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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Crop Bioprotection Research » Research » Publications at this Location » Publication #144462

Title: MALE-PRODUCED AGGREGATION PHEROMONE OF CARPOPHILUS SAYI, A NITIDULID VECTOR OF OAK WILT DISEASE, AND PHEROMONAL COMPARISON WITH CARPOPHILUS LUGUBRIS

Author
item Bartelt, Robert
item KYHL, JOHN
item AMBOURN, ANGIE
item JUZWIK, JENNIFER
item SEYBOLD, STEVEN

Submitted to: Agricultural and Forest Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2003
Publication Date: 4/20/2004
Citation: Bartelt, R.J., Kyhl, J.F., Ambourn, A.K., Juzwik, J., Seybold, S.J. 2004. Male-produced aggregation pheromone of Carpophilus sayi: A nitidulid vector of oak wilt disease, and pheromonal comparison with Carpophiluslugubris. Agricultural and Forest Entomology. (6):39-46.

Interpretive Summary: Oak wilt is a serious source of mortality in red oaks in the United States. The disease is caused by a fungus that can be transmitted between trees by a number of sap beetle species (nitidulids). One of these is Carpophilus sayi. Studying disease transmission by these beetles is very difficult because they are very inconspicuous in appearance and secretive in habits. A pheromone for C. sayi would be a useful and sensitive tool for studying their dispersal. Information could be readily obtained about flight times, population sizes, dispersal distances, and quantities of fungal spores on their bodies. The pheromone of C. sayi was identified in this project, and synthetic pheromone was shown to be attractive to the beetles in oak woods in Minnesota. The pheromone is chemically very similar to another that was identified previously for a closely related species, Carpophilus lugubris, and a careful chemical comparison of these pheromones was made. The pheromone is expected to be used by entomologist, plant pathologists, and land managers involved in oak wilt research.

Technical Abstract: Carpophilus sayi, a nitidulid beetle vector of the oak wilt fungus, Ceratocystis fagacearum, was shown to have a male-produced aggregation pheromone. Six male-specific compounds were identified from collections of volatiles. The two major ones were (2E,4E,6E,8E)-3,5-dimethyl-7-ethyl-2,4,6,8-undecatetraene and (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6,8-undecatetraene, in a 100:18 ratio. These compounds, in a similar ratio, were previously reported to be the pheromone of C. lugubris, a closely related species. The four minor C. sayi compounds (less than 4% as abundant as the first) and were also alkyl-branched hydrocarbons and consisted of two additional tetraenes and two trienes. A synthetic mixture of the two major compounds was significantly attractive to both sexes of C. sayi in oak woodlands in Minnesota. The pheromone was tested in combination with fermenting whole wheat bread dough (a potent synergist of nitidulid pheromones), and dough by itself served as the experimental control. The synergized pheromone has potential as a tool for monitoring or managing transmission of oak wilt. The pheromone of C. lugubris was re-examined to refine the comparison with C. sayi, and C. lugubris was found to have the same additional, minor tetraenes as C. sayi, but not the trienes.