Hate Mosquitoes? Consider a Bat House! Fight Insect-Borne Illness by Partnering with Furry Fliers

The National Weather Service reported last week that 35 trillion gallons of water fell in the state of Texas during the month of May. The ground is soaked for what may well be weeks to come, our bayous have swollen far beyond their usual limits and residents in Harris and Ft. Bend counties continue to pick up the pieces after flooding pushed them from their homes. We know what 35 trillion gallons looks like in terms of disrupting the lives of Texans, but it’s difficult to imagine just exactly how much that is.


That’s a lot of water…

NBC’s Nelson Hsu put together a graphic breaking down the staggering amount of water that drenched our state — evenly distributed and dropped all at once, it’s enough to cover Texas in eight inches of water; enough to fill California’s 200 surface reservoirs to thrice their capacity, enough to cover Manhattan four times, and if we had caught all that rainwater and spread it across the globe, the world’s population would have a supply of 64 ounces of water for at least the next 27 years. And most people fail the eight-glasses-a-day challenge!

With Zika virus making headlines in the aftermath of May’s downpour, our soaking city seems like prime real estate for ground zero of the next outbreak. But fear not. Mosquitoes are ubiquitous, that’s true, but they’re easy enough to fight. They fly at less than 1.5 miles an hour, with a typical range of only about 300 feet in still weather. Their strength is in their numbers, not their speed — kind of like zombies.


America’s worst enemy, but to bats, they’re food for thought.

First, there have as yet been no locally-acquired cases of Zika virus in the United States, according to the Center for Disease Control; the 618 reported cases were all travel-associated. It’s also important to understand that while Zika poses a serious threat to developing infants during pregnancy, the disease presents no more than a few days of flu-like symptoms in adults and children.

Second, since mosquitoes are the main vector of Zika, the best way to directly combat them is to wear insect repellent. Sure it smells nasty, but Off! and other spray-on products could save you from serious symptoms and the awful itching of the world’s most annoying insect.

Third, you can stop mosquitoes from breeding by eliminating areas of shallow, stagnant water. Take a lesson from the residents of Flamingo, Fla., a community in the Everglades and home to one of the most voracious populations of mosquitoes: Get rid of aluminum cans, bottles and plastic containers, store recycling in plastic bags, don’t let water accumulate in garbage can lids or empty garbage cans, flush bird baths and plant trays twice a week, store pet food and water bowls indoors when Fido and Felix aren’t using them, and use mosquito “dunks” in areas that can’t be drained. These dunks utilize bacteria that consume mosquito larvae but leave fish and other animals unharmed.


(Yawn!!!) It it dusk yet? I’m hungry for mosquito breakfast.

For the long term, my favorite method of laying waste to mosquitoes involves enlisting the assistance of another population of flying creatures — by hanging bat houses! The Mexican free-tailed bat (Tadarida brasiliensis) is a hardy, numerous species (and they’re super cute), but their propensity to roost in a few huge colonies, like those you can find under bridges in Austin and Houston, leaves them vulnerable to habitat loss. Hanging one or two bat houses around your home keeps these adorable flying mammals close by, which means far fewer insects.


Vote Bat for Harris County Mosquito Exterminator! I eat bugs so they don’t eat you!

While female mosquitoes have an insatiable appetite for blood, which they need to lay their eggs, bats have an equally ravenous hunger for the insects. A single bat can eat around 1,000 mosquitoes every night, and a single small bat house offers shelter for up to 25 bats. Do the math with me — two shelters is 50 bats, which could eat a total of 50,000 mosquitoes a night or 350,000 mosquitoes a week. That’s not just the mosquitoes around your house; that’s probably every mosquito on the block. If you convince your neighbors to hang houses, too, you could form a bat colony coalition for an even more formidable mosquito-fighting force.


When we have a problem, we hug it out. #justbattythings

The capacity of a bat house, of course, is also adjustable according to its size. Many bat house companies, like P & S Country Crafts or Habitat For Bats offer a variety of dimensions available for purchase, or you can build one yourself. It’s an easy enough project to knock out in your garage in a few days, and an even easier project to hang up a pre-made one. Each house promotes an environmentally-friendly semi-symbiotic relationship with our adorable bat friends, which stay long enough to raise their pups and then move on when the weather cools down. And by this time, the mosquitoes will have disappeared for the season, as well.


Bat houses by www.pscountrycrafts.com, mounted on a pole. Bat houses can also be attached to the sides of houses or barns. Trees are not ideal for bat house mounting.

So do what you can to fight mosquitoes, but consider teaming up with the bats, our neighborhood insect-fighting superheroes. Check out Bat Conservation International for more information on ways to help these furry fliers.

Visit the Farish Hall of Texas Wildlife at the Houston Museum of Natural Science to learn more about bats and other native species in need of conservation.

Beach Bugs!

I recently returned from a wonderful trip to Galveston. It was so relaxing, sitting on the beach, listening to the waves and watching the birds. The beach is such a peaceful place and Galveston is very close to my heart because my husband and I got married there! Although I escaped with nothing but a few mosquito bites (my husband was not as lucky!), I got to thinking about bugs at the beach and the horror stories I have heard. I’ve heard about sand flies, sand fleas, sea lice; all kinds of crazy stuff. I decided to do a little research to see what was true and what was nothing but beach bug lore. I was absolutely shocked at some of the things I read, especially when Googling “sand fleas”! Most of the things I found were contradictory, inaccurate, and just plain ridiculous! The biggest problem seems to be the confusion between all of the common names. People in different parts of the world may refer to the same organism as several different things. That’s why scientists use Latin scientific names that are consistent across the world. So, here it is, the skinny on some of those beach pests we all hear about, what you should worry about, and what is no big deal!

Sea Lice

she don't use jelly
Creative Commons License photo credit: brainware3000

Well here’s a misnomer for you! I’ve never even heard of sea lice, but one of my co-workers mentioned them while I was researching. Many of you may have heard of them because apparently they can be quite a problem! It’s a misnomer because the real sea lice are tiny crustaceans that live in the ocean and feed on certain types of fish, but don’t bother humans at all. What we call sea lice are actually larvae of jellyfish that float around in clouds in the ocean. Although they are tiny, they still possess those nasty stinging cells or nematocysts. If you’re swimming in the ocean, they can become trapped between your bathing suit and skin. This is when you can be stung. The stings cause intense itching and burning which result in a rash with small raised blisters.  The rash can last anywhere from two days to two weeks, but most of the time they go away with no medical attention necessary, just lots of cortisone cream and Benadryl! Sea lice are common along the gulf coast, the Caribbean islands, Mexico and South America. Most beaches have warnings if the waters are heavily infested. The season for these pesky baby jellyfish usually runs from April through August.

Sand Fleas

It took me forever to get to the bottom of this one. I asked people I knew if they’d ever been bothered by what are known as “sand fleas”. The general consensus was, no. I read some of the most ridiculous things, however. I read that they attack your feet and burrow into your skin. I read that they attack fish and kill them. I read that they are crustaceans with wings, that feed on seaweed and also suck blood, but only from your feet. What?!?! So, this is what they really are. The common sand flea (Orchestia agilis) is an amphipod, or a small, terrestrial, shrimp-like crustacean. They burrow into the sand and they feed on decaying plant and animal matter that washes up on the shore, especially seaweed. They do not want anything to do with people. They obviously are not fleas, not even insects. However, they jump, similar to the way fleas do and they live in the sand, so hence the name sand flea. They are found all along the Atlantic coast, so you’ve probably seen them before. There is a more malicious animal that sometimes goes by the name sand flea, but more often is referred to as the chigoe flea. Tunga penetrans is actually a type of flea, but they are not like the more common cat flea that bites our domesticated pets. They are the smallest known species of flea. The chigoe flea lives in soil and in sand. They feed on the feet of warm blooded hosts such as humans, dogs, cattle, sheep and mice. When the female is ready to reproduce, she will burrow into the skin of the host, which is where she stays until after she releases her eggs, in about two weeks. After this, she dies and is sloughed off with the skin of the host. They can jump no higher than 20 centimeters, so they usually burrow into the foot or ankle. So, this is a little creepy, but don’t worry, they’re only native to the tropics, such as Central and South America.

Sand Flies

Female horse fly
Creative Commons License photo credit: Radu P

This is a pretty general term that can really refer to any biting fly you would encounter at the beach, besides a mosquito. This could even be a type of horsefly that is associated with that type of habitat. Most commonly, the name sandfly refers to flies in the family Ceratopogonidae. These are small biting midges, only 1-4 millimeters in length that live in aquatic habitats all over the world. Like mosquitoes, it is only the female that sucks blood to get protein in preparation for laying her eggs. The bite itself is too small to feel. It’s not until later when your skin starts to react with the proteins in their saliva that you start to feel the itch.  Because they go unnoticed, they can bite you a lot, that’s why they are such a pest! Bug spray is sufficient protection against these flies, but I never wear bug spray and haven’t been bothered by them, so I don’t think they’re much of a problem around us.

Salt marsh mosquitoes

I’m sure almost everyone has run to the car to get away from these vicious mosquitoes and their painful bites! Aedes taeniorhynchus and Aedes sollicitans are two common species found along the Texas coast. They lay their eggs in brackish and saltwater pools left over from the tides. There is no mystery about these ladies. They’re big, they’re hungry and they will come after you any time of the day whether you’re swatting at them or not. They are larger than many freshwater mosquitoes so they’re bites actually sting a bit. In other parts of the world, they are vectors of Venezuelan and Eastern Equine Encephalitis. Luckily, in our area, this is not a problem, but they are a prime vector of dog heartworm, so if you live near the beach, keep your dogs on a heartworm preventative.

I certainly had my fair share of them at the beach, which is what got me thinking about other parasites that may be lurking at some of our favorite vacation destinations. My conclusion: wear bug spray and heed any warnings at the beach and you should be in tip-top shape. You’ll hopefully leave with nothing worse than a minor sunburn and relatively few mosquito bites! Until next time, happy bug watching!

Photo From You: Insect Identification

This comment and photo were emailed to us on the blog a few days ago.

Angies car critters

“My friend was out on the Katy prarie the other day and left her window down. Upon her return to the vehicle, she discovered nearly 100 of these little guys swarming inside her Tahoe. Can you please tell me what they are?”

The insect in question this time is one that is VERY common around here, and perhaps, like most insects, quite misunderstood! This picture was taken inside a woman’s car out near the Katy Prairie. Since the photo is blurry, it’s hard to get a really positive identification, but it looks to me like a member of the family Tipulidae, or crane flies. These flies are not usually called  by this name. Growing up, I knew them as mosquito hawks, or skeeter eaters! Some might even think that they are actually giant mosquitoes. It was not until I started studying Entomology in college that I learned their true identity and what they really do, which is…not much of anything at all!

The family Tipulidae contains 14,000 different species of crane flies, making it the largest family of flies. They are found literally all over the world.  They may resemble their close cousins the mosquitoes, but they want nothing to do with human blood or any blood for that matter. Often the adults don’t feed at all, but if they do, they stick to flower nectar. Mosquito hawk is definitely a misnomer. The larvae, which are active eaters, don’t eat mosquito larvae, they only feed on rotting organic matter and sometimes roots. The larvae of some European species can become pests in lawns.

D like Dragonfly :)
Dragonfly, also sometimes known as
mosquito hawks.
Creative Commons Licensephoto credit: chris bartnik photography

The real mosquito hawk is actually a type of mosquito! These awesome mosquitoes belong to the genus Toxorhynchites, which is just as fun to pronounce as it is to spell! As adults, these are one of the very few types of mosquitoes that do not feed on blood. They prefer nectar as well. The larvae are active predators, especially on other mosquito larvae, so we really like these guys! Dragonflies are also sometimes known as mosquito hawks also since they chow down on them during all stages of their lives.

Crane flies are usually one of the first bugs I see emerging in the spring. You can identify them by their extremely long legs, which are very fragile, and their clumsy flight. The woman who took this picture said that she had nearly 100 of these in her car since her window was left open. I’m not sure exactly what they were doing, but my best guess was that they were late season adults swarming together in search of a mate to complete their lifecycle before it’s too late.  So next time you see something that looks like a giant mosquito, don’t swat at it, it means you no harm! Happy bug watching!

Poisoning Pesky Pests

 © Photo credit: Gerald Yuvallos

April showers bring flowers – and mosquitoes!!!  The one good thing about our prolonged dry spell is that we have had almost no mosquitoes for months…but that is about to change.  Truly, mosquitoes are some of the most pestilential insects on this earth – not only is their bite unpleasant, but some species have the capacity to transmit diseases.  People will do almost anything to get rid of them.  And pest control companies prey on this urge, and will sell you just about anything. 

The device the pest companies are pushing these days – the “mosquito misting system” – costs several thousand dollars to install, but it does actually kill mosquitoes.  These systems use a series of nozzles, usually placed around the periphery of the homeowner’s yard, which emit a fine mist at intervals (many have programmable timers).  The mist, which contains water mixed with a pyrethroid insecticide, kills mosquitoes on contact.  Pyrethroids are widely used, generalist insecticides touted as “safe” for humans and pets such as dogs and cats, because they are derived from plants (learn more about these “safe” chemicals by clicking here.)

  © Photo credit: Foxypar4

Some pest control companies boast right up front that these misting systems also kill “spiders, ticks, fleas, wasps, gnats, and roaches” as well as mosquitoes.  Of course, they don’t mention that along with these “undesirables,” the mist also destroys butterflies, honeybees, ladybugs, praying mantids (and some of us consider spiders to be beneficial), etc., and is toxic to fish and amphibians.  In other words, although the chemicals used in these systems may be relatively safe for humans (but check out this link for some sobering information)  I wouldn’t want my child or dog or cat to be directly exposed to them.  Yes, pyrethroids are derived from plants, but they are generalist poisons that are bad news for many creatures.  And just because something comes from a plant doesn’t mean it is safe – would you want to be sprayed with extracts of oleander, foxglove, or poison ivy???

We frequently receive calls from butterfly gardeners around town who worry when their neighbors install one of these systems that it will impact their gardening efforts.  We don’t have good news for them – yes, it will.  Gardening for butterflies with one of these systems next door (since the mist can drift, and flying insects don’t stay put) is like putting out bird food if you have an outdoor cat.  You are luring butterflies and other beneficials to their death. 

The companies installing these systems will assure you that since you can use the spray just at night, day-flying insects will not be affected.  But think about it:  first, many beneficial insects are active at night, and many larval insects (e.g., butterfly caterpillars) are not able to fly away from areas that are sprayed.  Furthermore, plants or other objects near the spray nozzles build up a residue of the poison that is certainly not good for anything eating them or living in or on them.

 Mosquito Misting System

You may be surprised to learn that scientists working on mosquito control do not like these home misting systems any better than I do.  A couple of years ago, while doing research on mosquitoes and careers in entomology for the new insect wing, I talked at length to Dr. Rudy Bueno, head of the Harris County Mosquito Control Division (part of Harris County Public Health and Environmental Services, www.hcphes.org ).  I was impressed (and frankly surprised) by the conservative nature of their spraying programs.  For Dr. Bueno’s crew, spraying is a last resort, done in specific areas where their field workers have identified large populations of mosquitoes that may vector diseases such as West Nile virus (not all mosquitoes transmit disease), and where they cannot use other treatment methods such as getting rid of the standing water or treating with mosquito dunks.  They only spray when an outbreak cannot be controlled with more benign methods, and – here’s the rub – the sprays they use contain the same chemicals as the home mosquito misting systems.  Dr. Bueno’s concern is that through constant exposure to these chemicals that mosquitoes get through the home systems helps mosquitoes to evolve resistance to the chemicals – making the county’s spraying efforts much less effective, and meaning that more potent and dangerous chemicals may have to be used to control outbreaks.

 © Photo credit: akeg

I asked Dr. Bueno what he would recommend to the homeowner concerned about mosquitoes.  Their mantra in HCPHES is “reduce the source” – in other words, eliminate as much as possible any place around your home where mosquitoes might breed.  Some mosquitoes can breed in less than a tablespoon of water, or even in wet leaves, and can complete their life cycle in less than a week.  Most homeowners are fairly careless about leaving potential breeding spots on their property.  Clogged gutters, plant saucers, bird baths, dog or cat water bowls, and many other containers that hold water are all potential breeding sites.  So clean out those gutters and change the water regularly in bird baths and drinking bowls, and turn wheelbarrows or pots or buckets upside down so they don’t hold water.  Put mosquito fish (Gambusia affinis, a small native fish species that eats mosquito larvae) into any outdoor ponds.  In areas of standing water that can’t be drained you can use “mosquito dunks” – floating “donuts” that release a bacterium (Bacillus thuringensis israelensis,) that infects only mosquitoes.  One of the main places mosquitoes breed in Houston is in clogged storm sewers, so be sure not to put leaves or other debris into these sewers.  Of course, if you live next to a salt marsh or other area with shallow standing water, you may still be plagued by mosquitoes from time to time.  But there is a lot we as homeowners and good citizens can do to reduce the number of mosquito breeding areas right in our own neighborhoods.  Click here for more information on mosquito prevention

In my opinion, these home misting systems should be outlawed!  Yet to date they are almost completely unregulated, and people are so eager to rid their surroundings of mosquitoes that they don’t think about the consequences of the widespread use of these poisons.  Please do your research, and some thinking, before you spend any money on mosquito control.  One thing you can do is check out information in the lower level of the Butterfly Center – a computer kiosk rates a variety of potential mosquito control methods.  You’ll learn that in addition to “reducing the source,” using repellent with 33% DEET (more is overkill) and/or wearing long-sleeved shirts and pants when outdoors in mosquito-infested areas are the best ways to prevent bites.  And in your backyard, a simple fan can keep mosquitoes away during outdoor activities, and in fact is as at least as effective, and much safer, than any of the candles or coils on the market.

I hope one day the Environmental Protection Agency will ban the use of home mosquito misting systems and other supposedly “benign” poisons that may make our lives more comfortable but that on closer examination have deleterious effects.  It would be nice if pest control companies would voluntarily stop installing these systems, but as long as the public demands (and shells out money for) them, why should they?  In the meantime, I’ll be trying to educate as many people as I can – and I hope you will too.  Butterflies, honeybees, ladybugs, frogs, fish, and many other wonderful creatures would join in the chorus, if only they could!