Antifeedant and Growth Inhibitory Effects of Non-edible Oils Against Tobacco Caterpillar, Spodoptera litura (Fabricius)
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Date
2008
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Publisher
MPUAT, Udaipur
Abstract
Investigations on the “Antifeedant and Growth Inhibitory Effects of Nonedible
Oils Against Tobacco Caterpillar, Spodoptera litura (Fabricius)” were carried
out under laboratory conditions in the Department of Agricultural Zoology and
Entomology, Rajasthan College of Agriculture, Maharana Pratap University of
Agriculture and Technology, Udaipur during May to October 2007.
Five non-edible oils viz., neem, karanj, ratanjot, mahua and eucalyptus were
tested against the 6-day old larvae of the test insect to find out the most effective oil in
causing antifeedant activity. Of the five non-edible oils tested, neem oil (10%)
showed the maximum antifeedant activity (98.10%).The antifeedant activity of these
non-edible oils in descending order was neem oil>karanj oil> ratanjot oil> mahua oil
> eucalyptus oil.
The fecundity of adult females that developed from the larvae that were fed on
castor leaves treated with non-edible oils reduced significantly. However, the nonedible
oils did not have any significant effect on the incubation period. Based on the
parameters like larval and pupal periods, length and weight of larvae and pupae, larval
survival, adult emergence, adult longevity and fecundity, neem oil was found to be
most effective, followed by karanj, ratanjot, mahua and eucalyptus oils. In control the
total life cycle was completed in 28.88 days (for male) and 32.24 days (for female),
while in neem oil treatment the total life cycle took the maximum duration of 58.75
days (for male) and 61.29 days (for female).
The effect of non-edible oils on food utilization indices for the tobacco
caterpillar was determined. The ECI, AD and ECD values were significantly lower for
the larvae fed on leaves of castor treated with non-edible oils in comparison to
control. Neem oil (2%) proved to be the most effective for reducing food utilization
by S. litura, as the value of all food utilization indices were the lowest viz., ECI
(10.85%), AD (37.62%) and ECD (28.85%) as compared control (16.08%, 50.81%
and 31.64%)
The comparative toxicity based on LC50 values of non-edible oils against 6-
day old larvae of S. litura was determined. The descending order of comparative
toxicity was neem oil (1.659%) > karanj oil (1.918%) > ratanjot oil (2.152%) > mahua
oil (2.588%) > eucalyptus oil (3.372%).
Description
Antifeedant and Growth Inhibitory Effects of Non-edible Oils Against Tobacco Caterpillar, Spodoptera litura (Fabricius)
Keywords
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Citation
Kevat and Jain, 2008