The risks of standard mosquito control practices to ecosystems and human health: A case study for an ecologically designed approach, with Rella Abernathy, Ecologist from City of Boulder, Colorado for the Best Practices for Pollinators Summit 2024.
This presentation was recorded at the best practices for pollinator Summit for more information contact pollinator friendly. org well thanks for for inviting me to speak um and it’s another been another great um Summit this year and um I’m really happy to to be here as part of it
So hello from Boulder Colorado a college town of about 100,000 that’s located about 25 miles Northwest of Denver at the foot of the Rocky Mountains my name is Rel abery and I work as a senior ecologist for the city of Boulders climate initiatives department on the nature-based climate Solutions team so
You might be wondering why a person is giving a talk about mosquito control a pollinator Summit and one answer to that question is that we know that some species of mosquitoes are pollinators and it’s likely that many others are too and another reason is that some mosquito control practices can have direct
Impacts on pollinators and ecosystems but one of the points that I hope to make today is that the very best of intentions can lead to unintended consequences even when following the best management practices from the agencies and academic institutions that are considered the ultimate authorities and those unintended consequences can
Have very real impact on people’s health and the Integrity of the Living World we all rely on but before we dig into that I’d like to take a few minutes um to to show you a little bit more about this fascinating group of insects the mosquitoes so most people hate
Mosquitoes and think of them as these vile blood suckers that have no real purpose and whenever there are stories about mosquitoes in the news you can pretty much count on seeing these photos or videos of people sticking their arms in laboratory C ages to feed colonies but this is actually a much
More accurate representation of how mosquitoes feed um almost all species use nectar as their energy source and only the female mosquito will take a blood meal to get nutrients and proteins she needs to produce eggs and as a rule mosquitoes feed on nectar the rest of
The time and for most species the males do too so most of the photos on fun facts that I’m going to show you in the next few slides are from two articles about wonderful moito biologists who study the beauty diversity and ecological importance of mosquitoes and I can’t I
Just can’t recommend enough this article in the Smithsonian Magazine that features Avon Marie linton’s work and it also has some amazing photographs and research from Lawrence Reeves who’s an enologist at University of Florida and this is another great article in the conversation by Dan Peach who’s now on the faculty of the
University of of Georgia and he does all kinds of really interesting and exciting work on mosquitoes so if you aren’t familiar with the amazing diversity of these little creatures you are in for a treat they there are at least 3750 known species of mosquitoes and Counting around the world and as aom
Linton says here we have grossly we have been grossly underestimating the diversity of mosquitoes the number of new mosquitoes that we find everywhere we go is phenomenal of the nearly four th000 um species of mosquitoes just a 100 are known to be Vector um vectors for disease but the few species that do
Transmit diseases to humans have caused a devastating amount of illness and death to humans of the 700,000 deaths from mosquito Barn illness each year over half of those are from malaria which is carried by anop mosquitoes but of the 430 species of malop anopheles only 30 to 40 of those can transmit
Malaria and of the 200 species that we’ve identified here in the US we regularly and um only 12 of those are known um to transmit pathogens or parasites and our control efforts are mostly in the US focused on West n virus in Colorado we have 57 species identified and we regularly catch around
A dozen or so in our city traps so mosquitoes have a long relationship with flowering plants and mosquito diversity took off um with the evolution of flowering plants and we don’t know a whole lot about the role in pollination and mostly that’s because it hasn’t been well studied but there are
Examples of both generalist and specialist um pollinators that are mosquitoes so this is an example of a pollinator specialist and it’s the snow poool mosquito it pollinates the bluntleaf Orchid which blooms at the same time that the snow pool mosquito merges and when the mosquito takes a
Little drink of nectar its head is just the right size to fit inside the orchid flower and it picks up these little pollen balls or pollenia that stick to its head and it carries on to the next Orchid blunt flower like other insects um some mosquito species have evolved some
Pretty bizarre behaviors which is why I love insects and Dan Peach studied a mosquito that feeds on honey due from sap sucking insects and when an insect like an aphid is capped into the flo of a plant they ex excrete sugary droplets out of their back end and that’s what we
Call honeydew and in SS like ants can feed on honey do actually guard and farm the AIDS um mosquitoes use the odor can use odors are really good at using odors to find cues for flowers and hosts including us and apparently they also use it to track these odors emitted by
Honeydew and when they locate the ants the mosquito Strokes the ant’s antenna and sticks their prosus into the ant’s mouth inducing the ant to regurgitate honeydew and they’re even predacious mosquitoes I’ve heard this the elephant mosquito referred to is the best mosquito because they feed um their
Larva feed on other mosquitoes and on the lower right side here you can see the regular size mosquito larva is being eaten by this huge elephant mosquito larvae and the entire their entire life cycle is really interesting so if you like that kind of stuff um it’s a good thing to look
Up so mosquitoes come in all different shapes sizes and colors and their host preferences for blood seeking um varies widely too many species feed on birds and mammals but there are some that feed on reptiles and even some on fish or worms and there are all kinds of
Fascinating mating behaviors and in this the case of this guy here called the iridescent paddle mosquito he not only has this incredible plumage on his legs but he does a mating dance to trct females there are even examples of mosquitoes that guard their young and this is a hairy lipped mosquito guarding
Her eggs until they hatch so the ecological role of mosquitoes is critical um around the role the globe for ecosystems and they’re an important food source for other insects and animals at every life stage and they and other Aquatic flies form the foundations of wetland food chains so each species
Is different and that’s an important consideration that’s often overlooked in mosquito control programs okay which brings me to the topic of my talk today which is about the risks from mosquito control practices both to human health and ecosystems and I feel like um the mosquito management approach that we’re
Using here at the city of Boulder to reduce West Nile Virus risk can serve as a case study about how to develop a management program of any kind using Eco using ecosystem management principles and this is the West V West Nile Virus web page of the CDC and
Almost all state and local government and agencies look to the CDC for guidance on how to protect the public from mosquito born disease disease so the transmission cycle of West Nile Virus is actually much more complicated than this diagram but people and horses can get West Nile from being
Bitten by an infected mosquito and we’re what’s called a dead end host which means that West Nile um transmission only goes one way from mosquitoes to us and we aren’t the source of West Nile for mosquitoes birds are the main host though some mammals can be hosts too and
Birds not only get West Nile from mosquitoes but mosquitoes can pick it up from birds so once West Nile is high enough levels in bird and insect populations Bard mosquito populations the the levels can build up quickly and amplify which is increasing which increases the number of mosquitos and
The risk for transmission to people so each species whether it’s a bird a mammal a mosquito has different levels of vector competency or the ability for a virus for them to pick up a a virus and replicate it so it can be transmitted and all players in this can
Also develop immunity to the virus and of course viruses mutate so this is a very complex cycle and remember all mosquitoes are not the same all species aren’t the same and so this is a very general classification that um for our purposes talking about mosquito management um
Well so we’re looking at mosquitoes in two rough categories so Vector mosquitoes are the mosquitoes that can be come infected with and transmit West Nile virus and CX um mosquitoes lay their eggs on water in these little rafts mosquitoes AB bite people but don’t translate um transmit disease are
Nuisance mosquitoes and the majority of nuisance mosquitoes in our areas are floodwater mosquitoes they lay their eggs on mud and their eggs dry out which you can see in these photos so mosquitoes are flies and all flies go through complete metamorphosis so on the left is a the life cycle for
Mosquitoes like cix that lay their eggs directly on water and on the right are delayed hatching or floodwater mosquitoes their eggs dry out and can build up over over time like a seed bank in the soil sometimes for years and then once an area becomes um inundated with
Water the eggs reconstitute and hatch and once they hatch the larv have to remain in the water to complete their life cycle so if a sight if sight dries out at this point it’ll kill them just like it would a cix larvae and when there’s a big rain event in the spring
That saturates your large area you can get a synchronous emergence of floodwater mosquitoes leading to a huge Spike they can be aggressive biters and some species can travel Miles and Miles like up to 25 miles beyond the site where they emerge we often see cix and flood water mosquitoes at same sites and
So the flood water mosquitoes hatch in the water and then the CX females come along and lay their eggs at these wet sites so it may seem like lots of rain would mean more mosquitoes and therefore a higher risk of West Nile virus but this study looked at West Nile Virus and
Climatic data and from several states to determine what the drivers are for what human cases and one of the states I analyzed in depth was Colorado so when West Nile first arrived in 2003 we were one of the hardest hit States and this study found that drought and Immunity were the main
Drivers for human cases in Colorado so drought increases the risk and Immunity decreases the risk and drought may not seem to make that much sense because cix lay their eggs on water but when it’s droughty it’s thought that birds that are the main host and mosquitoes will be
More concentrated around water and the odds of coming into contact with each other to spread West Nile um seems higher when immunity has to do with the way that West Nile Virus Infection manifests in people so when a person’s bit by an infected mosquito 80% of people won’t have symptoms at all and
Won’t even know they were infected but after being exposed they become immune and since Colorado is an outdoorsy State there are likely many people who are now immune since West Nile is in pmic and and is always present um present in the summer at some level so most of the 20%
Of people who get infected with what’s called West Nile fever have flu like symptoms ranging from mild to severe and they become immune but the reason we care so much about this disease is because a few people who are infected about one in 150 will develop neuroinvasive diseases that
Cause en sephtis menitis or a poal like um illness called flaccid paralysis and these people become very ill they it can be fatal and people who survive can suffer from life-changing disabilities and thankfully most mosquitoes aren’t infected with West Nile first you know the kixs are just part of the mosquitoes
Out there and then only between two to 8% of mosquitoes are usually infected but since people can get sick if they get the neuroinvasive form of the disease Public Health officials take this disease very seriously and unlike the flu or covid west nile can be prevented by taking precautions to avoid
Being bitten by mosquitoes which is why education is so important so I want you to pay attention to the shape of this graph um the first year West NY arrived in Colorado is zero on the axis x- axis and at that point no one was immune and then in that year we
Had over 3,000 cases in the state but it dropped off in successive years and this graph shows neuroinvasive um cases but the shape um is similar and when when we if if they were plotting just human cases and what’s interesting about this study is that they ran um climate and
Epidemiological models for different scenarios and these symbols past a dotted line are future projections for human risk M is for mean and E is for extreme and they predicted that although um there will continue to be cases that they didn’t expect an epidemic so the rest of this talk I’m
Going to focus on Boulder County and this map of Colorado shows you where we’re located so I don’t know you can see also here if you can see my cursor is the area that we’re talking about here’s the Border um of Boulder County and um about two-thirds of the
County is in the mountains so we’re really focusing on um this area um that’s um onto in the Front Range the western or the Eastern Front Range and these areas that are yellow shaded in yellow and blue are larvel breeding sites that are mapped um um that we visit regularly inspect at the
City okay and I also wanted to point out that we have um we have 45,000 Acres of open space line ENT ring around the city and that’s why we have all these sites um that are on um grasslands egg lands and wetlands so this is a chart um of human
Cases in all of Boulder count County from 2003 to last year and above each bar denotes number of deaths so if you remember what that graph looks like from the study the pattern’s similar now we had the the big um number of cases in 2003 and then it dropped down and stayed relatively
Low um and since the health department relies on Physicians um to report West Nile viruses and the test and then they also have an investigator go out and confirm them and in West the the and the the 20% % of people have West Nile fever have really similar symptoms to the flu
We may may not have the best reporting for those cases but we do have decent reporting of course for neuroinvasive cases and for deaths now this is for all cases in Colorado and you can see kind of um towards the end that they’re starting to rise a little bit Again but this is what’s really alarming this is like a plot of deaths um and as you can see I don’t know if you guys are covered up by um by the by me and um the other presenters but it goes up to 50 this
Last year which is almost as high as it was in when we initially you know had a had the epidemic in in 2003 no we can see your whole slide re okay excellent so the the best method that we have to estimate the risk is by of West
Nile is by trapping mosquitoes and we we set these traps overnight and they have a light source and the carbon dioxide source which attract female mosquitoes looking for a blood meal and the mosquitoes are then keyed to species and counted in the cix mosquitoes from Sentinel traps are tested for West Nile
Virus Infection the population of cix mosquitoes and the infection rate are used to calculate a value called the vector index and z .75 is the threshold that predicts that human cases are likely to occur so let’s look at the vector index values in Boulder County for the last three years when we’re
Starting to see human cases increase and we’ll start with 2021 so the Boulder County Health Department has a mosquito control district and divides the county into three zones the city of Boulder isn’t part of that District so we design and manage our own program and test our own
Mosquitoes um so here are the breeding sites on on um on City owned property again down here to give you a reference and the county inspects and treats mosquito larv on their own properties and trap mosquitoes and spray neighborhoods in unincorporated areas outside the LI the city limits so
Boulder County Zone one is part of the mosquito district and not the city and that would is mainly the areas over here towards the west side of the county okay zone two is I’m going to show you the cursors up here in and around Longmont which is a
City that is north east of Boulder and Zone 3 is this Eastern Area um that’s over here and that’s Superior Louis fil off yet and area which is hiding under this one map so all three of these charts have the same scale on the X index I mean the
X axis to make it easier to compare and the green box um signifies the 05 threshold so once the vector index reaches that point you know it’s likely that enough people will get infected that we’ll start seeing human cases so here’s Boulder um and you can
See um that we didn’t ever exceed the the the 0 Z the 0.75 threshold and each we we test once a week um and so we did have um some positive mosquitoes during 3 weeks but there the light the rate was pretty low okay let’s look and see what happened in
2022 so once again we see multiple weeks in values exceeding 75 sometimes by quite a lot and these four charts are also scaled with each other for comparison in that particular year and um the city of Boulder had no positive test the whole season now let’s look at um
2023 and here we see some of the highest vectors index index values I’ve ever even heard of so the highest um in 2022 was 3.52 and in 20121 was 5.03 which felt crazy at the time but this last year there was one over 15 um I had the data for the Cy since
They share it with other with all the municipalities but the vector index numbers some of them that I saw throughout the state were very high and there are some of the highest trap numbers and the largest number of cix that I’ve ever seen in some of these
Other areas so here in Boulder we had high mosquito numbers too but not nearly as high as other areas and our CX numbers never came close I mean by orders of magnitude to nearby cities and we never exceeded the vector index so the big question is why is
There a difference um between the city and the other jurisdictions and what’s crazy about last year was as unseasonably wet year for us so drought was not a factor but before St talking about the difference between the city’s approach and the other cities and counties in Colorado I
Want to say this I started working for the city 15 years ago and part of my job was managing the mosquito program and so this was in 2009 so it was just six years past the West Nile epidemic and although there were still some human cases eight of eight of the next nine
Years no one died in the whole County but there’s always this fear that there could be a bad West Nile year and the weight is heavy on your shoulders as someone running a program when you worry that the decisions you make can affect somebody else so I just want to make it
Clear that when the other cities are following the guidance of CDC and the state and County Health departments they are doing what they feel is the very best they can do to protect the public okay so let’s um start with all the pro what all the all that we have in
Common between the programs before we look at the difference so we all set up traps and test for us Nile we all map and ins larel breeding sites and we all spend time educating the public there is one difference in how we inspect our laral sites um the city has
Kept data on the density of mosquito larvey at each of our over 500 sites going back to 2002 when we created our program and it just so happens that skilled field teexs can tell the difference between CX and other mosquito larvey so cix are on the bottom and
Mosquito larve don’t have gills so they have to come up just to the surface of the U water to get air and cxs have this long angled siphon on their back ends it’s like a snorkel and this 80s lva looks different at the left um so it’s
The even when they’re tiny and younger instars a skilled field techer colist can tell the difference so we have all of this data tracked for over 20 years of larel data for every site every week for both clex and non-x mosquitoes so here’s integrated mosquito management our um our IM IMM from the
CDC public education involvement and evaluating actions are important and something that we do too but notice that IMM includes controlling nuisance mosquitoes and nuisance mosquitoes don’t carry disease there’s a reason why the city ID’s um cix lar in the field and I’ll explain why in a bit and this is a
Pretty major assumption that these methods are safe and effective because first mosquito populations continue to rise one study showed as much by tfold in the last 50 years and the other zones in the county used every tool they had at their disposal to try to lower numbers when in in West Nile infection
When it was Rising so what does it mean to control mosquitoes at all life stages okay there is an insecticide for every life stage adulticides are broadspectrum insecticides that are fogged from trucks are spray on vegetation this includes trees grasses and plants from backpack sprayers some
People use Organo fos Fates like NAIT or malathion but I think that only pyrethroids are used in Boulder County so pyrethroids are incredibly toxic to both Aquatic and terrestrial invertebrates and associated with the whole Suite of issues in people including cognitive issues in kids and reproductive issues in adults and pasas
Has been um detected in Anvil one of the adul aside products and the initial thought was at at Leech from the plastic container but past is also purposely added to products until the last few months the EPA was past additives and pesticide formulations but what most people don’t
Realize is the active ingredient of many pesticides are actually past themselves and a py a one of the pyrethroids that’s used for mosquito control by fenin including here in Boulder County is a pasas so this is um a page from the Minnesota Department eggs website showing Ben banthin listed as pasas and
I pulled out bifenthrin but this list contains many insecticides and herbicides that are applied everywhere across the country and the chemical industry is lobbing to challenge and limit the definition for past these flated chemicals but fluorinated chemicals are the are the norm now in New pesticides and the Scientific
American article points out that over 70% of new pesticide products are these forever chemicals and do they even work um this estimate from David pimel shows that 0.000000001 % of adul aside droplets even hit a mosquito and last season as West n was Rising others jurisdictions sprayed every week for weeks the
Threshold I used to spray for nuisance mosquitoes normally is 150 per trap and some of these sprayed areas had traps week after week with thousands of mosquitoes including thousands of clex so mosquitoes don’t only become resistant to insecticides but they learn to avoid them as they as we and as we
Get more heat spikes in some cases could become less sensitive there are also studies showing different pesticides um affect the the infection of pathogens in mosquitoes or the ability of them become infected there are just a these are just um a couple of multiple papers on ecological impacts at pids bifenthrin
And prometh have on aquatic ecosystems and surface soils are often used for later um laral in stars and pupy and surface film products are non- selective they’re lethal to All Surface breathing insects including mayflies aquatic beetles and bugs and they are known to impact duck eggs insect growth
Regulators like methoprene which is a synthetic analog of juvenile hormone is applied to water and juvenile hormone is common to all insects as insects grow molda keeps them in an immature stage and when it decreases they can mold into a pupa or an adult so keeping it artificially constant and high blocks
Them blocks insects from maturing it can also keep eggs from hatching um so what impact does this have on non-target invertebrates at these sides and what about larvicides some places still use synthetic insecticides including Organo phosphates for larv though I’m not um aware of any that use in Boulder County
Anymore but one thing I see in mosquito Management Programs is using more and more um of these bacterial larva sides and environmental organizations also really promote their use because they’re trying to get people to avoid synthetic products and fogging and spraying but it’s a big mistake to assume that
Natural products are benign it is in fact just the opposite in the case of these larva sides and I’ll talk about that when I explain the city’s approach so the approach the CDC recommends is really focused on killing as many mosquitoes as possible at every life stage and this seems to make sense
To our human brains that want to efficiently and quickly tackle a problem in a linear and reductionist way but there’s a lot of collateral damage from this approach so what does the city of Boulder do we have an integrated pist management policy that takes the opposite approach so instead of focusing
On killing a Target organism the focus is on managing the ecosystem by promoting the stability of desirable species to discourage pests and promote the natural balances within it this means a lot of observation and monitoring it also means reviewing the literature Consulting with ecologists and applying ecological principles when
Making management decisions it takes patience and it’s ever evolving as we Learn so this view of the moscito life cycle is more in alignment with what we’re trying to achieve in functioning ecosystems are predators at every life stage and the questions we ask are what are the characteristics of the sites where Predators Thrive and how do we increase biodiversity not only of
Predators but of different mosquito species and other fly aquatic larv like caredit that compete with each other as well as feeding predators and they also graze on Plankton and detrus how can we manage our land and our Wetlands to encourage as much biodiversity as possible and what impact do management
Decisions have on desirable species and to the system as a whole I’m going to do a quick review of how the city’s mosquito program came together during the highest point of West Nile so when Colorado was hit in 200 3 we had the highest number of cases in
The nation and people panicked and started spraying insecticides from trucks and from aircraft the city chose not to spray this is before my time um I came on a few years later so traps are set in the grid throughout the city and the mosquitoes collected an ID to see if
They were clex and then the clex sent for testing West n virus testing and there was no risk of West Nile inside the city neighborhoods based on the data so there was no reason to even consider spraying but I found these clippings in an old file and I also found letters
From the CDC from the state and from the county health departments demanding that Boulder sprayed but without evidence that it could help and you know there wasn’t a reason to spray we didn’t spray then and we never have sprayed um for mosquitoes now as I mentioned before
Field text check to see whether mosquito larva ACX or nuisance and from the very beginning and for many years the only sites that were ever treated with bti um were those with CX to avoid necessary um unnecessary bti in our wetlands and later Under Pressure um from the county
And from some recreational facilities a few sites were added um to be treated with bti for for high nuisance um mosquito larvey so that was how this program was structured when I joined the city we made a few minor tweaks but in 2018 we made some pretty major
Changes so um the open space and Parks e colist first categorized every one of our 550 sites as either low or high quality and then we reviewed every site visit since a program began I mean we went through spreadsheets line by line and we created a fairly complex
Threshold to determine if bti could be used we divided the sites by larel breeding history and those that were consistent or high breeding were visited once a week and those that were sporadic breeders were visited monthly in addition every site had biodiversity city data collected I did an in-depth literature
Review to learn as much as I could um about the Ecology of mosquitoes and other Critters associated with these sites and there are also lots of new papers about bti and what we learned made it even more clear that we needed to reduce it as much as
Possible so here’s a simple food pyramid with the planks um Plankton algae microorganisms at the bottom and when this isn’t imbalance we end up with shifts that can water quality the diversity and abundance of primary consumers and even lead to alal blooms when it gets out of whack bti kills
Mosquitoes but it also kills cids and other Aquatic fly larvey and when they’re pulled out of the system it can create a shift at the base level the and they also there’s also a lack of food um that impacts a Predators you Fe on mosquitoes and flies and then Cascades up the food
Chain and as research shows um that this is actually What’s happen happening so I’m just going to show a sample of the many studies that continue to be published on the impacts of bti the mosquitoes themselves adapt but bti is also persistent and since it’s a bacteria it can replicate and can be
Moved to other places and long-term studies show it affects phytoplank the phytol Plankton Community there are multiple studies showing it harms cedit and other invertebrate communities and we see cascading trophic impacts that you’d expect from all that so by reducing odonates who feed on mosquitoes and fly
Larvey and bird populations that feed on dragon flies and other insects that are also impacted we’ve lost nearly three billion birds in North America in the last 30 years and we need to take these impacts from our different practices very seriously but one of the most troubling
Effects of bti is that it’s direct it’s directly toxic to amphibians at field rates and what it does is it tears up the their guts as you can see in this photo so that’s normal gut on the left and on and on the right is a gut from a tadpole exposed to
Bti I don’t think bti should ever be applied to a site with Tad pulse so we’re very fortunate that our contractor is one of the best aquatic entomologists in the region and the staff all passionate and experienced field ecologists who do this work because they want to make a difference
So when you see one of the field ecologists applying a tiny amount of bti um so here what you see is a field ecologist applying a tiny bit of bti to a depression where there is um a lot of heavy mosquito breeding and they’ll also
Do things like just scoop it out if it’s around the margins of a a bigger Wetland the bigger Wetlands almost never have um mosquito larv or or at least not enough to make it worthwhile to even consider treatment and they use an aquatic net for biodiversity surveys and here the if the videos
Working for you guys you can see what they find damsel fly larvey all different sizes and species and different bugs and beetles it’s just like a whole um bunch of Life happening under there and of course they find lots of Tad PS and when they’re just out doing their
Normal dipping with the the um Cup on the end of the of a stick here there’s so much biodiversity at lots of these sites they here’s a whole bunch of um dragonfly nymphs they also do terrestrial um biodiversity survey so they use sweep Nets and they also record fish birds and
Amphibians and what we’re finding is that this fact sheet from Indiana’s DNR is true healthy Wetlands really do devour our mosquitoes we almost never find um mosquitoes at sites with lots of biodiversity and we take the biodiversity of a site into consideration before we would even consider treating at all with
Bti so as we destroy habitat and fragment we are losing um biodiversity at a staggering rate we filled in wetlands and replaced it with homes and Farms of millions of Acres of monocultures of trans dunic corn with bti or BT in every cell with neonic
Coated seed and then we spray it with a cocktail of herbicides that rain miles away and contaminate all of our surface and groundwater and and then end up with dead zones in the oceans where it drains and we landscape our yards and monocultures of grass and as we destroy our habitat and
Fragment that we’re losing vertebrates at an enor alarming rate but we’re also losing insects and with climate change we have winners and losers and mosquitoes are winners they can easily adapt and thrive in all these degraded environments that other insects including their predators and and that
Birds can’t so why are we seeing a rise of mosquito populations in Western a virus well the worse it got the more people tried to fix it and the more they treated with bti with oils and insect growth regulators and sprayed adulticides trying to keep people from
Getting sick but we also had a a very wet year and so that meant more weeds and more herbicides and doing a quick look at the literature there’s several studies showing the impacts on mosquito larvey um from herbicides on their growth and development and in in in some
Cases it makes them more susceptible to pathogen infection so how do we manage mosquitoes instead of in in a way that um can keep people safe well I think that instead of focusing on killing them which is a zero some game that they are winning that instead what we should be
Doing is managing ecosystems we need to restore degrad areas and use Land Management practices that conserve insects so this beautiful diagram um was created by a local artist Faith Williams for the xeri society during the Colorado pollinating insects study and here is is the the the the the solution to what we
Saw from all the destruction the prev diagram in the Wagner paper here are the answers to reversing insect Decline and by doing that we not only save insects but the foundation of the world’s ecosystems and ourselves we need as many insects as possible to be winners during this time
Of Rapid change and we need mosquitoes to be part of thriving ecosystems and it’s not too late when when eel Wilson died I saw this article and this is something we have to keep in mind so in closing I want to share um this video of one of our field techs out
Doing her biodiversity and not field tech and ecologist a field ecologist out doing her weekly checks biodiversity checks as she went through a field of butterflies and not butterflies I mean dragon flies all of those are dragon Flies is they’re Beautiful okay thank you for your time and I hope that more and more people will start considering um that the true impacts that trying to control mosquitoes has raella that was amazing um we do have some questions if you’re up for it all right everybody loves you um thanks for all the
Love and remember that mosquitoes aren’t always the bad guys and we make them the Bad Guys by the way we try to control them yeah while we are on the top of the food chain aren’t we so all all blame is on us almost every time right um do you have any
Recommendations for presenting this idea to homeowner associations or neighborhood groups or even communities yeah um one of the things that we need to do is take this complex topic and and present it in a way that you know is more concise and that we could share as a short case
Study um you know people come to me and say well how can we do this in our community and it really is a fundamental shift in the way that Health departments um and communities manage for mosquitoes you know and as climate keeps the climate change keeps um becoming more
Severe we’re going to see more and more um insects and mosquitoes moving in you know insects are on the Move everything’s on the move and so we need to really not panic and stop and think about the Ecology of a system before we make you know rash decisions that could
You know just compound the problems that we’re having you know with some of these pest insects but um go back to your question um one of the things that’s really really problematic are these barrier treatments that so many people use in in HOA properties and in their yards and those are the mosquitoes
Without you know the the Summers without mosquitoes that are advertised by mosquito Joe and and um True Green and a whole bunch of companies there’s just H tons of them and what they do is they go every two weeks the entire season and spray everything because different mosquitoes have different behaviors and
Some rest in trees some rest in flowering plants or grasses and they just spray everything and the idea is that it’s persistent enough um that it lasts for those two weeks and it’s toxic enough that when a mosquito lands on it it kills them so think about what that
Means for everything else that’s in your yard and for your kids and your pets and so that’s one thing to really educate people about is is that these things are not good ideas to use right and uh it if it’s okay with you re we we recorded this talk and we
Can uh post it along with the other videos on the YouTube page and I encourage people to send that link to your communities to your Public Works departments and your U mosquito control agencies yeah and like I said it’s it’s you know when when you’re concerned about keeping people from getting these
You know really scary diseases is it you have to really um have some confidence that you know an ecosystem can take care of itself and that may mean restoring them before you are ready you know to pull the trigger on a program like this um but you know
From what I saw the the more and more people treated the worse things got and I was just alarmed when I saw some of the numbers you know in in a city close to us where they were spraying praying every week and doing everything they could think of and they were had
Incredibly High Vector indexes they would have more mosquitoes more CX mosquitoes in one trap than we had in all of our traps across the entire city of Boulder so you know if it worked um and kept mosquito numbers down then you could see the rationale behind
It but it doesn’t seem to work and and then you add all these other issues that compound the problem so it really comes down to biodiversity and a paradigm shift in how people think about things yeah and there actually believe it or not there’s actually controversy among the disease ecology Community
About rather the biodiversity actually um slows down the transmission of zoonotic diseases or if it’s protective and um I think you know when you the more and more data we can get um in stud that are done you know you know according to the ecological principles
It should dilute or slow down the effect so if you have a site that has five species of mosquito larv and 20 species of kids you know they’re all going to be competing for space and for resources and that just there just fewer CX mosquitoes you know to come into contact
With West Nile so you know I I really think that diversity is key to this at least in this situation have you seen other communities use Boulders model I haven’t but one thing that’s interesting is Wisconsin takes bti seriously you have to get a permit from the state to be
Able to apply it for mosquitoes and they will only apply allowed to be applied for clex and so they do actually you look key between when and when they’re out in the field you know they they they only can treat if they see CX mosquitoes so that and
You know compared to Colorado um Wisconsin has like a much bigger mosquito problem as far as like um nuisance mosquitoes and people just live with it you know because they’re not treating with larvicide for nuisance mosquitoes well thank you so much re this has been a really important um talk
I’m so glad you were able to join us um and we’re gonna do you have any final important words or tips you’d like to share well I I you know what what I’m hoping is that whenever we’re thinking of managing for any any organism we consider a pest whether it’s a weed or
An insect know that we really take the time to dig in and learn about it and observe and um and not be reactionary I think that could make such a difference in um in in healing the land and and starting to reverse these really alarming trends