Figure 2
24-hour monitoring of M. persicae population in leaf colonies. (a) Appearance of aphid colonies on leaves. WT plants were treated with HrpNEa and EVP, respectively. Five days later, uniform aphids were placed on lower sides of the top two expanded leaves, 10 aphids/leaf; leaves were photographed 24 hours later. The arrowhead points a nymph produced after leaf colonization. The numerical values, given as mean ± standard deviation (SD), indicate the number of aphids that stayed on the leaf colony for 24 hours. A photo represents 120 leaf colonies on 60 plants. (b) Changes of aphid population in 24 hours. Leaf colonies on plants from (a) were surveyed, the number of aphids that stayed in a leaf colony was scored, and percent decrease in the number of aphids that left the leaf colonies was calculated as mean ± standard deviation (SD) of replicate results (n = 120 leaf colonies). The numerical values indicate total proportions (means ± SDs) of decreases in aphid populations within 1, 6 and 24 hpt (hour posttreatment).