Effectiveness of fenitrothion for area control of ticks Ixodes ricinus (L.).

Susceptibility to fenitrothion in all stages of unfed ticks Ixodes ricinus increases with their age and this fact is reflected in the effectiveness of various dosages of insecticides applied for area control. The following minimum, but fully effective dosages of the dust Metation P-5 and the spray Metation E-50 (both preparations contain fenitrothion) for application in separate seasons have been ascertained: In September and October 1 kg of fenitrothion per ha of treated area ensures complete control of unfed ticks until the winter of current year. In Aril 3 kg of fenitrothion per ha is necessary, if tick control is to be ensured until the appearance of the new generation, i.

Use of KT 50 for orientative evaluation (screening) of sensitivity of flies to insecticides.

The author describes a modification of the method of determining the median knock-down time (KT50) in flies and its utilization for orientative determination of the current sensitivity of flies under field conditions. The method and its reliability were tested both in the laboratory and in field trials and were found to be entirely adequate and sufficiently reliable for the required purpose.