Shoot characteristics affect oviposition preference of the willow spittlebug Aphrophora pectoralis (Homoptera: Aphrophoridae)

Abstract

The relationships of shoot abscission, shoot toughness, and egg parasitism with shoot length were investigated in relation to oviposition preference by the willow spittlebug Aphrophora pectoralis Matsumura on Salix miyabeana, S. sachalinensis, and S. integra. Spittlebugs strongly preferred shoots >20 cm long even though this size class was a small proportion of all shoots. Oviposition increased with shoot length up to 40 cm but leveled off, or even decreased, on longer shoots. Shoot abscission rate decreased and toughness increased with increasing shoot length, but egg parasitism was not affected. Spittlebug oviposition preference is therefore likely to be affected by shoot abscission and shoot toughness.