How Mosquito Repellents Work

How mosquitoes find us:

Before we can understand how mosquito repellants work, we need to understand how mosquitoes find us in the first place.  Unfortunately for us, mosquitoes have evolved 3 ways of seeking out a meal. Each of these methods, used in tandem, enables them to fly in for the bite.

  1. 33 – 99 feet: At this distance mosquitoes rely on their sense of smell, specifically the CO2 plumes we, or other animals, emit.  Experiments have shown that the female mosquito only pays attention to the next cue once the first is present and they are closer to the source.
  2. 15 – 33 feet: The mosquito has homed in on the scent and at this distance is now searching for visual clues to spot you.  They are seeking the source of the CO2, not for a shape or body. 
  3. 1 – 3 feet:  The mosquitoes now rely on thermal sensory input to locate heat and moisture sources.  This prevents them from wasting time on objects such as a rock or vegetation.  

Mosquito repellents are designed to block the mosquito’s sense of smell in stage one.  This is important as it means that someone standing next to you, without repellent, will be attracting mosquitoes.  Of course, once the insect is within 33 feet of you, it now will not distinguish between you and your un-protected friend, meaning you are equally as likely to be bitten as they are.  We often hear people tell us that mosquito repellents don’t work. This is not necessarily true and is more a factor of those around you, as well as how well the repellent has “stuck”.  For example, if you are out in the yard with your spouse, and they just happen to sweat a lot, the repellent may have run off them. Hence, they are the magnet bringing them in to bite you.

What repellents do:

So how do repellents work?  DEET was developed by the military over 50 years ago but it was only more recently that studies have been done to understand exactly what it does.  Mosquitoes smell with their antennae, which are covered in olfactory nerves. The nerves are essentially equipped with odor receptors, that bind to odor molecules and trigger neural activity.  Simply put, DEET binds to these receptors leaving the mosquito confused and unable to smell you. The DEET over-activates the receptors rendering their ability to smell useless. 

According to many studies, the only repellent that comes close to the ability of DEET is lemon eucalyptus oil with the caveat that natural products break down faster and thus must be applied more regularly.  It should not be applied in its pure form and is also not recommended for children under the age of 3. Do not confuse it with the essential oil of lemon eucalyptus either (easy to do). Lemon eucalyptus oil has a different mode of action, simply creating a powerful smell to override that of CO2.  

The market is saturated with alleged mosquito repellents.  Wearables have become popular, although scientific studies show they are not capable of repelling mosquitoes.  Many people prefer to stay away from DEET and make natural repellents. We wrote a blog about DIY repellants recently and you can check out more here. However, they have not been proven to be effective in the fight against mosquito bites.  Folks also like to burn citronella candles and burn tiki torches, but these again will only confuse and delay you being found. 

It’s not enough to wear repellent in your own yard.  The most effective way to avoid or reduce the bites in your own yard is to remove all stagnant water sources from it.  Remember, one small capful of water is enough for 300 eggs. The more water you remove the better you will be. Of course, calling us to manage that water and treat your yard is the best way we know to make your outside fun.  Then you can ditch the repellant and just enjoy.

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It’s Time to Talk Ticks

It is easy to be complacent and to believe that Texans don’t have to worry too much about ticks.  In fact, many people believe it is an issue for the Northeast and not a concern for us. The fact is that the CDC has singled out Lyme Disease as the most common, and fastest growing vector-borne disease in the US.  The Texas Lyme Disease Association and Texas A&M’s Lyme Lab caution the same.

At Mosquito Joe we have several customers who have acquired Lyme Disease in the past and, as a result, are focused on managing the tick population in their yard.  And with good reason. A recent study confirmed that Lyme Disease is a significant risk for the state of Texas and that the tick-borne bacterial infectious agent that causes it is now endemic to the Texas/Mexico border.

To bring it closer to home, in the decade between 200 and 2010, 106 cases of Lyme Disease were confirmed in Harris County, and 31 in Montgomery County. Between 2011 and 2016 those number were 58 in Harris County and 29 in Montgomery, displaying the increasing rate of disease.  Since the CDC data only represents confirmed cases, the actual cases may be far greater. According to TickCheck they estimate the number of cases in Texas at 16,260. For more information on ticks, the CDC has a great website full of information: CDC Tick page including advice on how to remove a tick and what to look for after a tick bite.

It is also worth noting that Lyme Disease is not the only concern with ticks.  They also spread Ehrlichoiosis and Heartland virus (the Lone Star Tick), Rocky Mountain Spotted Fever (the American dog tick), Tickbourne relapsing fever (soft ticks) and Tularemia (lone star tick and dog tick), to name a few. So, what should we do about it and how can we protect ourselves?

Keeping your yard as tick free as possible requires upkeep and some common sense.  Keep your grass mowed and trees trimmed. Remove wood piles away from the home and keep your pets out of wooded areas.  Keep leaf litter picked up and remove any trash from your yard (old furniture and mattresses make a great hiding place for ticks).  When you go out in the woods, wear long pants and sleeves, and do a check of pets and children when they come inside from those areas.  

Another great prevention trick is to lay a 3-foot-wide barrier of wood chips or gravel between your lawn and wooded areas.  This helps restrict tick migration from the woods around your home.

Of course, you can also hire the folks at Mosquito Joe to help protect your yard from ticks (and mosquitoes) so you can rest easy knowing your family is protected when outside.  Our educational flyer can be helpful and you can check it out here: Tick Prevention & Education flyer

Our December blog goes into detail on Lyme Disease and Rocky Mountain Spotted Fever, so feel free to hop over there to learn more about the diseases themselves. And if you want to learn more about how we can help give us a call.  Mosquito Joe of NW Houston & S Brazos is focused on helping and educating and we are always happy to lend our input to anyone with concerns and questions. 281-815-0228

 

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How to Treat Fire Ants

Fire ant service from Mosquito Joe (and some fascinating information on Fire Ants)

Fire ants are not just a nuisance in Texas, they are dangerous and do an incredible amount of damage.  Red imported fire ants are an invasive species, not just to the US but to Australia, China and Taiwan.  Over five billion dollars (yes, BILLION) are spent each year in the States on medical treatments, damage and control of fire ants.  They also cause $750 million dollars’ worth of damage per year to agriculture in the US.  What is just as incredible is the amazingly fast adaptation some of our local creatures have gone through to deal with these imports.  In 2009, a study found that in just 70 years, lizards have adapted both their behavior and their leg length to help them avoid and escape the danger of fire ants.

Distinguishing native and imported fire ants is difficult, particularly since the imported ants vary in size.  Imported ants are also composed of two genetically distinct types: Monogyne (one queen colony) and polygyne (multiple queen colony). Regardless of which type we look at, there are some common themes amongst all fire ants that are fascinating and impressive.  This understanding of their behavior is what enables us to treat them effectively.

Image of the fire ant colony's QueenFire ants don’t bite, they sting.  Well actually they do both – they bite to grip and then sting, but the latter is what causes us the pain and lends them their name, as a sting really can feel like a small fire.  We all know that when one bites, so do many.  However, there is no evidence that pheromones are the cause of this.  Typically, one ant bites us, we jerk in reflex and this motion causes the other ants to bite as well.

There are up to 250,000 ants in a colony.  These ants are made up of workers – who forage for food, soldier ants – these have larger and more powerful mandibles, and the queen (or queens depending on the type).  The queen lives up to 7 years, while the males live between 5.5 – 6.5 years each.

Fire ants’ mate when the temperature is between 70 and 95 degrees, the humidity is high, and the winds are low (a typical day in this part of the country).  They also tend to breed within 24 hours of rain.  Once they mate the male dies.  The female will then fly for 2-3 miles, up to a height of 2,000 feet, until she lands to nest.  It is interesting to note that 99.9% of these females die before they nest (a fact we should all be thankful for).

When the female lands she pulls off her wings and eats them.  This meal sustains her until her eggs hatch and her offspring are ready to head out and forage.  The queen will then burrow and lay her eggs.  Forty-five days later her offspring hatch.  The workers head out of the nest and gather food to bring back.

Fire ants don’t eat solid food.  Instead they bring the food back to the nest and place it near the late-stage larvae.  The larvae secrete enzymes which digest the food into liquid.  The ants then pass this liquified food to one another to eat in a process called trophallaxis.  This behavior creates a built in “taster ant” process.  Simply, if an ant gets sick or dies from a liquid, the queen is not fed that same liquid.  This process is in place for a couple of days, meaning we can get around it by delaying the effect of our bait.

The most successful treatment for fire ants is a two-step method and this is what we employ at Mosquito Joe.  The first step is a bait broadcast that is placed in the yard.  This bait has a 3-day delay on it, which enables us to circumvent the taster ants and kill the queen.  Particularly in a monogyne colony, killing the queen will end the reproductive ability of the colony.  We combine this broadcast with a nest service that we perform at each visit.  We recommend the broadcast be repeated every 10-12 weeks, and a visit once in between to directly treat the nests.  For this portion of the service, we inject down into each nest and kill all the ants we contact with the product.

While we may kill all the queens in the yard, it is important to remember that new queens will fly in.  Fire ants are also excellent at moving locations when circumstances require it.  You may recall the images posted after Hurricane Harvey of fire ant rafts floating along the flood waters.  These rafts are composed of a colony of ants, gripping to one another to form a living raft, with the queen protected within.  This behavior will occur whenever circumstances dictate, so while your yard may be fire ant free one day, a heavy downpour and localized flooding can change that quickly.  Treating consistently and using this two-step method will get rid of them and keep them out of your yard.

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The Life-Cycle of a Texas Mosquito

How Long Do Mosquitoes Live?

Customers and potential customers ask us every day “How long do mosquitoes live?”. We also often find ourselves answering other questions like “How do you keep mosquitoes away?” and “What’s the best way to stop mosquitoes in my backyard?”. Knowledge is power, and once you understand the life-cycle of a mosquito you can gain valuable insight into how to manage them, keep them away and alter your expectations for your own backyard.

There are more than 3,500 different species of mosquitoes, with about 85 of those found in Texas. While they have varying preferences for a breeding habitat, they all undergo the same four stages of life. The mosquito’s life cycle is composed of the egg, larvae, pupa and adult stages.

First Stage: Egg

Life cycle of of a mosquito: eggs, larva, pupa, adultFemale mosquitoes lay eggs in a variety of ways: some lay single eggs in water, some lay in rafts on water, where they float in numbers of up to 200. Other species opt to lay eggs on damp soil, where evidence of water remains. A mosquito egg can live up to 10 years in dry conditions, only to hatch when a drop of water hits it. They can be frozen and still hatch the following spring (not that we experience this in Texas), eggs can be churned over in soil and lie in wait until they are brought back to the surface when gardening. That new sod you had brought in? The new mulch in your yard? Full of mosquito eggs, just waiting for some water to allow them to hatch. Most eggs hatch within 48 hours of being laid, but all require water to do so. Keep in mind, it only takes about a teaspoon of stagnant water for 300 eggs to begin the process of transformation.

Second Stage: Larva

Mosquitoes in the Larva StageMosquito larvae live in water and come up to the surface to breathe. Known as “wrigglers” these guys kick around in the water, going through 4 molting cycles where they shed their skin and grow into a larger one. Many species have a siphon tube which they use to breath, laying parallel to the surface of the water. These guys feed on organic matter in the water, so stagnant water is their home. They won’t be found in chlorinated water (like a swimming pool). Our technicians are well versed in spotting these guys and have found them just about anywhere you can imagine. Outdoor cushions, frisbee’s, cap-less fence posts and holes in trees. We use a larvicide in this water that prevents the larvae from moving into the next stage of life.

Third Stage: Pupa

Otherwise known as “tumblers”, this stage of life is a resting state. These guys do not feed and respond to light by flipping their tail and tumbling to the bottom of the container they are in. During this time, the mosquito is in its cocoon stage, preparing to hatch as an adult mosquito. Depending on the species, this can take around 2 days. At the end of this state, the pupal skin splits open and the adult emerges.

Final Stage: Adult

Once the mosquito emerges it rests on the water, allowing its body to harden and its wings to dry. Males typically emerge earlier than females and then lay in wait for the females to emerge. Once they are bred, the female mosquito of most species requires a blood meal to lay her eggs. This is where you, your pet or any number of animals in your yard get bitten. Once she has taken her blood meal, and has the protein she requires for the job, the female lays her eggs. She then seeks out a place to rest and feeds off of plant nectar (typically the underside of leaves away from the sun). The females will lay eggs every two to three days, repeating the process each time. The remainder of their short life is typically spent at rest, in dark moist areas of your yard. Males typically live about 10 days, while females live on average about 42-56 days. During that time, one female can lay up to 5,600 eggs. Depending on the location and the temperatures, this entire life-cycle can take about 2 weeks, with the right conditions and species, as short as 4 days.

Now that you know more about the life-cycle, you can answer the questions “How do you keep mosquitoes away?” and “What’s the best way to stop mosquitoes in my backyard?”. The main solution is in the water in your yard. The less water, the less locations for mosquitoes to lay eggs. Our certified pest control technicians will dump all the water in your yard that they can, treat the water they cannot to prevent larvae from hatching, and provide a barrier treatment to all that foliage in your yard where the adults spend time feeding and resting. They will also provide valuable insight for you into what you can do to help – cleaning gutters, storing kids toys out of the rain, even correcting drainage areas causing standing water. Be sure to give us a call at 281-815-0228 and let us help you take your backyard back from pesky mosquitoes!

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Different Types of Mosquito Breeds in Texas

Do you know what types of Texas mosquitoes are bugging you?

There are 85 species of mosquitoes living in Texas. Even though there are over 3,000 species in the world, and 176 of those can be found in the USA, 85 still seems like a high number. However, when you consider the size of our great state of TX and the variation of weather within it, 85 actually seems like a reasonable number. Also remember that mosquitoes date back over 260 million years and classifications have been a work in progress for some time.

So which ones do we encounter in the Northwest Houston area? Keep reading to learn more about each of the different species that could be found in your very own backyard! We should first premise this by letting you know that there is an abundance of species in our area. We also note that many of the current maps are not reflective of what we see in the field. For example, we have located Aedes albopictus in areas not noted on the AgriLife maps. Still, to get a better sense of the breadth of species and locations in which they are found, you can visit here.

It is helpful to keep in mind a couple of facts about mosquitoes that apply to all the Genus below:

  • Only the female mosquitoes bite, and they do so to get the protein they need to lay eggs. When a mosquito bites you, you can be certain that she just bred and is preparing to start a new family.
  • Mosquitoes need stagnant water to lay their eggs in. Chlorinated water or circulating water (think pools and fountains) are not going to cut it for them.
  • Mosquitoes have a rapid life cycle so they don’t mess around. We did the math: one teaspoon of water allows for 300 eggs every 4-7 days. Given a 50% male to female ratio, one mosquito laying150 females will produce over 2 billion female mosquitoes in under a month – Yikes!

It’s probably easiest to begin with the genus of the mosquitoes we live within the Houston, Texas area. The genus groups mosquitoes by a common characteristic and just within our area, there are nine different kinds: the Aedes, Anopheles, Culex, Culiseta, Mansonia, Orthopodomyia, Psorophora, Toxorhynchites and Uranotaenia.

1. Aedes:

The Aedes mosquitoes are located on every continent except the Antarctic. They are visually distinct from other genus’s with black and white stripes on their body. These are the mosquitoes responsible for Dengue, Yellow Fever, West Nile, Chickungunya, Eastern Equine Encephalitis and the Zika virus. Most notable amongst these are the Aedes aegypti (Yellow Fever Mosquito) and Aedes albopictus (Asian Tiger Mosquito). These guys are all over our area and are very aggressive. Unlike other species, they don’t mind the sun and are often seen during the day. These are responsible for the majority of calls we receive when folks are looking for a mosquito repellent service for their yard.

The Yellow Fever mosquito is the primary carrier of Zika and they lay eggs in the smallest amount of stagnant water – such as the water in flower vases, tires, and opened containers. They are active all year and prefer dawn and dusk.

The Asian Tiger was introduced into the States in 1985 in a shipment of tires to the Port of Houston. Since then they have spread up to NY State and as of 2017 have been found in every state in the US. They carry West Nile, Encephalitis, Dengue and heartworms. Asian Tigers take full advantage of any water in your yard – holes in trees and tires are popular breeding choices for the Asian Tiger mosquito. They are active all year and are aggressive daytime breeders.

2. Anopheles:

This genus is composed of 460 species, with 100 of those capable of transmitting Malaria, while others transmit Canine Heartworm.

Around Northwest Houston, the Anopheles quadrimaculatus, otherwise known as the Marsh Mosquito, is prevalent. These guys have a “tell” to help you identify them. Unlike other species, who rest on your skin with their body parallel to your limb, the marsh mosquito holds its body at an angle with its rear end raised. They are very dark in color with dark spots on their wings. After Hurricane Harvey, we saw a dramatic uptick in the number of marsh mosquitoes, a result of the massive increase of waters in our area. They prefer to lay their eggs in swamps, wet vegetation and around ponds and lakes.

The Anopheles freeboni is one of several species in Houston that are more active in the winter than the summer. Just when some other species are slowing down (mosquitoes don’t hibernate until temperatures fall under 50 degrees and remain there, something that never happens in Texas!) the freeboni is just getting started.

3. Culex:

The Culex genus is responsible for the transmission of West Nile, St. Louis Encephalitis and Avian Malaria. In our area, the most common of these is the Culex pipiens, also known as the house mosquito. These guys love feeding on nectar and a pile of decaying fruits is a perfect meal for them. If you happen to have fruit trees, keeping the ground clear of fallen fruits will help you control these pests in your yard. They also love wet trash, wastewater and bird baths. These guys generally don’t start biting until after dusk.

4. Culiseta:

The Culiseta is a genus of mosquitoes that are cold-adapted, meaning that they are active in the cooler months in our area and not during the summer. The Culiseta inornata, otherwise known as the Winter Marsh Mosquito, is common in Houston, Texas, more so with wet weather. We certainly saw an increase in them after Harvey. As the name suggests, these guys love stagnant water and wet vegetation.

5. Mansonia:

Mansonia mosquitoes are big and black or brown in color. They breed in ponds and lakes that contain floating plants and use the underside of the leaves to lay their eggs. The larvae use the rootlets to obtain their air supply. The best way to remove these mosquitoes is to remove their habitat by controlling floating plants on any bodies of water in your yard. They are also a potential vector for the Rift Valley Fever virus.

6. Orthopodomyia:

The beauties of the mosquito world, this genus is marked with bands of white, silver and sometimes gold. They lay their larvae predominantly in tree holes, or in bamboo and the females feed mostly on birds. Our technicians are always on the lookout for holes in trees, so we can get a jump start on killing their larvae. They may be pretty, but they still bite!

7. Psorophora:

A few species of this genus are in the Northwest Houston area. The Psorophora ciliata is a very large mosquito and is also very aggressive. Interestingly, they are known to prey on the larvae of other mosquito species, so while they are scary to look at, they at least help control other species. The females will lay eggs on damp ground, which can then hatch years later. The Psorophota columbiae is a floodwater mosquito that can travel up to 8 miles from its breeding area. We see them after large weather events and they are active both during the day and at night.

8. Toxorhynchites:

Otherwise known as Elephant Mosquitoes, these are the largest mosquitoes. These pesky bugs don’t feed on blood. Instead, feed on plants and fruits.

9. Uranotaenia:

These small mosquitoes use a multitude of habitats including holes, bamboo, plants and artificial containers. The good news is that the females rarely feed on humans, preferring reptiles and birds. Many of the species are attracted to light and are occasionally found resting in homes. Uranrtaenia lowii are found in our area.


Fortunately, Mosquito Joe of Northwest Houston and South Brazos Valley is here to help get rid of all these different types of mosquitoes that are found in our area of Texas. We can provide many mosquito repellent spray options for both your home and business including barrier spray treatments, all-natural sprays, special event sprays and more. Our team is knowledgeable about these mosquitoes and the best way to get them out of your yard ASAP. If you’d like more information on how we can help eliminate these pesky mosquitoes so you can get back to enjoying your outdoor space, give us a call at 281-815-0228 or email us at NWHoustonBrazos@MosquitoJoe.com.

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