Abstract.1. The data for dispersal ofDrosophila pseudoobscuraof Dobzhansky&Wright (1943) were re‐examined and an improved description found for them.2. The equation that best described the dispersal ofD.pseudoobscurawas found not to be applicable to the dispersal of five other insect species.3. Eight equations describing the density‐distance relation were fitted to the dispersal data of eight insect species. No equation fitted all the data adequately.4. A general expression was deduced from comparison of the eight equations, and found to fit all species better than any of the special ca