异色瓢虫和多异瓢虫对两种色型豌豆蚜的捕食偏好研究

Study on predation preference of Harmonia axyridis(Pallas) and Adonia variegata(Goeze) on red and green color morph pea aphids

为了明确异色瓢虫和多异瓢虫对红色型和绿色型豌豆蚜的偏好性及对种群的控制作用,本文将异色瓢虫捕食豌豆蚜的总密度设置为90头?皿?1、120头?皿?1、150头?皿?1,多异瓢虫捕食豌豆蚜的总密度设置为42头?皿?1、60头?皿?1、78头?皿?1,分别进行了异色瓢虫和多异瓢虫对2种色型豌豆蚜的选择捕食作用研究。结果显示:当2种色型豌豆蚜共存时,异色瓢虫雌成虫对红色型豌豆蚜在低密度(90头?皿?1)和中密度(120头?皿?1)时均不表现喜(偏)好性,而在高密度(150头?皿?1)时表现正喜(偏)好性,对绿色型豌豆蚜在各密度条件下均不表现喜(偏)好性;对2种色型豌豆蚜的转换效应因总猎物密度的不同而表现不同,即红色型豌豆蚜在低密度(90头?皿?1)时无转换行为,在中密度(120头?皿?1)和高密度(150头?皿?1)时均表现负转换效应,而绿色型豌豆蚜则在各个密度条件下均不表现转换效应。多异瓢虫雌成虫对2种色型豌豆蚜在各密度下均不表现明显的喜(偏)好性;对2种色型豌豆蚜的转换效应因总猎物密度的不同而有所不同,即在低密度(42头?皿?1)时对2种色型豌豆蚜均不表现转换效应,在中高密度(60头?皿?1和78头?皿?1)时,对2种色型豌豆蚜均表现为负转换效应。由此可知,多异瓢虫对2种色型豌豆蚜无明显的选择偏好;异色瓢虫在红绿色型种群数量较低时,对2种色型没有明显的选择偏好作用,但当红色型和绿色型种群数量较高时,异色瓢虫对红色型豌豆蚜具有一定的偏好性,可能影响2种色型豌豆蚜虫种群动态变化。说明优势天敌瓢虫是引起2种色型豌豆蚜种群数量变化的因素之一。

In order to explore the inhibition effectof Harmonia axyridis （Pallas） andAdonia variegata （Goeze） on red and green pea aphids （Acyrthosiphon pisum Harris） populations and their predation preferences, pea aphids with total densities of 90 head·dish^-1, 120 head·dish^-1 and 150 head·dish^-1 forH. axyridis, and 42 head·dish^-1, 60 head·dish^-1 and 78 head·dish^-1 for A. variegate were used to determine predation preferences ofH. axyridis andA. variegata on two color morphs of pea aphids. The results showed that when red and green pea aphids co-existed, female adults of H. axyridis were insensitive to red morph in low and medium total prey densities （90 head·dish^-1 and 120 head·dish^-1）, sensitive to red morph in high total prey density （150 head·dish^-1）, and insensitive to green morph in all total prey densities. Female adults of H. axyridis also variably switched to red pea aphids in different total prey densities, showing zero switch in 90 head·dish^-1 density, and negative switch in 120 head·dish^-1 and 150 head·dish^-1 densities. However, female adults showed zero switch to green morph. When red and green pea aphids co-existed, female adults ofA. variegate were insensitive to red and green morphs pea aphid in all total prey densities. Female adults ofA. variegata also variably switched to the two morph pea aphids in different total prey densities, showing zero switch in 42 head·dish^-1 density, and negative switch in the 60 head·dish^-1 and 78 head·dish^-1 densities. Therefore while female adults of A. variegata had no obvious preference for the two morphs of pea aphids, female adult ofH. axyridis had no preference for the two morphs of pea aphids in lower population density but had positive preference for red morph in higher population density. The results suggested that dominant natural enemies （ladybird） were among the many factors for the changes in the populations of the two types of color of pea aphids.