甘薯田被寄生鳞翅目幼虫尸体种类识别

<正> 在甘薯田,鳞翅目害虫种类很多,为害也较严重,如何进行薯田鳞翅目害虫天敌调查,特别是如何正确判断寄生物与寄主的种间关系,对于薯田天敌资源调查,害虫的发生量测报,全面评价药剂防治效果,以及探索天敌保护和利用等,有着重要的意义。确定鳞翅目害虫与寄生性天敌之间的关系,通常的做法是从田间采回活的虫体进行饲养,等待寄生蜂成虫的羽化,然后根据寄生蜂成虫鉴定种类;田间采集或者室内饲养未能获得寄生蜂成虫时,可根据寄生蜂幼虫鉴定种类(赵修复,1977)。这是在寄主种类明确的情况下,通过鉴定寄生蜂种类来确定寄主和寄生物之间的关系。但是有时寄主种类并不容易鉴

ON THE IDENTIFICATION TO SPECIES OF THE LARVAL BODY REMAINS OF THE PARASITIZED LEPIDOPTEROUS INSECT PESTS OF SWEET POTATO

One way to determine the host-parasite relationship is to study the larval body remains of the lepidopterous insect pests together with the nearby cocoons of the parasites collected in the sweet potato field. The larval body remains of the lepidopterous insect pests of sweet potato can be grouped into three types: the shrivelled type, the empty-skinned type and the distented and twisted type. Those that belong to the shrivelled type are: the larvae of various host species parasitized by eulophids, the second instar larvae of Herse convolvuli Linnaeus parasitized by Charops bicolor Szepligeti, the 4th instar larvae of Brachmia trianuella H. S. the second instar larvae of Herse convolvuli Linnaeus, the last instar larvae of Cretonia vegeta (Swinhoe), the last instar larvae of a species of ctenuchid. the last instar larvae of Creatonotus transiens (Walker) and the last instar larvae of a species of noctuid parasitized by Apanteles spp.. Those that belong to the empty-skinned type are: the third instar larvae of Brachmia trianuella H. S. parasitized by Apanteles sp., the 4th instar larvae of Brachmia trianuella H. S. parasitezed by Macrocentrus sp. and the last instar larvae of Cretonia vegeta (Swinhoe) parasitized by a species of undetermined braconid. The one that belongs to distented and twisted type is the last instar larvae of plusia agnata Staudinger parasitized by Litomastix truncatella (Dalman). A key based on the structure of the head capsules of the dead insects is given and well illustrated in order to facilitate the determination to species of the larval body remains of the sweet potato lepidopterous insect pests.