宁夏苜蓿草田主要害虫与天敌昆虫发生动态和相关性及其对气候因子的响应

Dynamic and correlation of major pests with natural enemies and response to climatic factors in alfalfa fields in Ningxia

中文关键词:苜蓿草田  害虫  天敌昆虫  昆虫多样性  气候因子  相关性

keywords:alfalfa field  pest  natural enemy  insect diversity  climatic factor  correlation

中文摘要:为探究苜蓿草田主要害虫与天敌昆虫间的关系，对宁夏回族自治区种植结构和田间管理不同的2处苜蓿草田内主要害虫以及天敌昆虫的发生动态进行调查，对天敌昆虫进行群落组成和多样性分析，并对主要害虫与天敌昆虫优势种及其与气候因子的相关性进行分析。结果显示：园林场苜蓿草田在2022年6月中旬和7月下旬害虫百枝条虫口数量达到峰值；茂盛苜蓿草田在8月11日害虫百枝条虫口数量达到峰值。园林场苜蓿草田共采集到捕食性天敌9种679头，寄生蜂38种284头；茂盛苜蓿草田共采集到捕食性天敌8种540头，寄生蜂33种122头。园林场苜蓿草田天敌昆虫的Shannon-Wiener多样性指数、Simpson优势度指数和Margalef丰富度指数均在6月最高；茂盛苜蓿草田天敌昆虫的Shannon-Wiener多样性指数、Simpson优势度指数和Pielou均匀度指数均在6月最低，Margalef丰富度指数在9月最高。在园林场苜蓿草田中豌豆蚜Acyrthosiphon pisum与多异瓢虫Hippodamia variegata正相关，在茂盛苜蓿草田中豌豆蚜与东亚小花蝽Orius sauteri和龟纹瓢虫Propylea japonica显著正相关。园林场苜蓿草田捕食性天敌优势种+常见种的数量与温度显著正相关，豌豆蚜数量与最低湿度显著负相关；茂盛苜蓿草田蓟马的数量与平均温度、最低温度显著正相关，苜蓿斑蚜Therioaphis trifolii的发生数量与最高湿度显著负相关。

Abstract:In order to investigate the relationship between major pests and natural enemies in alfalfa fields, two alfalfa fields with different field treatments in Ningxia were selected as the study sites. Field surveys were carried out by using the 100-branch method, the swept-net method and the yellow disk method to gather data on pest populations, predatory natural enemies, and parasitic wasps. The α-diversity indices of natural enemies were calculated, and correlation analyses of the pests, natural enemies and climatic factors were performed. The results showed that the 100-branch pest population density peaked in mid-June and late July 2022 in the Yuanlinchang area, while the highest total pest population was observed on August 11 in the Maosheng area. A total of 679 predatory natural enemies from nine species and 284 parasitic wasps of 38 species were collected in Yuanlinchang; 540 predatory natural enemies from eight species and 122 parasitic wasps from 33 species were collected in Maosheng. The Shannon-Wiener diversity index, Simpson dominance index and Margalef richness index of natural enemies were all highest in June,significantly higher than in April-May and July in Yuanlinchang. Conversely, in Maosheng, the Shannon-Wiener diversity index, Simpson dominance index and Pielou evenness index of natural enemies were all lowest in June. Margalef richness index was highest in September. Pea aphid Acyrthosiphon pisum was significantly positively correlated with Hippodamia variegata in Yuanlinchang, while A. pisum was significantly positively correlated with Orius sauteri, and Propylea japonica in Maosheng. Additionally, the number of dominant+common predatory natural enemies was significantly positively correlated with air temperature, while the number of pea aphids was significantly negatively correlated with the lowest air humidity in the Yuanlinchang area. The number of thrips was significantly positively correlated with the average and lowest air temperatures in the Maosheng area, and the number of alfalfa spotted aphids Therioaphis trifolii was significantly negatively correlated with the highest humidity.