Talking wetlands, wildlife and mosquitoes at the 2017 Australian Entomological Society Meeting

homebushbay_mangroves_jan2016

I’ll be in Terrigal, on the NSW Central Coast, for the 2017 Australian Entomological Society conference and taking the opportunity to present a summary of a number of collaborative projects undertaken in recent years, from working out how surrounding landuse influences the mosquito populations in urban mangroves to how important mosquitoes are to the diet of local bats.

Together with a range of colleagues, I’ve been undertaking research into the factors driving mosquito and mosquito-borne disease risk in urban wetlands. It is a complex puzzle to solve with more than just mosquitoes determining local pest and public health risks. However, with outbreaks of mosquito-borne Ross River virus on the rise in recent years, including urban areas of Australia, there is a need to better understand the factors at play.

There is a range of factors that may increase the risk of Ross River virus, they include suitable wetlands, wildlife reservoirs of the pathogen and mosquitoes. Understanding the mosquitoes associated with urban estuarine and freshwater wetlands is critical.

Investigating the role of surrounding landuse in determining the mosquito communities of urban mangroves, we found that industrial and residential areas tended to increase abundance of mosquitoes, perhaps due to direct or indirect impacts on the health of those mangroves. We’ve found previously that mosquitoes problems are often associated with estuarine wetlands suffering poor health, perhaps this is determining the increased mosquito risk we identified? You can read more in our publication here.

Expanding the investigation to look at urban freshwater wetlands, it was found that there was a high degree of variability in local mosquito populations and that each wetland needed to be assessed with consideration to be given to site-specific characteristics. You can read more about our work investigating mosquito assemblages associated with urban water bodies in our publication here.

More research is underway in this field and my PhD student, Jayne Hanford, has already started collecting some fascinating data on wetland biodiversity and local mosquito populations.

While the focus of our studies is often prompted by concern about Ross River virus, interestingly, in recent years we’ve found considerable activity of Stratford virus. This is not currently considered a major human health concern but given how widespread it is, it raises concerns about the suitability of local wildlife, even in Western Sydney, to represent important reservoirs of mosquito-borne pathogens. You can read more about Stratford virus in our publication here.

The final piece of the puzzle is to understand the ecological role of mosquitoes. Where their potential health threats are deemed significant, how could management of mosquito populations have unintended consequences for other wildlife. What about the animals that eat mosquitoes? A number of years ago we did some research to determine the importance of mosquitoes in the diet of coastal bats. While there was no indication that mosquitoes are a critical component of their diet, they are still being snacked on and mosquito control programs need to consider any local ecological impacts.

Now, how am I going to squeeze all this into 15 minutes….

The presentation abstract is below:

What drives mosquito-borne disease risk in urban wetlands?

Webb, C. (1, 2), J. Hanford (3), S. Claflin (4), W. Crocker (5), K. Maute (5), K. French (5), L. Gonsalves (6) & D. Hochuli (3)

(1) Department of Medical Entomology, NSW Health Pathology, Westmead Hospital, NSW 2145; (2) Marie Bashir Institute of Infectious Diseases and Biosecurity, University of Sydney, Camperdown, NSW 2006; (3) School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camperdown, NSW, 2006; (4) Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, 7000; (5) Centre for Sustainable Ecosystem Solutions, Biological Sciences, Faculty of Science, Medicine & Health, University of Wollongong NSW, 2522; (6) School of Arts and Sciences, Australian Catholic University, North Sydney, NSW, 2060.

Managing pest and public health risks associated with constructed and rehabilitated urban wetlands is of increasing concern for local authorities. While strategic conservation of wetlands and wildlife is required to mitigate the impacts of urbanisation and climate change, concomitant increases in mosquitoes and mosquito-borne disease outbreak risk must be addressed. However, with gaps in our understanding of the ecological role of mosquitoes, could control strategies have unintended adverse impacts on vertebrate and invertebrate communities? A series of studies were undertaken in urban wetlands of greater Sydney to investigate the role of land use, wetland type and wetland aquatic biodiversity in driving the abundance and diversity of mosquito populations. A diverse range of mosquitoes, including key pest an vector species, were found in urban environments and mosquito-borne pathogens were detected in local populations, implicating local wildlife (e.g. water birds and macropods) as potential public health risk factors. Estuarine wetlands are locally important with the percentage of residential land and bushland surrounding wetlands having a negative effect on mosquito abundance and species richness while the amount of industrial land had a significant positive effect on species richness. Mosquito control in these habitats is required but insectivorous bats were identified as mosquito predators and the indirect implications of mosquito control should be considered. The aquatic biodiversity of urban freshwater wetlands influenced the species richness of local mosquito populations indicating vegetation plays an important role in determining local pest species. However, the matrix of wetland types also influences the abundance of mosquitoes in the local area. These results demonstrate the need for site-specific investigations of mosquito communities to assist local authorities develop policies for urban development and wetland rehabilitation that balance the need for conservation with reduced public health risks.

To keep up to date on what’s happening at the conference, check out the program online or follow the conversation on Twitter.

 

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Social media and blood suckers showcased at the International Congress of Entomology

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Digital technology is changing a lot about how we undertake entomological research and communicate the results of that research to the community and policy makers.

This week in Orlando, Florida, is the International Congress of Entomology (ICE). A huge gathering of entomologists from around the world. While it was a great pleasure to be invited to participate, I couldn’t get over there this time.

I will, however, have a chance to present my work in the Symposium “Entomology in the Digital Age”  Friday, September 30, 2016 (01:30 PM – 04:45 PM), Convention Centre Room W222 A.

In the presentation I’ll share some of the reasoning behind my use of social media to engage the community with both entomological research and public health communication. Most importantly, it will focus on some of the metrics I’ve recorded alongside my use of social media, maintaining a blog of research and writing for outlets such as The Conversation.

I’ve written about my use of social media and how it can help extend the reach of public health messages and presented on the topic alongside a range of great speakers at the 2014 Entomological Society of America meeting in Portland.

This time around, technology is playing an even more direct role in my presentation! I’ve pre-recorded my presentation and it will be shown to the audience on the day among other presentations. I’ll also be checking into the session to answer questions. Despite the fact I’ll need to be up around 1:30am due to time differences, it should be fun.

See the abstract below…

Taking entomological research from the swamps to the suburbs with social media

Cameron E Webb

Connecting scientists and the community is critical. This is particularly the case for medical entomologists working in the field of mosquito-borne disease where the translation of entomological research into improved public health outcomes is a priority. While traditional media has been the mainstay of public health communications by local authorities, social media provides new avenues for disseminating information and engaging with the wider community. This presentation will share some insights into how the use of social media has connected new and old communications strategies to not only extend the reach of public health messages but also provide an opportunity to promote entomological research and wetland conservation. A range of social media platforms, including Twitter, Instagram, and WordPress, were employed to disseminate public health messages and engage the community and traditional media outlets. Engagement with the accounts of traditional media (e.g. radio, print, television, online) was found to be the main route to increased exposure and, subsequently, to increased access of public health information online. With the increasing accessibility of the community to online resources via smartphones, researchers and public health advocates must develop strategies to effectively use social media. Many people now turn to social media as a source of news and information and those in the field of public health, as well as entomological research more generally, must take advantage of these new opportunities. doi: 10.1603/ICE.2016.94611


If you’re at ICE, you can also catch up with my PhD student David Lilly who’ll be presenting our research into the development of insecticide resistance in bed bugs as part of the symposium “New Insights into Biology, Resistance Mechanisms, and the Management of the Modern Bed Bug” Friday, September 30, 2016, 01:30 PM – 04:45 PM, Convention Center, West Hall F4 (WF4).

Novel insecticide resistant mechanisms in the common bed bug, Cimex lectularius

David Lilly, Cameron E Webb and Stephen Doggett

Introduction: Research on field strains of Cimex lectularius from Australia has identified widespread resistance to pyrethroid insecticides, but variability in the magnitude expressed. To determine if differences in resistance mechanisms exist, collected strains were examined for the presence of metabolic detoxification and/or cuticle thickening. Methods: The presence and relative contribution of detoxifying esterases or cytochrome P450 monooxygenases were assessed. Bed bugs collected from Parramatta (NSW), Melbourne (VIC) – 2 strains, ‘No.2’ and ‘No.4’, and Alice Springs (NT) were exposed in topical bioassays employing deltamethrin and two pyrethroid synergists: piperonyl butoxide (PBO) and EN16/5-1. PBO inhibits both monooxygenases and esterases, whereas EN16/5-1 will inhibit esterases only. Thus in a comparative bioassay, the results can infer the dominant enzyme system. The Parramatta strain was then selected to study the potential presence of cuticle thickening. Nine-day-old male bed bugs were exposed to filter papers treated with the highest label rate of Demand Insecticide®(200mL/10L of 25g/L lambda-cyhalothrin) and were grouped according to time-to-knockdown (< 2 hours, ≥ 4 hours, and survivors at 24 hours). Measurements of mean cuticle thickness at the transverse midpoint of the second leg tarsus were taken under electron microscope. Results/Conclusion: All strains possessed resistance that was inhibited by the synergists, with the Parramatta and Melbourne No.2 indicating esterase-dominance, and Alice Springs and Melbourne No.4 indicating cytochrome P450 monooxygenase-dominance. Cuticular measurements demonstrated that bed bugs surviving deltamethrin exposure had significantly thicker cuticles, denoting a novel form of resistance in these insects. doi: 10.1603/ICE.2016.92553

 

You can also see Stephen Doggett (co-author and photographer of A Guide to Mosquitoes of Australia) speaking on photographing mosquitoes to in the symposium “Insect Photography Symposium: Bringing the Small to the World.


You can join the conversation on Twitter and keep an eye on all the fun in Orlando by keeping an eye on the tweet stream!

 

The five best non-buggy things about Entomology 2014

portland_oldtownThere was lots of love about Entomology 2014 but some of the biggest highlights had nothing to do with the bugs. Here are some non-entomological hits from the conference.

1. Portland, OR.

Host city makes a difference. I know many considerations are taken into account when deciding on a venue but an interesting host city (or region) can really tip the scales. Portland was a great decision. One of the great things about Portland was that it provided many conversation starters. Tips on where to find the best coffee, craft beer and donuts dominated plenty of on- and offline conversations during the course of the meeting (plus a few “field trips” thrown in for good measure).

I’ve seen interesting/new locations boost the numbers of conference attendees for the Australian Entomological Society and Mosquito Control Association of Australia in recent years too.

bluestardonuts2. Free public transport

Brilliant. With the meeting attracting over 3,000 people, it wasn’t possible to hold the event at a single venue that also provided accommodation for the bulk of attendees. As everyone was spread out across the city, getting back and forth from the Oregon Convention Center could have been quite tricky. Portland has a great public transport network but, better still, conference registrants received a free pass for travel throughout the course of the meeting! It certainly took the stress out of getting around.

sizzlepie3. Promotion of social media

The Entomological Society of America really needs to be congratulated on the way they’re employed social media as a critical component of their scientific conferences. I’ve been to conferences where social media has been tolerated but rarely encouraged. At this meeting, social media use was integrated into the day-to-day conference experience.

There was promotion of #EntSoc14 before, during and after the meeting. From the registration website to the opening address by David Gammel, social media was embraced and encouraged. Probably the best element was the use of a series of large screens throughout the conference center with a cascade of twitter and instagram posts. There was even a large display in the trade hall! Wonderful idea because it brought the “non-tweeting” conference attendees into the mix. I had a few a few conversations with people who don’t use social media but tracked me down because they’d seen tweets on the screen earlier in the meeting.

tweetscreen

An example of the “social media screens” dotted throughout the conference venue (Source: Christie Bahlai ‏@cbahlai)

Having an opportunity to meet in real life many of the wonderful people I’d only ever corresponded with via social media was one fo the highlights of the conference.

I was tempted to post something about tweeting at conference but there are already a bunch of great resources on the use of social media during conferences. Here are just a few “How to live-tweet a conference: A guide for conference organizers and twitter users“, “A Guide to Tweeting at Scientific Meetings for Social Media Veterans” and “Ten Simple Rules of Live Tweeting at Scientific Conferences“.

Here are the key slides (plus a bonus) from my conference presentation on the use of social media to extend the reach of public health messages:

4. Free WiFi

Whether we like it or not, we’re tethered to work. I learned a valuable lesson this year when I took myself “off the grid” for a few weeks during a holiday break. It took me the best part of a month to catch up. Being able to regularly check in with work emails during a conference (without having to pay exorbitant access rates) really helps. It is also handy chasing up papers referenced in presentations and other resources shared throughout the conference.

I know it is no fun seeing a conference room full of people checking email during someone’s presentation and I personally don’t do it myself. However, there were plenty of places and spaces to sit down and do that outside the presentation rooms.

5. A sustainable conference venue

I know this isn’t always possible but having a conference venue that put a high priority on sustainability was great. From recycling of coffee cups to stormwater runoff, most of the bases were covered. Nice for me, given my interest in constructed wetlands and stormwater management, to see the systems in place at the Oregon Conference Center.

Oregonconvention_urbanstormwaterTo some, these may seem like trivial aspects of a major scientific conference but they really made for a great experience at Entomology 2014 for me.

What do you love (or loathe) about scientific conferences (beyond the science itself)? Join the conversation on Twitter.

Solving the common mystery of the cat flea

You may be inclined to think that we know everything we need to know about the flea but we don’t. They infest our pets and our homes; we treat them with a variety of substances and yet they are near impossible to exterminate. Importantly, they occasionally bite people, causing annoyance and sometimes severe skin reactions. You may also think this is all we really need to know them. In fact, these parasites are often overlooked in terms of their significance to animal health, their competence as disease vectors and the impacts they make on our everyday lives. There is much more to these irritating insects than meets the eye.

This is the first “guest post” on my blog and comes from my PhD student Andrea Lawrence (University of Sydney) ahead of her presentations at the Australian Society for Parasitology conference in Canberra next week (looks like a wonderful program of events this year!). I’m hoping that there will be plenty more guest posts from Andrea and my other students in the near future.

The most common flea encountered in Australia is the cat flea, Ctenocephalides felis. Just because your dog has fleas, it doesn’t mean it has dog fleas (Ctenocephalides canis). This is a common misconception. In fact, it appears as if the dog flea is something of a mythical creature in Australia. Despite historical records and anecdotal reports of dog flea infestations, there is no recent literature confirming their presence. A recent study of over 2,500 pets failed to find a dog flea. As such, if your pet is troubled with fleas, you can likely lay the blame solely on the cat flea.

The cat flea is the top ectoparasite affecting cats and dogs globally for a variety of reasons. They are the cause of up to 50% of all dermatological cases presented to vet clinics world-wide. Pet owners are spending $40 to $70 on flea and tick control products per month and, based on figures from the United States, over $1 billion annually. That is a lot of money to spend only to have the fleas come back time after time.

As well as the nuisance-biting, the cat flea also carries zoonotic pathogens such as Bartonella (bacteria that causes cat scratch disease in hypersensitive or immunocompromised people) and Rickettsia (bacteria that causes murine typhus and flea-borne spotted fever).

There may also be many cases of underdiagnosed febrile illnesses caused by flea-borne pathogens that fly under the radar due to the presentation of generic fever and flu-like symptoms that rarely warrant further pathological investigation. Of course, the most famous and historically significant pathogen spread by fleas is the plague bacteria: Yersinia pestis. Plague is certainly not a thing of the past with recent outbreaks in Madagascar and up to 17 cases reported from North America each year. Considering the highly ubiquitous nature of fleas in human environments, and many species’ tendency to be host generalists – particularly the cat flea – shouldn’t we be more concerned, or at least more aware, of their biology, taxonomy and potential public health risks?

Professional Ratcatchers from Views taken during Cleansing Operations, Quarantine Area, Sydney, 1900

Although the pathogens that cause plague are not endemic to Australia, plague has touched Australia with significant impact. Here are some professional ratcatchers from Sydney, Australia, during the plague outbreak in 1900 (Source: State Library Image Collection)

Given the impact these little parasites have on our lives, it is baffling how little we know about them. The genetic profile of the cat flea is highly understudied and yet within the genetic code lies hidden implications for the evolution of insecticide resistance, disease transmission and the passage of fleas across continents and the global sphere. A study from the Veterinary Parasitology unit at the University of Sydney found that in 2011 across 5 states of Australia cat fleas collected from veterinary practices were 100% genetically identical at the mitochondrial DNA. This was a very unusual result as populations of other flea species are generally very diverse. The result was comforting news at the time for the regulation of veterinary pharmaceuticals as the efficacy of flea control products were able to be compared against flea populations across the entire country.

Taken from “How to get rid of fleas at home” via Appliances online blog.

We know fleas from Australia are genetically similar but what about elsewhere? We broadened the scope of the investigation and compared the fleas from Australia to those collected from Thailand, Fiji and Seychelles: a group of Islands north-east of Madagascar. These results showed that from a global perspective, cat fleas are genetically diverse. The 2013 flea season yielded a novel second Australian haplotype found in north-east Australia which contradicts the unanimous results from the previous study in 2011. This haplotype was shared with most fleas tested from Fiji, suggesting some recent flea transfer between the two countries. With the rapid emergence of this second haplotype since the previous study, it sparks the question of whether there may be a division of fitness between the two haplotypes. Could this division be resulting in a steady ‘invasion’ of Australia by the second haplotype?

To investigate the haplotype diversity in this study we developed a novel genetic marker capable of clearly delineating different flea species, subspecies and haplotypes. Previously, genetic studies primarily used a mitochondrial DNA marker called cox2. However, there is an emerging global standard of genetic taxonomy called DNA barcoding, which uses a similar gene called cox1. This method involves storing massive amount of short DNA sequences in an electronic database, accessible to anyone with internet access. Currently the database called Barcode of Life Database or BOLD holds 3 million ‘barcodes’, 2 million of which are arthropod barcodes. I wanted to align fleas with this emerging global standard by developing a cox1 marker that would work for fleas. It is surprising given the global significance fleas that the marker has not been optimised before. The ‘barcodes’ collected from this study are now available on BOLD and can be searched allowing greater dissemination of and accessibility to flea genetic data.

A change in the genetic makeup of Australia’s flea population as discovered recently has implications for the pharmaceutical companies who can no longer apply a blanket approach to flea control efficacy testing. Research is continuing this year in the Veterinary Parasitology Unit at The University of Sydney to monitor the rate of spread of this second haplotype. In time I hope this may yield greater understanding of the cat flea genetic puzzle that will lead to finding the key to effective control of these tenacious blood-sucking creatures and the diseases they carry.

The abstract for Andrea’s paper is below:

The cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae) (Bouché), is the most common flea species found on cats and dogs worldwide. We investigated the genetic identity of the cosmopolitan subspecies C. felis felis and evaluated diversity of cat fleas from Australia, Fiji, Thailand and Seychelles using mtDNA sequences from cytochrome c oxidase subunit I (cox1) and II (cox2) genes. Both cox1 and cox2 confirmed the high phylogenetic diversity and paraphyletic origin of C. felis felis. The African subspecies C. felis strongylus (Jordan) is nested within the paraphyletic C. felis felis. The south East Asian subspecies C. felis orientis (Jordan) is monophyletic and is supported by morphology. We confirm that Australian cat fleas belong to C. felis felis and show that in Australia they form two distinct phylogenetic clades, one common with fleas from Fiji. Using a barcoding approach, we recognize two putative species within C. felis (C. felis and C. orientis). Nucleotide diversity was higher in cox1 but COX2 outperformed COX1 in amino acid diversity. COX2 amino acid sequences resolve all phylogenetic clades and provide an additional phylogenetic signal. Both cox1 and cox2 resolved identical phylogeny and are suitable for population structure studies of Ctenocephalides species.

The full reference of the paper is:

Lawrence, A. L., Brown, G. K., Peters, B., Spielman, D. S., Morin-Adeline, V. and Šlapeta, J. (2014), High phylogenetic diversity of the cat flea (Ctenocephalides felis) at two mitochondrial DNA markers. Medical and Veterinary Entomology [early view]doi: 10.1111/mve.12051 [Online]

(The image of the cat flea, Ctenocephalides felis, at the top of this blog post is taken from the PaDIL image collection by K Walker)

Anticipating infectious threats to Australia

What are the human, agricultural, wildlife and entomological infectious disease threats to Australia? To answer this questions, the University of Sydney’s Marie Bashir Institute of Infectious Diseases and Biosecurity co-ordinated a “collective brainstorm” session to map out the way forward in assessing and address these future risks.

Moderated by Professor Eddie Holmes, the session included “five top leaders in their respective fields” to provide an overview and discuss recent advances, as well as determining the key challenges with discussion amongst attendees. A fascinating collection of topics and I was fortunate enough to be invited to contribute my knowledge on mosquito-borne disease threats in the Australia region.

Professor Jon Iredell spoke about the development of antibiotic resistance in human pathogens. Most interestingly, he touched on the role humans play in exposing our environment and wildlife to these antibiotics and the resulting impacts on the broader community. Although the issue of antibiotics hasn’t touched my work directly, I’m aware of this issue in relation to the role of constructed wetlands associated with agricultural and urban wastewater facilities. Notwithstanding the direct human health issues, interaction with wildlife may have implications for emerging zoonotic pathogens.

Professor Robert Park spoke about agricultural disease. A fascinating presentation on a topic I wasn’t familiar with but was surprised as to the relevance to exotic vector-borne pathogens. Robert spoke about the Australian Cereal Rust Control Program and how it plays an important role in monitoring the incursions of this fungi.

Dr Karrie Rose spoke about wildlife disease and highlighted some of the issues surrounding the investigation of outbreaks where the environmental, agricultural or human health issues may not be clear from the outset. Additional issues surround the diagnosis of these pathogens and determining the authorities responsible for the outbreak. Karie is the manager of the Australian Registry of Wildlife Health, a program of Taronga Conservation Society Australia and provided a great overview of the diverse nature of zoonotic pathogens, from Chytrid fungus to orbivirus, local authorities must deal with.

Monitoring mosquitoes and the pathogens they're carrying will remain critical in assisting the assessment and management of public health risks in Australia

Monitoring mosquitoes and the pathogens they’re carrying will remain critical in assisting the assessment and management of public health risks in Australia

I spoke about the endemic and exotic mosquito-borne disease threats to Australia, from Ross River virus to dengue. My presentation highlighted issues surrounding globalisation, urbanisation and a changing climate with particular emphasis on the potential introduction of the Asian Tiger Mosquito to mainland Australia and the recent increase in Australian travellers returning home with dengue and chikungunya virus infections. Analysis by WA Health authorities have highlighted the increased risk associated with travel to Bali in recent years. There have also been cases of “airport” or “baggage” dengue, including the first locally acquired cases of dengue in WA for over 70 years as well as a case of infection under similar circumstances near Darwin. The Darwin case was also reported in this PLOS NTD paper. At a time when FNQ is experiencing multiple outbreaks of dengue, there seems to be ever increasing opportunities for the pathogens and vectors to be entering mainland Australia.

You can catch up on the slides from my presentation below:

and a collection of tweets from the session collated by @MarieBashirInst is here.

[The photo at the top of this post is taken from the CDC]

Entomology 2013: Science Impacting a Connected World

IMG_7511The annual meeting of the Entomological Society of America takes place this week in Austin, Texas. I’ll be presenting a “virtual poster” on the mosquito-borne disease risk factors associated with wetland rehabilitation, urban development and climate change.

I wish I could be there in Austin. I was luck enough to visit in February 2012 when I attended the annual meeting of the American Mosquito Control Association. It is a wonderful city and I hope to make it back someday soon.

IMG_5671Even though it will only be “virtual” attendance, I’m still excited about sharing my work at this meeting. It summarizes some of the my major research interests that revolve around the use of urban planning to assist the reduction in mosquito-borne disease. Particularly with regard to wetland rehabilitation and wildlife management. The use of planning instruments is important and just as authorities reconsider the approach to urban plannign in bushfire prone areas, perhaps authorities should consider approving new developments in areas where another hazard of the Australian environment is present…..mosquitoes. Some councils are already aware of the risks and attempting to manage those risks.

The Saltmarsh Mosquito (Aedes vigilax) (Photo: Stephen Doggett)

The Saltmarsh Mosquito (Aedes vigilax) (Photo: Stephen Doggett)

Although the option to discuss my poster with attendees via Skype isn’t available this time, I hope that there is a bit of interest via Twitter. Check out #EntSoc13

Here are the details of my poster:

Managing mosquito-borne disease risk in response to weather, wetlands and wildlife in coastal Australia

Cameron E Webb

Mosquito-borne disease management in Australia faces challenges on many fronts. Many gaps exist in our understanding of the drivers of mosquito-borne disease risk, particularly with regard to Ross River virus (RRV) that causes a potentially severe flu-like illness. Notwithstanding the environmental drivers of mosquito abundance, the role of interactions between mosquitoes and wildlife may play a role in disease outbreaks. Local authorities in coastal Australia responsible for the management of new residential developments and wetland rehabilitation projects are increasingly aware of strategies to reduce mosquito-borne disease risk. Mapping actual and potential mosquito habitats, with consideration to the environmental drivers of mosquito abundance, such as rainfall and tidal inundation of estuarine wetlands, can inform an assessment of nuisance-biting and public health risks. These assessments can further inform urban planning approvals and adaptive management of wetlands. “Mosquito risk zones” based on mosquito-specific dispersal ranges from local habitats, characterised by vegetation type and potential environmental drivers of mosquito abundance, are being used to guide the design of new residential developments. In conjunction with these developments, constructed wetlands and other water conservation approaches (e.g. rainwater tanks, stormwater infrastructure) are assessed with regard to the potential to produce pest mosquito populations. Site-strategies to reduce these risks are considered. The role of macropods in urban mosquito-borne disease outbreaks, particularly RRV, requires further investigation. The presence of macropods has been shown to increase the risk of mosquito-borne disease. Studies have shown that RRV is more likely to be isolated from local mosquitoes in regions where macropods are present. Therefore, the management of wildlife corridors between urban developments and wetlands may increase the public health risks. Environmentally sensitive mosquito control strategies may be required to reduce the risks where suitable mosquito habitats and wildlife occur close to residential developments.

If you’re at ‘Entomology 2013’, check out my poster on Saturday, November 9, 2013: 3:20 PM (Austin time) in Meeting Room 11 AB (Austin Convention Center).

You can also view the poster here.

Australian Entomological Society conference 2013

bedbug_stevedoggett

Common bed bug (Photo: Stephen Doggett, Medical Entomology, Pathology West – ICPMR Westmead)

The annual conference of the Australian Entomological Society is on next week. Although I’ll be missing the trip to Adelaide this year, our lab will be represented with some presentations on bed bugs and biting insects!

The 44st AGM and Scientific Conference of the Australian Entomological Society will be held from 29 September through until 2 October 2013 in Adelaide, South Australia. These meetings are great and I’m disappointed not to be attending this year. The meetings attract a wide range of researchers in the field of entomology, from those working on agricultural pests through to ecologists using arthropods to measure environmental change.

The theme of the conference is “Invertebrates in extreme environments”. I was originally planning on presenting some work on the saltmarsh mosquito, Aedes vigilax. This is an insect that thrives in the super saline conditions of tidally influenced saltmarsh habitats. It has adapted to these environments be developing dessication resistant eggs, the ability to lay its first batch of eggs without the need for a blood meal and can disperse many kilometers from the wetlands. It also happens to be a major nuisance-biting pest and vector of pathogens including Ross River virus. Time and budgets squished that plan unfortunately, perhaps next time.

I will be there in spirit though as co-author on a couple of presentations:

A New Resource on Medical Entomology

Webb, C.E., Doggett S.L. & Russell R.C.

The field of medical entomology covers much more than just mosquitoes! A new resource will soon be available to those government and non-government organisations that often need to provide advice on a range of arthropods of medical importance in Australia. The Environmental Health Committee (enHealth) of the Australian Government Department of Health and Ageing has commissioned the production of revised guides for the management of arthropod pests of public health importance in Australia. The original document, Guidelines for the Control of Public Health Pests: Lice, fleas, scabies, bird mites, bedbugs and ticks, was produced in 1999 and, while providing a useful resource for environmental health officers responding to enquiries from the general public, much of the information had become outdated. There was also a number important pests and/or pest groups left out of the original document. A new version of the document is expected to be made available for public comment in 2013 and this presentation will summarise some of the key features of, and additions to, the revised document.

and

Insecticide Resistance In Bed Bugs In Australia: Are They Getting A Little Too Cozy In Your Bed?

Lilly, D.G., M.P. Zalucki, S.L. Doggett, C.J. Orton, R.C. Russell & C.E. Webb

Insecticide resistance in bed bugs has been nominated as a major factor in the pest’s resurgence. Recent studies using field and laboratory strains of Cimex lectularius and C.hemipterus across Europe, Africa, Asia and North America have variously demonstrated resistance to the pyrethroids, carbamates and, to a lesser extent, the organophosphates. Resistance has been suspected in Australia, with anecdotal reports of treatment failures due to poor product performance. Early efficacy investigations on a range of formulated products found indications of resistance in an Australian derived strain of C. lectularius. To confirm if resistance was present, four compounds (permethrin, deltamethrin, bendiocarb and pirimiphos-methyl) encompassing the major groups of insecticides then registered for bed bug control in Australia were selected for bioassay along with one compound (imidacloprid) to which strains should not have received any exposure at that time. LD50 values (at 24 h) were determined via topical application of the technical grade compounds serially diluted in acetone against a suspected resistant strain (collected from and designated the ‘Sydney’ strain) and a susceptible laboratory strain imported from Bayer CropScience AG, Germany (the ‘Monheim’ strain). All tests were conducted using mixedsex adult bed bugs that had been offered a blood meal within the last 7 days. All compounds tested against the Monheim strain demonstrated high levels of insecticidal activity. However, for the Sydney strain only pirimiphos-methyl and imidacloprid showed high levels of efficacy. Bendiocarb, permethrin and deltamethrin all failed to return greater than 60% mortality at the maximum applied rate of 100μg/μL. The resistance factor (calculated as: Sydney LD50 / Monheim LD50) for each compound was:permethrin = 1.4 million, deltamethrin = 430,000, bendiocarb = 240, pirimiphos-methyl =2.8, imidacloprid = 2.7. Thus using this experimental protocol, resistance was detected with the pyrethroids and carbamates, but not the organophosphates or neonicotinoids (with thedifferences reflected against those compounds likely due instead to a minor resistance- related fitness cost or physiological difference between the strains). This research has significant implications for current and future insecticide management when attempting to control bed bugs. Further studies are ongoing to determine the mechanism(s) of resistance.

It looks like it will be a great meeting with lots of interesting presentations. The full program is available here and I hope there’ll be some tweeting using the hastag #AES2013