Effect of sub-lethal doses of phosphine on macromolecular concentrations and metabolites of adult beetles of stored grain pest,Trogoderma granarium,previously exposed to phosphine

Effect of different concentrations of phosphine for various exposure periods (24-120h) has been studied on macromolecular concentrations and metabolites of adult beetles of a stored grain pest trogoderma granarium (everts) previously exposed to phosphine (= resistant) and those not previously exposed (= susceptible) strain. the lc50 values for adult beetles of phosphinesusceptible and resistant populations were 4.5 and 4.87 ppm,respectively. sub lethal dose of phosphine (lc20) significantly decreased the glycogen,lipids,dna and rna contents of all adult beetles,while free amino acids and glucose contents were increased in resistant population throughout the exposure period. soluble proteins in resistant population,free amino acids and glucose contents in susceptible population was first increased after exposure to sub lethal dose of phosphine but then started to decrease after 72 h exposure period. soluble protein contents of susceptible population was first raised after exposure to sub lethal dose but then started to decrease after 48 h exposure. resistant population showed a significant increase in soluble proteins,amino acids and glucose contents from 24-96 h with reference to susceptible population while resistant population,showed a significant decrease in glycogen,lipids,dna and rna contents with reference to susceptible population. these metabolic derangements induced by phosphine over various exposure periods provide a raw biochemical data to adopt better control strategy by regulating exposure period for this stored grain pest. copyright 2016 zoological society of pakistan.