Elementary Studies On Biology Charaeteristics And Sex Pheromones Extracts Of Bradysia Difformis

Bradysia difformis Frey,1948is the main fungi pests, which has seriously threatened sustainabledevelopment of fungus industry. A systematical observation of Bradysia difformis， biologycharacteristics、emergence and mating behaviors, preliminary study on the sex pheromone withbehavior and chemical ecology method under laboratory condition. We have not found the best way tocontrol it at present. The main study results were the follows：1. Bradysia difformis occurred one generation spend20days. The developmental period ofegg3-4days,larvae11-13days, pupae2-3days and adult2-4days. The peak of female emergence from16:00to21:00and that of males from17:00to23:00, accounting for72%of the total in the lightperiod, sex ratio of is more than1.2:1(female:male) through the population. Ten minutes afteremergence, adults could copulate and keep for3minutes. Female mate only once in her life, but malehas several times.2. The biological activity tests showed that female adults and primary extract of sex pheromonefrom female abdomen were both attractive to the males（P<0.01).Sex pheromone was released byfemale.3. The sex pheromone of Bradysia difformis were analyzed by GC-MS. By comparing males thefemale abdomen extracts of hexane,methylene dichloride and isopropyl alcohol were attractive to themale, hexane should be the candidate solvents. By GC-MS，three compounds are only belonged toabdomen extracts from female. The components are as follows: Dodecane、n-Hexadecanoic acid、(Z,Z)-9,12-Octadecadienoic acid, which are the potential sex pheromone components.4. Using Y tube olfactometer, we measured the trend response of Bradysia difformis to singlesubstance, It’s found that Dodecane＞n-Hexadecanoic acid＞(Z,Z)-9,12-Octadecadienoic acid. buteffect of Dodecane+Hexadecanoic acid with a ratio of3:2was better than control.The three mixedwith a ratio of6:4:1attractive to the males but the difference was not significant.5. Field efficacy trials shows that:100μl Dodecane with a density of5.65ng/μl and Dodecane+Hexadecanoic acid+(Z,Z)-9,12-Octadecadienoic acid with a ratio of6:4:1and a density of10ng/μlwas better than control. The differences of total number is not obvious, but the number of male havesignificant difference. There was no difference between these four groups with same concentrations.