Experience with Behavior-Modifying Chemicals for Insect Control J. W. Jenkins C.C. Doane Pest Select International Inc. 3131 North 35th Avenue Phoenix, AZ 85017 Insect behavior-modifying chemicals are being used in pest management programs in two basic ways. Indirect control of pests involves the use of baited traps for detection and monitoring of populations. Pests are controlled directly through mating disruption and by drawing adults to attractive sites where they are removed from the population, either with traps or insecticides. Recent advances in combinations of behavior-modifying chemical technology and insecticides have resulted in improved pest control. Examples of techniques for employing pheromone systems and experience with various pests are discussed. Keywords: Pheromone, mating disruption, traps, attracticide. Insects employ chemical messages to direct a wide range of behavior. Recent advances in the utilization of synthetic chemicals that affect insect behavior have spawned innovative methods for use in integrated pest management programs. Sex pheromones, intraspecific chemical messages, have been in- vestigated more than any other group of behavior-modifying chemicals. These materials mediate sexual behavior and have been used in two basic ways in the management of pests: indirect control through monitoring or surveying pest populations and direct control via mass trapping, mating disruption and attrac- ticide techniques. When employed for survey and detection, the pheromone is formulated in a lure and placed in traps. These are used to monitor the presence of the pest or fluctuations in its population level so that control measures may be applied. This technique is the most widely used application of sex pheromones and has been a common practice for many pests for more than 15 years. Although traps and lures are commercially available for many pests, considerable effort must go into their development. Each insect pest may require a distinct trap or lure system, dependent upon its biology, ethology and the chemical nature of its specific pheromone. For instance, a trap system developed for the pink bollworm, Pectinophora gossypiella Saunders, utilizes a delta trap design. For maximum efficiency the trap must be placed at the cotton canopy, the level at which mating activity occurs. Once inside the trap, the male moth is captured on the sticky lower sur- face. For many insects exact release rates of pheromone from the lure must be maintained to achieve trap capture. Lures that are too weak may not attract the target pest to the trap while lures that are too strong may halt searching behavior at some distance from the trap. Ideally, fluctuation in trap captures should be positively cor- related with pest activity and crop damage. Captures of pink bollworm males in delta traps have been positively correlated with mating activity and subsequent larval infestations (Brooks et al., 1980). This correlation allows the early prediction of popula- tion trends and improved timing for control measures. For many pests, monitoring populations with traps and lures is more effi- cient than visually searching for signs of damage (Saario et al., 1970; Kaae and Shorey, 1973). 154 A trap system developed for the boll weevil, Anthonomus grandis Boheman, takes advantage of the adults' attraction to specific wavelengths of light and their habit of climbing up upon encountering the trap. Various cotton growing areas within the United States have established trap indexes for determining the need for early season control of the boll weevil. Researchers are also developing a trap index for Heliothis spp. The unique nature of these moths requires a different trap design. After approaching the lure, the male moth flies up in an escape response. Because of the moth's size, a sticky trap would be less efficient; therefore, a live trap with sufficient capture space is needed. Also, the chemical nature of the Heliothis sex pheromone requires protection from ultraviolet light for max- imum stability. Traps and lures may also be used for direct control through the mass trapping technique. In this method those individuals re- sponding to the trap are removed from the population. The suc- cess of the technique depends upon various factors including sex and mating status of the captured insects. For maximum efficien- cy the system should remove a large proportion of reproductively active adults before mating takes place in the field. If traps remove only males from the population, a much larger propor- tion of the population must be captured, especially if multiple mating is common. Although mass trapping programs have been tried for a number of pests, they have certain limitations: the technique is less effective on moderate to heavy populations, is labor intensive and requires isolation from mated immigrants. A modification of the mass trapping technique is the use of pheromone traps to enhance the attractiveness of trap crops. A trap crop is a small portion of the principle crop that has been manipulated to provide protection for the remainder of the plan- ting. Early investigation of this method demonstrated the poten- tial for use in control of the boll weevil (Boyd, 1973; Gilliland et al., 1976). During 1983 this technique was evaluated using the boll weevil pheromone, grandlure, and cotton plant volatiles in microtube formulation. The material was applied along field borders to intercept and hold weevils as they moved into the field from overwintering sites. These zones were then repeatedly sprayed with a combination of weevil feeding stimulant and in- secticide. This treatment reduced or eliminated the need to apply PROCEEDINGS of the CARIBBEAN FOOD CROPS SOCIETY-VOL. XX