Incidence of Polyphagotarsonemus latus(Banks) (Acari: Tarsonemidae) on Green Perilla (Perilla frutescens var. japonica Hara)

摘要

The populations of Polyphagostarsonemus latus (Acari: Tarsonemidae) peaked two times on green perilla grown in greenhouses of Geumsan-Gun, Chungchungnamdo. The first peak of P. latus was in the middle of June, after it was first detected in late May.The population of P. latus peaked for the second time in mid July as its density stared rapidly increasing in early July. The application of chemical pesticides and eco-friendly agricultural materials, the two management methods used to control P. latuson green perilla, did not alter the occurrence patterns of P. latus; population size of the mite was much larger in greenhouses using chemical pesticides than in the ones using eco-friendly agricultural materials. This difference might be cuased by continuity of the management methods. Chemical control of P. latus should be limited owing to pesticide residue. The highest density of P. latus on green perilla plants was observed after 25 days after inoculation. The density was the highest in mid-aged leaves (e.g., the largest leaves) and the lowest in newly developed leaves (e.g., smallest leaves). However, there was no significant (P > 0.05) correlation between leaf size and density oi P. latus. These results indicate that leaf size (e.g., leaf age) didnot affect the occurrence of P. latus. Thus, any leaf of a green perilla plant is available as a sample unit for P. latus.