Microparticle Dispensers for the Controlled Release of Insect Pheromones

• Published in: Journal of agricultural and food chemistry 2004-04, Vol.52 (8), p.2301-2308
• Main Authors: Stipanovic, Arthur J, Hennessy, Patrick J, Webster, Francis X, Takahashi, Yae
• Format: Article
• Language: English
• Subjects: 1,2-epoxyoctadecane; 1-dodecanol; alcohols; alkanes; Alkanes - administration & dosage; analytical methods; Animals; Biological and medical sciences; codlemone; Control; Cydia pomonella; disparlure; Dodecanol - administration & dosage; Dodecanol - analogs & derivatives; encapsulation; evaporation; Fundamental and applied biological sciences. Psychology; insect control; insect pests; Integrated pest control; Lymantria dispar; mating disruption; Microspheres; Moths; Pest Control, Biological - instrumentation; pheromones; Pheromones - administration & dosage; Phytopathology. Animal pests. Plant and forest protection; plant pests; polymers; Protozoa. Invertebrates; thermogravimetric analysis; volatilization
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf0352576

The potential utility of micrometer-sized particles as controlled-release devices for the volatilization of insect pheromones for mating disruption applications is evaluated in this study for two pheromone/model compound systems (codlemone/1-dodecanol and disparlure/1,2-epoxyoctadecane). To expedite the measurement of release rates from these particle devices, two techniques based on thermogravimetric analysis (TGA) have been exploited:  isothermal TGA (I-TGA) at elevated temperatures (40−80 °C) with N2 convection and volatilization temperature (VT) by dynamic TGA. A correlation between these two methods has been established. Samples that exhibit a higher VT provide a lower release rate from a particle substrate. Using these techniques, it has been demonstrated that chemical interactions between adsorbed liquids and particle surfaces may play a small role in defining release characteristics under conditions of low surface area, whereas parameters associated with total surface area and micropore structure appear to be much more significant in retarding evaporation for uncoated particles containing an adsorbed liquid. Additional regulation of release rates was achieved by coating the particle systems with water-soluble or water-dispersible polymers. By careful selection of particle porosity and coating composition, it is envisioned that the evaporation rate of pheromones can be tailored to specific insect control applications. Keywords: Pheromones; controlled release; gypsy moth; codling moth; microparticles; codlemone; disparlure; thermogravimetric analysis; TGA