Migration of organophosphorus insecticides cyanophos and prothiofos residues from impregnated paper bags to Japanese apple-pears (Pyrus pyrifolia Nakai cv. Nijisseiki)

Bags impregnated with the organophosphorus pesticides prothiofos and cyanop hos in three levels were used to cover Japanese apple-pears to protect them from insects. The amounts of prothiofos residue in the bags collected 4 mo nths after application ranged from 0 to 34% of the amounts (81, 148, and 33 3 mu g) found in the bags prior to a bagging. The amounts of cyanophos resi due in bags collected 4 months after application ranged from 11 to 29% of t he amounts (335, 2860, and 3740 pg) present prior to a bagging. Amounts of prothiofos found in fruits after 4 months ranged from 0 to 0.076 ppm. Amoun ts of cyanophos found in fruits after 4 months ranged from 0 to 0.011 ppm. Results of the present study indicate that these two pesticides migrated fr om pesticide-impregnated bags to fruits during the growing season.