Mortality of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) Pupae at Elevated Temperatures and Effective Period for Practical Use of Solar Radiation for Population Management.

Abstract

Previously, we reported that subterranean Liriomyza trifolii pupae can be killed with solar radiation by covering the ground with transparent polyvinylchloride film after cropping of a leafy vegetable, Chrysanthemum coronarium var: spatiosum. In order to quantify the conditions necessary to achieve effective control of L. trifolii in Osaka Prefecture, we investigated the mortality of pupae at selected temperature and duration combinations, as well as the soil temperatures attained under transparent polyvinylchloride film in a closed greenhouse at specific times of the year. L. trifolii pupae were killed by exposure to either 44°C for 24 h, 46°C for 3 h or 48-54°C for 30 min. Maximum temperatures of 48°C or higher were attained from early April to mid October at a depth of 1-2 cm beneath the soil surface under transparent polyvinylchloride film in a closed greenhouse. Many L. trifolii pupate at 1-2 cm beneath the soil surface. Therefore, this control method for L. trifolii pupae is effective during the period from early April to mid October.