EFFECT OF SOME INDIGENOUS PLANT EXTRACTS AGAINST LESSER GRAIN BORER, RHYZOPERTHA DOMINICA (COLEOPTERA : BOSTRICHIDAE)
Date
2013-12
Authors
Journal Title
Journal ISSN
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Publisher
HAJEE MOHAMMOD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR
Abstract
The study was carried out in the laboratory of the Department of Entomology, Hajee
Mohammad Danesh Science and Technology University, Dinajpur during the period from
April to December 2012 to evaluate the efficacy of different plant extract viz. Ata (Annona
reticulata), Karabi (Nerium oleander), Neem (Azadirachta indica), Biskatali (Polygonum
hydropiper) and Akanda (Calotropis gigantea) in petroleum ether for the toxicity, residual
and repellent effects against lesser grain borer, Rhyzopertha dominica. The leaf extracts of
above mentioned plants were applied at three doses viz. 4.0, 6.0 and 8.0% concentration. The
result showed that extracts of five tested plants had toxic and repellent effects on lesser grain
borer. Neem leaf extract showed the highest toxicity and repellent efficacy on lesser grain
borer. Even thuugh all the doses had toxicity, residual and repellency effects but the highest
efficacy showed at 8% concentration ( 8% dose showed the highest response). On the basis of
the 2%, values, it was observed that the neem extract showed the highest performance.
Considering all the concentrations, the order of toxicity levels of five plant extracts on lesser
grain borer was found as neem> biskatali> karabi> akanda > ata. Mortality percentages were
directly proportional to the time after treatment. In case of repellency, it was found that all the
tested extracts were in the same repellency ab i.e. class II. As the progress of time
mortality percentage increased (with the progress of time) meanwhile the repellency effect
decreased.
Description
Losses due to insect infestation is one of the most serious problem in storage, particularly in
villages and towns of developing countries like Bangladesh. Storage loss may also be
significant in developing countries where more than 70% of cereal production is stored in
farms (Kavita, 2004). It has been estimated that about 15-20% of the world agricultural
production is lost every year due to insect infestation (Wright, 1985). In Bangladesh, the
annual grain losses cost over taka 100 cores (Alam, 1971) whereas in India losses caused by
insects accounted for 6.5% of stored grain (Kumar, 2009). The climate nia storage
conditions, especially in the tropics, are often highly favorable for insect growth and
development (Jacobson, 2004).
Keywords
Collection and rearing of test insect, Collection of test plant, Preparation of plant dust and extracts