Recipient Organization
COL OF ENVIRON SCI & FORESTRY
(N/A)
SYRACUSE,NY 13210
Performing Department
FACULTY OF CHEMISTRY
Non Technical Summary
Over the past several decades it has been firmly established that the primary mechanism of communication among insects involves chemical compounds called pheromones. Although these molecules are generally released by insects in very low concentrations, they play a vital role in mating and other functions. Once a pheromone is isolated and its chemical structure elucidated, synthetic analogs can be used to control the mating behavior of specific insects. To exploit pheromones in pest management, it is necessary to incorporate these synthetic analogs into a controlled release device from which they can evaporate slowly at a rate similar to the natural emission of female insects. If sufficient pheromone sources are distributed in the environment, male insects become confused and cannot find mates. In this study, we will develop micron sized control release particles that can be sprinkled in orchards and forests to control several agricultural pests including the codling
and gypsy moths. These micro-dispensers will have several advantages over existing controlled release devices: they will be relatively inexpensive, easy to implement in the field and they will be biodegradable. This study will also investigate, from a fundamental molecular perspective, how pheromones diffuse through solid matrices and how they evaporate into the atmosphere. It is anticipated that a model can be generated using "Neural Networks" that predicts the release rate of pheromones from relatively simple physical and chemical measurements.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Goals / Objectives
1. This study will focus on the fabrication and characterization of novel micron-sized particles containing the insect pheromones disparlure (cis-7,8-epoxy-2-methyloctadecane) and codlemone (trans,trans-8,10-dodecadien-1-ol). These molecules are known to be effective in mating disruption for the gypsy and codling moths, respectively. In the case of disparlure, the (+)-isomer is known to be most effective but we will conduct preliminary experiments with a racemic blend as well as model compounds to minimize costs. Micron-sized microcrystalline cellulose (MMC), zeolite and glass microsphere particles will be evaluated as substrates to which pheromones will be adsorbed. These particles will then be coated with biodegradable polymers and gels to create a controlled release barrier. 2. Particle fabrication will then be followed by an analysis of the release kinetics of the pheromones (and model compounds) into the atmosphere using "aeration" procedures and instrumental
methods including Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). This will include a study of pheromone diffusion within the device and a systematic evaluation of how atmospheric release rates are influenced by initial pheromone concentration, temperature, air flow rate (wind), and device engineering factors such as substrate and coating type, particle size, coating thickness, etc. It is anticipated that various Nuclear Magnetic Resonance spectroscopy (NMR) techniques (including CP/MAS and DOSY) will be used to characterize, on a molecular scale, the morphology of the substrate and coating materials while also measuring pheromone diffusion rate within a solid matrix. 3. Finally, we plan to exploit the power of a Neural Network modeling package to develop a computational tool enabling the release rate of pheromones to be predicted from the fundamental physical and chemical properties of the controlled release device. It should be noted, however, that we
do not plan to conduct any laboratory or field tests involving actual insect pests, since the fica of both disparlure and codlemone is already well established. We will conclusively demonstrate, however, that the level of pheromone released from our dispensers is appropriate for their ultimate application based on the field data accumulated by others. Also, in the later phases of this program, we hope to identify suitable partners to expedite the commercialization of this technology.
Project Methods
Over the past several decades it has been firmly established that the primary mechanism of communication among insects involves chemical compounds called pheromones. Although these molecules are generally released by insects in very low concentrations, they play a vital role in the mating process and other functions. Mating disruption makes use of an insect's sex pheromone that usually guides a male to a female for mating. This strategy focuses on creating sufficient point sources of volatilized pheromone in the area requiring protection so that males become confused and cannot find mates. Field application of this method has proved successful against a variety of forest and orchard pests including the gypsy and codling moths. Based on the low level of pheromone required to elicit a biological response and the high cost of synthesizing or isolating these molecules, controlled relcase strategies are an essential part of their application. "Controlled release" has been
defined as "the permeation-moderated transfer of an active material from a reservoir to a target surface to maintain a predetermined concentration or emission level for a specific time". Although mating disruption devices for forest and orchard pests are available commercially, these products suffer from a number of inherent limitations: 1) The concentration of active ingredient falls off rapidly with distance from the device and efficacy is assured only for relatively localized attraction. 2) The devices are expensive, time consuming to fabricate, and are not amenable to mass production. 3) Implementation in the field is manpower intensive and placing dispensers in the tree canopy, where they are most effective, is frequently difficult. 4) The device "packaging" is not biodegradable or environmentally benign and can accumulate over time. The approach to be taken in this study is to fabricate and characterize micron-sized particles as vehicles for the application of insect pheromones.
Specific phenocopies will be immobilized on a porous, biodegradable or environmentally benign substrate coated with a biodegradable polymer film membrane. It is envisioned that the pheromone-containing particles could be widely applied from airplanes or through conventional ground-based spraying equipment. We also plan to study the kinetics of pheromone diffusion within the substrates and membrane coatings using NMR techniques while evaluating the thermodynamics and kinetics of pheromone volatilization using several instrumental methods. Coupled with evaporation rate data from "aeration" experiments, such characterization will enable us to generate a release rate model using Neural Networks based on fundamental molecular parameters such as pheromone polarity or hydrophobicity, molecular weight, matrix diffusion rate, heat of vaporization, etc. The development of a "predictive" tool will provide benefits that transcend the fabrication of microparticles for the specific insects
mentioned above.