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0:04
<LAUREN> I'm Lauren Fordyce, the Urban and Community IPM educator for UC IPM. And today's presentation will be on mosquitoes and ticks of public health concern. So we're excited to have presenting today Mary Sorensen. Mary has over 25 years of experience using integrated pest management principles to approach insect problems in the real world. In her current role as senior research scientist with the Placer County Mosquito and Vector Control
0:30
District, Mary integrates scientific and data management best practices to enable evidence-based decision making in mosquito and vector management. Mary is a board-certified Public Health Entomologist and holds a doctoral degree in entomology from the University of California, Riverside and a Bachelor of Science degree in Molecular and Environmental Biology from the University of California, Berkeley. We're honored to have you join us today,
0:53
Mary. And you can now begin sharing your slides. <MARY> I'm happy to be here today and to talk to you guys about mosquitoes and ticks of public health importance. It's something that I've spent a lot of my life working on and I care a lot about, and I'm excited to share it with you today. It's a big topic for only an hour. So my goals today are to give you just a taste for the topic and, hopefully a couple of fun facts and some information that you can take with you
1:28
and use in your day to day life. And because this is an integrated pest management webinar series, I want to make sure and tie in it what we in this public health field like to call integrated vector management, which pulls a lot of the same principles from integrated pest management. So there's a lot of different definitions of what IVM is. But here is one: All right. Integrated vector management. Integrated vector management is the application
2:01
of biological and ecological knowledge of vectors and their pathogens to reduce public health risk from vectors and vector-borne disease in the most efficient and sustainable manner, while protecting public health and the environment. And I know that's a lot, but we'll talk about each element of these things as we go through this presentation today. So some of the key important parts of IVM or integrated vector management include
2:32
public information and education, as well as surveillance of vectors and pathogens and of course, control. And this is a little bit different than traditional agricultural IPM, partly because of the emphasis on public information and education, because we're talking about public health prevention. Our partnerships become really, really important and probably the most important of all of our partnerships is with the general public.
3:00
That is who we are serving and whose health we're trying to protect. The agency I work for, the Placer County Mosquito and Vector Control District is located in Placer County, California, just outside Sacramento, shown in the red here. We are a local special district founded in 2001. We have around 22 full time employees, and we focus our activities on mosquitoes and ticks primarily, also yellowjackets, and a few other vectors. And it's important for this talk partly
3:37
because it's where I work, but also partly because we are one of many similar agencies throughout our state, generally called mosquito and vector control districts or vector control districts. And, while they are different in some aspects, they are all focused on protecting public health throughout our agency. Most of what we do is focused on mosquitoes. So mosquito surveillance, mosquito pathogen testing, disease testing and also mosquito control also ticks, yellowjackets
4:12
and of course the very important public outreach. The map of our district. And, we like Placer County. It tends to be really interesting from a biological perspective because we have very diverse habitats. So we start from just outside Sacramento, which is in the Sacramento Valley, close to sea level, all the way up to Lake Tahoe. and some parts are around 6000ft elevation, very different habitat, very different vectors and very different
4:43
strategies for protecting public health. One of many interesting aspects of Placer County is that in the western part of the county, there's a lot of rice agriculture. So mosquitoes develop in standing water and rice is grown in standing water, which means that rice is very important when you're thinking about mosquito control. And on top of that, we have one of the fastest growing cities in the entire country I believe, Roseville, California.
5:13
And some of that new development is less than a mile away from rice growing areas. So we have a lot of interaction between mosquitoes and people. So, like I mentioned, Placer mosquito is only one of many, many mosquito and vector control agencies in California. Not all parts of California are covered by a similar agency, but nearly the whole state is. Some of these are local special districts. Some are part of a county government system or a city government. But
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they're all focused on protecting public health, primarily mosquitoes, but also other vectors, and they all use integrated vector management. One of the fantastic things about these local agencies is that they're able to really target and specialize in local problems and become specialists in those local issues. I mentioned collaborations and partnerships. All of these agencies collaborate with each other, as well as with the California Department of Public Health,
6:17
the University of California, and other agencies that are focused on public health. And those collaborations are super important. I mentioned area-specific problems. There's a few kind of interesting ones that I wanted to mention. So in some parts of the state, rodent control is less important, but some mosquito and vector control districts also focus really heavily on urban rodent control, which is really different. There are parts
6:48
of Los Angeles that have problems with a flea borne typhus that is associated with opossums. So those people have had the opportunity to become experts in opossum biology and control. We also have lots of areas of the state where urban stormwater management becomes incredibly important for mosquito control. One of the interesting things my district does that not all districts do is yellowjacket surveillance and control, particularly in the Tahoe area,
7:20
and various parts of the state also deal heavily in wetland management. So that's an overview of mosquito and vector control districts. But I wanted to shift gears and get into the specific species of interest in California, starting with ticks and then moving on to mosquitoes. So diving into ticks, our most important tick in California for public health is Ixodes pacificus, which is the western
7:50
blacklegged tick. This is the most important tick for public health because it's also the primary vector in California of Lyme disease. Most people have heard of Lyme disease. It's, I think, very much in the public consciousness at this point, but a lot of people might not know the specifics of how it's transmitted or how to protect yourself. So this species of tick is active year round, but particularly in the winter and spring.
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The life stages that can bite people include the adult female and male,
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as well as the juvenile stages, which are the nymph and larva. And you can see from the tip of the pencil in the photo that these are very small creatures, particularly the nymph and the larva. However, when the adult female feeds, she can become quite a bit larger. So this is an unfed female in this picture on the right, along with a fed female that is engorged with blood. So they do ingest quite a bit of blood,
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and they do change size pretty significantly. It takes them a while to do this. A mosquito might land and bite you in just a couple moments, but ticks can remain attached for several days. The tick that transmit Lyme disease are primarily found in mixed oak grassland, although they can be found in other habitats as well, and are most common in mid elevation foothills type regions, in both the Coastal Range and also in the Sierras. Adult ticks are most
9:34
often found on grass or low vegetation, whereas the younger stages, the nymphs and larvae, are most often found on rocks, logs, and leaf litter. This is sort of a newer finding and a newer public health message that we're trying to get out to the public is to be careful when you're hiking, when you sit down on a rock or a log, because that is exactly where these nymphal ticks are located. Nymphs are considered more risky or more dangerous than adult ticks for a couple of reasons.
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One is that they're simply harder to see. If you receive a bite from an adult tick, you're more likely to notice it and remove the tick. Whereas nymphs are so small it's more possible for them to be overlooked. There's also some evidence that nymphs have a higher infection rate with Lyme disease and are more likely to transmit the illness than adult ticks. The life cycle of the pathogen that causes Lyme disease is a little bit complicated,
10:41
but in this diagram, it shows starting over on the far left that tick larvae emerge from the egg and they are not infected with Lyme disease. In order to be infected, they have to bite the host. So each stage of the tick lifecycle bites and takes a blood meal.
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The younger, smaller stages of the tick tend to feed on smaller animals like rodents and lizards. If they bite a rodent that is infected with the Lyme disease bacterium, then that larva or a nymph will pick up the pathogen, become infected, and then have the potential to transmit it to a person after that. So in a later life stage, as a nymph or an adult, if that infected tick bites a person,
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it has the potential to transmit the infection. If it bites a mammal like a deer or a rodent, it can also pass on the pathogen and maintain that cycle in nature for future ticks to pick up and transmit to people. After an adult tick is fed, it will drop off the host where it will mate, and then lay eggs in the grass or leaf litter and start the cycle again. While Lyme disease is the most commonly known tick-borne disease and the Lyme
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disease transmitting Western blacklegged tick, or Ixodes pacificus, is one of the more common and more well-known ticks. We also have many, many other species in California. Here are just a few others that are of interest for public health. Two species of Dermacentor ticks, the Pacific coast tick and the American dog tick, which are pictured here and then also not pictured is Rhipicephalus sanguineus, which is the brown dog tick. So these three other species are also hard ticks,
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and they have a similar lifecycle of questing by sitting on grass or other vegetation and waiting for a host to come by. They're all capable of transmitting other illnesses as well. The illnesses include tularemia, spotted fever, group rickettsia, and tick paralysis. And while none of these are nearly as common as Lyme disease, they are all serious illnesses, so avoiding tick bites is a good idea. The last tick species I want to talk about is
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Ornithodorus hermi, which is a soft tick and has a very different lifecycle than the other ticks that we've talked about. Rather than existing primarily out in vegetation, soft ticks tend to live in the nests of their host. So this particular soft tick can feed on and live in the nest of several different rodent species, but seems to be particularly associated with chipmunks, which makes sense because they are also seem to be most often found at higher elevation mountainous
14:05
locations and where they most often come into contact with people is in mountain cabins. So what we sometimes see is that people use mountain cabins seasonally, and when there are no people present, rodents, including chipmunks, might move in and make nests. The ticks move in along with them. And then when people come to use their cabins less frequently, as they're sleeping at night, these ticks will emerge from the rodent nesting areas, crawl surprisingly quickly toward
14:37
the sleeping person, and take a blood meal. Also different than hard ticks, they don't feed for several days. It's a much shorter feeding period, so they take their blood meal and then scurry back to their hiding places. Besides just being unpleasant, this is also dangerous because this particular species of tick can carry tick-borne relapsing fever. And we do see a couple of cases a year in the mountainous areas of California.
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So I want to talk about what mosquito and vector control districts do with ticks. So ticks in California are primarily a threat for people who are doing outdoor recreation or outdoor work, as opposed to people who are spending time on their own residential property. On the East Coast and in the northeast, what we see a lot is exposure to ticks in people's backyards. And that's really different than
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what we see in California, what the epidemiology of ticks and tick-borne diseases is in California. So in California, mosquito and vector control districts really go out onto hiking trails and outdoor recreation areas to do tick surveillance. And the way that they do that is with the tool pictured here, which is called a tick flag or tick drag, which is a big white piece of cloth that is passed along the ground or along the vegetation that ticks that are sitting and
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waiting for a host, animal or person to walk by will grab onto that cloth and can then be collected for identification and testing. Pathogen testing lets us know which tick-borne diseases are present in the area and at what frequency.
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And then I want to talk about what you can do when it comes to ticks. So even though backyard exposure is not as important in California, it's good to know that if you're the manager of a property or if you have a larger yard, particularly if your yard backs to open space or is connected to any kind of wilderness area, it can help to keep grass trimmed short and remove debris from the yard. It can also help to exclude wildlife, for example
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by fencing for deer, that can cut down on the tick population and also reduce tick exposure. But because most of our tick encounters in California are in wilderness areas, really what's most important to know is about personal protection. So there's a few ways that you can avoid being bitten by ticks while you're in natural areas and tick habitat. One of the most important ones is repellent. We may be more familiar with repellent for
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mosquitoes, but there are repellents available that work for ticks as well. So spraying, yourself, particularly the legs and feet, can help a lot. Also, wearing clothing that covers your skin and tucking your clothing in so that ticks can't crawl underneath your clothing. So, for example, tucking your pants into your socks. There's also been some really good research showing that bathing, either showering or
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taking a bath soon after visiting tick habitat can be very effective for reducing tick bites and reducing tick-borne illness. We think this is probably because some ticks might be crawling, but not yet attached, and so bathing can remove those. Performing tick checks is super important as well, even if a tick has already bitten you. For Lyme disease specifically, it's thought to take about 24 hours for the pathogen to actually transmit to the host.
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So if you can find and remove a tick very quickly after the bite occurs, then you drastically reduce your chance of picking up any tick-borne illness. And finally, if you do know that you've been bitten by a tick, we advise people to monitor themselves for any sign of illness. So for tick-borne illnesses, Lyme and others, symptoms can vary, but are often flulike, and there's often some kind of rash involved. You may have heard of the stereotypical bullseye
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rash that comes from Lyme disease, and that is true, but the public health messaging is getting away from that a little bit, because it's been found that not all people who are ill with Lyme disease experienced the rash. Additionally, if the rash occurs in an area where it's less visible, like on the scalp, or if the person has very dark skin, the rash may not be visible. So rather than telling people to look for a bullseye rash, we want to encourage people
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to just monitor for any symptoms of illness. And if you do see those symptoms or have concerns, you'll want to talk to your physician and just let them know that you've been exposed to a tick bite. So moving on from ticks, I want to talk about mosquitoes.
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So there are so many kinds of mosquitoes. A lot of people think of a mosquito as being a single type of organism. But really they're all very different. In the United States, we have about 150 species, and in California we have more than 50. Not to brag about Placer County, we think we have the most species in the entire state. Like I said earlier, we have extremely diverse habitat, and that means we have a lot of different mosquito species. Not all of these species
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are of any interest to public health or people. Not all mosquitoes even bite. And those that do bite, not all of them bite humans. To review the mosquito lifecycle: in order to complete their lifecycle, mosquitoes require water. So the larval stage and the pupal stage require water for their development. Adult mosquitoes lay eggs on or near water, or in areas which will be flooded by water at some point. Mosquito larvae, most species,
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but not all, tend to hang out in this sort of position at the surface of the water, where they breathe air through a tube in their abdomen, called a siphon. They have a unique escape behavior where, if they're disturbed by a potential predator, they drop down from the surface of the water and dive with a characteristic wiggling motion.
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The pupae, the pupal stage of many insects is immobile, but the pupal stage of mosquitoes is actually fairly mobile. They similarly hang out at the surface of the water and have a similar escape behavior, where if they're disturbed, they wiggle and dive down. One of the old fashion names for mosquito larvae was wigglers and mosquito pupa, tumblers, because of the characteristic motion that they make. Because mosquitoes are so specialized and so
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important for humans, sometimes we forget that they are actually a species of fly. So they have two wings like other flies, as opposed to four, like most insects. Then only the female mosquitoes feed on blood. This is different than ticks, where the males and females feed on blood. As I mentioned, not all mosquitoes bite or bite people, and those host-seeking females use cues like carbon dioxide, which is exhaled when we breathe out, as well as skin odors, heat,
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and other cues to find the hosts that they're looking for so they can take that blood meal. Mosquito bites alone, even without the threat of disease, can be a serious public health threat. Large numbers of mosquito bites or severe reactions to bites, like many people have, can cause lost work time, and decreased quality of life. I mentioned that not all mosquitoes bite people. So here are just a few of the other hosts that
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certain species of mosquitoes will bite. Other species of mammals are very common, as are birds, and there are a few interesting and unusual types of mosquitoes that specialize on biting reptiles and amphibians, and there's one that even specializes on feeding on flatworm blood. Mosquito mouthparts appear a little bit like a straw, but they're actually much more complex. When a mosquito starts to bite, it actually injects its host with materials that contain
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compounds similar to an anesthetic to decrease the pain response, and also an anticoagulant to keep the blood flowing. During this injection phase is when many pathogens are transmitted because the material is coming out of the mosquito and into the host, so if that mosquito is infected with a pathogen, that's how it's transmitted to the host.
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As I mentioned, there are many, many species of mosquito in California, but I'll talk about just a few of the most important for public health. The first one I'll talk about, and possibly the most important is Culex tarsalis or the western encephalitis mosquito. These mosquitoes in some areas of California are the primary vector of West Nile virus. Their larvae are able to develop in a wide range of habitats, including green swimming
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pools and agricultural sources like rice fields. They tend to like larger bodies of water that have some organic material, but not a heavy, dense organic material. The adults prefer to seek their blood meals from birds but will bite people given the opportunity. West Nile virus is currently our most important mosquito-borne illness in California, so I wanted to review the life cycle of West Nile virus. So in nature, West Nile virus is actually a bird
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virus that exists in a cycle with mosquitoes. So birds carrying the virus are bitten by mosquitoes, which usually then go on to bite another bird. However, sometimes those mosquitoes may bite a person, or horses are particularly susceptible to West Nile virus as well.
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The other most important West Nile virus vectors in California are Culex pipiens and Culex quinquefasciatus, the northern and southern house mosquitoes. These two species are considered sister species. They're indistinguishable under a microscope, and they have similar habitat habits. But the northern house mosquitoes live in the north and the southern house mosquitoes live in the south. Both are important
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vectors of the West Nile virus in California. Their larvae can also adapt to a wide range of sources, but they're particularly associated with urban sources like stormwater systems and also very organic sources like sewage, water or dairy ponds. Like Culex tarsalis, the adults prefer to feed on birds if they're available but will also bite people.
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In areas of California that are more urban, like large parts of Southern California and the coast, these are considered the most important West Nile virus vectors. Anopheles freeborni, or the western malaria mosquito, is another important mosquito in California. Some people may not be aware, but historically California had a big problem with malaria, which has gone away now due to improved mosquito control as well as improved health care
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for health care and the availability of treatment for humans who have contracted malaria. So the last locally acquired case of malaria we had in the state was in the 1980s. However, we still have a lot of these mosquitoes, and they can be a big nuisance. But larvae develop in larger water bodies, particularly those with a lot of algal growth, and they're heavily associated with rice fields. Anopheles freeborni mosquitoes prefer to feed
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on large mammals, particularly cattle, and they will also readily and aggressively bite people. Depending on where you live in the state, you may be familiar with these because they are particularly notable for their tendency to come out and bite people on the first warm days of spring, or if we have an unusual stretch of warm days in the middle of winter. it can be surprising to see mosquitoes at those times of year when they're not expected,
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particularly when these are a little bit larger than your average mosquito and very aggressive. Aedes sierrensis is the western treehole mosquito, and they have a very specific larval habitat, which is the holes, k not holes or tree holes that are formed in old trees, particularly where a branch might have died. Small pools of water form in those holes, and that is the habitat for the larval development of the species. These are not very important vectors of human
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disease, but they are very important vectors of canine heartworm, which is an important and dangerous, pathogen for dogs and cats, as well as many types of wild animals. So if you've never heard of canine heartworm or dog heartworm and you have a pet cat or dog, I would encourage you to talk to your vet about that and see whether it would be appropriate to get your dog or cat on preventative medication to prevent them from getting infected with heartworm.
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As you might guess, they prefer to feed on mammals like dogs and cats, but they will also readily and aggressively bite people. They tend to stick close to their treehole habitat, and they tend to bite mostly in the shade. The next mosquitoes that I want to talk about are a very, very large group that have a few things in common. So we call these floodwater Aedes or floodwater mosquitoes, and there's many, many similar species that all have slightly
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different preferences for habitat. But all of these lay eggs that remain dormant in the soil, potentially for years, which creates a condition where those eggs will wait to hatch until conditions are just right for that species. When the conditions are right, they may emerge in extremely large numbers. Most of these floodwater Aedes prefer to feed on mammals, and there they all tend to be fairly aggressive biters of people. So some of them are springtime
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floodwater Aedes, for example. In my area we have a lot of Aedes increpitus that develop in low areas in fields and woods where water has accumulated from spring rains. But there are also summer and fall floodwater mosquitoes. There are mosquitoes that specialize in developing in brackish water on the coastal salt marshes, and there are even mosquitoes, floodwater type mosquitoes that develop in snow pools. And we have these in Placer County near
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Lake Tahoe. There are several different species. They tend to be some of the ones that we have around Tahoe are somewhat rare or uncommon, but the eggs all remain dormant in the soil, even in below freezing temperatures, buried in snow all winter long. The eggs are viable. They're very durable. They're able to survive that and wait until the water starts to melt in the spring, the eggs hatch and the larvae are able to live and develop at extremely low temperatures. And
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these snow pools, almost all insect species and mosquito species tend to thrive in warmer weather, so it makes it more interesting and remarkable that these snowmelt mosquitoes have evolved to develop in these low temperatures. Like other floodwater species, they can emerge in very large numbers and can be aggressive biters of people. The last group of mosquito species that I want to talk about here are the invasive Aedes. We also call them invasive mosquitoes as container
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mosquitoes and anthropophilic mosquitoes, which means they are people-loving mosquitoes. So starting about ten years ago, our state started to see first Aedes aegypti, then Aedes albopictus and finally Aedes notoscriptus popping up first in Southern California and now Aedes aegypti has spread throughout a good portion of our state. Besides just that, these are new species and they don't belong here. There are other reasons for pretty big concerns with what
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we're seeing, Aedes aegypti in particular. So I've talked about how different mosquitoes have different biting preferences and different preferences for larval development habitat. Aedes aegypti has a preferred larval development habitat of artificial human-created containers. So given a choice of a pond or a tree hole or any other habitat, this picture here kind of shows a typical Aedes aegypti development location besides just sort of like random containers
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laying around. They are also really well known to develop in flowerpots and flowerpot saucers. And beyond that, their biting preferences are also concerning. Aedes aegypti prefers to feed on people over any other animal. In other parts of the world, Aedes aegypti is a primary vector of things like dengue, chikungunya and Zika virus, which are all very serious mosquito-borne illnesses. Last year, we saw our first locally
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transmitted cases of dengue in California. In Southern California, I believe there were two, and we expect to see more in the future. Aedes albopictus and notoscriptus are similar but have a less strong association with humans. Nonetheless, they're all sort of backyard mosquitoes that will readily utilize artificial habitats for development and will readily bite people and all our potential disease vectors. Here are some maps showing the spread of these
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three invasive species in California. Aedes aegypti, on the left you can see all of the yellow. Green is places that have been, have experience, trapping and surveillance, looking for those invasive species but have not found it. And yellow is where it has been found. Aedes albopictus is less widespread, but still pretty widely distributed in the state. And then Aedes notoscriptus for now is fairly limited to Southern California.
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So back to integrated vector management. We've talked a lot so far about biological and ecological knowledge of our vectors. So where do they live? What do they feed on? How do they interact with the environment? I want to talk now more about how mosquito and vector control districts, and also the public, can reduce public health risks in an efficient and sustainable way. So we like to think of our mosquito and vector control activities in terms of this triangle.
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So at the bottom is source reduction which means removing the potential for mosquitoes to develop. And we have a corresponding green box over here showing what stages we're targeting. With that. So source reduction could be something as simple as dumping out a bucket in your backyard. All the way up the triangle, we move through biological control, larval control, finally to adult control, and correspondingly this arrow in the middle shows prevention,
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future prevention as opposed to an immediate and emergency intervention. So in a situation where we know that there are infected mosquitoes imminently flying around biting people and transmitting disease, that might be an appropriate use of adulticide or adult mosquito control. One of the most important and also time-consuming parts of vector control is doing inspections. So here are a couple of people doing inspections with one of our most important vector control tools.
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It's called a dipper, and it's essentially a little white cup on a stick. But what this allows our technicians to do is to check water sources for the presence of mosquitoes. And this ties into integrated vector management, whereas we don't want to be using pesticides to treat places that are not actually producing mosquitoes. So we verify the presence of mosquitoes, and we also identify the species. Similarly, we have, most vector control districts,
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have a surveillance program for adult mosquitoes that involves mosquito trapping. These are some photos of just a couple kinds of the many, many types of mosquito traps that are out there. Mosquito traps vary in their exact design, but most of them use some kind of attractant, often carbon dioxide, to bring the mosquitoes close, and then most use some kind of a fan to suck the mosquitoes into a collection device like a mesh bag.
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Like I said, there are many types, but they all have kind of a similar principle. Once the mosquitoes are captured, they're brought back to a laboratory where they are identified, counted, and often tested for pathogens as well, primarily West Nile virus. But there are also other pathogens like St Louis encephalitis, and more recently, with our concern about dengue, Zika and Chikungunya. Some mosquitoes are tested for those as well.
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I also wanted to throw in that mosquito and vector control districts also do pathogen testing on dead birds. So I mentioned that West Nile virus is actually primarily a disease of birds. So one of the things that can be helpful is if the general public calls in sightings of dead birds, some of those are collected by mosquito and vector control districts and tested for West Nile virus. I mentioned source reduction,
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which can be as simple as dumping out a bucket in a backyard. It also can be much more complex. Source reduction is not at all a new idea. back in maybe the 1800s, there were large areas of swamp that were drained to prevent mosquito production and for other reasons due to environmental concerns. That's not a tactic that most people would advocate now is draining huge swamps. But we do nonetheless do source reduction on things like tire collection programs,
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public awareness campaigns for things like dumping out plant saucers. And this picture is of some of our technicians removing a beaver dam that was causing a mosquito source in a residential neighborhood. Biological control is also a very important tool for integrated vector management, and our primary biological control agent is mosquito fish. The mosquito fish themselves are not native to California. However, they are widely naturalized,
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especially in urban areas. So their use has to be, again with integrated vector management, really balanced with the pros and cons and the exact habitat needs to be considered. So an appropriate use of mosquito fish might be in a green, abandoned swimming pool in a backyard that is not connected to any natural waterways, and an inappropriate use of mosquito fish might be in a sensitive creek restoration environment. Larval control, or larvicide with pesticides is
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also an important tool in mosquito control. It can be used on a small scale. This is an unmaintained backyard Jacuzzi, and someone's doing a hand application of a granular product. There's also backpack application. This is an Argo vehicle applying larvicide in a pasture and in some instances, like rice agriculture, larvicide can actually be applied by airplane. As I mentioned in the slide with the triangle, adult mosquito control is really seen as a last
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resort when everything else has failed. But it is really essential in certain circumstances where the risk of virus transmission to the public is very high. And like larval mosquito control, it can occur on a very small scale, an acre or less, with a handheld application device on up through a truck or a drone all the way to a wide, large area of aerial application of mosquito adulticide. Other mosquito and vector control activities address the efficiency and sustainability of
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our IVM programs in a lot of different ways, but a couple of those are with resistance testing and efficacy evaluation. And what the resistance testing looks at is whether insecticide resistance is occurring to the materials that we're using. It's known that if insecticides are used continuously for a long period of time, the population that they're being used against can actually build up a resistance or a tolerance, and the material can become no longer effective.
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So one important thing that vector control agencies do is to monitor and check and take measures to prevent that from occurring. Efficacy evaluation involves putting out sentinel mosquitoes in a treated area to verify that the treatment is working as expected, so small cages of mosquitoes, and then we look for mortality after the treatment.
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I wanted to take a quick minute to talk about how innovative mosquito and vector control districts, particularly in California really try to stay on the cutting edge and are always looking for new and better ways to do their jobs. So there's things like sterile insect technique, the use of UAV or drones, pathogen resistant mosquitoes, automation and artificial intelligence, and big data and machine learning that are very much a part of mosquito control.
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And I'm pleased to say that California really is on the cutting edge of investigating and trying to adopt some of these newer technologies. So some of the things residents can do include source reduction in your own yard. Keeping pools and fountains maintained, replacing birdbath water. Dumping out standing water from saucers under plants. Consider if you have an appropriate location for mosquito fish and over the counter mosquito control products
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that are based on BtI. Excluding mosquitoes from your home by keeping window screens in good repair. Spatial repellents are readily available to buy, and they some of them are disguised to look like lanterns, and they claim to repel mosquitoes from a small area. A lot of these products are effective, but they require people to stay near them and can provide a false sense of security. The most important thing, in my opinion,
45:47
that people can do to protect themselves is the personal protection with things like mosquito repellent spray. There are a variety of kinds of mosquito repellent spray that are very effective, including Deet, which most people have heard of, as well as other active ingredients that you may not be familiar with. And if you don't remember anything else from my talk today, the thing I'd like you to remember is that you can tell if a mosquito repellent
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will be safe and effective by checking the bottle for an EPA registration number. There is a very rigorous process that a repellent has to go through to receive an EPA registration number, and they have to prove two things. They have to prove that it is safe, and they have to prove that it is effective. Without an EPA registration number, those things are not guaranteed, and you don't know what you're getting.
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If you have mosquito problems where you live and you need help, I would encourage you to find out who is your local mosquito and vector control agency and to report problems. Most of these agencies take requests from the public for inspections and service in their area. To find out which agency is in your area, you can go to www.mvcag.org and they have an interactive map where you can look up your address. Thank you for your attention today and I hope
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you enjoyed learning about mosquitoes and ticks. <LAUREN> Yeah. Thank you, Mary, for that great information. I definitely learned a lot.
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