Rassoulian Gh Reza
Dept. of plant protection, Agricultural college of Karaj, University of Tehran, Karaj, Iran.
Commun Agric Appl Biol Sci. 2005;70(4):745-51.
Among alfalfa pests in Iran three aphid species, green alfalfa aphid Acyrthosiphon pisum Harris spotted alfalfa aphid Therioaphis trifolii forma maculata Buckton and blue alfalfa aphid, Acyrthosiphon kondoi Shinji are important pests. The green alfalfa aphid can be observed all along the growing season particularly from late May to mid June at Karaj climate conditions. During this period, the mean monthly maximum temperature and relative humidity were about 28 degrees C and 60-65% respectively. This aphid overwinters as nymph and viviparous female. Sexual forms and eggs could not be seen under field conditions. Spotted alfalfa aphid, Therioaphis trifolii fonna maculata is the most prevalent aphid in summer time, when the mean monthly maximum temperature and relative humidity are about 33-34 degrees C and 44-58% respectively. Sexual individuals have been observed in the laboratory but not in the field. Among predators (Coccinella septempunctata, Adonia variegata, Syrphus cinctus, S. corolae, S. grassulariae, Chrysoperla carnea and Nabis capsiformis) one coccinellid species, C. septempunctata, had greatest impact on fluctuations of population. Among hymenopterous parasitoids two species have been collected from alfalfa field they were Aphidius ervi and Praon palitans. These parasitoids destroyed a good percent of aphids and statistically proved to lower aphid populations significantly.
在伊朗的苜蓿害虫中，三种蚜虫，即苜蓿绿蚜豌豆蚜（Acyrthosiphon pisum Harris）、苜蓿斑蚜（Therioaphis trifolii forma maculata Buckton）和苜蓿蓝蚜（Acyrthosiphon kondoi Shinji）是重要害虫。在卡拉季气候条件下，整个生长季节都能观察到苜蓿绿蚜，尤其是在5月下旬至6月中旬。在此期间，月平均最高温度和相对湿度分别约为28摄氏度和60 - 65%。这种蚜虫以若虫和胎生雌蚜越冬。在田间条件下未见有性型和卵。苜蓿斑蚜是夏季最常见的蚜虫，此时月平均最高温度和相对湿度分别约为33 - 34摄氏度和44 - 58%。在实验室中观察到了有性个体，但在田间未观察到。在捕食性天敌（七星瓢虫、多异瓢虫、狭带食蚜蝇（Syrphus cinctus）、科罗拉多食蚜蝇（S. corolae）、草间小黑蛛（S. grassulariae）、大草蛉（Chrysoperla carnea）和帽翅姬蝽（Nabis capsiformis））中，一种瓢虫，即七星瓢虫，对种群数量波动的影响最大。在膜翅目寄生蜂中，从苜蓿田中采集到了两种，即豌豆蚜茧蜂（Aphidius ervi）和淡色普朗茧蜂（Praon palitans）。这些寄生蜂消灭了相当比例的蚜虫，经统计证明能显著降低蚜虫种群数量。
