or less was inadequate to killing S. cerealella eggs and pupae. Also, ozone gas data reported same trend where egg stage was more tolerant to ozone followed pupae and larvae stages. It was the maximum reduction % in adult emergence 69.67 % for eggs followed by 78.00 and 86.11% for pupae and larvae stages at 8 h exposure period. The results appear ozonated wheat grains do not change the quality of baking bread and improved viability of wheat grains. The obtained results demonstrated that the LD95 of gamma radiation were 1630, 840 and 1550 Gy for eggs, larvae and pupae stages, resp. These findings for LT95 values of ozone for different stages were 33.08, 17.45 and 25.24 hrs for eggs, larvae and pupae stages, resp.