| The Chinese pine caterpillar moth, Dendrolimus tabulaeformis Tsai and Liu (Lepidoptera: Lasiocampidae) is one of the most important defoliator of coniferous trees in northern China. Its outbreak often leads to the death of enormous areas forests. The useful method to control this species is using sex pheromone traps to monitor and make mating disruption.Five components of Z5-12:OH, Z5-12:OAc, Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr were detected from the virgin pheromone glands by means of HS-SPME, SGE, derivatization, GC, GC-MS. Because the distribution coefficients in polarity and non-polarity column are different, so the average amounts of Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr per calling virgin female through HP-5MS and DB-WAX capillary column were different as well. Quantitative analyses on the DB-WAX column by HS-SPME showed that one calling virgin female contained on average0.62±0.42ng (mean±SD) of Z5,E7-12:OH,0.57±0.39ng of Z5,E7-12:OAc, and0.10±0.04ng of Z5,E7-12:OPr, corresponding to a ratio of100:91.94:16.13. Average amounts of Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr per calling virgin female were0.54±0.34ng,0.42±0.72ng, and0.23±0.33ng by SGE on DB-5MS capillary columns and in a ratio of100:90.13:57.61.The above five standand components all elicited EAD responses, with Z5,E7-12:OAc and Z5,E7-12:OH giving the largest response EAG activities (14.59±6.09mv,12.02±5.72mv(mean±D),N=25, respectively). In addition, EAG dosage and responses to Z5,E7-12:OAc was higher than others, but in the amount of10μg, the antennal responses reached saturated value. For the other four components, the responses were increased following the increasing amount between0.01μg and100μg. GC-EAD analyses of extracts by HS-SPME extracting one calling virgin female for6hours revealed the presence of the above five compounds all eliciting antennal responses. In wind tunnel bioassay, filter paper lures loaded with Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr blend in a ratio of1000:1000:44.37could elicit the complete flight behavior, and Z5,E7-12:OPr played an important role in males approaching the source and contacting source. In order to develop effective uniform lures and prolonge the release of the biologically active compounds, it is necessary to evaluate the effect of the most common substrates polyethylene (PE) and gray rubber on the release rate and isomerizaiton of the active compounds. In this paper, the release rates of nine synthetic conjugated dienes and mono-unsaturated pheromone compounds were measured by the collection of volatiles released from polyethylene (PE) vials and gray rubber septum at intervals of exposure under wind tunnel conditions. The method involved the passage of air over dispensers containing pheromone, and entrapment of the pheromone on Porapak Q. Desorption of the absorbents with hexane solvent was followed by quantification by GC. The results of release rate measurements from PE vials showed that the release rate of nine sex pheromones in PE vials maintained lower level in the first two weeks, then increased sharply to the maximum phase during29-43d, and then reduced to a lower level. However, a different release pattern was observed in the rubber dispensers. The largest release rate occurred from freshly prepared lures, and then fell rapidly to the lower level after15d, and the release rate after29d maintained lower level. In the PE vials, the E5, Z7-dodecadien-l-ol, and its corresponding acetate and aldehyde derivatives retained higher release rates than that of Z5, E7configurations, 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 between the two dispensers had significant difference. |
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