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1868 Canadian Entomologist  
The Canadian Entomologist 131: 399 -404 (1999) Fourteen species of parasitoids (13 hymenopterans, 1 dipteran) were reared from larvae or pupae of the obliquebanded leafroller, Choristoneura rosaceana (Harris), collected from commercial raspberry fields in the Fraser Valley, British Columbia, Canada, over 3 years. Levels of parasitism ranged from 5 to 15%. Among these 14 species, five represent new host records. A polyembryonic wasp, Macrocentrus nigridorsis Viereck (Hymenoptera: Braconidae),
more » ... ra: Braconidae), was the most abundant parasitoid. External feeding on the final host instar is obligatory for M. nigridorsis to complete development. On average, each parasitized host larva produced about 36 M. nigridorsis, in either unisexual or mixed-gender groups. Overall male to female sex ratio was 1:4. Head capsules of mature parasitized host larvae were significantly larger than those of unparasitized ones, suggesting that C. rosaceana larvae parasitized by M. nigridorsis might have an extra larval stage. Li SY, Fitzpatrick SM, Troubridge JT, Sharkey MJ, Barron JR, O'Hara JE. 1999. Parasitofdes BlevCs sur des Tordeuses B bandes obliques (Lepidoptera; Tortricidae) recueillies dans des framboisiers infest&. The Canadian Entomologist 131 : 399404. Quatorze espbces de parasitoi'des (13 hymknoptbres, I diptbe) ont Ct C ClevCes 2 partir de larves ou de nymphes de la Tordense ?I bandes obliques, Choristoneura rosaceana (Harris), recueillies dans des champs commerciaux de framboisiers dans la vallCe du Fraser, Colombie-Britannique, Canada, au cours d'une pkriode de 3 ans. Le degrC de parasitisme allait de 5 a 15%. Parmi les 14 espbces, cinq reprksentaient des relations hate-parasite encore inCdites. Une guCpe polyembryonnaire, Macrocentrus nigridorsis Viereck (Hymenoptera: Braconidae), s'est avkrCe le parasitoi'de le plus abondant. Pour complkter son dkveloppement, M. nigridorsis doit se nourrir obligatoirement ?I meme la larve de stade terminal de son hbte, par 1'extCrieur. En moyenne, chaqne larve hate parasitCe a produit environ 36 M. nigridorsis, en
doi:10.4039/ent131-4 fatcat:dblk4o2ohfcilnlxtk6me3bkba