Determining meteorological drivers of salt marsh mosquito peaks in tropical northern Australia

Abstract

In northern Australia the northern salt marsh mosquito Aedes vigilax is a vector of Ross River virus and is an appreciable pest. A coastal wetland adjacent to Darwin's residential suburbs offers a favorable habitat for Ae. vigilax, and despite vigilant mosquito control efforts, peaks of Ae. vigilax occur in excess of 500/trap/night some months. To improve mosquito control for disease and nuisance biting to nearby residential areas, we sought to investigate meteorological drivers associated with these Ae. vigilax peaks. We fitted a cross-sectional logistic regression model to weekly counts of female Ae. vigilax mosquitoes collected between July, 1998 and June, 2009 against variables, tide, rainfall, month, year, and larval control. Aedes vigilax peaks were associated with rainfall during the months September to November compared with January, when adjusted for larval control and tide. To maximize mosquito control efficiency, larval control should continue to be implemented after high tides and with increased emphasis on extensive larval hatches triggered by rainfall between September and November each year. This study reiterates the importance of monitoring and evaluating service delivery programs. Using statistical modelling, service providers can obtain solutions to operational problems using routinely collected data. These methods may be applicable in mosquito surveillance or control programs in other areas. Journal of Vector Ecology 40 (2): 277-281. 2015.

Mosquito distribution in a saltmarsh: determinants of eggs in a variable environment

“…Moisture is an essential component in saltmarsh mosquito egg conditioning Baker 1962, Kay andJorgensen 1986) and hatching (Andreadis 1990, Rydzanicz et al 2011, Cardo et al 2012) and many studies correlate Aedes spp. with wet, lower regions of saltmarshes that are periodically flooded by tide (De Little et al 2009, Jacups et al 2009, Cardo et al 2012. We found that soil moisture was greatest in bare soil and runnel habitat than shrubby glasswort and samphire, but there was no relationship between soil moisture and elevation.…”

“…Thus, both soil moisture and elevation may be relevant factors contributing to egg distribution. Generally, there are strong correlations among elevation, tide height, and soil moisture within saltmarshes (Saintilan 2009b, Prahalad et al 2012, which also correspond to mosquito abundance , Jacups et al 2009). Moisture is an essential component in saltmarsh mosquito egg conditioning Baker 1962, Kay andJorgensen 1986) and hatching (Andreadis 1990, Rydzanicz et al 2011, Cardo et al 2012) and many studies correlate Aedes spp.…”

Fine-temporal forecasting of outbreak probability and severity: Ross River virus in Western Australia

“…Transmission of mosquito-borne disease is controlled by a combination of environmental, and vector and reservoir host dynamics, which vary across geographical and climatic regions. In forecasting the transmission of RRV, previous studies have used monthly environmental data and have highlighted the importance of having mosquito trapping data to supplement environmental predictors [13,30,36]. While these studies have been vital in developing our understanding of RRV epidemics, their course temporal resolution and recruitment for labour intensive surveillance [13,24,29,[37][38][39][40][41][42] limit practical application for timely forecasts to inform mitigation activities and public awareness campaigns.…”

Comparison of Climatic Factors on Mosquito Abundance at US Army Garrison Humphreys, Republic of Korea

“…Therefore, it is important to identify optimum temperature ranges at which the maximum mosquito abundance occurs for each species to effectively implement vector control measures. An estimate of the nonlinear relationship between mosquito abundance and daily average temperatures, based on the lag effect that takes into account the period of 2 weeks from egg to adult before the collection date, was performed [23,24]. In subsequent years, these data can be used to determine the effectiveness of vector control measures, e.g., different type of adult fogging measures (e.g., ULV or thermal fogging) or larval control (e.g., use of Bti) to reduce disease risks.…”