学习经历在平腹小蜂寄主选择过程中的作用

研究了已经交配与未经交配的平腹小蜂在羽化后不同时间对中间寄主柞蚕卵信息记忆的持效性，比较了经学习训练与未经学习训练的平腹小蜂在不同时间对其自然寄主荔枝蝽卵和中间寄主柞蚕卵的选择性。结果表明：交配过的平腹小蜂在大量羽化后96h检验柞蚕卵的时间和数量都显著增多，而未经交配的平腹小蜂在此时搜索寄主的时间也显著延长，说明平腹小蜂在此时对柞蚕卵信息的记忆开始明显减弱。经学习训练的和未经学习训练的平腹小蜂在大量羽化后96h对荔枝蝽卵的第一选择数和刺卵数都明显提高，并且前者较后者在各个时段对荔枝蝽卵的第一选择数、检验卵数以及刺卵数都多，说明经学习训练的平腹小蜂对荔枝蝽卵的趋性较高，并且随着时间的延长受柞蚕卵信息的干扰逐渐减小，对荔枝蝽卵的学习效果不断增强。

The effects of learning experiences of Anastatus japonicus on its host selection process

Anastatus japonicus(Ashmead) is an efficient egg parasitoid against Tessaratoma papillosa(Drury),a major litchi(Litchi chinensis)pest,in Southern China.However,the practical biocontrol efficacy of A.japonicus mass produced using middle host Antheraea pernyi eggs is low in field.It is known that parasitoids response to a host can be affected by the experience on host cues gained during and immediately after emergence from the host.Does the experience in middle host affect the host selection process of A.japonicus? If so,how long does it last? It is unknown whether experiences trained on natural host cues will improve the responses of a parasitoid raised by middle host to its natural host.In this study,first of all,we investigated the memory persistence of mated and unmated A.japonicus for information from middle host eggs(Antheraea pernyi eggs) at different times after eclosion.Secondly,we compared the selectivity of trained and untrained A.japonicus on natural host(Tessaratoma papillosa eggs) and middle host(Antheraea pernyi eggs) at different times post-emergence.Finally,we evaluated the searching efficiency of A.japonicus after learning experiences in processing T.papillosa egg.The results showed that the time and the amount of inspecting host eggs of mated A.japonicus were increased significantly after A.japonicus had emerged from the middle host eggs 96h later.We observed that the time for searching host eggs for unmated A.japonicus was also delayed remarkably,therefore the memory of A.japonicus for information from A.pernyi eggs began to weaken distinctly after 96 h.On the other hand,the number of first-selectivity for T.papillosa eggs and the amount of poking T.papillosa eggs for trained and untrained A.japonicus were increased obviously at 96 h after emergence.Interestingly,the number of first-selectivity for T.papillosa eggs and the amount of inspecting and poking T.papillosa eggs for trained A.japonicus were more than those of untrained A.japonicus at different times post-emergence.The results showed that trained A.japonicus has higher attraction to T.papillosa eggs compared to untrained A.japonicus,and the interfering information from middle host A.pernyi decreased gradually.