Preference and consumption of Macrolophus pygmaeus preying on mixed instar assemblages of Myzus persicae
Preference and consumption of Macrolophus pygmaeus preying on mixed instar assemblages of Myzus persicae
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DOI：
10.1016/j.biocontrol.2009.06.006
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发表时间：
2009-10-01
影响因子：
4.2
通讯作者：
Maselou, D. A.
中科院分区：
文献类型：
--
作者：
Fantinou, A. A.;Perdikis, D. Ch.;Maselou, D. A.
在实验条件下，研究了捕食者pygmaeus对桃蚜四龄虫捕食频率和丰度变化的影响。中心假设是，随着猎物密度的增加，pygmaeus会变得更有选择性。我们还观察到，pygmaeus偶尔会放弃已经被杀死的猎物（非消耗性猎物死亡）。据推测，这种行为的频率会随着猎物的大小和密度而增加。为了这些目的，通过同时以相等的比例和增加的密度向捕食者呈现桃蚜的所有阶段来评估猎物选择。在不同的捕食密度下，褐皮夜蛾均表现出较高的捕食率和对较小捕食星的偏好。然而，如果捕食者的捕食率以消耗的生物量表示，那么当捕食较大的桃蚜时，生物量增加更高。猎物的选择性由总猎物死亡率（食性和非食性猎物死亡率）和非食性猎物死亡率表示，与相对较高的猎物密度相关，取决于猎物的年龄。因此，我们认为pygmais对不同阶段蚜虫的捕食影响不仅取决于猎物的特征，还取决于它们在斑块中的相对丰度。观察到的大型猎物生物量增加的减少可能是在饱和之前密度较高的猎物可用性的结果，这可能导致捕食者选择猎物的混乱。(C) 2009爱思唯尔公司版权所有。
This study examines the effects of changes in the prey frequency and abundance on prey selection among the four instars of Myzus persicae by the predator Macrolophus pygmaeus under laboratory conditions. The central hypothesis was that M. pygmaeus will become more selective as prey density increases. It was also observed that M. pygmaeus can occasionally abandon a prey item that had already been killed (non-consumptive prey mortality). It was assumed that the frequency of this behavior would increase with the prey size and prey density. For these purposes prey selection was evaluated by simultaneously presenting all instars of M. persicae to the predator in equal proportions and at increasing densities. M. pygmaeus showed a higher predation rate and a higher preference for smaller prey instars at all prey densities. However, if the predation rate by the predator is expressed in terms of biomass consumed, then biomass gain was higher when feeding on the larger instars of M. persicae. The prey selectivity was indicated by the total prey mortality (consumptive plus non-consumptive prey mortality) as well as by the non-consumptive prey mortality, was associated with relatively high prey densities, depending on the prey instar. Therefore, we argued that the predatory impact of M. pygmaeus on the various instars of the aphid depends not only on prey traits but also on their relative abundance in a patch. Observed decreases in biomass gain from larger prey were likely the result of high prey availability at densities before saturation, which might have caused confusion in the predator's prey selection. (C) 2009 Elsevier Inc. All rights reserved.