讲座内容简介：

The tea green leafhopper Empoasca onukii is one of the most predominant insect pest threatening the tea production. Based on our earlier field studies, I will present pest control models in tea plantations where a generalist predator mite Anystis baccarum serves as a natural enemy to control green leafhopper Empoasca. These models contain life cycle of the pest leafhopper in three stages, including egg, nymph and adults. In this talk, I will present the nilpotent singularities and their bifurcations including saddle-node bifurcation of codimension 1 and 2, Hopf bifurcation, Bogdanov-Takens bifurcation, bifurcations of nilpotent singularities of elliptic and focus type. In particular, I will focus on the nilpotent singularities and their bifurcations of codimension 3, discuss the classification and properties of the two different types of nilpotent singularities and bifurcations, as well as their connections to the bifurcations of codimension 4 in the system.

讲座人简介：

朱怀平，加拿大约克大学数学和统计系教授，疾病建模中心主任。长期从事动力系统分支理论及其应用、希尔伯特第十六问题、种群生态学与传染病学的数学建模和应用分析研究、气候变化模拟和影响、以及蚊虫疾病的实时预报和防控等研究工作。在数学及生物数学的国际顶级或高水平期刊上累计发表文章100多篇。多次组织举办了动力系统分支理论以及应用，生物数学，气候变化以及影响等学术会议，并先后在重要国际会议做特邀报告20余次。作为项目负责人获得加拿大国家工程和自然科学基金会 (NSERC)，国家创新基金 (CFI)，加拿大健康研究院（CIHR), 加拿大公共卫生部(PHAC)，以及安大略省卫生部、环境部、科技部等部委的资助。2007年曾获安大略省青年科学研究奖。