SURVEY, DAMAGE ASSESSMENT AND BIOLOGY STUDY OF SAW-TOOTHED GRAIN BEETLE, ORYZAEPHILUS SURINAMENSIS

Abstract

Biology and damage assessment of saw-toothed grain beetle, Oryzaephilus surinamensis were studied on the different dried fruit and nuts in the laboratory during August 2016 to December 2016.Cashew nut, almond, ground nut, nut meg and dates were used as experimental materials. Experiments were laid out in a completely randomized design (CRD) with five replications. Four major markets of Dhaka city were selected for survey and samples were collected from those markets to detect the infestation of saw-toothed grain beetle. The highest percent of infestation on saw-toothed grain beetle was found at Kawran bazar (7.5%) in cashew nut. In the biological study the adult female beetle laid 103-118 eggs. The ovipositional, incubation, larval, pupal periods and the adult longevity were 10.20±1.93, 8.60± 1.97, 18.20 ± 1.93, 7.80 ± 1.50 and 90.00 ± 1.21 days, respectively. Morphometric measurement of different life stages of the beetle were also recorded. Infestation was the highest (19.18%) in cashew nut at 1st generation of the beetle and it raised up to (75.29%) in cashew nut also at 2nd generation. Whereas the lowest infestation was recorded in dates (8.44%) and (20.23%) at 1st and 2nd generations respectively. The highest weight loss was found in almond (4.90%) and (6.81%) in ground nut respectively and the lowest were recorded in dates at 1st and 2nd generations respectively.