Pheromone systems, controlled release

C. C. Doane, Controlled-Release Devices for Pheromones. In Controlled-Release Delivery Systems for Pesticides, H. B. Scher, Ed. Dekker New York, 1999. 

Another aspect of the sex pheromone communication system concerns the endogenous signals that control pheromone production and release from the emitting insect. A number of hormones have been found to be involved in the control of pheromone production in various insect species (18). Juvenile hormone was found to induce vitellogenesis and sex pheromone production in some cockroach and beetle species. However, ecdysteroids were found to be involved in regulating reproductive processes, including vitellogenin synthesis, in dipteran species. 

A thorough understanding of the release performance of a controlled-release system under field conditions is essential, in order to have confidence that measurements of mating disruption (or trap capture) are due to biological effects of pheromone treatments and not formulation effects. 

The emission of a pheromone from a controlled-release formulation can depend on the diffusion through holes in the matrix or on the penetration of the compound through a wall or membrane by absorption, solution and diffusion (8). Thus variation in the parameters of the formulations, such as film thickness, particle size, solvent, pore dimensions, etc., alters the release rate. The design of the formulation must therefore take into account the effect of each variable on the emission rate in order to develop a system that is effective during the appropriate cycle of the target insect. 

Klassen, W. L. Rldgway, R. L. Inscoe, M. Chemical Attractants in Integrated Pest Management Programs, In "Insect Suppression Using Controlled Release Pheromone Systems", Kydonieus, A. F. and Beroza, M. Eds., CRC Press, Boca Raton, FL, In Press. 

Klassen, W. Ridgway, R.L. Inscoe, M. In "Insect Suppression with Controlled Release Pheromone Systems", Vol. 

Inscoe, M.N., In "In Insect Suppression with Controlled Release Pheromone Systems , Vol. II, Kydoneius, A.F.,... 

Development of an Aqueous-Based Controlled Release Pheromone-Pesticide System... 

The second system was developed by the Hereon Division of Health Chem Corporation and consists of a laminated plastic chip. Figure 2. The chip is composed of a pheromone saturated polymer reservoir with a semi-permeable plastic membrane on either side. The pheromone is thus released by diffusion from the reservoir through the membrane. The rate is controlled by the membrane composition and thickness(2,). The two systems are applied in a polybutene sticker to facilitate adhesion to the plant surface. 

Qulsumblng, A. R. Kydonleus, A. F., In "Insect Suppression With Controlled Release Pheromone Systems" Kydonleus, A. F.j Beroza, M., Eds. CRC Press Boca Raton FI., 1982 Vol, I, Chap. 8. 

Kydonieus, A., and Beroza, M. (1982). Pheromones and Their Use. In Insect Suppression with Controlled Release Pheromone Systems, Vol. 1, ed. A. Kydonieus and M. Beroza. Boca Raton, EL CRC Press. 

For such plumes to be created and maintained for long time periods, much work on controlled release systems in aquatic environments will be needed. In the insect world, dispensers have had to be optimized on a trial-and-error basis, based on behavioral reactions (trap catch) to various dispenser types and pheromone loading rates. Optimization has had to be assessed on a species-by-species trial system because each species has different pheromone components comprised of differing molecular weights and functionalities such as aldehydes, alcohols, and acetates. The field longevity of these same dispensers had to be similarly assessed based on trap capture levels over time. 

Kydonieus Beroza (eds.). Insect Suppression with Controlled Release Pheromone Systems, vols. I II, Boca Raton CRC-Press 1982 Nachr. Chem. Tech. Lab. 37, 478-483 (1989)" Naturwissenschaften 69,457 (1982) Planta Med. 55, 333-338 (1989) Ridgway, Silverstein Inscoe (eds.). Behavior-modifying Chemicals for Insect Management, New York Dekker 1990 "Tetrahedron 45,3233-3298(1989)... 

The first section. Bioregulation of Insect Behavior and Development, includes chapters on arthropod and insect repellents, the identification of a beetle pheromone, nonparalyzing factors fi om hymenoptera, endogenous regulation of pheromone biosynthesis and mating, and systems for controlled release of pheromones. 

The most well known commercial reservoir controlled release systems deliver hormones for contraception from hydrophobic polymers. The Norplant subcutaneous device controls the release of levonorgestrel with silicone rubber, and the Progestasert intrauterine device (lUD) releases progesterone from reservoir devices of ethylene vinyl acetate. In the field of insecticides, reservoir dispensers called BioLure were developed to provide zero-order release ofinsect pheromones to disrupt mating (Smith et al, 1983). The dispenser consists of a slab configuration with a rate-controlling membrane, with constant release described by Eq. 1. 

Smith, K. L., Baker, R. W., and Ninomiya, Y., 1983, Development of BioLure controlled release pheromone products, in Controlled Release Delivery Systems (T. J. Roseman and S. Z. Mansdoif, eds.), Marcel Dekker, New York, pp. 325-335. 

Clarification of the roles of the various components of this pheromone system will require further behavioral analyses with blends formulated to release precise ratios of components at controlled rates. 

The market for special control techniques that are appropriate for integrated pest management systems is closer to the scope of smaller companies where large-scale production facilities are not essential. Smaller companies have found unique niches in the pest management field, based often on particular expertise or experience. Controlled-release technology is an essential component for formulation and application of pheromones, therefore small companies have entered the market on the strength of this combination of expertise. Patent protection may be obtained to cover the devices and materials used to formulate pheromones, whereas the information relating to the composition of many pheromones is available in the open literature. 

Daterman, G. E., and L. L. Sower Douglas-fir tussock moth pheromone research using controlled-release systems. In Proceedings 1977 Controlled Release Pesticide Symposium. Oregon State Univ. Corvallis, Oreg. 

---