Relationship of Aphid Density to Altitude

THE dispersal of small insects to high altitudes by convection and turbulence is known to produce an insect-density gradient in which density decreases with height 1,2 . The distribution has never been expressed mathematically; and since the insect population of the air varies considerably from hour to hour, and most of the observations at the different heights were made at different times, mathematical analysis would have yielded little of value.