Population Dynamics Of The Diamondback Moth Plutella Xylostella And Overwintering In Taibai

Taibai county is located in the southeast of BaoJi, Shaanxi, in the hinterland of QinlingMountains.The county at an average altitude of1543meters, the highest altitude in all107counties of Shaanxi province. Cruciferous vegetables are the main crops in the areas,thediamondback moth is a major pest of the cruciferous vegetables,occurs in an area of36000Km2.In the ares, causing great economic losses.In this thesis,I reported what I have performed in the past years:monitored populationdynamics of the diamondback moth using sexual pheromone traps in Taibai and measuredthe local temperatures and humidities,analyzed the effect of climate factors on thediamondback moth populations.In addition to the monitoring of the diamondback mothpopulation dynamics.I also studied whether the diamondback moth could overwinter in Taibaiarea. The results are as follows：1. In Taibai,the diamondback moth was low form January until April,and then thediamondback moth population began to increase, peaked in August or September,thediamondback moth population is still high in October and November until the vegetablesharvested,farmers no longer spray insecticide.Population dynamics is consistent with the localvegetable planting season.2. The population dynamics of the diamondback moth has certain correlation with thelocal temperature.In addition,the diamondback moth population was also affected by thehumidity,cultivation and other condition.3. The local minimum temperature is about minus15℃, the maximum temperaturedifference between day and night up to25℃. The highest temperature inside the cabbagehead was lower than the highest temperature of outside and the minimum temperature ishigher than the temperature outside.The temperature difference inside the cabbage head issmaller than the air temperature difference.4. Our date showed that the diamondback moth can winter Taibai.