ISSN:
1573-1561
Keywords:
Carrot fly
;
Psila rosae
;
Diptera
;
Psilidae
;
host odor
;
leaf aldehydes
;
propenylbenzenes
;
trans-asarone
;
trans-methylisoeugenol
;
gas chromatography linked electroantennographic detection
;
attractants
;
field traps
;
aldehydes
;
aromatics
;
alcohols
;
terpenes
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Cold-trapped carrot leaf volatiles were analyzed by gas chro-matography with an outlet splitter to a flame ionization detector and to a carrot fly antennogram preparation as the second detector (GC-EAD). Strongest EAD responses were elicited by products whose elution temperatures corresponded to the propenylbenzenes,trans-methylisoeugenol (3,4-dimethoxy-1-propenylbenzene) andtrans-asarone (2,4,5-trimethoxy-1-propenylbenzene) and, to a lesser extent, by-products matching the elution temperatures of the leaf aldehydes hexanal, (E)-2-hexenal, and heptanal, and of the terpenes linalool and caryophyllene. The identity of the propenylbenzenes was confirmed by gas chromatography-mass spectrom-etry. GC-EAD permitted accurate estimation of the olfactory thresholds; it was lowest fortrans-asarone at 500 attogram (5 × 10−16g)/ml of air passing over the antenna. Both the leaf aldehydes and propenylbenzenes were attractive when tested individually in the field with yellow sticky traps; fly captures were linearly related to the quantity of propenylbenzenes applied per trap. A combination oftrans-asarone and hexanal was more attractive than either compound singly, suggesting that the fly is adaptively equipped to respond to a mixture of compounds emanating from carrot foliage. In laboratory choice tests, flies were more attracted by vapors from intact carrot foliage than by that from a nonhost; leaf odor alone also mediated oviposition. We conclude that through the selectivity and sensitivity of its response to foliar volatiles, the carrot fly may achieve host-plant orientation and also at close range, in union with its response to less volatile leaf surface components, selection of an oviposition site.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00987809
Permalink
