The Effect of the Extent of the Exposure and Concentration for the Three Types of Surface Treatment in the Mortality of Larvae and Adults of Confused Flour Beetle, Tribolum confusum (Du Val)
Two concentrations (0.1, 0.05 Mg/L) of chemical insecticides Lambda cyhalothrine were used in combination with Castor oil (Ricinus communis) in mixtures of 1:1, 1:2 and 1:3 ratio of insecticide: castor oil for their effect to the mortality of larvae and adult of confused flour beetle, Tribolium confusum (Du Val) which exposed to different surface substrates (aluminum, cardboard, and wood surfaces). The mortality data were recorded after 24 and 48 hours. The calculated mortality in aluminum surfaces were 53.00%, 56.00% and 62.00% in 1:1, 1:2 and 1:3 mixing ratio, respectively, after 24 hours, in adults. With the cardboard treatment, the mortality were 43.00%, 56.00% and 57.66% in 1:1, 1:2 and 1:3 mixing ratio, respectively, in the same treatment time. Whereas in wood surface the mortality were 56.33%, 58.00% and 61.00% in 1:1, 1:2 and 1:3 mixing ratio, respectively, in the same treatment time. The results showed that 1:3 mixing ratio had the higher mortality ratio and the 1:1 mixing ratio had the least mortality against T. confusum. The results also revealed that all tested mix ratios are more efficacies on aluminum surface followed by cardboard and wood surface, respectively. In general, efficacy was the best on non-porous surfaces compared with more porous surfaces.