为了研究黑龙江省兰西县苜蓿田害虫群落的组成及危害情况,试验随机选取样本点,对兰西县人工种植苜蓿田害虫进行调查和采集,并进行分类、鉴定和统计分析。结果表明:采集的24 457头害虫隶属于6目14科14种,其中害虫群落以同翅目、直翅目和鞘翅目种类较多,优势种群是大青叶蝉、蚜虫、蓟马、黄胫小车蝗和盲蝽;群落的丰富度指数和多样性指数在6月末最高,此时害虫种类最多。 In order to study the composition and the damage of the pest community in alfalfa field in Lanxi County, Heilongjiang Province, the sampling points were selected at random to investigate and collect alfalfa pests cultivated in Lanxi County. The pests were classified, identified and statistically analyzed. The results showed that there were 14 457 pests belonging to 6 orders, 14 families and 14 species. Among them, there were more Homoptera, Orthoptera and Coleoptera in the pest community, and the dominant species were leafhopper, aphid, thrips, yellow Tibia locust and Apodemus agrarius. Community richness index and diversity index were the highest at the end of June, with the largest number of pest species.