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ARS Home » Research » Publications at this Location » Publication #103949
Title: INCREASED MORTALITY OF GYPSY MOTH LARVAE EXPOSED TO GYPSY MOTH NUCLEAR POLYHEDROSIS VIRUS AND THE PHENOLIC GLYCOSIDE SALICIN

Author
item COOK, S - UNIV. OKLAHOMA
item WEBB, RALPH
item PODGWAITE, J - USDA FOREST SERVICE
item REARDON, R - USDA FOREST SERVICE

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: The gypsy moth nuclear polyhedrosis virus (NPV) has been registered as a general use pesticide against the gypsy moth, a serious defoliator of forest and shade trees. Other workers have demonstrated that the presence in the leaves of host plants of certain phenolic compounds (tannins), decrease the efficacy of Gypchek against gypsy moth. The present study demonstrated that a member of a second class of phenolic compounds, the phenolic glycoside salicin, increases the impact of Gypchek. Results suggest that Gypchek should be more effective sprayed on gypsy-moth infested aspen forests, which would potentially help managers of gypsy moth-infested properties (homeowners and local, state, and federal programs) when setting priorities as to where to use this environmentally friendly gypsy moth control material.

Technical Abstract: Second-instar gypsy moth larvae suffered significantly greater mortality from aerially-applied Gypchek (gypsy moth nuclear polyhedrosis virus) when the virus was consumed on quaking aspen versus red oak foliage. Laboratory assays in which various doses of virus and salicin (a phenolic glycoside present in aspen foliage) were tested in combination demonstrated that salicin significantly increased total larval mortality and lowered LD(50) estimates for larval mortality when consumed along with the virus. While salicin did not impact larval survival in the absence of virus, it did act to significantly decrease feeding when it was present in high concentrations (up to 5%) within the treatment formulations. The enhancement of viral activity by salicin is similar to prior reports of enhanced activity of the bacterial pathogen Bacillus thuringiensis when consumed concurrently with phenolic glycosides commonly present in aspen foliage. The enhancement of viral activity is in contrast to the inhibitory effects on the virus reported for another common group of phenolic compounds, tannins.