Progress 08/15/07 to 08/14/10
OUTPUTS: Objective 1: We identified by a combination of retention index comparisons and mass spectral interpretation the gross structure of the female-produced sex attractant pheromone of the cerambycid beetle Prionus californicus Mots. (Cerambycidae: Prioninae) as an isomer of 3,5-dimethyldodecanoic acid. Laboratory and field bioassays in southern California and Idaho showed that male beetles were strongly attracted the mixture of the four stereoisomers of 3,5-dimethyldodecanoic acid. Three minor components identified from GC-EAD analyses were also synthesized for field and lab testing: two, 3,5 dimethyltridecanoic acid and 3,5 dimethylpentadecanoic acid are chain length homologs of 3,5 dimethyldecanoic acid. The remaining compound, methyl 3,5 dimethyldocecanoate, is the methyl ester of the synthetic pheromone. Objective 2: Field and lab studies demonstrate that male beetles are attracted to (3R,5S)-3,5-dimethyldodecanoic acid, but not to (3S,5R)-3,5-dimethyldodecanoic acid, indicating that the (3R,5S) enantiomer is the active pheromone component. The (3R,5R)- and (3S,5S)-enantiomers were excluded from consideration because their gas chromatography retention times were different from that of the insect-produced compound. The mixture of four stereoisomers of 3,5-dimethyldodecanoic acid was as attractive as the pure (3R,5S)-enantiomer, indicating that none of the other three stereoisomers antagonized the active enantiomer. Beetles responded to as little as 10 ng and 10 ug of synthetic 3,5-dimethyldodecanoic acid in laboratory and field studies, respectively. Field studies indicated that capture rate did not increase with dosages of 3,5-dimethyldodecanoic acid that were greater than 100 ug. Minor components show little to no activity to males in the presence of (3R,5S)-3,5-dimethyldodecanoic acid. In the absence of the synthetic pheromone, 3,5 dimethyldocecanoate is moderately attractive to males. Recapture of marked male beetles to 1 mg lures containing synthetic pheromone decrease sharply with distance and was 5% or less at 800-1000 ft from traps. The number of males captured at traps baited with live females or to lures baited with 0.1 mg of synthetic pheromone was significantly reduced when these traps were surrounded similar lure-baited traps or by lures alone than when surrounded by traps baited with control lures or by control lures alone. These results indicate that the synthetic pheromone has excellent potential for managing P. californicus in hop. Objective 3: Field bioassays conducted in southern California captured males of a congeneric species, P. lecontei, but that species was not captured in Idaho. Additional field bioassays captured Prionus congeners in North America, (Georgia (P. laticollis, P. imbricornis), Idaho (P. integer), Arizona (P. linseleyi) and Northern Mexico (P. aztecus)), and Western Europe (P. coriarius) Objective 4: Pheromone synthesis technology and pheromone activity information has been released. To date at least two pheromone manufacturing companies are testing synthetic pheromone in commercial lures towards release in grower fields for managing P. californicus in hop. PARTICIPANTS: Individuals: James D. Barbour (PI), Jocelyn G. Millar (PI), and Lawrence M. Hanks (PI), Diane Alston (collaborator), James Dutcher (collaborator) Organizations: Idaho Hop Commission, Washington Hop Commission, Hop Research Council University of Idaho University of California, Davis, University of Illinois University of Georgia Utah State University TARGET AUDIENCES: The audiences for this project are hop growers and pricvate and public scientists working in cerambycid mating behavior, and pheromone production PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
This research documents the identification and development of a synthetic volatile sex pheromone of P. californicus. Experiments conducted to date indicate that the compound ise potentially useful when incorporated into an IPM program for this pest using mating disruption or mass trapping. Prionus californicus is one of the most destructive pests of hops in the Pacific Northwest. Currently there are no effective strategies for managing this pest in hops. Thie pheromone appears to have significant potential for managing P. californicus in apples, cherries, and other orchard crops of which it is a pest, and managing the congeners P. imbricorni and P. laticollis in apples and pecans. It also may have application monitoring for rare and endangered Prionus species in N. America and Europe.
- E. C. Maki, J. G. Millar, J. Rodstein, L. M. Hanks and J. D. Barbour. 2011. An Evaluation of Mass Trapping and Mating Disruption for Managing Prionus californicus (Coleoptera: Cerambycidae) in Hop Production Yards. J. Econ. Entomol. Submitted .
- E. C. Maki, J. G. Millar, J. Rodstein, L. M. Hanks and J. D. Barbour. 2011. Attraction of Male Prionus californicus (Coleoptera: Cerambycidae) to Non-Pheromone Compounds from Ovipositor Extracts. J. Econ. Entomol. Submitted.
- J. D. Barbour, J. G. Millar, J. Rodstein, A. M. Ray, D. G. Alston, M. Rejzek, J. D. Dutcher, and L. M. Hanks. 2011. Pheromones of North American and European Prionus species (Coleoptera: Cerambycidae) appear to be highly conserved: attraction of multiple species to 3,5-dimethyldodecanoic acid, the sex pheromone of Prionus californicus Motschulsky. J. of Insect Behavior. Submitted
- J. Millar, J. D. Barbour, J. Rodstein, J. Steven McElfresh, I. M.Wright, K. S. Barbour, A. M. Ray, and L. M. Hanks. 2011. Field evaluation of synthetic female-produced sex pheromone of the cerambycid beetle Prionus californicus. J. Chem. Ecol. Submitted.
Progress 08/15/08 to 08/14/09
OUTPUTS: Several experiments were conducted characterizing the activity of the synthetic pheromone for Prionus californicus, including recapture rate of marked males over distance, relative response of male beetles to minor pheromone components, evaluation of trap types for beetle capture and initial experiments evaluating pheromone efficacy for mass trapping and mating disruption. Results were dessiminated in peer-reviewed pulications at professional meetings attend by research peers and at research reports and field tours attended by hop industry personnel. PARTICIPANTS: Individuals: James D. Barbour (PI), Jocelyn G. Millar (PI), and Lawrence M. Hanks (PI), Diane Alston (collablrator), James Durcher (collaborator) Organizations: Idaho Hop Commission, Whashington Hop Commission, Hop Research Council TARGET AUDIENCES: The audiences for this project are hop growers and scientists working in cerambycid mating behavior, and pheromone production. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period
Recapture of marked male beetles to 1 mg lures containing synthetic pheromone decrease sharply with distance and was 5% or less at 800-1000 ft from traps. Although there was some respnse to minor pheromone components, this response was generaly small in the presence of the major pheromone component. The number of males captured at traps baited with live females or to lures baited with 0.1 mg of sythetic pheromone was significantly reduced when these traps were surrounded similar lure-baited traps or by lures alone than when surounded by traps baited with control lures or by control lures alone. These reults inidcate that the synthetic pheromone has excellent potential for managing P. californicus in hop.
- Rodstein, J., Millar, J. G., J. J.D, Barbour J. S. McElfresh, A.M. Ray and Lawrence M. Hanks. 2009. Identification of Female-Produced Sex Pheromone of the Primitive Longhorned Beetle Prionus californicus. J. Chem. Ecol. (in press)