CHEMICAL BIOLOGY OF INSECT AND PLANT SIGNALING SYSTEMS
Location: Chemistry Research Unit
Title: Monitoring grape berry moth (Paralobesia vitianna: Lepidoptera) in commercial vineyards using a host plant based synthetic lure
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 25, 2011
Publication Date: December 1, 2011
Citation: Loeb, G., Ho Cha, D., Hesler, S., Linn, C., Zhang, A., Teal, P.E., Roelofs, W. 2011. Monitoring grape berry moth (Paralobesia vitianna: Lepidoptera) in commercial vineyards using a host plant based synthetic lure. Environmental Entomology. 40:1511-1522.
Interpretive Summary: Although sex pheromones have been used effectively to monitor populations of pest moths cases males are captured using these pheromone lures. Therefore this method does not allow for monitoring of females who lay eggs on crops of economic importance. Clearly, direct monitoring of female activity in crops would allow for more effective population monitoring and to predict the potential for outbreaks of larval attack. One way to do this is to identify chemicals attractive to female moths ready to lay their eggs. Scientists at Department of Entomology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY; the Invasive Insect Biocontrol and Behavior Laboratory, USDA-ARS Beltsville, MD and Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, FL identified a chemicals from grapes that are attractive to the Grape Berry moth. They conducted field tests to determine if two formulations of these attractants were as effective in monitoring populations of the moth in the field as was the traditional method using the sex pheromone. The results showed that the host plant attractants were as good as pheromone traps in identifying the first flight of moths in the spring but outperformed pheromone traps in identifying second and third generation invasions by adult moths. Interestingly, both sexes were attracted to host plant volatiles where as only males were attracted to the pheromone. The results are important because they demonstrate that host plant volatiles provide an effective monitoring method that can outperform traditional population monitoring techniques.
For some Lepidopteran pests, such as the grape berry moth Paralobesia vitianna, poor correlation between male captures in traps baited with sex pheromone and oviposition activities of female moths has called into question the value of pheromone-based monitoring for these species. As an alternative, we compared the capture of female and male grape berry moth (GBM) in panel traps baited with synthetic lures based on host volatiles with captures of males in pheromone-baited wing traps over two growing seasons in two commercial vineyards in upstate New York, USA. Both a seven-component thirteen-component synthetic lures formulated to release host volatiles captured significantly more male and female GBM on panel traps compared to the numbers captured on panel traps without any attractants. For both sexes over both years, more moths were captured in panel traps along the wood edge compared to the vineyard edge early in the season but this pattern was reversed by mid-season. Capture of male moths in pheromone-baited wing traps also displayed this temporal shift in location of greatest captures. There was a significant positive correlation between capture of males and females on panel traps although not between female captures on panel traps and males captured in pheromone-baited traps for both years suggesting pheromone traps do not accurately reflect either female or male activity. Pheromone trap data of male moths indicated a large peak early in each season corresponding to first flight followed by lower and variable captures that did not clearly indicate second and third flights. Panel trap data, combining males and females, indicated three distinct flights, with some overlap between the second and third flights. Peak captures of moths on panel traps correlated well with predictions of a temperature-based phenology model, especially in 2008. Although effective, panel traps baited with synthetic host lures were time consuming to deploy and maintain and captured relatively few moths making them impractical, in the current design, for commercial purposes.