Radar-tagged bee. Bumble bee,Bombus sp.,tagged with the smallest-ever radar antenna,on a flower. The bee's antenna does not need a battery,working by reflecting a component (harmonic) of an incom- ing radar signal. Consisting of a Schottky detect- or diode mounted at the centre of the antenna in parallel with an inductor,the tag weighs about 3 mg,about 1.5% of the bee's weight. The tag is used in pollination research to track the bee as it forages amongst flowers. A smaller antenna is being developed to track the movement of tsetse flies,the carrier of sleeping sickness (trypano- somiasis) in Africa. Photographed at the Rotham- sted agricultural research institute,UK,in 1996 |