Conventional 3 cm entomological radars have been successfully used for
many years to observe the migratory flight of the larger insect speci
es, but the range at which these radars can detect individual small in
sects is limited to a few hundred metres. This paper outlines the desi
gn and application of an 8.8 mm wavelength radar to study the flight o
f insects weighing only 2 mg. Detection ranges in excess of 1 km were
achieved for individual insects, and estimates of aerial density made
by the radar were found to be within 50% of those made by an aerial sa
mpling device.