View source for Canadian Journal of Zoology (2001) 79, 1697-1703

{{Publication
|Publication authors=Astrid Schoenmaker, [[Michel Cusson]] and [[Kees van Frankenhuyzen]]
|Author Page=Kees van Frankenhuyzen, Michel Cusson
|Publication date=2001
|dc:title=Interactions between ''Bacillus thuringiensis'' and parasitoids of late-instar larvae of the spruce budworm (Lepidoptera: Tortricidae)
|Publication journal=Canadian Journal of Zoology
|prism:volume=79 (9)
|prism:startingPage=1697
|Last page=1703
|DOI=10.1139/z01-127
|Publication abstract=We investigated interactions between ''Bacillus thuringiensis'' Berliner var. ''kurstaki'' and parasitoids that attack late instars of the eastern spruce budworm, ''Choristoneura fumiferana'' (Clemens). In a petri-dish arena, females of ''Tranosema rostrale rostrale'' (Brishke) (Hymenoptera: Ichneumonidae) were able to discriminate between untreated fourth instars and fourth instars that had been given a known dose of a commercial product (Foray 48B). When the choice tests were conducted before host mortality due to ''B. thuringiensis'' had occurred among treated larvae (24 h post ingestion), the parasitoid attacked untreated larvae more readily. When females were given a choice between control larvae and treated larvae that were still alive 72 h post ingestion, they were able to discriminate between the two only when the larvae had been treated with at least a 50% lethal dose. Under laboratory conditions, female ''T. r. rostrale'' were thus able to detect and avoid treated larvae that exhibited a lethal response to the pathogen, and to a lesser extent larvae that had survived pathogen exposure. The ability of the latter was not apparent under field conditions. When treated and untreated larvae were exposed for 1 week to a complex of indigenous parasitoids in the field, there was no difference between treatments in the rates of parasitism by either ''T. r. rostrale'' or ''Actia interrupta'' Curran (Diptera: Tachinidae). Parasitism averaged 91% for larvae in the control treatment compared with 92% for larvae treated with Foray 48B. The field data suggest that spruce budworm larvae that survive exposure to ''B. thuringiensis'' are just as likely to be parasitized as unexposed, healthy larvae. This means that prolonged development of late-instar spruce budworm larvae after treatment with ''B. thuringiensis'' could possibly result in increased attack rates by parasitoids.
|AbstractCC=Yes
|Research topic=biocontrol - natural enemies
|Benf research=environment/habitat manipulation
|Is book=No
}}
{{Pest record
|Pest=Choristoneura fumiferana
|Quarantined=No
}}
{{Beneficial record
|Beneficial=Bacillus thuringiensis var. kurstaki (entomopathogen)
|Pest=Choristoneura fumiferana
}}
{{Beneficial record
|Beneficial=Tranosema rostrale (parasitoid)
|Pest=Choristoneura fumiferana
}}
{{Beneficial record
|Beneficial=Actia interrupta (parasitoid)
|Pest=Choristoneura fumiferana
}}