A pest management system for the southern pine beetle, Dendroctonus frontalis Zimmerman, in East Texas

Abstract

Research conducted in East Texas, where a southern pine beetle, Dendroctonus frontalis Zimmerman, outbreak has been in existence for more than a decade, was designed to answer two important ecological questions: 1) Has the use of a persistent, chlorinated hydrocarbon insecticide served to convert a periodically occurring bark beetle problem to one of chronic outbreak proportions?, and 2) Can a more biologically sound pest management system be developed by employing recently synthesized southern pine beetle population-aggregating attractants? The southern pine beetle has only a brief ambulatory period between emergence and colonization of a new host. Colonization is facilitated through pheromones released by the male and female. In addition, visual stimuli dictate the beetles' distinct preference for vertical host tree configuration. Analysis of historical records of the current outbreak revealed that more efficient application of chemical control was coincident with a higher beetle population, dispersed over a larger area each year. Insecticidal control measures are designed to control the pest beneath the bark of infested trees or during adult emergence. Studies of response behavior of parasites, predators, competitors and associates of the southern pine beetle to chemically sprayed trees showed that the recommended BHC-diesel oil solution (0.5 percent) was more detrimental to them than the target insect. Important predators are able to utilize prey produced odors to accomplish synchrony of colonization. In contrast to the southern pine beetle however, their adult life is spent outside the tree in search of mate and/or oviposition site. Eggs are deposited on the outer surface of the bark and are thus directly exposed to insecticidal application. ...