EFFECT OF REARING TEMPERATURES AND STORAGE PERIOD OF Oryzaephilus surinamensis ( L. ) ( Coleoptera : Silvanidae )

Abstract

The present research aimd to study the effect of temperatures (25 . 30 0C) and rice varieties (Americani. Pakistani. Anber. Chini. Indi. Argantini and Thailandi) and grain situations (complete grain . crushed grain and flour) and effect of storage period (2 . 4 and 6 month) on the population density of sawtoothed grain beetle Oryzaephilus surinamensis (L.) (Coleoptera : Silvanidae) with reproductive rate and loss weight . The results showed that the temperatures had a significant effect on the population density with general average of 51.30 and 59.34 insects and loss weight 1.38 and 1.87 gram and reproductive rate 1.13 and 1.33 for temperatures 25 and 30 0C. respectively. Anber variety had a higher susceptibility have other varieties with significant differences were its general average were (60.59 and 65.53 insects) for the two temperatures. respectively. According to grain situations. the crushed grains was more infested by the insect and in loss weight from complete and broken grain . It was clear significant for storage period with a significant effect on the population density of insect and the general average numbers of insects were 14.93. 39.10. 99.86 insects at 25 0C and 18.03. 47.09. 112.91 insects at 30 0C for the storage period of 2 . 4 . 6 months . respectively .