A new electric trap for tsetse flies (Glossina spp.), based on a circuit producing the necessary high voltages from a small 2-V battery, is described. Power consumption is reduced to less than 1% of its level in other circuits designed for the same purpose so that in theory up to 300 h operation per charge is available from a single 2-V dry cell with a 7-Ah capacity (weight approximately 460 g). In practice this time is more likely to be limited by the shelf-life of the cell in tropical climates. The new circuit and a modified grid were tested against G. morsitans submorsitans Newst. during field trials in Ethiopia and the results are discussed. A high percentage of females was obtained only when a stunning capacitor was introduced across the output. The capacitor stores the charge from the circuit and gives a bigger impulse as flies land across the wires. It seems that, in the absence of the capacitor, females that visit the catching device escape from the electrified grid. When they are caught they are stunned for about the same length of time as male flies.