Wolbachia reduces virus infection in a natural population of Drosophila.

Wolbachia is a maternally transmitted bacterial symbiont that is estimated to infect approximately half of arthropod species. In the laboratory it can increase the resistance of insects to viral infection, but its effect on viruses in nature is unknown. Here we report that in a natural population of Drosophila melanogaster, individuals that are infected with Wolbachia are less likely to be infected by viruses. By characterising the virome by metagenomic sequencing and then testing individual flies for infection, we found the protective effect of Wolbachia was virus-specific, with the prevalence of infection being up to 15% greater in Wolbachia-free flies. The antiviral effects of Wolbachia may contribute to its extraordinary ecological success, and in nature the symbiont may be an important component of the antiviral defences of insects.

Reemergence of St. Louis Encephalitis Virus in the Americas.

We summarize and analyze historical and current data regarding the reemergence of St. Louis encephalitis virus (SLEV; genus Flavivirus) in the Americas. Historically, SLEV caused encephalitis outbreaks in the United States; however, it was not considered a public health concern in the rest of the Americas. After the introduction of West Nile virus in 1999, activity of SLEV decreased considerably in the United States. During 2014-2015, SLEV caused a human outbreak in Arizona and caused isolated human cases in California in 2016 and 2017. Phylogenetic analyses indicate that the emerging SLEV in the western United States is related to the epidemic strains isolated during a human encephalitis outbreak in Córdoba, Argentina, in 2005. Ecoepidemiologic studies suggest that the emergence of SLEV in Argentina was caused by the introduction of a more pathogenic strain and increasing populations of the eared dove (amplifying host).

2015 AMCA Memorial Lecture Honoree: Dr. Richard Floyd Darsie, Jr.

Richard Floyd Darsie, Jr. (1915-2014) is the 2015 American Mosquito Control Association Memorial Lecture Honoree. He was one of the greatest mosquito taxonomists of the 20th century and died peacefully on April 10, 2014, in Grove City, PA, at the age of 99 after a professional career that spanned eight decades. Dick's broad areas of interest and training made him a versatile scientist, teacher, and researcher. His intense interest in adult and immature mosquito morphology and taxonomy, as well as mosquito distribution and bionomics, started early in his career at two early academic postings: Franklin and Marshall College (1949-54) and the University of Delaware (1954-62). Dick would take his mosquito interests with him to postings and research projects around the world: Nepal, the Philippines, Atlanta, El Salvador, Guatemala, Fort Collins, South Carolina, Argentina, and Florida. His travels and studies would make him an international expert on mosquito taxonomy. Dick's legacy lives on in the hundreds of students from across the globe who learned mosquito identification skills from this world-renowned mosquito taxonomist. All will proudly profess that, "I learned mosquito identification from Dr. Darsie." And that is all that is needed to prove one's credentials in the field, learning the art from the best there is.