IMPACT OF TEMPERATURE ON MOSQUITO AND ARBOVIRUS ECOLOGY

我们正在进行和拟议中的研究的长期目标是 林分的季节性和持续性机制， 蚊子传播的虫媒病毒。 温度 被认为是影响传播的主要因素， 虫媒病毒，因为它调节季节性 丰度、脊椎动物宿主接触频率、病毒持续时间 外源性孵育、对病毒感染的易感性和对 获得性病毒感染。 因此，我们提出的新领域和实验室 调查将具体评估温度对 跗库蚊的生态学、遗传学和 传播西部马脑脊髓炎（WEE）和圣路易斯 在加州的灌溉沙漠山谷中的脑炎（SLE）病毒。 这项研究提出的主要假设是， 东南部山谷的年平均气温上升摄氏度， 加州已经改变了Cx的遗传、生态和载体能力。 足可使每年持续的WEE和SLE病毒 活动，相比之下，更北方和凉爽的圣华金河谷 这些病毒的活动现在相当分散。 这 假设将通过启动新的研究进行测试，其中有4个特定的 目的：1）确定科切拉和圣华金的病媒种群 山谷在它们的耐受性和对温度的反应方面有所不同， 未成熟和成熟阶段; 2）阐明生理和行为 使东南部山谷的病媒种群 在夏季和冬季条件下生存; 3）评估 温度对病媒感染的易感性、 WEE和SLE病毒感染的外源性孵育和调节 科切拉山谷的野外种群; 4）检测季节性和 空间差异的病媒种群的遗传结构， 科切拉和圣华金河谷。 我们认为，我们提出的研究解决了一个主要的需要， 设计了现场和实验室实验，以评估 温度是控制病媒和病原体的主要因素 相互关系

The long-term objective of our on-going and proposed research has been to stand mechanisms which govern the seasonality and persistence of mosquito-borne arboviruses at temperate latitudes. Temperature is believed to be the principal factor that impacts the transmission of arboviruses as it regulates the mosquito vector attributes of seasonal abundance, frequency of vertebrate host contact, duration of virus extrinsic incubation, susceptibility to virus infection and modulation of acquired virus infection. Thus, our proposed new field and laboratory investigations specifically will assess the impact of temperature on the ecology and genetics of Culex tarsalis Coquillett and its ability to transmit western equine encephalomyelitis (WEE) and St. Louis encephalitis (SLE) viruses in the irrigated desert valleys of California. The principal hypothesis addressed by the proposed research is that the 5 degrees C warmer mean annual temperature in the southeastern valleys of California has altered the genetics, ecology and vector competence of Cx. tarsalis sufficiently to allow persistent annual WEE and SLE virus activity, compared to the more northern and cooler San Joaquin Valley where the activity of these .viruses is now quite sporadic. This hypothesis will be tested by initiating new research with 4 specific aims: 1) determine if vector populations in the Coachella and San Joaquin Valleys differ in their tolerance and response to temperature during immature and adult stages; 2) elucidate physiological and behavioral mechanisms which allow vector populations in southeastern valleys to survive during both summer and winter conditions; 3) assess the impact of temperature on the vector's susceptibility to infection, duration of extrinsic incubation and modulation of WEE and SLE virus infections in field populations from the Coachella Valley; and 4) detect seasonal and spatial differences in the genetic structure of vector populations in the Coachella and San Joaquin Valleys. We believe our proposed studies address a major need for carefully designed field and laboratory experimentation to evaluate the importance of temperature as a major factor that controls vector and pathogen interrelationships.