Evaluation of porous silica glasses as insect pheromone dispensers

Abstract

Este trabalho demonstra a viabilidade da utilização de vidros porosos como materiais para armazenar e liberar feromônios de insetos, visando o controle de pragas na agricultura. Feromônios de diferentes insetos foram impregnados em vidros porosos do tipo Vycor (PVG), e o material impregnado foi caracterizado por espectroscopia de absorção no infravermelho. A determinação da taxa de liberação do feromônio em laboratório, bem como o teste prático de captura de insetos em diferentes plantações, foram subseqüentemente realizados. Foram realizados testes com feromônios da Grapholita molesta (Lepidoptera: Tortricidae) e Leucoptera coffeella (Lepidoptera: Lyonetiidae), as principais pestes da maçã e café, respectivamente, em plantações brasileiras. Verificou-se que a taxa de liberação do feromônio depende do tipo de interação com as paredes dos poros do PVG. Os resultados indicaram uma boa performance do PVG, semelhante à de septos de borracha utilizados comercialmente como liberadores. Estes resultados, somados ao fato de que o PVG não é nocivo ao meio ambiente e pode ser reutilizado em vários ciclos de impregnação e liberação, fazem destes vidros porosos candidatos em potencial para aplicação no controle de pragas na agricultura.This work demonstrates the viability and advantages of using porous silica glass as an insect pheromone dispenser, in order to control insect population in agriculture. Pieces of so-called Porous Vycor Glass (PVG) were impregnated with pheromones of different insects (both consisting of a single compound or a mixture of compounds). Studies were conducted to characterize the impregnated-PVG and to determine the pheromone release ratio under laboratory conditions. The practical application was verified in two different plantation areas, using the PVG impregnated with pheromone from Grapholita molesta (Lepidoptera: Tortricidae) and Leucoptera coffeella (Lepidoptera: Lyonetiidae), the main pests of apple and coffee plantations in Brazil, respectively. The release rate was dependent on the interaction between the molecules of the impregnated pheromone and the surface of the PVG pores. A good performance of the porous glass was observed, similar to that of rubber septa commercially used as pheromone dispensers.Keywords: porous glass, adsorption, pheromones, slow release, chemical ecology IntroductionThe number of insects and other species that are developing resistance to pesticides is growing steadily, forcing chemical companies to work out novel pesticide formulas. The concept of integrated pest management (IPM) was developed in response to the problems caused by the increased use of conventional pesticides. IPM combines chemical, biological, and agrotechnical approaches to achieve pest control at a reasonable cost, while minimizing damage to the environment. The first step in IPM is to perform effective monitoring through the uses of pheromones. [1][2][3] Pheromones are substances which occur in nature and are used for chemical communication between animals of the same species. The main ways by ...

Nanomaterials: A Review of Their Action and Application in Pest Management and Evaluation of DNA-Tagged Particles

“…The release rate was dependent on the interaction between the molecules of the impregnated pheromone and the surface of the PVG pores. A good performance of the porous glass was observed, similar to that of rubber septa commercially used as pheromone dispensers (Aline Tiboni et al 2008).…”

“…The commercially available dispensers are mainly made from different kinds of polymers. Among several kinds of silica-based porous glasses, porous vycor glass (PVG) is a commercial transparent porous material obtained by acid leaching of a phase-separated alkaline borosilicate glass (Aline Tiboni et al 2008). The soluble borate phase is dissolved, leaving an open porous structure of essentially pure silica with interconnecting pores, a narrow pore size distribution, and a pore volume of nearly 28 %.…”

“…The nanometric pores in PVG have been used to incorporate several compounds (conducting polymers, oxides, semiconductors, amorphous carbon, and carbon nanotubes), with the purpose of obtaining novel functional nanocomposite materials. PVG was impregnated with pheromones of Grapholita molesta (Lepidoptera: Tortricidae) and Leucoptera coffeella (Lepidoptera: Lyonetiidae), the main pests of apple and coffee plantations in Brazil, respectively (Aline Tiboni et al 2008). The release rate was dependent on the interaction between the molecules of the impregnated pheromone and the surface of the PVG pores.…”

Monitoramento do percevejo marrom Euschistus heros (Hemiptera: Pentatomidae) por feromônio sexual em lavoura de soja

“…Tiboni et al (2008), ao comparar a liberação de feromônio em septos de borracha com vidro poroso do tipo Vycor (PVG), observaram que o PVG apresentou liberação mais estável, enquanto o septo de borracha apresentou grandes flutuações de liberação do feromônio. Além disso, Borges et al (2011), ao avaliar a taxa de liberação de lures (Fuji Flavor Co. Ltd., Tóquio, Japão) contendo 1,0 mg do feromônio do percevejo E. heros, relataram taxa de liberação com baixa variabilidade ao longo de 63 dias.…”

Physicochemical Properties and Field Evaluation of Monolithic Wax Formulations for the Controlled Release of a Forest Pest Pheromone

“…They also found that depletion of pheromone components from the polyvinyl chloride-resin formulations was characterized by the exponential equation y = ae -bt , where y is the pheromone percent remaining, t is the time (days), e is the base natural of logarithms, and a and b are constants. Tiboni et al 23 used silica porous glass as an insect pheromone dispenser and impregnated this material with different kind of insect's pheromones. They evaluated these silica porous glass dispensers in field obtaining good results, releasing a concentration of active agent of approximately 20 µg per day during 20 days.…”