How do Japanese beetles discriminate between host and non-host plants?
Daniel A. Potter, David W. Held, and Henry H. Southgate. University of Kentucky, Department of Entomology, S225 Agricultural Science Center North, Lexington, KY With few exceptions, the sensory receptors involved in taste mediation by polyphagous insects are poorly known. We studied the role of olfactory and gustatory organs in close-range dietary discrimination by the Japanese beetle, Popillia japonica, which as an adult feeds on >300 plant species in > 80 families. Scanning electron microscopy revealed clusters of sensilla basiconica at the tips of the labial and maxillary palps, sensilla coeloconica and placodea on antennal lamellae, and patches of small coeloconic pits on the labium and labrum. Unilateral or bilateral ablation of lamellae, tips of palps, or tarsi in various combinations did not impair beetles’ ability to discriminate between host and non-host plants. Such ablations also did not impair normal discrimination among acceptable hosts of varying palatability, or beetles’
