Insecticidal and repellent activities of eucalyptus oil against lesser grain borer rhyzopertha dominica (fabricius)

whole, sound grain and cause extensive damage. Larvae are internal feeders whereas adults are free living and bore into the commodity
and can fly. Fumigation is the most useful and effective method to manage this insect pest. There are several insecticides available in the
market to manage this pest but some insecticides have been banned because of environmental pollutions and for some insecticides this
insect pest has developed resistance. Therefore efforts are required to find safe, effective and viable alternatives. Natural products are
well known to have a range of useful biological properties against insect pests. Recently, there has been considerable interest in essential
oils and extracts of medicinal and edible plant and herbs for the development of alternative insecticides and fumigants. This research
was initiated to evaluate the fumigation toxicity and repellent action of Eucalyptus globulus Labill essential oil against adults of R.
dominica. GC/MS analysis showed the major components of E. globulus essential oil as 1,8-cineole (22.35%), α-pinene (12.58%)
limonene (4.01%), aristolene (3.35%), p-cymene (3.25%), trans-verbenol (3.02%), isosativene (2.85%), α-myrcene (2.15%) and
terpinen-4-ol (2.10%). Fumigation toxicity and repellent activity showed that as the concentration and exposure time increased the
mortality and repellency also increased. Maximum repellency of 62.0% was observed at 0.32μl/cm2
concentration after 36 hours of
exposure.