关键词: 性信息素, 异构化, 释放速率, 聚乙烯管载体, 复合橡胶载体

Abstract:

In order to develop effective lures that can uniformly and persistently release the biologically active compounds, it is necessary to evaluate the release rates and isomerizations of the active compounds in the most commonly used release substrates of polyethylene (PE) vial and gray rubber septum. In this paper, the release rates of six synthetic conjugated dienes pheromone compounds were measured by collecting volatiles released from polyethylene (PE) vials and gray rubber septum at intervals of exposure time under wind tunnels conditions. The method is involved in the passage of air over dispensers containing pheromone, and entrapment of the pheromone on Porapak Q. Desorption of the absorbents with hexane solvent is followed by quantification by Gas Chromatography (GC). The results showed that the release rates of six sex pheromones in PE vials maintained lower level in the first two weeks, then increased sharply to the maximum phase during 29-43 d, and then reduced to a lower level. However, a different release pattern was observed in the rubber dispensers. The largest release rate occurred from lure loading, and then the rate rapidly declined after 15 d, and maintained a relatively low level after 29 d. In the PE vials, the E5, Z7-dodecadien-1-ol, and its corresponding acetate and aldehyde derivatives had higher release rates than that of Z5, E7 configurations, and the release rates of alcohols and aldehydes were greater than that of acetates. During the peak release period, the release rates of sex pheromones (except Z5, E7-12:OH) from PE dispensers were significantly greater than that of rubber dispensers. The residuals of sex pheromones in rubber dispensers were significantly greater than that in PE dispensers, and the isomerization rates of sex pheromones were significantly different between the two dispensers. The variation of blend ratios in PE and rubber dispensers was determined. These shifting patterns of relative release in the two substrates could interpret the variations in relative catch of Dendrolimus spp. The effects of PE and rubber dispensers on release rate s and the isomerization are discussed.

Key words: sex pheromone, isomerization, release rate, PE vial dispenser, gray rubber dispenser