Document Type

Dissertation

Date of Award

1977

Keywords

Pheromones, Insect sex attractants

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Philip J. Kocienski

Second Advisor

Bruce E. Norcross

Third Advisor

Julian Shepherd

Abstract

“Investigations of biologists and chemists have established the importance and complexity of chemosensory communication amongst many marine and land animals” (D. A. Evans & C. L. Green, Chem. Soc. Rev., 2, p. 75). “To date literally hundreds of pheromonal interactions have been demonstrated or implicated in organisms as diverse as rodents, coelenterates, …” (J. G. MacConnell, R. M. Silverstein, Angew. Chem. Internat. Edit., 12, p. 644). The insect kingdom has been the subject of the most intense work and it has now been revealed that many facets of insect behavior are governed by chemical stimuli.

The name “pheromone” is derived from the Greek pherein (to bear, transmit) and hormon (impel, excite). Karlson and Butenandt, in 1959, proposed the term “pheromone” for “substances which are secreted to the outside by an individual and received by a second individual of the same species in which they release a specific reaction, for example, a definite behavior or a developmental process.” Wilson, in a review, described two classes of pheromones and related stimuli, those termed ‘releasers’ and ‘primers,’ in which the releaser pheromone elicits an immediate behavioral response upon reception, and the primer pheromone causes physiological changes which ultimately result in a behavioral response.

A sex pheromone was defined by Green as a substance secreted externally by an adult insect to attract, over a distance, the opposite sex of the same species. “This method of intra-species communication over a distance may be vital for the species survival of low density populations of some non-social insects” (Evans & Green, p. 75). Thus, many of these substances are effective at very low concentrations. Generally, an insect sex pheromone may consist of one or more components secreted by the virgin adult which induces copulatory movements over a short time range, “and in species where mating occurs only once, pheromone production ceases after copulation” (ibid.). It has been shown that the female of the species is responsible for sex pheromone production, although exceptions are known, where male pheromones were reported to perform “the dual role of attraction of females over a distance and provision of a stimulus at short range for copulation” (ibid.).

The current outcry over indiscriminate use of insecticides has provided motivation for vigorous research into field applications of sex pheromones to control insect pests. The intellectual stimulus afforded in the synthesis of sex pheromones provided the ‘motivation for our interest, and coupled with the demand for these compounds by field workers, provided our efforts with the proper sense of urgency.

Specifically, our goal was the preparation of sex pheromones whose demand by field workers was well documented. The efforts that comprised this thesis were directed towards the synthesis of these insect sex pheromones. The first, the sex pheromone of the Douglas Fir Tussock Moth Orgyia pseudotsugata, was prepared with the hope that appropriately situated lures containing the pheromone could be employed to control the defoliation of fir forests in western North America. The second pheromone, the sex pheromone of the smaller European dried bean beetle, Acanthoscelides obtectus (Say), was rare in insect pheromone chemistry in that it was produced by the male of the species (vide supra), and unique in that it was the first known naturally occurring allenic sex pheromone. The third, and final system investigated was one of the components of the aggregation sex pheromone of the European Elm bark beetle, Scolytus Multistriatus (Marsham), the latter of which is the principal vector of Dutch Elm disease in the northeast United States. Similarly, appropriately baited lures containing this pheromone and its other constituents could enable control of this insect pest on a large scale.

Download

Share

COinS