250 - The Effects of Climate Change on Mosquitoes and Mosquito-borne Disease in Iberia Parish, Louisiana

Abstract: Our planet is getting warmer. This can have unexpected consequences on mosquito populations and mosquito-borne disease at the local level. The organization Climate Central defines a mosquito day as a day in which the temperature does not drop below 50 degrees nor rise above 95 degrees, and the mean humidity is at least 42%. By this definition, mosquito days are increasing many northern areas of the U.S., but declining somewhat in parts of the South. In Iberia Parish, Louisiana, there is an indication of a downward trend in mosquito days over the last 22 y, mainly due to excessive summer temperatures. Climate Central defines a mosquito disease danger day as one with a mean temperature between 61 and 93 degrees. By this definition, disease danger days have been increasing north and south. In Iberia Parish, disease danger days have been increasing, particularly in the spring. This is the time that many birds are nesting, which could contribute strongly to viral amplification. In Iberia Parish we have also found that West Nile Virus positives are becoming increasingly common among smaller pools of mosquitoes. We may be seeing smaller numbers of potentially disease-carrying mosquitoes, due to excessive summer temperatures, yet an increasing West Nile threat due to faster amplification in the spring.