A considerable body of evidence has demonstrated the positive impact of the diversity of plant species on biological control of pests at the field scale. However, very few studies have assessed the effect of crop diversity on natural enemy performance and pest control. In order to test our hypothesis that crop diversity could increase natural enemy development and performance, we examined the mechanisms underlying the effect of two types of crop succession, i.e., multiple-crop succession (tomato, squash and soybean) and mono-crop succession (each crop alone), on population dynamics, predation capacity and spillover of Nesidiocoris tenuis Reuter (Hemiptera: Miridae) in a greenhouse experiment. We found that (1) the polyculture supported lower population growth of N. tenuis and lower predation rates of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs compared to tomato and squash monocultures, but that correspondingly (2) the predator performed better on the polyculture than on the soybean monoculture. These results revealed that crop identity within the succession is a major factor in determining population dynamics and biological control. We found that compared to soybean monoculture, the presence of soybean Glycine max L. (Fabales: Fabaceae) in the polyculture treatment reduced the population dynamics of the mirid predator but increased biological control. This result suggests that non-host crops in a polycultural succession could benefit from the natural enemy populations that were increased by other suitable crops in the succession.

中文翻译：

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作物多样性对the捕食者Nesidiocoris tenuis捕食活动和种群动态的影响

大量证据表明，在田间规模上，植物物种多样性对有害生物的生物防治具有积极影响。但是，很少有研究评估作物多样性对天敌表现和病虫害防治的影响。为了检验我们的假设，即作物多样性可以增加自然天敌的发育和生长，我们研究了两种农作物演替类型（番茄，南瓜和大豆）和单农作物继种（在温室试验中，对尼氏猪笼草的种群动态，捕食能力和溢出进行了研究。我们发现（1）多元文化支持猪笼草的较低种群增长与番茄和南瓜单一培养相比，Ekustia kuehniella Zeller（鳞翅目：Pyralidae）卵的捕食率更低，但是相应地（2）捕食者在混合培养中的表现要好于大豆单一培养。这些结果表明，演替过程中的作物特性是决定种群动态和生物控制的主要因素。我们发现，与大豆单培养相比，在混合培养中大豆最大大豆大豆（Fabales：豆科）的存在降低了rid捕食者的种群动态，但增强了生物学控制。这一结果表明，多文化演替中的非寄主农作物可以受益于天敌种群，而天敌种群又被其他合适的农作物演替所增加。