Effects of Ants on the Guild Structure of Herbivorous Beetles

1.在日本金泽的一个丘陵地区，研究了五种丰富的以蓟叶为食的甲虫之间的共现。研究的物种是：1.食草瓢虫Epilachna niponica（Epilachninae）和四种金线虫Dactylispa masoni（Hispinae）、Cassida rubiginosa（Cassidinae）、Altica crisicola（Alticinae）和Lema crisicola（Criocerinae）。对5种蓟的枝条和叶片分别进行标记，记录蓟的生长和害虫危害情况，以及成虫、卵、幼虫和蛹的位置和数量。通过对不同物种的季节发生率、空间分布、成虫寿命、成虫扩散、幼期死亡率等指标的量化分析，比较了不同物种的资源利用模式.这些甲虫没有表现出产卵位点的分离，不同种类的卵团经常在同一片蓟叶上同时出现.蓟上严重感染了两种蚜虫。蓟上蚂蚁密度很低，蚂蚁不参与蚜虫的活动.在实验室条件下，进行了存活率和生育时间表以及食物选择的实验。

1. Co-occurrence among five abundant species of beetles that feed the leaves of thistle Cirsium matsumurae was examined in a hilly region of Kanazawa, Japan. The studied species were : a herbivorous ladybird Epilachna niponica (Epilachninae) and four chrysomerid species Dactylispa masoni (Hispinae), Cassida rubiginosa (Cassidinae), Altica cirsicola (Alticinae) and Lema cirsicola (Criocerinae).2. Thistle shoots and their leaves were individually tagged to record (1) the growth and damage by the herbivores of the thistle, and (2) the position and number of adults, eggs, larvae and pupae of the five species. Seasonal occurrence, spatial distribution, longevity and dispersal of adults, and mortality rates in immature stages are quantified to compare the resource utilization patterns among the species.3. These beetles did not show the segregation of oviposition sites : more than one egg mass of different species was frequently found together on one thistle leaf.4. The thistles were seriously infested with two species of aphids. Ant density on the thistles was very low and ant did not attend the aphids.5. Under laboratory conditions, experiments for survivorship and fertility schedules and food selection were carried out.