Increased extinction of aphid colonies in an apple orchard with floral strips

Abstract: Floral strips of native perennial species were introduced into the alleyways of
untreated apple plots in an experimental orchard to promote functional biodiversity. Their
effects on green apple aphid biocontrol were compared to unmanaged control plots. Green apple aphid colonies and their natural enemies were monitored weekly in the central rows of each plot for three seasons. From mid-June to mid-July, extinction rate of aphid colonies was higher in floral strips than in the control treatment. However, there was no difference in the density of aphidophagous predators between treatments. Potential explanations for this increased extinction rate are discussed.