Differences in esterase isozymes between Panonychus citri populations infesting citrus and Osmanthus

Gene frequencies were investigated in the -Est1 locus between Japanese populations of Panonychus citri occurring on some fruit trees and on the garden trees, Osmanthus trees and Ilex crenata. A new allele, A₃, was found in the -Est1 of populations collected on Osmanthus trees. Populations on I. crenata, Citrus unshiu and Pyrus serotina had one or both A₁ and A₂ alleles. However, the populations on Osmanthus trees had only the A₃ allele and did not vary geographically.