|
Introduction
Although the melon fly (Dacus cucurbitae Coq.) is not known
to occur on the mainland of the United States, it is found in Hawaii
and in many other parts of the world. On several occassions, this
economically serious pest has been intercepted at ports of entry.
With increasing travel and foreign trade, the possibility of accidentally
importing the melon fly from Hawaii or elsewhere is a matter of
continuing concern to the agricultural community. A more effective
lure is needed to detect quickly any flies that may gain entry and
become established. Such a lure should be highly specific, attractive
over great distances, and, if possible, long lasting. Should an
infestation become established, the lure would be invaluable in
guiding eradication operations by indicating where and when insecticides
should be applied. In just this way, attractants aided in the rapid
elimination of the Mediterranean fruit fly [Ceratitis capitata].
In 1957, Barthel and coworkers reported that anisylacetone was
an effective lure for the melon fly. In the search for better lures,
compounds related to anisylacetone were synthesized. Several of
the them, particularly Cuelure [4-(p-acetoxyphenyl)-2-butanone],
were not only much more potent than anisylacetone, but also attractive
to newly emerged flies. Under optimum Hawaiian conditions, anisylacetone
does not attract male melon flies until about 7 days after they
emerge from pupation, and then only after they approach or attain
sexual maturity. The search for an effective melon fly lure has
been based on the same empirical approach that has resulted in the
discovery of new insecticides, pharmaceuticals, and a host of other
physiologically active substances. Briefly, many types of compounds
were screened, and the structures of those exhibiting the greatest
attraction were modified further to increase attractiveness. The
finding of cuelure, the most effective attractant in this study,
illustrated the value of volume screening as a means of discovering
new insect lures.
|
