Wide Band Permittivity Measurementsof Palm(Phoenix Canariensis)andRhynchophorus ferrugineus (Coleoptera Curculionidae)for RF Pest Control

Rhynchophorus ferrugineus Oliv., known as the red palm weevil (RPW), has quickly spread in Southern Europe, infesting and destroying an increasing number of palms, particularly the Phoenix canariensis ones. Of the various techniques suggested for treating the palms, high power microwave applications are considered an attractive, eco-compatibile solution. However, in order to correctly design the exposure system, a knowledge of the electromagnetic properties of the materials involved is required. In this paper, we present a broad-band electromagnetic characterization in the 0.4–18 GHz frequency range of the tissues (both healthy and damaged) of the P. canariensis, with different moisture content, and of the R. ferrugineus in different stages (larva, pupa and adult). The palm tissues had a high water content and a dielectric model of the vegetation was applied to the experimental data in order to estimate the volume fraction of free water and of the bulk vegetation-bound water mixture as well as the ionic conductivity of the free-water solution.