Basic studies on chemical control of acaroid mites part 5 cholin esterase activities in mice and rats maintained on fenthion impregnated paper sheets sewed up in tatami mat
Nakazato, Y.; Miyazaki, M.; Hirakoso, S.
Medical Entomology and Zoology 26(4): 213-220
The acaroid mite, Tyrophagus putrescentiae, is a household insect commonly seen in Japan. This mite can be controlled using paper sheets which were sewed up to the entire upper and lower surface in Tatami-mat impregnated with fenthion. The safety evaluation was conducted on the paper sheets. Animals were maintained on the Tatami-mat or on the paper sheets during periods of 1, 2 and 3 mo. The amounts of fenthion applied were 0 (untreated), 0.25, 0.7, 2.0 and 6.0 g/m2. In the practical amounts of 0.7 g/m2, there was no adverse effect on the general condition and appearance in the mice and rats as compared with the untreated group. On the indirect contact test to the Tatami-mat, the inhibition of plasma and erythrocyte cholinesterase activities was observed in the mice after a 2-3 mo. period. When animals were indirectly in contact with the paper sheets, the plasma cholinesterase activity and body weight gain were reduced in the mice and brain cholinesterase activity was inhibited in rats after a 1 mo. period.