地里纤恙螨是我国恙虫病最主要的传播媒介，传统观点认为该螨广泛分布在北纬30°以南广大地区和中国西南地区，但近年来自云南的研究不支持此传统认识。结合我国西南地区特殊的地理位置、复杂的地形地貌和生态环境以及地理纤恙螨在该地区分布情况尚不清楚和国内外对此研究较少等诸多实际，该项目根据研究假设，拟在我国西南地区的不同地域生境开展分层抽样调查和对比研究，运用现代生态学研究手段和方法，研究并阐明地里纤恙螨在西南地区不同地域、生境和鼠类宿主的分布趋势、分布规律和基本成因，确定该螨的主要分布区域、生境和宿主，同时揭示该螨的季节分布规律以及该螨与其他媒介恙螨在鼠类宿主选择上的种间共存、协调、竞争和排斥等生态关系。通过地里纤恙螨在西南地区分布规律的系统阐明以及对研究假设的验证，弥补此前对该螨认识的不足和局限，实现知识创新，为未来恙虫病媒介预测、预警、防控和相关后续研究提供直接可靠的科学依据。

Leptotrombidium deliense is the most important vector of tsutsugamushi disease (scrub typhus) in China. According to a traditional view, L. deliense was considered to be widely distributed in the south of north latitude 30 ° and the southwest China. The recent investigations from Yunnan, however, do not support the above traditional view. To date, little has been known about the distribution of L. deliense in southwest China with few literatures. Considering the special geographical location, complex landforms and ecological habitats of southwest China and based on a hypothesis, a stratified sampling investigation and contrast study will be made in southwest China. Some modern ecological methods will be used to study and illustrate the distribution tendency and distribution patterns of L. deliense along different geographical regions, ecological habitats and its rodent hosts. The main distribution areas, habitats and hosts of this chigger mite species (L. deliense), together with some causative factors, will be determined and explained. Besides, the project will also study the seasonal fluctuation of the mite and elucidate its ecological relationships with some other vector species of chigger mites including species coexistence, interspecific association, competition and repulsion, etc. Through the elucidation of the distribution patterns of L. deliense and the verification of the hypothesis, the results of the project will enrich the knowledge about L. deliense and provide reliable scientific data for future prediction, surveillance, control and some other related researches on the vectors of tsutsugamushi disease.