• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
YouFeelGreen

YouFeelGreen

Your green news

  • Home
  • Blog
  • Contact form

model

The amorphous, heterogeneous spatial spread of Wolbachia

July 9, 2019 By gk104 Leave a Comment

Penelope A. Hancock presents recently published work on ‘Predicting the spatial dynamics of Wolbachia infections in Aedes aegypti arbovirus vector populations in heterogeneous landscapes‘.

Uncertainty surrounding density-dependent mosquito population growth rates prevents us from predicting the outcome of mosquito control interventions. A timely example is the introduction of Wolbachia bacterial infections into wild Aedes aegypti populations, the major vector of the dengue, Zika and chikungunya viruses. Wolbachia suppresses the ability of mosquitoes to transmit these viruses to humans. Once introduced, it spreads via a driving mechanism that allows the bacteria to infect a higher proportion of mosquitoes over successive generations of the mosquito population.

Field releases of Wolbachia into the wild Aedes aegypti populations in Cairns, northeast Australia, resulted in surprising patterns of spatial spread that were highly variable and difficult to predict. We developed a new mathematical model incorporating the results of experimental studies of density-dependent dynamics in this mosquito species. The model produces patterns of spatial spread that show similar features to those observed in the natural populations of Cairns (see animation below). Spatial spread is slow and amorphous, with the Wolbachia advancing further in some directions than others.

Variability is the norm

High variability in fundamental demographic traits, such as survival and fecundity, is characteristic in Aedes aegypti mosquito populations. Body size, as measured by wing length, shows a wide range of values over a typical sample of individuals collected from the field (Figure. 1A). This variation is important because body size is closely associated with fecundity in female mosquitoes, an essential parameter in models of mosquito populations and how they respond to interventions. Experiments conducted in field-caged mosquito populations show a close relationship between female body size, fecundity and the level of density-dependent competition that the mosquito experiences during its larval development stage (Fig. 1B). In addition, the time it takes for larvae to develop into adults is also strongly density dependent. This means that density-dependent dynamics need to be accounted for when predicting mosquito generation times, and in modelling the spread of Wolbachia from generation to generation.

Figure 1Figure 1. A. Wing lengths of female mosquitoes sampled from the field and the field cage. B. Female fecundity (red) and larval development time (blue) resulting from different larval densities.Putting it all together

Our experimental studies of density-dependent demographic relationships have enabled the development of a mathematical model that represents variation in mosquito numbers across space and time. The model was able to produce patterns of spatial variation in mosquito abundance that are similar to those seen in field populations (Figure. 2A). We also found that the rates of spatial spread of Wolbachia predicted by the model were similar to those observed following the field releases conducted in northeast Australia (Figure. 2B). Our models can help interpret Wolbachia field release dynamics by allowing the effects of environmental and demographic heterogeneity to be considered.

Figure 2Figure 2. A. The number of pupae per house, observed in the field and predicted by the model. B. The observed spread of Wolbachia at two sites in Cairns in comparison to the model prediction.

Figure 2. A. The number of pupae per house, observed in the field and predicted by the model. B. The observed spread of Wolbachia at two sites in Cairns in comparison to the model prediction.

Read the full article, ‘Predicting the spatial dynamics of Wolbachia infections in Aedes aegypti arbovirus vector populations in heterogeneous landscapes‘ in Journal of Applied Ecology.

Photo by Kmaluhia

Share this:

TwitterFacebookLinkedIn
Like this:

LikeLoading…
Related

First published on 2019-07-09 08:00:50

Original Source

Filed Under: Applied Ecologist, Australia, model, mosquito, pathogens, Pathogens and disease, Research Summary, spatial spread, Wolbachia, Zika

Primary Sidebar

Recent Posts

  • Step by step
  • Colonnina igienizzante eco-sostenibile fatta a mano
  • “HeartH” and Me
  • Ncc e Taxi: ecco i pannelli di contenimento del Covid-19
  • VPPs with smart inverters offer crucial flexibility to the changing grid

Recent Comments

  • Viola on “HeartH” and Me
  • Viola on “HeartH” and Me
  • Emy on “HeartH” and Me
  • Stefania Bartolo on “HeartH” and Me

Archives

  • June 2020
  • May 2020
  • April 2020
  • July 2019
  • June 2019
  • May 2019
  • February 2019
  • January 2019

Categories

  • aluminum
  • Announcements
  • Applied Ecologist
  • Australia
  • Author post
  • beaver
  • Bioenergy
  • books
  • Britain
  • C&I
  • canopy
  • cardboard
  • climate change
  • coevolution
  • Community Solar
  • competition
  • Conferences
  • conservation
  • Dartmoor
  • DER
  • Ecological Inspirations
  • Ecological Reviews
  • ecology
  • Ecology and Evolution
  • Ecology Community
  • Editor's Choice
  • education
  • Energy Efficiency
  • Energy Storage
  • Europe
  • evolution
  • facts
  • family
  • favorites
  • food production
  • food security
  • forests
  • fun
  • fun facts
  • HeartH
  • herbivory
  • Home and Garden
  • horizon scan
  • Hydropower
  • journal of ecology
  • kids
  • Lifestyle
  • list
  • local recycling program
  • Microgrids
  • model
  • moorland
  • mosquito
  • News
  • Off-Grid
  • Onshore
  • Opinion & Commentary
  • paper
  • pathogens
  • Pathogens and disease
  • people and nature
  • Perspectives
  • pine marten
  • plant ecology
  • plants
  • plastic bottles
  • Project Development
  • reading
  • Recycling
  • recycling tips
  • reintroduction
  • Renewable Energy
  • Research Summary
  • Rewilding
  • rice
  • Rooftop
  • salinity
  • salt-tolerant rice
  • Scotland
  • sea eagle
  • self-willed nature
  • small pieces
  • soil
  • Solar
  • spatial spread
  • Special Features
  • speciation
  • spring cleaning
  • Storage
  • sustainability
  • sustainable
  • teaching
  • The Ecology Journal
  • tips
  • Top 5
  • UK
  • Uncategorized
  • wild boar
  • Wind Power
  • Wolbachia
  • Women in Science
  • Zika

Copyright © 2021 · Made by Gavilab