SALWA PRODHAN1* and M. KHALEQUZZAMAN2
1Former MS Student, 2Professor, Department of Zoology, University of Rajshahi, Rajshahi, Bangladesh.
*Corresponding author’s Email:salwaprodhan@gmail.com
ABSTRACT
The study was conducted at the Laboratory, Department of Zoology, University of Rajshahi, Rajshahi, Bangladesh during October 2005 to July 2006 to find out the effectiveness of Diatomaceous Earth (DE) at different temperatures on the pulse beetles Callosobruchus maculates (F.).The beetles used in experiments were collected from a private store house of Shaheb Bazar in Rajshahi and Chapianawabganj districts. Cultures were maintained in the Crop Protection and Toxicology Laboratory, Department of Zoology, University of Rajshahi. A sample of Silico-Secwas obtained from Agrinova GmbH (Germany). The bioassay was done on adult beetles by applying them with normal food in combination with different doses of DE. The data was subjected to probit analysis. The study found that DE is the most effective when silica particles are broken down by milling processes into very sharp fragments. Because its action against insects is wholly mechanical, no harmful residues are released to enter digestive systems of other life forms and, furthermore, insects probably cannot develop resistance to diatomaceous earth. As scientists are searching for pesticides that will be rather nontoxic and decompose rapidly in nature after being deposited on vegetation or in the soil use of DE could be a scientific proposition in quest of that search.
Keywords: Diatomaceous earth, Temperature and Pest.