Spatial processes and diversity in host-parasite systems

shimada研究了1个寄主-2个拟寄主实验系统的动力学特性，该实验系统使用了一个野蜂寄主、一个斑蜂寄主和一个小蜂寄主。虽然种群最初在寄主- ac中有轻微的振荡。系统中，添加hp后，寄主和a.c.s种群波动幅度逐渐增大，最终两种群波动幅度较大，通过LENNS和RSM检测到3种系统中出现了混沌现象。这两种黄蜂从四龄幼虫寄生到蛹，尽管h.p.比A.c更喜欢更年轻的寄主阶段。a.c.a的侵染率与每颗豆子的寄主密度密切相关，而与hp无关。在两种寄生蜂之间的幼虫竞争中，无论哪种寄生蜂，第一个攻击者都可能更有优势。Shimada， M.Tuda和h.c.j.g udray通过两种方法构建模型：自上而下的时间序列模型和自下而上的阶段结构模型。我们考察了在具有hp的3个物种系统中，是哪些因素和过程使寄主种群和a.c.a l种群从稳定动态转变为混沌动态。此外，Shimada还研究了新大陆豆科植物系统的群落结构；夏威夷，亚利桑那和墨西哥。他收集干燥成熟的豆科种子豆荚，研究了新兴的毛糙种类和相对丰度。在此基础上，他构建了3个地区野鼩的生态位相似性树。在亚利桑那州和墨西哥，由于豆科植物和豆科植物之间的一对多对应关系，它们表现出更复杂的分支。结果表明，宿主通过适应的转移可能足以与系统发育约束相媲美，或者比系统发育约束强得多。y.i wasa研究了宿主植物-食草动物相互作用中的进化基因，并与Tuda一起研究了基于ESS的当地种群容量和种群动态的进化变化。Godfray和M.P.Hassell进一步研究了宿主-寄生虫动力学和与超种群结构的共同进化。有关国际联合项目的所有研究都在发现空间过程对宿主-寄生虫系统生态和遗传多样性的重要影响。少

M.Shimada studied dynamical properties of 1 host-2parasitoid experimental systems, using a bruchid host, a pteromalid wasp (A.c.) and a braconid one (H.p.). Though the populations first oscillated mildly in the host-A.c.system, after adding H.p., the host and A.c.increased gradually the amplitude of population fluctuations and, finally, the two populations fluctuated quite large and emergence of chaos was detected by LENNS and RSM in the 3 species system. The two wasps parasitize from the fourth instar larva to the pupa, though H.p.prefers a slightly younger host stages than A.c.. The attacking rate of A.c.depends strongly on host density per bean but not for H.p.. In larval competition between the two parasitoids, the first attacker is likely to be more advantageous irrespective of the species. Shimada, M.Tuda, and H.C.J.Godfray constructed models by two approaches : a top-down time-series model and a bottom-up stage-structured model with niche separation. We examined which factor (s) … More and process (es) change the host and A.c.populations from stable to chaotic dynamics in the 3 species system with H.p..In addition, Shimada studied community structure of legume-bruchid systems in the New World ; Hawaii, Arizona and Mexico. Collecting drying matured legume seed pods, he investigated emergent bruchid species and the relative abundances. Based on the data, he constructed trees of niche similarities among bruchids in three districts. They showed more complicated branching in Arizona and Mexico because of one-to-multiple correspondence between legumes and bruchids. The results suggest host-shift through adaptation may be comparable enough to, or much stronger than, phylogenetic constraint.Y.Iwasa studied evolutionary gemes in host plant-herbivore interactions and, with Tuda, evolutionary changes in local population capacity and population dynamics, based on ESS.Godfray and M.P.Hassell further studied host-parasite dynamics and coevolution with metapopulation structures.All the studies concerning the international joint project are discovering important effects of spatial processes on ecological and genetic diversities in host-parasite systems. Less