Preference and performance are correlated in the spittlebug Aphrophora pectoralis on four species of willow

Abstract 1. There was a positive correlation between oviposition and feeding preferences and offspring performance in the spittlebug Aphrophora pectoralis Matsumura (Homoptera: Cercopoidea, Aphrophoridae) on four species of willow Salix sp. (Salicaceae) growing near Sapporo, Japan. Spittlebugs preferred rapidly growing shoots where performance was highest.
2. When the effects of shoot length were removed, egg densities on willow species were associated with offspring performance on three of four species. Egg densities and survival rates were low on Salix integra and Salix miyabeana . Survival rates were high on Salix sachalinensis , which had high egg densities, and Salix hultenii , which had low egg densities.
3. Aphrophora pectoralis formed mating aggregations almost exclusively on S. sachalinensis but then dispersed to other willow species to oviposit.
4. Nymphs dispersed from the oviposition site to feed on nearby shoots within the same plant but they did not disperse to other willow plants. Nymphs had the same preference for rapidly growing shoots as ovipositing females, so they were able to refine the maternal choice by moving to larger shoots near the shoot on which they had eclosed.
5. The spittlebugs were highly aggregated at all life stages so that even at high densities only a small proportion of the most vigorously growing shoots was utilised.