About Pheromones

The drawing on the left, by Peter Fluri, shows a female of the codling moth, Cydia pomonella, raising her abdomen and protruding her sex gland. She takes this calling posture for a short period in the early evening hours. Codling moth males casting through the apple orchards will eventually be caught in the plume of a calling female, get aroused and steer upwind until they find her and mate with her.

Chemistry

During the past 40 years, pheromones of hundreds of insect species have been chemically elucidated, including the sex pheromone of the codling moth. Its main component is (E,E)-8,10-dodecadien-1-ol, a primary alcohol containing a straight chain of 12 carbons and two conjugated double bonds. Other moth pheromones are hydrocarbons, epoxides, acetates or aldehydes. These molecules all vaguely resemble fatty acids, from which they are indeed biogenetically derived.

Most pheromones consist of blends of two or more chemicals which need to be emitted at exactly the right proportions to be biologically active. The female effluvia or sex gland can contain additional compounds which are related to the pheromone components and whose biological function is often unclear. On the other hand, many attractants of male moths have been discovered simply by field screening. In several cases it could later be shown that the attractant found with this technique was identical to the natural pheromone produced by the female. In most others, the composition of the true pheromone is still unknown. You can click the structural formula above to see a list of all the species for which (E,E)-8,10-dodecadien-1-ol has been reported as a pheromone or attractant component.

Use for pest control

When used in combination with traps, sex pheromones can be used to determine what insect pests are present in a crop and what plant protection measures or further investigations might be in order to assure that there will be no excessive damage to the crop. If the synthetic attractant is exceptionally seducing and the population level is very low, some control can be achieved with pheromone traps or with a technique called "attract and kill".

Generally, however, a technique called mating disruption is more effective: Synthetic pheromone is released from numerous sources placed throughout the crop to be protected; the males are then unable to locate the females and the number of matings and offsprings is reduced.

	Mating disruption is effective in:
	pink bollworm	Pectinophora gossypiella
	Oriental fruit moth	Grapholita molesta
	European grape moth	Eupoecilia ambiguella
	grapevine moth	Lobesia botrana

Mating disruption has been successful in controlling a number of insect pests. More than 20% of the grape growers in Germany and Switzerland employ this technique and produce their wine without using insecticides. If you are interested in this technique, you could look at the proceedings of conferences held by the Working Group "Use of pheromones and other semiochemicals in integrated control" of the International Organization of Biological Control (IOBC).

In this database we have included, species by species, any reports on sex pheromones and related chemicals that were thought to be of value to scientists interested in identifying Lepidoptera pheromones, studying biosynthetic pathways or using pheromones for insect monitoring and control. Not included are pheromones produced by males, such as aphrodisiacs and arrestants.

* Fluri P, Mani E, Wildbolz T & Arn H. 1974. Untersuchungen über das Paarungsverhalten des Apfelwicklers (Laspeyresia pomonella L.) und über den Einfluss von künstlichem Sexuallockstoff auf die Kopulationshäufigkeit. Mitt. Schweiz. Entomol. Ges. 47: 253-259