Correlation between accessory gland condition and pheromone production by male boll weevils

摘要

Improved understanding of the dynamics of boll weevil pheromone production would facilitate ecological interpretation of weevil dispersal patterns and development of improved trapping systems. Methods for measuring pheromone production by individualmale weevils were recently developed in this laboratory. Initial observations suggested a correlation between accessory gland condition and pheromone production. A system of classifying accessory glands was devised and used in a new study to further examine this relationship. Accessory glands were divided among four classes. Class 1 and 2 glands were transparent, and class 3 and 4 glands were more translucent. Class 1 glands were smaller and less apparent than class 2 glands. Similarly, class 3 glandswere smaller than class 4 glands, which dominated the volume of the abdomen. Relationships between pheromone production and accessory gland classes were examined by analysis of variance and simple linear regression. Pheromone production varied considerably within accessory gland class, but weevils with class 3 or 4 glands produced substantial amounts of pheromone while weevils with class I or 2 glands produced little or no pheromone. Regression analyses also indicated a relationship between accessory gland condition and pheromone production. Observed relationships between gland condition and pheromone production are sufficient to permit the identification of pheromone-producing weevils from field or trap collections. This ability should be useful in field studies of the role of pheromone in the ecology and distribution of boll weevil populations.