[assessment of resistance to permethrin of german cockroaches (blattella germanica l.) caught in poland]. | resistance to permethrin was tested in cockroaches caught in health service institutions in various parts of poland. the tests were carried out by the contact method as recommended by the who. the density of the insecticide was 20 mg/m2. the experiment was done only on male insects, calculating the values of lt50 and lt90 in insect groups caught in various localities. these values were compared with lt50 and lt90 values in sensitive insects exposed to the insecticide, and the resistance indices ... | 1994 | 7878339 |