[The attractiveness of various heat insulation substrates and their effect on the reproductive rate of the German cockroach and recommendations for preventing cockroaches].

Attractivity of some heat-isolating materials (glass wool, mineral wool, foam polystyrol, "texdur"-sheets and textile isolating mats) to the German cockroach, Blattella germanica L. and the effects on rate of increase were studied in the laboratory in comparison with folded cardboard as a check. The influence of structure (pressed sheets or loosely quilted materials) and exposition (single, piled or between sheets of plaster) was represented. Loose glass wool, open or between plaster sheets, shows a clearly higher attractivity than the other materials tested. increase of populations on glass wool is almost the same as on folded cardboards. The solid variants were less suitable for the settlement of the cockroaches. General recommendations for the prevention of infestations by cockroaches are given.