Abstract:
Synthetic pesticides are widely used to control pests in stored grains. In recent years, consumer
awareness of the health hazard from residual toxicity and the growing problem of insect
resistance to these conventional insecticides have led the researchers to look for alternative
strategies for stored grains protection. Nanoemulsions are now widely using for enhancing
delivery and biological functions of pesticides. Therefore, in the present investigation, the oil
extracted from Hydnocarpus pentandra (Garudphal / Maravattai) seed were first tested for its
physical, chemical properties and active compounds like free fatty acids through TLC and HPLC
methods. Then it has been utilized to produce a nanoemulsion as an alternative and efficient tool
to control rice weevil (Sitophilus oryzae) population. After 72 hrs of exposure time
nanoemulsion oil possess phytotoxic effect against Sitophilus oryzae (adult mortality) which
caused 94% mortality at the low doses of 1, 2, 3 and 4 mL/mg when compared to oil alone
treatment. This toxic effect might be due to the aromatic flavonoids and free fattyacid contents
present in the essential oil of H. pentandra. Hence, it can be concluded that nanoemulsion
produced from Hydnocarpus pentandra seed oil can be used as a biopesticide to control
Sitophilus oryzae. However, further investigations on its mode of action, side effects, effects on
other pests and effects on grain quality are important.
