Heatwaves cause fluctuations in < i > w < /i > Mel < i > Wolbachia < /i > densities and frequencies in < i > Aedes aegypti < /i >

by Perran A. Ross, Jason K. Axford, Qiong Yang, Kyran M. Staunton, Scott A. Ritchie, Kelly M. Richardson, Ary A. HoffmannAedes aegypti mosquitoes infected with thewMel strain ofWolbachia are being released into natural mosquito populations in the tropics as a way of reducing dengue transmission. High temperatures adversely affectwMel, reducingWolbachia density and cytoplasmic incompatibility in some larval habitats that experience large temperature fluctuations. We monitored the impact of a 43.6 °C heatwave on thewMel infection in a natural population in Cairns, Australia, wherewMel was first released in 2011 and has persisted at a high frequency.Wolbachia infection frequencies in the month following the heatwave were reduced to 83% in larvae sampled directly from field habitats and 88% in eggs collected from ovitraps, but recovered to be near 100% four months later. Effects of the heatwave onwMel appeared to be stage-specific and delayed, with reduced frequencies and densities in field-collected larvae and adults reared from ovitraps but higher frequencies in field-collected adults. Laboratory experiments showed that the effects of heatwaves on cytoplasmic incompatibility and density are life stage-specific, with first instar larvae being the most vulnerable to temperature effects. Our results indicate that heatwaves inwMel-infected populations will have only temporary effects onWolbachia frequencies and density once the infection has established in the population. Our resu...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research