Aphis migration and the efficiency of the trapping method.

摘要: Reproducible results were obtained when adhesive traps for aphides placed at the same height in different parts of a potato field. The total catches localities seasons can therefore justifiably be compared. During summer dispersal flights, species flew heights, so one only are not suitable comparing relative abundance species. There was less variation numbers caught on 3–4 ft. above ground than 5–6 or ground-level. During first fortnight July an average 200 aphides, 1.6% which Myzus persicae, position plants. Most these but it is suggested that some them might act as vectors viruses. number roughly proportional to volume free air space around traps, and foliage increased density lower decreased proportion. Wind-speed records within crop discussed shown conditions often voluntary aphis flight near relatively windy days. Records half-traps facing wind other halves showed with increasing height. Brilliant yellow coated grease, more white turn black.