Spider predation on a mirid pest in Japanese rice fields
Spider predation on a mirid pest in Japanese rice fields
复制标题
DOI：
10.1016/j.baae.2011.07.007
复制
发表时间：
2011-01-01
影响因子：
3.8
通讯作者：
Washitani, Izumi
中科院分区：
文献类型：
--
作者：
Kobayashi, Tetsuya;Takada, Mayura;Washitani, Izumi
蜘蛛是常见的多面性捕食者，了解它们在生物防治方面的潜力对于开发综合害虫管理计划具有重要意义。本研究以DNA为基础的肠道内容物分析技术，研究了三组蜘蛛对稻田小食心虫的捕食作用。一项实验室饲养研究显示，在25摄氏度的温度下，蜘蛛肠道中检测到的昆虫DNA的半衰期，狼蛛科为3.4天，四角蛛科为1.5天。通过对野外采集的蜘蛛猎物DNA的检测，研究了个体蜘蛛对食心虫的捕食作用。共测定了3个蜘蛛类群1199只蜘蛛，分别为Pirata subpiraticus(Lycosidae)、Tetragnatha spp.Pachygnatha clercki(Tetra-gnathidae)和Pachygnatha clercki(Tetra-gnathidae)，它们各自在喜好的微生境以及捕食习性上有所不同。在所有蜘蛛种群中，随着猎物密度的增加，蜘蛛体内猎物DNA的检测率显著增加。P.subpiraticus和Tetragnatha spp.捕食对猎物密度的饱和响应曲线表现出较好的拟合度，而克氏松鼠则与猎物密度呈简单的线性关系。可供选择的猎物物种的密度不会影响大脑的检测率。这些结果表明，在农业生态系统中，通用捕食者对害虫的捕食不仅受猎物丰度的影响，还受捕食者对特定猎物的偏好的影响。因此，在评估天敌作为生防剂的作用时，捕食者的偏好是一个需要考虑的重要因素。
Spiders are common generalist predators, and understanding their potential in biological control is important for the development of integrated pest management programs. In this study, predation by three groups of spiders on the mind bug Stenotus rubrovittatus (Hemiptera: Miridae) in rice paddies was investigated using DNA-based gut-content analysis. A laboratory feeding study revealed that the detection half-lives of bug DNA in the spider gut at 25 degrees C was 3.4 days for Lycosidae and 1.5 days for Tetragnathidae. Individual spider predation on the mind bug was investigated by detecting DNA of prey in field-collected spiders. In total, 1199 spiders were assayed from three spider groups: Pirata subpiraticus (Lycosidae), Tetragnatha spp. (Tetra-gnathidae), and Pachygnatha clercki (Tetra-gnathidae), which each differ in their preferred microhabitat as well as their predatory habits. Detection rates of prey DNA in spiders increased significantly with the density of prey across all spider groups. P subpiraticus and Tetragnatha spp. predation showed a better fit to a saturated response curve to increasing prey density, while P. clercki showed a simple linear relationship with prey density. Densities of alternative prey species did not affect the detection rates of minds. These results suggest that predation on pests by generalist predators in an agroecosystem is affected not only by prey abundance but also by predator preference for specific prey. Predator preference is therefore an important factor to consider when estimating the role of natural enemies as biological control agents.