Identification of host fruit volatiles from hawthorn (Crataegus spp.) attractive to hawthorn-origin Rhagoletis pomonella flies.
Solid-phase microextraction (SPME) and gas chromatography coupled with electroantennographic detection (GC-EAD) were used to identify volatile compounds from hawthorn fruit (Crataegus spp.) acting as behavioral attractants for hawthorn-infesting Rhagoletis pomonella flies. Consistent EAD activity was obtained for six chemicals: ethyl acetate (94.3%), 3-methylbutan-1-ol (4.0%), isoamyl acetate (1.5%), 4,8-dimethyl-1,3(E),7-nonatriene (0.07%), butyl hexanoate (0.01%), and dihydro-beta-ionone (0.10%). In a flight-tunnel bioassay, there was a dose-related increase in the percentage of flies flying upwind to the six-component mixture. Hawthorn-origin flies also made equivalent levels of upwind flight with the synthetic blend and an adsorbent extract of volatiles collected from whole fruit, each containing the same amount of the 3-methylbutan-1-ol compound. Significantly lower levels of upwind flight occurred to a previously identified volatile blend of ester compounds that attracts R. pomonella flies infesting domestic apples, compared with the hawthorn volatile mix. Selected subtraction assays showed further that the four-component mixture of 3-methylbutan-1-ol, 4,8-dimethyl-1,3(E),7-nonatriene, butyl hexanoate, and dihydro-beta-ionone also elicited levels of upwind flight equivalent to the six-component mix. Removal of 3-methylbutan-1-ol from the four-component blend resulted in complete loss of upwind flight behavior. Removal of dihydro-beta-ionone, 4,8-dimethyl-1,3(E),7-nonatriene, or butyl hexanoate from the four-component mixture resulted in significant decreases in the mean number of upwind flights compared to the four- or six-component mixtures.
Nojima
Satoshi
S
Department of Entomology, NYS Agricultural Experiment Station, Cornell University, Geneva, New York 14456, USA.
Linn
Charles
C
Morris
Bruce
B
Zhang
Aijun
A
Roelofs
Wendell
W
D000818:Animals; D002623:Chemistry Techniques, Analytical; D002628:Chemoreceptor Cells / Q000502:physiology; D002849:Chromatography, Gas; D027825:Crataegus / Q000737:chemistry*; D004594:Electrophysiology; D005426:Flight, Animal; D005638:Fruit / Q000737:chemistry; D010675:Pheromones / Q000737:chemistry / Q000494:pharmacology*; D033621:Tephritidae; D014835:Volatilization
D010675:Pheromones