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.
Occurrence of pink scavenger caterpillar, Anatrachyntis rileyi (Walsingham), which was not known to be established in Japan, was investigated in eight rice mill facilities, two feed factories and one rice processing facility for Awamori brewing in Ibaraki, Kagoshima and Okinawa, Japan. Seasonal occurrence of the moth was investigated with two kinds of sticky trap, a ribbon trap suspended from the ceiling and a floor mounted trap, at ten different sites in a large scale rice mill, in Tsuchiura, Ibaraki from June 1996 to June 1997. Moths were caught at all sites, and were captured every week except during the winter. The moths emerged from old rice bran in the rice mills and the feed factories investigated in Ibaraki and Kagoshima and an adult was also captured in Okinawa, indicating that A. rileyi has already widely colonized Japan. On the basis of the total effective temperature for A. rileyi, this species is estimated to have six generations per year in Tsuchiura. The number of adults captured by the ribbon traps was better correlated to the temperature in the mill than that of the floor mounted traps. However, seasonal changes in the number of adults captured by the floor mounted traps corresponded better to the times of adult emergence in the year estimated by the total effective temperature(degree-day).
Seasonal occurrence of Tetranychus kanzawai Kishida and its predators in the border vegetation, Clerodendrum trichotomum and Akebia quinata, of pea-watermelon fields were investigated in Wakayama Prefecture, southwestern Honshu, Japan during 1993-1994. There were two peaks in the population density of T. kanzawai on C. trichotomum: one was in April-May and the other in November. However, the density was low in summer when predacious mites (mainly Amblyseius eharai and A. sojaensis) occurred. The application of cypermethrin caused a resurgence in T. kanzawai on C. trichotomum during summer and autumn, showing that the predators had suppressed the mite population. Oligota kashmirica benefica and cecidomyiid, Feltiella sp., and Scolothrips takahashii were the predominant predator species of T. kanzawai when its density was high on C. trichotomum and A. quinata.
Formulations of Beauveria bassiana conidia in a 10% corn oil mixture showed more superior infectivity in both sexes of Cylas formicarius than the formulation of conidia only in laboratory assays. The 50% lethal density of conidia of the oil mixed formulation was lower than that of conidia alone. Mortality of uninfected females reared with males infected with the formulation of oil mixture was higher than that of females reared w/males infected by conidia alone.