Phosphine was discovered in 17th century and has been used as important fumigant to control the stored grain pests all over the world since 1930.
Mechanism of phosphine toxicity is not well understood but biochemical and physiological changes which occur as result of phosphine exposure can be classified as neural, metabolic and redox related response (Nath et al.
The unplanned use of phosphine leads to development of resistance in T.
There is no report on the effect of sub lethal concentration of phosphine (LC20) on the activities and level of metabolites over wide range of exposure periods.
In this study a phosphine-susceptible (a population never exposed to phosphine previously) and phosphine-resistant populations (a population previously exposed to phosphine for at least 15 generations) of T.
Gaseous phosphine was generated in laboratory and different doses of phosphine were calculated according to the method described in FAO Plant Protection Bulletin (1969).
Control desiccators of both populations were prepared in the same way but they were not exposed to phosphine.
While data pertaining to effects of sub-lethal dose of phosphine (LC20) on metabolites was preceded through "t" test paired observations at 95% confident limit and comparison of individual mean for the determination of statistical significance was done.
Toxicity of phosphine for resistant and susceptible populations of T.
The effect of sub-lethal concentration of phosphine (LC20) was evaluated on metabolites of adult beetles of resistant and susceptible populations of T.
The insecticide resistance problem cannot be resolved only by increasing the concentration of phosphine because it is not only uneconomical but may also lead to necrosis, which in turn increase survival of insects (Nakakita and Kuroda, 1986).