Canadian Forest Service Publications
Differential mortality between male and female Choristoneura occidentalis (Lepidoptera: Tortricidae) larvae exposed to a baculovirus with or without optical brighteners. 1999. Li, S.Y.; Otvos, I.S. The Canadian Entomologist 131: 65-70.
Issued by: Pacific Forestry Centre
Catalog ID: 5162
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Fifth-instar larval mortality was compared between male and female Choristoneura occidentalis Freeman exposed in the laboratory to sublethal doses of C. fumiferana (Clem.) multicapsid nuclear polyhedrosis virus (CfMNPV) with or without optical brighteners. More female than male died when the virus was used alone, but differences were not significant. When 1% brightener was added to CfMNPV suspension, differences in larval mortality between males and females were significant for three of the four brighteners tested. In addition, times at which 50% of the larvae died indicated that female larvae died 23 and 39% more quickly than male larvae, respectively, when brightener Blankophor HRS and Tinopal LPW were added to the virus, whereas at times at which 95% of the larvae died indicated that females died 33 and 54% faster than males. Alteration of sex ratio favoring male survival can play a significant role in the biological control of C. occidentalis by the virus.