Optimisation of the pheromone blend of the swede midge, Contarinia nasturtii, for monitoring.
BACKGROUND
The swede midge, Contarinia nasturtii Kieffer, is a serious pest in crucifers. Its pheromone is a blend of (2S,9S)-diacetoxyundecane, (2S,10S)-diacetoxyundecane and (2S)-acetoxyundecane. The pheromone is used in monitoring traps, and this study examines possible ways to optimise the traps.


RESULTS
Two dispenser types were compared: polyethylene dispensers and cotton dispensers. Polyethylene dispensers attracted male C. nasturtii for more than 6 weeks, whereas cotton dispensers were attractive for only 2 weeks. All three pheromone components were important for attraction of male midges in the field. The importance of the stereoisomeric compositions of the pheromone compounds was also tested-both in the wind tunnel and in the field. In the case of 2,9-diacetoxyundecane and 2-acetoxyundecane, the non-natural stereoisomers did not inhibit male C. nasturtii attraction, whereas one or both of the stereoisomers of 2,10-diacetoxyundecane did.


CONCLUSIONS
Pheromone traps with the synthetic pheromone in a 1:2:0.02 ratio emitted from PE dispensers were highly effective and long lasting. As the mixture of stereoisomers of 2,10-diacetoxyundecane strongly inhibited attraction of male C. nasturtii while those of 2,9-diacetoxyundecane and 2-acetoxyundecane did not have any inhibitory effect, it is possible to produce traps that are effective and long lasting but cheaper to produce and maintain.
Boddum
Tina
T
Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden. tina.boddum@ltj.slu.se
Skals
Niels
N
Wirén
Marit
M
Baur
Robert
R
Rauscher
Stefan
S
Hillbur
Ylva
Y
D000818:Animals; D032561:Cotton Fiber; D004175:Diptera / Q000187:drug effects*; D005260:Female; D008297:Male; D010571:Pest Control / Q000191:economics / Q000379:methods*; D010675:Pheromones / Q000737:chemistry* / Q000494:pharmacology*; D020959:Polyethylene / Q000737:chemistry; D013237:Stereoisomerism
D010675:Pheromones; D020959:Polyethylene