The Role of Leaf Cuticle in Leaf Age Preference by Bayberry Whitefly (Homoptera: Aleyrodidae) on Lemon

Abstract

The effect of leaf cuticle on probing behavior by bayberry whitefly, Parabemisia myricae (Kuwana), was studied by enzymatically removing cuticles from young and mature lemon (Citrus limon (L.)) leaves and using the isolated cuticles as membranes over sucrose solutions. Duration of probes by whiteflies on sucrose solutions covered by young cuticles or stretched Parafilm was significantly greater than on those covered by mature cuticles. Differences between young and mature cuticles were similar to differences previously observed between young and mature leaves. Because media beneath cuticles was the same for both young and mature cuticles, the data suggest that reluctance or inability of bayberry whitefly to feed on mature lemon leaves was the result of properties of leaf cuticle. Experiments using Parafilm as a “neutral” membrane suggest that inability of whiteflies to feed through mature cuticles results from inhibitory properties of mature cuticle rather than lack of probing stimulants.