The chemical control of the lesser date moth,Batrachedra amydraula meyr., and residue levels of organophosphate insecticides in dates

Larvae of the lesser date moth (Batrachedra amydraula Meyr.) cause damage to dates in Iraq. A formulation based on a mixture of equal parts of wheat flour and pollen grains and containing either chlorpyrifos, fenitrothion or pirimiphos-methyl (all at 5 mg kg^?l) was dusted (5 g formulation bunch^?1) onto female clusters of dates at the time of pollination. Numbers of larvae, yield of dates and insecticide residues were monitored over a three-month period. Results showed that, by this technique, all three insecticides were effective in controlling the pest but that fenitrothion and chlorpyrifos were better than pirimiphos-methyl.     

Residue levels of three organophosphorus insecticides in sweet pepper grown in commercial greenhouses

The degradation rates and residue levels of diazinon, pirimiphos-methyl and chlorpyrifos in the leaves and fruits of pepper plants grown in commercial greenhouses were studied using g.l.c. Analysis of leaves at intervals following application showed that the initial residue of diazinon was higher than that of the other two insecticides, while its dissipation rate was faster. The dissipation of chlorpyrifos in fruits was faster than diazinon. The maximum residue levels (m.r.l.) of diazinon (0.5 mg kg^?;1) and chlorpyrifos (0.1 mg kg^?;1) were reached after 13 and 8 days of application respectively. With diazinon and pirimiphos-methyl, sprayed 3 weeks before inflorescence, very low concentrations of both insecticides were found in fruits, although these compounds have no systemic behaviour. Chlorpyrifos residue level of 0-2 mg kg ^?;1 in harvested fruits did not drop below m.r.l. after 11 days holding period.