X-ray irradiation as a quarantine treatment for the control of six insect pests in cut flower boxes

Abstract

Roses and chrysanthemums are the most exported cut flowers in Korea. We investigated the effects of X-ray irradiation on the disinfestation of six floriculture insect pests (Tetranychus urticae, Myzus persicae, Bemisia tabaci, Liriomyza trifolii, Spodoptera litura, and Frankliniella intonsa) placed in the top, middle, and bottom sections of rose and chrysanthemum boxes. After irradiation with an X-ray dose of 150Gy, the development of nymphs and adults of M. persicae and eggs, nymphs, and adults of B. tabaci was prevented at every position in the boxes. When T. urticae nymphs were irradiated at 200Gy, newly emerged adults laid eggs in the bottom section of rose boxes only. However, hatching was completely inhibited. When L. trifolii adults were irradiated at 200Gy, hatching of the F1 generation was completely inhibited in every section of both the rose and chrysanthemum boxes. The hatchability of S. litura was not completely inhibited in the bottom sections, even at 200Gy. In F. intonsa, the hatchability of eggs and emergence of nymphs were prevented at 150Gy. However, at 200Gy, the hatching of the F1 generation was completely inhibited only in the chrysanthemum boxes. These results suggest that the required dose of X-ray irradiation may depend on the type of flower, the species of insect pest, and the insect location within the box.