Effect of Overlap Some Varieties of Dates and Temperatures on The Biology of Saw-Toothed Grain Beetle Oryzaephilus surinamensis L. (Coleoptera: Silvanidae)

Abstract

The present research aimed to study of effect of overlap between three varieties of dates including: Brium, Barhi and Khathrawy and three temperatures of 25 , 30 and 35 ± 1 ºC on the biology of saw-toothed grain beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae) at Relative Humidity of 70 ± 5%. The results showed that significant increase happened in the larval stage period at Barhi as compared to Brium and Khathrawy where it were 33.90 , 25.80 and 28.30 days, respectively, at temperature of 25 ± 1 ºC, and it were 24.83 , 19.67 and 21.30 days, respectively, at temperature of 30 ± 1 ºC, and it were 22.83 , 18.25 and 19.67 days, respectively, at temperature of 35 ± 1 ºC. also the results indicated no significant differences in pupal stage period among the varieties at temperatures 30 and 35 ± 1 ºC, while significant increase happened in pupal stage period at Barhi as compared to Brium and Khathrawy where it were 10.4 , 8.2 and 9.7 days, respectively, at temperature of 25 ± 1 ºC, also the results showed that significant reduction happened in adult age and laid eggs number per female at Barhi as compared to Brium and Khathrawy at all temperatures above, and significant increase happened in eggs incubation period at Barhi as compared to Brium and Khathrawy at temperature of 25 ± 1 ºC, whereas eggs incubation period were at Barhi longer than Brium ,and it were at Barhi shorter than Khathrawy at temperature of 35 ± 1 ºC, while there were no significant differences in eggs incubation period among the varieties at temperature of 30 ± 1 ºC.