Time management of using eucalyptus essential oil for controlling Tribolium castaneum

The effects of time variable were evaluated in measures with eucalyptus essential oil (Eucalyptusglobolus) for managing Tribolium castaneum. Bioassays were conducted using adults and impregnated filterpapers (Whatman N°1) as source of essential oil. Mortalities cause by concentrations; 85, 170, 340, 510, 680and 850 μl/L of air were counted after 3, 6, 9, 12 and 24 h after treatment and 41.6, 91.6, 100, 100 and 100%of insects were killed after 24 hours, respectively. Majority of its activity were exerted during first six hours,based on these experiments. LC50 values for adults that exposed 1, 2, 4, 8 and 16h to essential oil were 840,201.2, 131, 130.2 and 109 μl/L of air, in another series of experiments. Suitable effectiveness of four hoursexposure time was resulted by these assays. Durability of essential oil was evaluated in another bioassayswhere insects exposed to the concentrations; 205, 328, 460, 615 and 902 μl/L of air, but introducing insectwere postponed 1, 2, 4, 8, 16 and 24 hours after treatment. Complete losing efficiency was observed asconsequence of 16h delay of exposing insects. As conclusion, our results proved E. globolus essential oilquick acting as fumigant, but decreasing its effectiveness during limited time makes precise monitoring ofinsects a fundamental necessity and via these dealings, application time of essential oil and its on-timereplication would well determine.

کلیدواژه ها:

Eucalyptus essential oil ، Red flour beetle ، Exposure time ، Fumigation effect