Regulation of Underground Insect Herbivores: Subterranean Trophic Cascades?

地下昆虫食草动物的调节：地下营养级联？

• 批准号: 9508673
• 负责人: Donald Strong
• 金额: $ 25.5万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9508673&HistoricalAwards=false
• 关键词: Regulation; Underground; Insect; Herbivores; Subterranean

9508673 STRONG This research focuses on a below-ground trophic cascade involving a root-feeding moth caterpillar, a bush lupine, a soil-dwelling entomopathogenic nematode, and predators on this nematode. It is the nematode predators that initiate this cascade. These predators are primarily the nematophagous fungi impertecti, which are speciose and abundant in soils. The trophic interactions are constructed as follows: Dead lupine killed by caterpillars are substrates for mushrooms that are putatively the reproductive stages of the nematophages. With opposite potential effect, leaves bearing copious alkaloids that are potent fungicides accumulate in thick blankets on the soil habitat of the nematophagous stages of the fungi. Neither the caterpillar, which consumes only wood low in alkaloid, nor the nematode appear to be affected by these alkaloids. The caterpillars are widely dispersed among lupine patches, yet their numbers are negatively correlated with nematode abundance. The nematodes suffer frequent local extinctions and are present only in areas where lupines flourish. However, where caterpillar densities are high, both lupine litter and the nematode-eating fungi are abundant. In these areas, there are a few nematodes. Soils are among the most poorly known habitats of life on earth. Underground insect herbivores, which are diverse, injurious to plants, and influential in ecosystems, have been studied to a degree in agriculture systems, but have had only had cursory treatment by ecologists. Population regulation of underground insect herbivores has been almost totally ignored by agriculturalists and ecologists alike. While underground insects are drawn from familiar above-ground groups, their natural enemies in the soil are distinctive. This research has clear linkages to understanding factors that regulate populations of below-ground herbivores in natural and agricultural communities.

9508673强 本研究的重点是地下营养级联涉及的根食蛾毛虫，灌木羽扇豆，土壤中生活的昆虫病原线虫，和捕食者对这种线虫。 是线虫捕食者引发了这一级联反应。 这些捕食者主要是食草真菌impertecti，这是specious和丰富的土壤中。 营养相互作用的构建如下：死羽扇豆杀死毛虫是基板的蘑菇是pupelant的噬菌体的繁殖阶段。 具有相反的潜在效果，带有大量生物碱的叶子是有效的杀真菌剂，在真菌食草阶段的土壤栖息地上积累厚毯。 毛虫只吃生物碱含量低的木材，而线虫似乎也不受这些生物碱的影响。 毛虫广泛分布于羽扇豆斑块中，但其数量与线虫丰度呈负相关。 线虫遭受频繁的局部感染，并且仅存在于羽扇豆繁茂的地区。 然而，在毛虫密度高的地方，羽扇豆凋落物和食线虫真菌都很丰富。 在这些地区，有一些线虫。 土壤是地球上最鲜为人知的生命栖息地之一。 地下食草昆虫种类繁多，对植物有害，对生态系统有影响，在农业系统中已有一定程度的研究，但生态学家只进行了粗略的处理。 地下食草昆虫的种群调节几乎完全被农学家和生态学家所忽视。 虽然地下昆虫是从熟悉的地上群体中提取出来的，但它们在土壤中的天敌是独特的。 这项研究与理解自然和农业社区地下食草动物种群的调节因素有着明确的联系。