Management of stored-grain insects using gamma radiation
could be enhanced by other feasible control methods such as essential
oils as potential alternatives to chemical insecticides. This work was
carried out to find the effect of two essential oils rosemary )Rosmarinus
officinalis L.(and cinnamon(Cinnamomum aromaticum ( and /or gamma
radiation doses separately on Tribolium castaneum adult's mortality and
the combined effect of gamma radiation doses and at LC50of each
essential oil (based on Probit analysis) on adult's mortality. The insects
were subjected to five radiation doses (150, 200, 250, 300 and 350 GY),
then exposed to the LC50’s from each essential oil and its effect on
certain biological aspects of T. castaneum. The mortality rate was
increased in the combined treatments of (LD50of gamma radiation and
LC50of the two essential oils) more than any of the separate treatments.
The additive effect was more detectable when higher doses of gamma
radiation were combined with LC50 of either of the two essential oils.
From the mentioned results, the mortality effect of the essential oils
against stored grain pests can be enhanced by its combining with gamma
radiation. As well, the results showed that the combination experiments
caused significant reduction in the number of eggs deposited per female,
hatchability percentage of eggs, total larval duration, the pupal period
and total developmental period, while the pre-oviposition period and
incubation period of eggs were obviously increased. From the mentioned
results, the insecticidal effectiveness of the essential oils against stored
grain pests can be enhanced by combining the oil treatments with
gamma radiation. |
