Polytrin-C, which is a mixture of cypermethrin, a synthetic pyrethroid and profenofos, an organophosphate has LC50 Of 33.11 ppm, and 30.20 ppm respectively for insecticide resistant (PAK) and insecticide susceptible (FSS-II) strains of red flour beetles, Tribolium castaneum. At a sublethal dose of 5 ppm the AcP and AkP activities increased 341% and 60%, respectively in the PAK adult beetles. All other enzymes remained unchanged. At a dose of 10 ppm, however a significant increase of 356%, 93%, 39% and 80% occurred, respectively in AcP, AkP, LDH and ICDH activities. Cholinesterase remained unchanged. In FSS-II strain, no significant change was recorded at a dose of 5 ppm. All metabolites such as soluble proteins, trehalose, cholesterol, DNA and RNA remained unchanged except for the glucose contents, which decreased 43% and total lipids which increased 54%. At 10 ppm the enzyme activities were not altered except for AkP, which decreased 13% and GOT activity, which increased 50%. The soluble proteins, total proteins and RNA contents increased significantly by 12%, 30% and 45%, respectively, while glucose decreased 32%. The results revealed that 10 ppm dose of Polytrin-C produced moderate changes in adult beetles of FSS-II strain and drastic changes in PAK strain of T. castaneum. It is suggested that stronger doses must be used and milder doses be avoided to control the red flour beetle population effectively in the field.
