S6-12
Insecticidal Activity of Cassava Seed Extract against the
Storage Pest, Sitophilus oryzae
(L) (Coleoptera: Curculionidae)
Jayaprakas C.A., P. Rajamma,
M.S.. Palaniswami and J. Sreekuma
Central
Tuber Crops Research Institute, Sreekariyam, Trivandrum 695 017,
Kerala, India
jprakash@ctcri.ren.nic.in
Sitophilus oryzae,
is an important pest on many stored products including plain and
parboiled dried cassava chips. Seeds
of cassava are generally discarded as a waste but the current
investigations proved that petroleum ether extract of cassava seed is a
potent biopesticide against S. oryzae.. Various
concentrations viz. 1, 3, 5, 10, 25, 50 and 100% of cassava seed extract
were prepared in acetone and their bioactivity was studied against S.
oryzae.. Small cotton ball (1 cm diameter) impregnated with 0.5 ml of
the aliquot was exposed to each batch of 25 insects in glass tube.
The fumigant action of the extract for 3 days resulted in 84.6%
mortality of the insects treated with undiluted extract but the
mortality was only 1.3% in the control.
Insect mortality was 100% 5 days after treatment (DAT) when the
insects were exposed to extract concentrations of 25, 50 and 100%
whereas mortality was 14.6% in the control.
The use of 300, 400 and 500 ml
of the extract at 100% concentration resulted in 100% mortality of the
insect 3 DAT. The
investigation revealed the potential of cassava seed as a source of an
effective, environmental friendly biopesticide, especially in the
context of IPM.
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