环斑猛猎蝽对烟蚜若虫的捕食作用

【目的】明确环斑猛猎蝽（Sphedanolestes impressicollis Stal.）对烟田烟蚜［Myzus persicae（Sulzer）］若虫的捕食潜力，为田间应用环斑猛猎蝽防控烟蚜提供参考。【方法】实验室条件下，在培养皿中设置1头饥饿24 h的环斑猛猎蝽4龄若虫与不同密度梯度的1~4龄烟蚜若虫，统计环斑猛猎蝽的捕食量并通过GrapPad Prism 8.0、DPS等软件进行生物学统计分析，明确环斑猛猎蝽对烟蚜若虫的功能反应和搜寻效应；以不同密度的环斑猛猎蝽4龄若虫与烟蚜4龄若虫在不同温度梯度及空间格局条件下，通过控制单一变量法并构建线性回归方程，明确环斑猛猎蝽4龄若虫种内干扰对捕食率的影响以及自身密度、温度、空间格局对捕食量的影响，评估环斑猛猎蝽4龄若虫对烟蚜4龄若虫的捕食功能反应模型。【结果】环斑猛猎蝽4龄若虫对烟蚜若虫的捕食功能反应符合Holling-II模型，其种内干扰及自身密度对捕食量的影响分别符合Hassell模型和Watt模型。环斑猛猎蝽4龄若虫对1~4龄烟蚜若虫中的3龄和4龄若虫捕食具有偏好性，对4龄若虫的捕食量最大，最大日捕食量为55.7头，其次为3龄烟蚜（55.3头）。在空间一定和烟蚜若虫定量条件下，环斑猛猎蝽4龄若虫个体间存在种内干扰，干扰系数为1.31，并随着自身密度的增加干扰增强，平均捕食量下降。在不同空间且烟蚜若虫密度一定的条件下，随着空间的增大，环斑猛猎蝽4龄若虫对猎物的捕食量减少。在16~32℃的温度梯度下，环斑猛猎蝽4龄若虫对烟蚜若虫的捕食量随着温度的升高而逐渐增强，32℃下的日捕食量最大，达23头。【结论】环斑猛猎蝽在烟田中具有防治烟蚜的潜力。

Predatory responses of Sphedanolestes impressicollis Stal. on the nymphs of Myzus persicae(Sulzer)

【Objective】 The aim of this study was to evaluate the predation potential of Sphedanolestes Impressicollis Stal. against the nymphs of Myzus persicae(Sulzer) in tobacco fields, and provide a scientific theoretical basis for ecological control of aphids in tobacco field.【Method】 Under laboratory conditions, a hungry S. impressicollis 4th instar nymph (for 24 h) and 1st-4th instar aphid nymphs were set up with different gradients in Petri dishes and the predation of S. impressicollis was observed to determine the functional response and predatory effect of S. impressicollis on aphid nymphs. The biological statistical analysis was performed using GraphPad Prism 8.0, DPS and other softwares. S. impressicollis and tobacco aphid with different densities under different temperature gradient and spatial pattern conditions By controlling a single variable method and constructing a linear regression equation, the influence of intraspecific interference on predation rate and density of the 4th S. impressicollis instar nymph as well as temperature and spatial pattern on the predation was verified to evaluate the predation functional response model of the 4th instar nymph of S. impressicollis to M. persicae.【Result】 The predatory functional responses of the 4th instar nymphs of S. impressicollis to nymphs of M. persicae were consistent with Holling-II model, and the effects of its intraspecific disturbance and density on nymphs of M. persicae were consistent with the Hassell model and Watt model, respectively. In the predation of the 4th instar nymphs of S. impressicollis on the 1st-4th instar nymphs of aphids, the 4th instar nymphs of S. impressicollis were partial to the 3rd and 4th instar aphid nymphs, and had the largest predatory number on the 4th instar aphid nymphs(the theoretical maximum of daily predation was 55.7), followed by the 3rd instar aphid nymphs(the theoretical maximum of daily predation was 55.3). Under the conditions of specific space size and aphid number, there was disturbed among the 4th instar nymphs of S. impressicollis, and the disturbance coefficient was 1.31. Moreover, with the increase of the density of S. impressicollis, the disturbance increased, and the average prey quantity decreased. At the same time, under the same aphid density but different spaces, with the increase of space, the predation amount of S. impressicollis decreased. Under 16-32℃, with the increase of temperature, the predation amount of the 4th instar nymphs of S. impressicollis on the aphid nymphs gradually increased. The predation amount was the maximum under 32℃(32 aphids).【Conclusion】 S. impressicollis has the potential to control M. persicae in a tobacco field.