Impact of Temperature Degrees and Periods of Exposure on Adult Emergence and Mortality of Red Flour Beetle, Tribolium castaneum Herbst [Coleoptera: Tenebrionidae] on Sorghum Flour

Abstract

The impact of temperature degrees and time of exposure on Red Flour Beetle, Tribolium castaneum was evaluated in the Laboratory of the Department of Crop Science, Adamawa State University, Mubi. The beetles were exposed to different temperature degrees of 50, 55, 60, 65 and 70 ̊C and varying exposure periods of 10, 15, 20 and 25 minutes respectively. The results obtained shows that, increase in both temperature degrees and time of exposure resulted in an increase in average mean adult mortality of T. castaneum (50 ̊C/20 = 65%; 60 ̊C/10 = 37%; 60 ̊C/15 = 100%; 65 ̊C/10 = 85.7%; 65 ̊C/15 = 100%; 70 ̊C/15 = 100%). Similarly, the average mean adult emergence of T. castaneum and percentage loss of Sorghum flour were significantly decreased (P˂0.05) with increasing temperature levels and exposure times as shown by the results (50 ̊C/15 = 97.00%; 60 ̊C/15 = 79.00%; 70 ̊C/15 = 50.20% and 50 ̊C/15 = 39.00%; 60 ̊C/15 = 36.00%; 70 ̊C/15 = 21.00%). There was no significant negative effect of temperature and exposure time on Sorghum flour which suggested that, thermal treatment of stored produce and products is one of the effective physical control methods of insect pests especially within the storage environment. Therefore, it is recommended for adoption and use to farmers and householders alike especially in the study area.