捕食性步甲在玉米与牧草之间的迁移

Dispersal Patterns of Carabids between Maize Field and Pastures

采用陷阱法研究了捕食性步甲在玉米田与牧草带(紫花苜蓿Medicago sativa、鲁梅克斯Rumex paientia×R.tianschanicus)之间的迁移规律。在以苜蓿带、鲁梅克斯带为边界的玉米田,捕食性步甲大量迁入玉米田,平均是迁出玉米田的1.6倍和2.4倍。而对照田边界为杂草,迁入相对较少。在9月份的大部分时间迁入玉米田的步甲数量均大于迁出玉米田的。因此,苜蓿和鲁梅克斯作为边界植物可以对天敌步甲起到保护作用。建议重视农田边界功能,对田埂、坡地的杂草进行管理,增加边界植物多样性和覆盖物,以提供天敌合适的生境,充分发挥天敌对害虫的自然控制作用。

Habitat management may enhance pest control by the carabids. The dispersal patterns of carabids were monitored by setting up pitfall traps in maize field and pastures. The results indicated that a large number of carabids moved into maize fields from adjacent alfalfa （Medicago sativa ） and rumexk （ Rumex paientia x R. tianschanicus ）, which were 1.6 and 2.4 times of these out of the maize field, respectively. By contrast, numbers of carabids moving from adjacent weeds to crop fields were similar to those from crop fields to adjacent weeds. It is suggested that field margins such as ridge and sloping fields may play a important role in protecting carabids, and the pasture plants may be planted adjacent to crops to increase the population size of natural enemies in crop fields.