RESISTANCE OF THE BUFFALO FLY, <i>HAEMATOBIA IRRITANS EXIGUA</i> (DE MEIJERE), TO TWO SYNTHETIC PYRETHROIDS AND DDT

Abstract

Abstract After 2 years of use, the synthetic pyrethroid fenvalerate failed to control a population of Haematobia irritans exigua from the Mackay district in central coastal Queensland. Dosage mortality tests on the flies indicated a moiety that was 45 x, 29 x and &gt; 1000 x more resistant respectively to fenvalerate, cypermethrin and DDT than a moiety in a reference population of flies which had not been subjected to control by fenvalerate.