Biological activities of some plant materials against two stored product insect pests of wheat

Abstract

Leaves of Acalypha sp., Caripa papaya, Santalum album and Calotropis gigantica were screened for toxicity, ovipository inhibition and reduction in F1 adult progeny in Sitophilus oryzae and Rhyzoperta dominica. A. indica showed remarkable biocidal and antiovipositant activities against S. oryzae adults, but was only slightly toxic to R. dominica adults. It also reduced the progeny emergence rate of R. dominica. C. papaya leaf was also very toxic to S. oryzae adults, but no mortalities were recorded with R.. dominica adults. S. album and Calotropis gigantica did not show any biological activity. The possibility of A. indica and C. papaya harbouring toxic principles which elicit adult mortality and slight ovipository deterrence against some storage pests of wheat and its limitations are discussed.
Key Words: Wheat; Insect pests; Biocidal properties; Antioviposition properties; Carica papaya; Azadirachta indica.