Comparative analysis of aphid vector behavior in response to potato plants grown from field tubers, minitubers or plantlets

The greater sensitivity to aphid vectored diseases of potato plants originating from plantlets or mini-tubers compared to plants originating from field grown tubers could not be explained by changes in probing behavior, by increased aphid movement between plants or by greater levels of aphid colonization favorable to virus spread. The number of seconds to first probe, the duration and number of seconds before the long probe and the duration of the long probe were statistically similar on all plant types. The average residency time of green peach aphids on each plant type was also statistically the same. Winged Myzus persicae (Sulzer) (green peach aphid) landed in greater numbers on older than on younger plants regardless of plant type. This suggests that the level of aphid colonization is determined by a combination of factors such as height, surface and age of plants but not by plant origin. Where virus vectors are present early in the season, the greater number of aphids landing on the relatively older and larger transplants may contribute to higher infection levels, but later in the season plant physiological factors favorable to virus multiplication or translocation are more likely factors.