| 저자(한글) |
Ozawa, Akihito,Saito, Tsutomu,Ota, Mitsuaki,静,岡県,農業試験,場,静,岡県,農業試験,場,静,岡県,農業試験,場 |
| 초록 |
The effectiveness of biological control against Liriomyza trifolii (Burgess) on tomatoes was evaluated in commercial greenhouses. Five experiments were conducted at 2 locations, Hamaoka and Shimizu in Shizuoka Prefecture, from summer to winter in 1994, 1995 and 1996. Diglyphus isaea (Walker) and Dacnusa sibirica Telenga were released 3 to 9 times weekly after planting at release rates of 178 to 500 wasps per 10 a in biologically controlled greenhouses. Only selective insecticides such as IGR and BT were applied in bio-controlled (BC) greenhouses, whereas various insecticides including non-selective pesticides were applied in chemical controlled (CC) greenhouses. In Hamaoka, the density of leafminer larvae in BC greenhouses was kept at the same level as in CC greenhouses, and the mortality of leafminer larvae increased up to 100%. The density of mines and the number of adults captured by yellow sticky traps were kept at the same as or lower than those in CC greenhouse, respectively. In Shimizu, the densities of leafminer larvae and mines, and the number of adults captured by yellow sticky traps in BC greenhouses were higher than those in CC greenhouses, but the mortality of leafminer larvae increased up to 100% and the damage to tomato plants was not severe. Maximum percentage of parasitism by the parasitoid complex based on the numbers of adult parasitoids that emerged from collected tomato leaves in BC greenhouses in Hamaoka and Shimizu were 100%. Dominant parasitoid species emerging from L. trifolii larvae in Hamaoka were D. isaea and D. sibirica, while dominant parasitoids in Shimizu were indigenous species, among which Neochrysocharis formosa and Hemiptarsenus varicornis were most dominant. Total frequency of insecticide applications in BC greenhouses were the same as or lower than those in CC greenhouses, but the frequency of insecticide application against leafminers was by far lower than those in CC greenhouses. These results suggest that biological control by the parasitoids against L. trifolii was practically effective on tomatoes in commercial greenhouses. |
