title: Number of attacks by Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae) affects the successful parasitism of Ostrinia furnacalis (Lepidoptera: Crambidae) eggs.
abstract: In laboratories, the parasitism rate of Ostrinia furnacalis (Güenée) (Lepidoptera: Crambidae) eggs by Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) is low; however, efforts to control O. furnacalis with T. dendrolimi in the field have been successful. In this study, the effects of the number of attacks by T. dendrolimi against O. furnacalis eggs and diet of O. furnacalis larva on wasp development were investigated. The results indicated that more attacks increased significantly not only the successful parasitism rate of O. furnacalis eggs by T. dendrolimi, but also the percentage of host eggs that failed to develop into either O. furnacalis larvae or T. dendrolimi. Both the size and female proportion of T. dendrolimi offspring decreased as the number of attacks increased. The number of T. dendrolimi eggs laid in per host egg increased significantly as the ratio of wasps to host eggs increased from 1:5 to 3:5. Host diet also significantly affected the developmental time of immaturity and the emergence rate of adults of T. dendrolimi. These results illustrate how inundative releases of T. dendrolimi can successfully control O. furnacalis despite the fact that pest parasitism by the subsequent wasp generation decreases sharply in the field. The suitability of O. furnacalis eggs to T. dendrolimi and the superparasitism effects on offspring of T. dendrolimi are discussed.
authors.affiliation: Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: J
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: H-Q
authors.initials: HQ
authors.lastname: Hua
authors.affiliation: Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: L-Y
authors.initials: LY
authors.lastname: Wang
authors.affiliation: Institute of Plant and Environment Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
authors.forename: F
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Y-X
authors.initials: YX
authors.lastname: Li
mesh_terms: D000818:Animals; D049628:Body Size; D004032:Diet; D005260:Female; D006790:Host-Parasite Interactions; D008297:Male; D009036:Moths / Q000469:parasitology*; D010058:Oviposition; D010063:Ovum / Q000469:parasitology; D014863:Wasps / Q000502:physiology*
keywords: 
                 Ostrinia furnacalis
              ; 
                 Trichogramma dendrolimi
              ; attack number; female proportion; inundative release; size; successful parasitism