title: Assessment of Trichogramma japonicum and T. chilonis as Potential Biological Control Agents of Yellow Stem Borer in Rice.
abstract: Two species ofTrichogrammawasps were assessed for their effectiveness against yellow stem borerScirpophaga incertulas. A laboratory cage test withT. japonicumandT. chilonisshowed that both species parasitized yellow stem borer egg masses at 60.0% ± 9.13% and 40.7% ± 7.11%, respectively, with egg parasitism rates of 15.8% ± 22.2% forT. japonicumand 2.8% ± 5.0% forT. chilonis. Once the host eggs were parasitized, emergence rates were high for both species (95.7% ± 0.12% forT. japonicumand 100% forT. chilonis). In paddy field trials, the twoTrichogrammaspecies were released at three densities (50,000/ha, 100,000/ha and 200,000/ha) in Southwestern China. Egg mass parasitism was 9% ± 7.7% forT. japonicumand 15% ± 14.1% forT. chilonis, and again only a relatively small fraction of eggs was successfully parasitized. No clear conclusion could be drawn on the most efficient release rate as no significant differences were found among the three release rates. A comparison of field-collectedT. japonicumwithT. japonicumandT. chilonismass reared onCorcyra cephalonicashowed significantly larger body size and ovipositor length in field-collected wasps, suggesting potentially higher effectiveness on yellow stem borer eggs after at least one generation on the target host. Factors contributing to the low field parasitism rates are discussed.
authors.affiliation: MoA-CABI Joint Laboratory for Bio-Safety, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 2 West Yuan-Ming-Yuan Road, Haidian District, Beijing 100193, China. r.tang@cabi.org.
authors.forename: Rui
authors.initials: R
authors.lastname: Tang
authors.affiliation: MoA-CABI Joint Laboratory for Bio-Safety, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 2 West Yuan-Ming-Yuan Road, Haidian District, Beijing 100193, China. d.babendreier@cabi.org.|CABI Europe-Switzerland, Rue des Grillons 1, Delémont CH-2800, Switzerland. d.babendreier@cabi.org.
authors.forename: Dirk
authors.initials: D
authors.lastname: Babendreier
authors.affiliation: MoA-CABI Joint Laboratory for Bio-Safety, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 2 West Yuan-Ming-Yuan Road, Haidian District, Beijing 100193, China. f.zhang@cabi.org.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Plant Protection and Quarantine Station, Dehong Prefecture Agriculture Bureau, Dehong 678400, China. kangmin318@sina.com.
authors.forename: Min
authors.initials: M
authors.lastname: Kang
authors.affiliation: Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Sciences, Hengshui 053000, China. hs_kai@126.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.affiliation: State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. mlhou@ippcaas.cn.
authors.forename: Mao-Lin
authors.initials: ML
authors.lastname: Hou
keywords: Trichogramma; field release; parasitism rate; yellow stem borer