Diversity And Temporal Patterns Of Soybean And Quinoa Insect Communities In The Yellow River Delta

Glycine max and Chenopodium quinoa,as salinity-tolerant plants,have important role in saline land improvement and efficient utilization,and are important for the optimization and adjustment of agricultural structure in the Yellow River Delta.In this study,we used the principles and methods of population ecology and community ecology to analyze the population dynamics and community characteristics of major pests and natural enemies,and clarify their temporal patterns based on the principle of optimal partitioning of ordered samples to provide scientific theoretical bases for further development of control techniques for pests on Glycine max and Chenopodium quinoa in saline lands and to guarantee green and sustainable production of Glycine max and Chenopodium quinoa.The main research results are as follows:1.There were 70 major pests and natural enemies of Glycine max fields in Yellow River Delta,belonging to 38 families.There were 49 species of pests in 2 classes,7 orders,25families,and 21 species of natural enemies in 2 classes,6 orders,13 families.There were 55main pests and natural enemies of Chenopodium quinoa,belonging to 30 families.Among them,there were 2 classes,6 orders,17 families and 34 species.There are 2 classes,6 orders,21 families and 21 species of natural enemies.2.The population dynamics of major pests and natural enemies on Glycine max and Chenopodium quinoa were investigated and analyzed.The main pests of Glycine max include Aphis craccivora,Aphis glycines,thrips,phytophagous mirids and noctuid pests.And the main natural enemies are Orius minutus,hoverflies,ladybugs,aphidiid wasps and lacewings.The main pests of Chenopodium quinoa include Hayhurstia atriplicis,Acyrthosiphon pisum,Apolygus lucorum,Adelphocoris fasciaticollis,Empoasca flavescens and thrips.The main natural enemies of pests on Chenopodium quinoa are Orius minutus,hoverflies,ladybugs,aphidiid wasps and lacewings.The time lag effect and following phenomenon between natural enemies and main pests were obvious.3.The relative abundance and dominant species of major pests and natural enemies on Glycine max and Chenopodium quinoa were analyzed.The number of plant-feeding pests and predatory natural enemies on Glycine max was the largest,accounting for 70.23%and 15.56%,respectively.The dominant pests were Aphis craccivora,Aphis glycines,Empoasca flavescens,Frankliniella intonsa and Thrips tabaci,while the dominant natural enemies were Orius minutus,Aphidius gifuensis,Apanteles ruficrus and Campoletis chlorideae.Chenopodium quinoa was mainly dominated by sucking insects and predatory natural enemies,accounting for 72.50%and 18.98%,respectively.The dominant insect species were Hayhurstia atriplicis,Acyrthosiphon pisum,Frankliniella intonsa and Thrips tabaci,and the dominant natural enemies were Orius minutus,Aphidius gifuensis and Campoletis chlorideae.4.The species richness,ecological dominance,diversity and evenness of main pest and natural enemy communities in soybean and quinoa fields were analyzed.Species richness in soybean and quinoa fields increased first and then decreased,while the trend of ecological dominance was opposite to that of diversity and evenness.5.The occurrence characteristics of pests and natural enemies on soybean and quinoa were analyzed by combining crop growth period and environmental conditions.Using the optimal temporal series segmentation method,the temporal patterns of main pest and natural enemy communities on soybean and quinoa were divided into three periods.In the first period on soybean from August 1^st to August 27^th,the dominant pests were Aphis glycines,Aphis craccivora,Thrips tabaci and Frankliniella intonsa,while the dominant natural enemies were Orius minutus,Aphidius gifuensis and Apanteles ruficrus.In the second period from September 7^th to September 27^th,the dominant pests were Empoasca flavescens,Thrips tabaci and Frankliniella intonsa,while the dominant natural enemies were Orius minutus and Apanteles ruficrus.In the third period from October 1^st to 23^rd,the dominant pests were Empoasca flavescens,Thrips tabaci and Frankliniella intonsa,while the dominant natural enemies were Orius minutus,Apanteles ruficrus and Campoletis chlorideae.During the first period on quinoa from May 11^th to May 23^rd,the dominant pests were Hayhurstia atriplicis,Acyrthosiphon pisum,Thrips tabaci and Frankliniella intonsa,and the dominant natural enemies were Orius minutus and Aphidius gifuensis.In the second period,from May 30^th to June 20^th,the dominant pests were Thrips tabaci and Frankliniella intonsa,and the dominant natural enemies were Orius minutus,Aphidius gifuensis and Campoletis chlorideae.In the third period,from June 26^th to August 1^st,the dominant pests were Thrips tabaci and Frankliniella intonsa,and the dominant natural enemies were Orius minutus and Campoletis chlorideae.