Effect of Leaf Type and Pesticide Exposure on Abundance of Bacterial Taxa in Mosquito Larval Habitats

Abstract

Lentic freshwater systems including those inhabited by aquatic stages of mosquitoes derive most of their carbon inputs from terrestrial organic matter mainly leaf litter. The leaf litter is colonized by microbial communities that provide the resource base for mosquito larvae. While the microbial biomass associated with different leaf species in container aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood. We used indoor aquatic microcosms to determine the abundances of major taxonomic groups of bacteria in leaf litters from seven plant species and their responses to low concentrations of four pesticides with different modes of action on the target organisms; permethrin, malathion, atrazine and glyphosate. We tested the hypotheses that leaf species support different quantities of major taxonomic groups of bacteria and that exposure to pesticides at environmentally relevant concentrations alters bacterial abundance and community structure in mosquito larval habitats. We found support for both hypotheses suggesting that leaf litter identity and chemical contamination may alter the quality and quantity of mosquito food base (microbial communities) in larval habitats. The effect of pesticides on microbial communities varied significantly among leaf types, suggesting that the impact of pesticides on natural microbial communities may be highly complex and difficult to predict. Collectively, these findings demonstrate the potential for detritus composition within mosquito larval habitats and exposure to pesticides to influence the quality of mosquito larval habitats.

Antibacterial Compounds-Macrolactin Alters the Soil Bacterial Community and Abundance of the Gene Encoding PKS

“…Further, many species of Firmicutes are macrolactins producer such as Bacillus , that are resistant to macrolactins and elevate in relative abundance by their products (Yuan et al, 2012a). In the previous studies, the abundance of Beta-proteobacteria and Gamma-proteobacteriaalso showed a positive correlation with agricultural chemicals such as glyphosate, atrazine, permethrin and DDT as they were able to degrade these chemicals (Lew et al, 2013; Muturi et al, 2013). Beta- proteobacteria and Gamma- proteobacteria might be responsible for degradation of macrolactins in soil.…”

Competition among Aedes aegypti larvae Kurt Steinwascher

“…Other experiments show that male and female 4th instar larvae are competent to pupate at 24-36 hours after they molt from the 3rd instar [70–73], but that high food levels cause them to delay pupation until they attain a maximum weight [53,70,72], and that the time to pupation and the actual size of the adult is affected by the temperature of the larval environment [25,61,70,72,74] as well as food level and density (see above), the type or quality of the food source [6,24,25,75–80] and, of course, the sex of the individual [21,37,70–72,74,81].…”

Bacterial populations of mosquito breeding habitats in relation to maize pollen in Asendabo, south western Ethiopia

“…These provide the nutriment to the microorganism as well as to the Anopheline larvae. Anopheline larvae usually feed on microorganisms (Muturi et al, 2013) and detritus (Merritt et al, 1992). The microorganisms are able to thrive on maize pollen, which in turn serve as Anopheline larvae nutriment.…”

“…While the microbial biomass associated with different larva aquatic habitats is well documented, the taxonomic composition of these microbes and their response to common environmental stressors is poorly understood (Muturi et al, 2013).…”