author(s)
Negesse Mekonnen, Yohannes Sika, Firew Lejebo and Tesfaheywet Zeryehun

abstract
Different technologies have been introduced and applied practically in the field for many years for the control of tsetse flies. The present study was conducted to test the efficacy and longevity of 20% deltamethrin impregnated targets in 0.2%, 0.4% and 0.8% concentrations checked against the tsetse fly at 5, 10 and 15 minutes of exposure. The selected concentrations of Deltamethrin 20% were applied to targets by dilating with respective dilutants. Then the targets were deployed in selected area for experiment. Flies were collected and brought to the site of the bioassay. The knockdown effect of the insecticide was observed at 5, 10 and 15minutes for every two weeks interval. A total of 900 tsetse flies were used for the bioassay excluding weak flies. The knockdown effect of the insecticides was equally effective in 0.2%, 0.4% and 0.8% concentration (P>0.05) in all the three exposure times. However, the number of knockdown flies significantly differ in between the three different exposure times (P<0.05).With regard to days of trial, as the number of days increases the number of knockdown flies decreased significantly. For instance, on day 85, at 5minutes, the number of knockdown flies significantly declined by half compared to day 1. The number of flies knockdown significantly differ as the exposure time and number of days increased since the concentration of deltamethrins declined through time. The present study demonstrated that deltamethrin impregnated targets at 0.2%, 0.4% and 0.8% concentrations were equally effective throughout the experimental period. Therefore, we recommend the use of 0.2% concentration to impregnate targets during fly control. However, this is a controlled experiment which has to be further validated in field condition using poor-on techniques on animals.