Modes of Insecticidal Action of Active Carbon and Clay on Tribolium castaneum (Hbst.)

Abstract

MAJUMDER et al.¹ reported that charcoal and clay samples having little insecticidal value could be converted to highly insecticidal substances by activation treatments. In later work, Majumder and Krishnamurthy² observed that the insecticidal potency of the clays was proportional to the oil-bleaching property of the activated earths. During the testing of activated clays and active carbon for their insecticidal effects, it was also noted that freshly prepared carbon was highly effective even at higher humidities; but there was gradual loss of the knock-down effects on storage of the active carbon samples. In contrast to this, activated clays did not show appreciable loss in their insecticidal potencies on storage. It was, therefore, considered worth while to investigate the differential modes of action of active carbon and activated clays for their insecticidal activities.