Study On The Interspecific Competition Mechanism Between Grapholitha Molesta And Cydia Pomonella

The planting area of fragrant pear,apple and peach in Xinjiang is large,and the occurrence of Grapholitha molesta and Cydia pomonella is also very serious.The G.molesta and C.pomonella are the two main kinds of fruit borers in fruit trees.They mainly feed on the fruit by hatching the larvae,which causes serious economic losses to the quality and yield of the fruit.The oriental G.molesta and C.pomonella are mixed in the orchard and have the same niche.Mixing occurs in many mixed orchards.Every year,Xinjiang is an important forest and fruit base because of the harm of the G.molesta and C.pomonella.The cultivation area of fruit trees is very large,and the economic loss caused by the harm of the G.molesta and C.pomonella is huge.It brings huge loss to the quality and yield of apple,pear and peach.Based on the systematic field investigation and the results of previous studies,the external factors affecting the population number of the two pests were evaluated by studying the key factors of resource competitiveness(food),adaptability of environmental conditions and adaptation strategies of different types of pesticides.Furthermore,the order of occupation of food resources and reproduction were proposed.The population competition and substitution of two pests were studied from the perspective of interference,and the interaction effect between two and three kinds of insectivores was mainly explored to study the interspecific competition between the two kinds of insectivores,in order to reveal the law of the competition and substitution mechanism and the internal key influencing factors between the two kinds of insectivores.The specific research results are as follows:1.Population dynamics of the G.molesta and C.pomonella in different orchards.The results showed that: G.molesta bugs were the dominant population in peach orchard,and C.pomonella were more numerous in apple orchards,and they alternated with G.molesta.Occurrence time of G.molesta in Shihezi,Xinjiang is from April to August,and G.molesta can occur in 3 generations in a year.C.pomonella occur from late April to September in one year,with 3 generations occurring throughout the year.The G.molesta appears earlier than the C.pomonella every year,and the C.pomonella survives longer than the G.molesta.2.The effects of temperature on the growth and development of the G.molesta and the C.pomonell have been studied.Research result: The growth rate of G.molesta is constantly increasing between 22-34 ℃.At 25 ℃,the net reproductive rate of G.molesta is at the maximum;when the temperature was over 31 ℃,the growth and development time of C.pomonella was prolonged,.At 28 ℃,the net reproductive rate is the largest;in the temperature range of 22-34 ℃,the growth of G.molesta is faster than that of C.pomonella,and the main generation time is less than that of C.pomonella.The results showed that temperature can inhibit the development of C.pomonella,but has little effect on the G.molesta.3.The growth and development of G.molesta and C.pomonella in different hosts and at different densities are significantly different: The populations of G.molesta and C.pomonella feeding on 7401 have shorter growth and development time and faster development than those on Red Fuji With the increase of population density,the growth and development time of the two kinds of carnivorous worms decreased.The development time of the C.pomonella population was longer than that of the G.molesta.4.The experiment of interaction between the population of G.molesta and C.pomonella.The results showed that the number of eggs,pupae and adults in the G.molesta and C.pomonella mixed population were significantly smaller than that in the individual population.With the increase of population density,the number of adult adults of G.molesta was significantly more than that of C.pomonella.It shows that the competition between G.molesta and C.pomonella is fierce.Under certain circumstances and food resources,G.molesta dominates the competition.5.Effect of the damage by G.molesta and C.pomonella on their host plant defensive enzyme activity.The results showed that the protein content,SOD activity,POD activity and CAT activity of the host fruits increased after being harmed by the heartworm.There were no significant differences in protein content,SOD activity,POD activity,and CAT activity in the host when G.molesta and C.pomonella were fed separately.However,the activity of defensive enzymes in the host was significantly higher than that in the feeding alone(P <0.05).6.Studies on the suitability of G.molesta and C.pomonella to different mechanisms of fungicide show that: SYP-9080,methylamino Avermectin sodium benzoate,beta cypermethrin,abamectin,nitenpyram,dipyridam,and acetamiprid to the C.pomonella was lower than that of the G.molest,This shows that the C.pomonella is more tolerant to the agent.