International DDEP: Grasshopper migration in the Asian steppe: investigating diet as a cue for polyphenism

本博士论文强化奖将支持亚利桑那州立大学博士生Arianne Cease对中国蚱蜢迁徙进行实地研究。本研究将解决几个具体问题，包括：1)蚱蜢的迁徙形式是由饮食质量的优劣造成的？2)植物的氮、碳、磷或生物碱含量等特定特征的变化是否会引发迁移和非迁移形式之间的转变？3)过度放牧是否通过降低植物的营养质量来促进迁移形式的形成？为了解决这些问题，我们将在实验室中对亚洲蝗虫的密度和食性进行控制，并在野外进行观察，记录蝗虫发育过程中的形态、生理和行为反应。该奖项将促进由美国国家科学基金会资助的生态学家和昆虫生理学家与中国蚱蜢生物学家和草原植物学家之间的高度跨学科合作。由该奖项资助的合作项目包括北京生命科学研究所和虫鼠病虫害综合治理国家重点实验室，涉及多名中美科学家。最后，这项研究将提供必要的关键数据，以了解和潜在地预防灾难性的蝗群。在蝗灾爆发的年份，蝗群（蝗虫）可遍布全球1100万平方英里的土地，对60多个国家产生负面影响，每10人中就有1人的生计受到影响。据预测，全球气候变化将增加降水变异性，并可能加剧蝗灾。虽然通常假设与恶化的环境条件相关的饮食线索可能引发蝗虫群，但可能导致这种发育可塑性的特定饮食线索尚不清楚。本研究将利用亚洲两种经济上重要的暴发蝗虫之一的蚱蜢O. asiaticus在中国调查这个问题。这项研究还将建立长期的国际研究联系，并促进一支专注于一个重要农业问题的全球参与的科学队伍。

This Doctoral Dissertation Enhancement award will support field research on grasshopper migration in China by Ph.D. student Arianne Cease of Arizona State University. Several specific questions will be addressed in this research including: 1) Do migratory forms of grasshopper result from superior or inferior diet quality? 2) Can transitions between migratory and nonmigratory forms be triggered by changes in specific plant characteristics, such as nitrogen, carbon, phosphorus, or alkaloid content? 3) Does overgrazing stimulate formation of migratory forms by lowering plant nutritional quality? To address these questions, the density and diet of Oedaleus asiaticus will be manipulated in the lab and observed in the field, and morphological, physiological and behavioral responses of developing grasshoppers will be recorded. This award will promote a highly interdisciplinary collaboration by a group of NSF-funded ecologists and insect physiologists with grasshopper biologists and grassland botanists in China. Collaborative activities funded by this award will include research at the Beijing Institute of Life Sciences and the State Key Laboratory of Integrated Management of Insect & Rodent Pests involving multiple Chinese and US scientists. Finally, this research will provide critical data necessary to understand and potentially prevent disastrous locust swarms. During an outbreak year, swarming grasshoppers (locusts) can populate 11 million square miles of land worldwide, negatively affecting more than 60 countries and the livelihood of 1 out of every 10 people. Global climate change is predicted to increase precipitation variability and perhaps exacerbate locust outbreaks. While it is often hypothesized that dietary cues related to deteriorating environmental conditions might trigger locust swarms, the specific dietary cues that may cause this developmental plasticity are unknown. This research will investigate the question in China, using the grasshopper O. asiaticus, one of two economically important outbreak locusts in Asia. This research will also establish long-term international research ties and promote a globally engaged scientific workforce focused on an important agricultural problem.