Abstract:

The paper investigated the constitutions of arthropod communities, the population dynamics of dominant pests and natural enemies, and their relationships in Qingdao alfalfa fields. The results showed that the arthropod communities in Qingdao alfalfa field were composed of 91 species belonging to 49 families and 13 orders, and the dominant pest insects included thrips, aphids, mirid bugs, Salebria semirubella etc; the major natural enemies included ladybirds, syrphid flies, parasitic wasps, lacewings, and spiders etc. For the main pests, aphids had two population occurrence peaks, mid-May and late-October, repectively; thrips had two peaks in early-July and early-October, respectively; S. semirubella had one peak in late-September; mirid bugs had three peaks, mid-July, early-August and late-September, respectively. For the natural enemies, ladybirds had two peaks, mid-May and mid-October; parasitic wasps had two peaks, mid-April and late-May; syrphid flies had three peaks, mid-April, early-June and mid-October, respectively; spiders had five peaks occurring in mid-May, late-June, early-August, early-September and early October, respectively. The relationships between pests and their natural enemies were analyzed using grey correlative degree analysis method and single-element regression method. The control effect of natural enemies was primarily evaluated.

Key words: Alfalfa, Arthropod, Dominant population, Dynamic, Correlationship

摘要：

本文对青岛地区苜蓿（Medicago sativa）田节肢动物群落种类、优势种田间种群动态进行了调查，分析了优势种群的田间动态规律，对主要害虫与优势天敌的相关性进行了研究。结果表明：青岛地区苜蓿田有节肢动物13目49科91种，其中主要害虫有蓟马（thrips）、蚜虫（aphids）、盲蝽（mirids）、苜蓿斑螟（Salebria semirubella）等，主要天敌有瓢虫（ladybirds）、食蚜蝇（syrphids）、寄生蜂（parasitic wasps）、草蛉（lacewings）、蜘蛛（spiders）等。蚜虫每年发生有2个高峰期，分别为5月中旬和10月下旬；蓟马在田间有2个发生高峰期，分别是7月上旬和10月上旬；苜蓿斑螟有1个高峰期是在9月下旬；盲蝽有3个高峰，分别是7月中旬、8月上旬和9月下旬。瓢虫类在田间有2个高峰期，分别是5月中旬和10月中旬；寄生蜂类有2个主要高峰期，分别是4月中旬和5月下旬；食蚜蝇类有3个高峰，分别是4月中旬、6月上旬和10月中旬；蜘蛛有5个发生高峰期，分别是5月中旬、6月下旬、8月上旬、9月上旬和10月上旬。应用灰色关联度分析方法和一元回归法探讨了天敌与害虫之间的关系，初步明确了对每类害虫有控制作用的天敌种类。

关键词: 苜蓿, 节肢动物, 优势种群, 动态, 相关性