Observation of the oviposition behavior of cotton bollworm demonstrated the
existence of substances that can act as oviposition deterrents. The scales
, abdomens and tarsi of the moths, the most likely carrier, were extracted
for the substances. An acetone extract exhibiting an oviposition deterrent
effect was analyzed using gas chromatography and combined gas chromatograph
y-mass spectroscopy. Three components, 4-methyl-4-hydroxyl-pentanone-2, hex
adecanoic acid and (Z)-9-octadecenoic acid, were identified, being present
in the ratio 1:2:2. Experiments with synthetic mixtures indicated that a mi
xture of equal amounts of the two organic acids exhibited similar repellent
and deterrent activity to a synthetic mixture of all three components. It
is concluded that the natural oviposition-deterring pheromone is a mixture
of hexadecanoic acid and (Z)-9-octadecenoic acid. (C) 2001 Elsevier Science
Ltd. All rights reserved.