| Tribolium castaneum(Herbst)is an important secondary stored grain pest.At present,the primary method for controlling Tribolium castaneumis phosphine fumigation.As long-term excessive and single use of PH3 to control red cockroaches,it has developed resistance to phosphine.The biological control technology combining insect pheromones with trapping equipment has become the focus of researches in the grain storage field.In this paper,we analyzed the differences of pheromone secretion and dose response between phosphine-resistant and sensitive insects.We studied on three different Tribolium castaneum phosphine-resistant populations.We tested the resistance of two populations by FAO assay.We used GC-MS to determinate the pheromone eluents or extracts extracted by headspace continuous gas flow collection and organic solvent extraction,comparing its pheromone type and relative content;Confirming the best trapping dose for different populations of Tribolium castaneum through cross-trapping test.The main research findings were below:(1)Determination of phosphine-resistant virulence of the Tribolium castaneum populations in Hainan and Guangdong,the results showed that both populations belonged to phosphine-sensitive populations,its LC50 is 0.0265mg/L and 0.0086mg/L,respectively,provided by Professor Lu Yujie from Henan University of Technology,the phosphine-resistance is 55.5 times,which is a medium-high resistance.(2)The pheromone eluent collected by the headspace continuous gas flow and the extract extracted by the organic solvent extraction method can be detected by GC-MS,can detect 4,8-dimethyldecanal and 1-pentadecenene which have been confirmed to be pheromone aggregations.The relative content of the two aggregation pheromones in the pheromone extract is higher than that of the pheromone eluent,and other new chemicals are also detected.The headspace gas flow collection method is easy to mix with pollutants,and needed a large number of insects,the methylene chloride is volatile,the concentration of the extract is unstable.Therefore,the hexane extraction method is used to extract the pheromone of different populations of insects.(3)We used GC-MS to detect the pheromone in three populations of Tribolium castaneum extracted by n-hexane extraction,there are 4,8-dinmethyldecanal and 1-pentadecene in it.However,the relative content of sensitive populations is higher than that of resistant populations,and the sensitive populations of group 1and group 2 are 3 times and 2.5 times that of resistant population(group 3),respectively.Compared with two sensitive populations,two unknown compounds(1,3-diisopropylnaphthalene and 2,4-disopropylnaphthalene)appeared in the pheromone extract of the resistant population.(4)The cross-trapping test showed that there was no significant difference between sensitive populations.The optimal trapping dose was 45 pL.The trapping rate of the trapping of sensitive populations is much lower than that of sensitive populations.The relative content of 4,8-dimethyldecanal in the n-hexane extract of the resistant population became lower,which further indicated that the secretion and dose effect of aggregation pheromones in phosphatide-resistant population changed.When we use the aggregation pheromone to monitor the number of insects in the granary,the level of phosphatide resistance in the pool should be investigated,so that the dose of the aggregation pheromone can be correctly.In order to prove the changes of pheromone secretion and dose response of the phosphatide-resistant populations,the following studies will be conducted:(1)whether the trapping resistant population is completely invalid or the reaction dose using 4,8-dimethylfurfural;(2)Purification of the new compounds 1,3-diisopropylnaphthalene and 2,4-diisopropylnaphthalene in the antagonistic population for bioassay to determine whether they are new pheromones in resistant populations. |
