南京地区棉蚜的飞行活动节律及其飞行能力

昆虫的飞行活动规律及飞行能力是研究其能否迁飞的基础。通过采用春季到秋季20 m高空黄盆诱蚜、高空所诱蚜和春季木槿树上有翅蚜的卵巢解剖，以及春夏秋三季田间有翅蚜的吊飞试验等方法，研究了南京地区棉蚜Aphis gossypii的飞行活动节律和飞行能力。结果表明，有翅棉蚜的日羽化高峰出现在19:00～20:00。2001年南京地区棉蚜的春、秋两季迁飞高峰分别在5月8日和10月25日。5月份高空诱集的棉蚜中，95.7%个体的卵巢小管数在7条以下，而木槿上羽化后1天的有翅蚜中有35.2%个体的卵巢小管数在7条以上；高空诱蚜和木槿上蚜的平均卵巢小管数存在极显著差异，分别为3.94±1.65和5.88±1.92。8月中下旬棉田棉蚜存在低空飞行行为，并且出现飞行高峰时有翅蚜的卵巢小管数平均在6条以下，超过6条则停止飞行。羽化后1～2天有翅棉蚜吊飞个体的飞行比率和平均飞行距离表现为春、秋季显著大于夏季，三季的最长飞行距离分别为3.89 km、6.15 km和1.44 km。

Flight activity rhythm of the cotton aphid, Aphis gossypii Glover in Nanjing and its flight capacity

Understanding flight behavior is basic to the study of insect migration. We investigated the flight activity and capacity of the cotton aphid, Aphis gossypii, in Nanjing, Jiangsu Province. Insects were captured using yellow basin traps placed on the top of a 20 m high building. Ovaries of trapped females were dissected and aphids collected from Hibiscus syriacus trees for tethered flight tests In spring, summer and autumn. The results show that the daily emergence peaks of alates occurred between 19:00 and 20:00.There were two migration peaks, occurring on 8 May and 25 October in 2001. 95.7% of female aphids trapped in basin traps in May had < 7 ovarioles. However, 35.2% of alate aphids captured on H. Syriacus had > 7 ovarioles. The average number of ovarioles in alate aphidstrapped in basin traps (3.94±1.65) and on H. syriacus trees (5.88±1.92) were significantly different. In cotton fields, alate aphids flying low in the sky were observed from middle to late August, 2001 These had < 6 ovarioles. Flight behaviour was not observed in aphids with > 6 ovarioles. The flight capacity of cotton aphids was measured using tethered flight tests. The results show that the flying rate and the average flight distance were greater in spring and autumn than in summer. Maximum flight distances in spring, summer and autumn were 3.89 km, 1.44 km and 6.15 km, respectively.