State Key Laboratory for Biology of Plant Diseases and Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
Scottish Oceans Institute, Institiud Chuantan na h-Alba, School of Biology, University of St Andrews, East Sands, St Andrews, Scotland, KY16 8LB, UK.
BMC Ecol. 2019 Sep 4;19(1):32. doi: 10.1186/s12898-019-0248-6.
The grasshopper Oedaleus asiaticus Bey-Bienko (Acrididae: Oedipodinae) is a dominant and economically important pest that is widely distributed across the Mongolian plateau. This herbivore pest causes major damage to the grassland of the Inner Mongolian steppe in China. The population dynamics of herbivore pests is affected by grassland management practices (e.g., mowing and heavy livestock grazing) that alter plant community structures and stoichiometric characteristics. For example, O. asiaticus outbreak is closely associated with plant preference changes caused by nitrogen loss from heavy livestock grazing. However, the manner by which small-scale variation in vegetation affects grasshopper performance and promotes outbreak is poorly characterized. To address this question, we investigated the relationship between small-scale (1 m) vegetation variability and measures of O. asiaticus performance associated with plant stoichiometric characteristics.
We found that food preferences of O. asiaticus varied significantly, but maintained a specific dietary structure for different plant compositions. Notably, small-scale changes in plant community composition significantly affected grasshopper food preference and body size. Partial least-square modeling indicated that plant proportion and biomass affected grasshopper body size and density. We found that this effect differed between sexes. Specifically, female body mass positively correlated with the proportion of Stipa krylovii grass, whereas male mass positively correlated with the proportion of Artemisia frigida grass. Further analyses indicated that grasshopper performance is closely associated with plant stoichiometric traits that might be responsible for the pest's plague.
This study provides valuable information for managing grasshoppers using rational grassland management practices.
东亚飞蝗（Oedaleus asiaticus Bey-Bienko）（直翅目：斑腿蝗科：蝗亚科）是一种广泛分布于蒙古高原的优势和重要的经济害虫。这种食草害虫对中国内蒙古草原造成了重大破坏。食草害虫的种群动态受草地管理措施（如刈割和过度放牧）的影响，这些措施改变了植物群落结构和化学计量特征。例如，东亚飞蝗的爆发与过度放牧导致的氮素损失引起的植物偏好变化密切相关。然而，小规模植被变化如何影响蝗虫的表现并促进其爆发尚不清楚。为了解决这个问题，我们研究了 1 米尺度的植被变异性与与植物化学计量特征相关的东亚飞蝗表现之间的关系。
我们发现，东亚飞蝗的食物偏好有显著差异，但对不同植物组成保持特定的饮食结构。值得注意的是，植物群落组成的小尺度变化显著影响了蝗虫的食物偏好和体型。偏最小二乘模型表明，植物比例和生物量影响蝗虫的体型和密度。我们发现这种影响在性别之间存在差异。具体而言，雌性体质量与羊草的比例呈正相关，而雄性体质量与冷蒿的比例呈正相关。进一步的分析表明，蝗虫的表现与植物化学计量特征密切相关，这可能是造成害虫灾害的原因。
本研究为利用合理的草地管理实践管理蝗虫提供了有价值的信息。
