Revenge of the (cricket) nerds

Jay Falk
Jay Falk

Cornell University PhD student Jay Falk with his cricket.

One of the great mysteries of my career as a Texas urban entomologist has been understanding the clouds of crickets that descend on lights and businesses nearly every year.  So I was intrigued last summer when I got an email from a PhD student at Cornell University interested in coming down to study our swarming crickets.

Jay Falk is actually a native Texan, who grew up in the Austin area and got his undergraduate degree at the University of Texas.  That’s where he got his first introduction to crickets, watching them swirl around the lighted University of Texas Tower each fall.  That experience and an enthusiastic professor at UT led him to decide to study crickets at Cornell.

When asked why we should care about crickets, he responds, “Crickets have all these dramatic behaviors that no one notices. And, they are such an important part of the biology of their ecosystems, being an important link in the food chain.”

Some of the dramatic behaviors, he explains, includes fighting for females and territory, mating flights, bursting into bouts of song, courtship, and just surviving all the things that want to eat cricket for supper.

Jay explains that there are at least three similar cricket species in Texas, but the only one known to swarm in large numbers is the Texas field cricket, Gryllus texensis.  In east Texas, a physically identical species exists, Gryllus rubens.  The two crickets can be told apart only by their song, and by the fact that rubens doesn’t swarm.  Both crickets have two generations per year. The spring generation is relatively small, and not frequently noticed.  The second generation is bigger, and responsible for sometimes spectacular swarming flights around lights and buildings.

Gryllus texensis

Who would guess that male Texas field crickets are such fighters?

As an evolutionary biology student, Jay is interested in how juvenile experiences influence mating behavior later in life.  The male Texas field cricket is known to have two strategies for attracting mates. The first strategy is to establish a mating territory and use a loud calling song to catch the interest of a passing female.  This strategy presumes the ability of the cricket to claim a good territory and defend it from other males.  These territorial fights can be spectacular, with males locking jaws and attempting to flip their opponents over.  The victors even break out into victory dances and a special victory song.

The second strategy involves sitting just outside a calling male’s territory and attempting to woo a female cricket drawn to his rival’s calls.  Jay theorizes that these so-called “sneaker males” adopt this strategy after having previously lost to the insufferable big boys.  If his theory proves correct, you might call this strategy the cricket version of “revenge of the nerds”.

When I ask Jay why this one species of cricket has adopted this swarming behavior, he shrugged. “There’s a lot biologists don’t know about the field behavior of even very common insects like the field cricket,” he said.  Even food. Apparently there is little evidence what these common insects eat. “I feed my crickets cat food,” he said.  But it’s likely that in the field much of a cricket’s diet is decaying plant material, and the occasional smaller insect.  They are not considered important crop pests in Texas.

“Texas field crickets are a unique part of the Texas experience,” Jay added at the end of our conversation.  And I think he’s right. They are part of what makes Texas a special place, at least for an evolutionary biologist.

My rabies story

stray dogs

[Note: This is not a story about insects, though it does relate to pest control.  As an urban extension entomologist I get to train and work with pest control professionals.  These good folks often find themselves called upon to handle and remove a variety of pests, including bats, raccoons and other urban wildlife that can be carriers of rabies.  So the following post is adapted from one I recently wrote for the pest management industry, with possible relevance to the readers of this blog.]

stray dogs

“Bonnie and Clyde” are the two stray dogs biting people in my neighborhood.  The dog on the left is the one that bit me in August.  Both are still on the loose. Uncollared, stray dogs are a rabies and public health risk, and should be reported to animal control.  Photo courtesy Plano Animal Services.

Last August I was out for an early morning run when a stray dog rushed me from an alleyway and knocked me down.  In light of other dog attacks in Dallas last summer, at least one of which was fatal, I naturally feared the worst as the dog clamped onto my ankle.  But as soon as I recovered my wits enough to defend myself, the dog was off.  The whole incident probably took no more than five seconds.

Thus began my education about rabies and rabies vaccinations.  I’ve known a long time about the seriousness of the rabies virus: how when it takes hold of its victim it is almost certainly fatal; how a victim’s last days are spent in convulsions, wanting and needing water but unable to swallow due to spasms of the voicebox; and how death from respiratory failure usually takes place within 3-5 days of when symptoms begin.

Although my bite was shallow, I knew enough about rabies to realize I shouldn’t ignore it.  On the other hand, I wanted to make sure I really needed the shots (I hate shots).  I learned within a few days that the same dog had been responsible for biting others in my community, and that the local animal control was working hard to catch it and its partner. I hoped that perhaps the animal would be caught and would test negative.  In fact, several days after the attack I spoke to the head of animal control in our town who was very familiar with these criminal dogs. He told me that in his opinion, given their behavior, they were likely not rabid. He explained that almost always a dog that has become infectious will show symptoms of rabies including abnormal behavior, partial paralysis, or lethargy within five days of becoming infectious.

At this point I had a big advantage of knowing someone in the Texas Department of State Health Services.  Dr. Shelly Stonecipher, at my local DSHS regional office was very helpful, answering my questions for over an hour, and advising me that the emergency room was probably my best, and most affordable, option.  My county health department, I was told, should have the necessary vaccines on hand, but would not take insurance and would have to charge the full wholesale cost of the vaccines.  This was my first big shock.  The health department cost for the first shot alone would likely be around $2,000.  The emergency room would be more expensive, but at least it would be covered by my health insurance.

Dr. Stonecipher explained that post-exposure treatment of rabies is very effective, but to work it needs to be given before symptoms occur (some sources say vaccination should take place within 1-6 days, other sources 10 days or more…a disturbingly loose margin of error). The treatment consists of five shots.  The first shot, called the human rabies immune-globulin shot, is given only if a bite has taken place and infection possibly already occurred.  The purpose of this shot is to confer rapid, though shorter lived immunity to the rabies vaccine.  This was the most uncomfortable of the injections, though not as bad as what I was told rabies shots used to be like (painful injections to the abdomen were the standard treatment up until the 1980s). I was told by my emergency room doctor that at least half of the 10 ml immune-globulin shot is supposed to be administered as close as possible to the site of the bite.

One online source says this shot should be given the day of the bite.  However, in my case, no one I talked to in the medical community seemed especially urgent about my getting the shot immediately. I thought I could wait up to 10 days, the quarantine time for some domestic animals.  This would, I’d hoped, buy some time for the dog to be caught [It never was caught and is still, six months later, on the loose in my community–our neighbors now refer to them darkly as Bonnie and Clyde].  As it was, I waited eight days; but if I had to do it over I probably would not have waited more than five days.

The next part of treatment is four rabies vaccine shots given in the arm–one the same day as the immune-globulin shot, and the others on days 3, 7 and 14 after the first shot.  Rabies vaccine confers longer term immunity via antibodies.  But the vaccine may not work quickly enough to prevent rabies if someone has already been bitten by a rabid animal. That’s why these are given in combination with immune-globulin.

The vaccine shots were easy and painless compared to the monster immune-globulin shot.  This rabies vaccine series is what anyone wanting pre-exposure rabies prophylaxis would receive.  After getting my first immunization at the emergency room, I was told that the most affordable and convenient way to get the rest of the series was through one of the local clinics that specialize in vaccines for travelers. Luckily there was a Passport Health office near my workplace.  Also, I discovered that some hospitals carry rabies vaccine shots which you can get by having a prescription from your doctor and making an appointment, thus avoiding the emergency room.

I was surprised by two things regarding my dog attack.  First, no one I spoke with seemed to care or really have strong opinions on when or whether to start the course of treatment. My doctor left the choice up to me. Some medical offices seemed not to know a lot about rabies treatment. Websites had conflicting information about virus incubation periods. In other words, I was on my own to figure out what to do about my health.

My second surprise was the cost.  Even with insurance, my out-of-pocket cost for the vaccine series alone was close to $1,000.  Even more appalling, the following month the bill from the hospital arrived.  The overall bill to myself and my insurance provider for an immune-globulin shot, first vaccine, and 15 minutes of an ER doctor’s time, came to $10,179.  The itemized bill (which I had to request) listed the immune-globulin shot as the biggest expense, $8,318!  According to the hospital, after “discounts” and insurance contributions I personally still owed over $1,800.  All this to say, saving your life after a bite from a rabies infected animal is expensive–even with insurance. Estimates of cost of rabies post-exposure treatment on the Internet are highly variable, but my sticker-shock experience does not appear to be unique.

Advice for anyone working with animals

Fortunately, human rabies cases and deaths in the U.S. are relatively rare, averaging 2-3 people a year.  This low rate is due to the wide use and effectiveness of the rabies vaccine, but it doesn’t mean that precautions are unnecessary. The CDC recommends that veterinarians and staff, animal control and pest control professionals, spelunkers, and rabies laboratory workers be offered the rabies vaccine.  The vaccine should also be considered for any one whose activities bring them into frequent contact with potentially rabid animals, and for international travelers who might come in contact with rabid animals (treatment may not be readily accessible in all foreign areas).

My ten pieces of advice for anyone concerned about rabies:

  • If bitten by a stray animal or any wildlife known to be a potential rabies carrier, don’t ignore the bite. Talk to your personal or ER doctor to assess your risk, and determine whether you need treatment for rabies. Wash the wound site from any animal bite as soon as you can with soapy water and iodine based disinfectant.
  • If possible, take steps to have the offending animal, like a bat, captured for testing. It could help you avoid expensive post-exposure prophylaxis. Care should be taken not to damage the head of the captured animal, as this may prevent laboratory testing for rabies. Your doctor or veterinarian, or in Texas any of the Department of State Health Services regional offices, can assist with instructions on how to submit an animal for testing.
  • Don’t attempt to feed wildlife or touch any stray or feral animal.  Use proper protective gear, including double plastic bags, when picking up dead animals.
  • Make sure your own pets and livestock, including horses, dogs, cats and ferrets, are up-to-date on their rabies vaccines.
  • If you work under conditions that bring you into close contact with bat roosts, do bat removal, or do urban wildlife control, getting the pre-exposure rabies vaccination series is highly recommended. It is much cheaper and easier than post-exposure treatment.
  • Even if you are pre-vaccinated, you may still require a series of two post-exposure vaccine boosters after a bite from a possibly rabid animal.  This is still much cheaper than post-exposure treatment. Check with your doctor.
  • When working around bats, bites sometimes go unnoticed. Bat bites may be extremely small and generally painless. ANY unprotected physical contact with a live bat puts you at risk for rabies–another good reason for rabies pre-exposure vaccine.
  • If you must handle a live bat, use thick leather wildlife gloves.
  • If you must enter areas of large bat colonies consider wearing a fit-tested respirator. Rabies is thought to be contracted only through bites; however there is some circumstantial evidence that urine or feces might on occasion be capable of aerial transmission, especially in areas of dense bat numbers.
  • If you’ve been bitten recently by a dog or other wildlife and not gotten the post-exposure treatment, consider getting it.  Rabies virus can incubate in humans quietly for months after exposure. Although ideally its best to start the shots very soon after the bite, the post exposure prophylaxis can be effective as long as it is given before symptoms appear.

Given that Bonnie and Clyde are still healthy and on the loose in my town, I know now that my emergency room visit and bills last summer were an unnecessary precaution.  But if it happened again, I wouldn’t do anything differently, except possibly start my treatment earlier. The risk of rabies is nothing to take lightly, and also I feel better knowing that I have a pre-exposure protection to a very serious health risk.

Animals at risk for rabies

Rabies is found only in mammals, especially carnivores and bats.  Animals that can and do get rabies include:

  • Skunks are among the highest risk mammals, especially in the south.
  • Raccoons are the most commonly infected wild animal in the eastern U.S.
  • Bats, have low levels of infection throughout the U.S.
  • Foxes, especially in the Southwest and eastern U.S. may be infected with rabies
  • Coyotes, are infected in rare cases
  • Unvaccinated dogs and cats can be infected with rabies. According to the CDC, dogs are responsible for 90% of human rabies exposures and 99% of human deaths from rabies worldwide.

Rodents and rabbits rarely get rabies–the woodchuck, Marmota monax, a rodent, is an exception. Other low risk animals include oppossums, armadillos, shrews, and prairie dogs. Livestock and horses can get rabies, and because of their close association with humans vaccination is recommended.

Not all presents under the Christmas tree are welcome

buggy xmas-tree

buggy xmas-treeThe last week in November and first three weeks in December are Christmas tree season in the U.S.  All over the country, excited families take to the nearest tree lot to pick a recently cut tree for home.  Some of these trees, however, come with more than just needles and flocking.

Giant conifer aphids in the genus Cinara, are among the most commonly encountered insects on fresh Christmas trees.  These aphids form colonies on trees outdoors.  Smaller colonies and lighter infestations are often missed by the tree farm, or by a bright-eyed family out on a U-cut adventure.


Closeup of a Cinara aphid, one of the most common Christmas tree pests.  Photo by Tom Murray, courtesy


Conifer aphids are sometimes mistaken for ticks by horrified tree buyers.  But ticks have eight legs, and are not likely to be brought into a home on a tree.  On the other hand, aphids are harmless. They feed only on plants and will not bite.  Nor do they live long off a live tree, so you need not be concerned about them laying eggs on, or infesting, their ornaments.

Conifer aphids are more likely to be present on cut Christmas trees after a warm fall like this year. The warm weather encourages higher late season populations on trees.

When introduced into a warm home after sitting in a cold tree lot, conifer aphids usually become active and many will move off the tree, as discovered by a local pest control professional who contacted me today (inspiring this post). His puzzled customer saw long-legged bugs crawling over the fireplace, kitchen, and bathroom of a small apartment–not linking them to the Christmas tree in the corner.

Insecticides are not necessary or desirable for control of conifer aphids or any other insects/mites on Christmas trees. If you bring home an infested tree and it has not been decorated, encourage take the tree outdoors, shake it well, and vacuum up as many of the bugs as possible.  Or better yet, return the tree to the lot for a replacement.  Be sure to inspect any new tree and pound the stump on the ground several times to check for live aphids before bringing it home.

Take care not to mash conifer aphids on carpet or furnishings.  They will stain.

Other pests sometimes brought in on Christmas trees include other species of aphids or adelgids, spruce spider mites, and even praying mantid egg cases.  None of these are harmful, and either replacing the tree or vacuuming the offending bugs is usually sufficient.

And don’t forget that firewood can be another source of insects, especially beetles, during the winter months.  A good preventive measure is to keep firewood outside until it is needed for a fire.

Luckily, none of these pests are especially common on live trees.  Nor should they discourage you from bringing a fresh cut tree indoors.  In my book the smell from a real Christmas tree more than makes up for the occasional arthropod hitchhiker.


Simple experiments, like art, sometimes the most delightful


Have you ever been to a modern art exhibit and wondered how an artist could become famous for such a simple work as a colorful abstract, or a painting of Campbell Soup cans?  I could have done that, we’re tempted to say.  The point, however, is that we didn’t.  The artist did, however; and now is laughing all his way to the bank.

The same could be said about some of the most elegant scientific experiments.  Once you hear of them, you think: “That idea was so simple; I could have designed that experiment!”  But of course, only the experimenter thought of the idea and used it to learn something new in the process.

That was my thought when I watched this video on some recent research on Paratrechina longicornis, the black crazy ant (or longhorned crazy ant as they call it in the video).  The experiment was designed to learn more about how crazy ants think and problem solve.  It used a colony of ants, some tuna fish and Lego® blocks.  Check it out and see if you don’t agree that it’s an elegant experiment.

It’s also an example of how someone (say, your child working on a science fair project) can come up with a brilliantly simple experiment with little fancy equipment.  Of course there is more to the experiment than playing with Legos.  The real genius here is not the experiment itself, but how the experimenters approached problem solving.  They first had to know something about their subjects, enough to ask an intelligent question about their behavior.  They also (not showed in the video) used some fancy statistics to quantify and analyze their video observations. They also had enough background in ant behavior to understand the results: namely understanding that ants are not brilliant thinkers so much as practical little beings with a plan A and plan B on getting food resources to a nest.  And smart enough to know when to give up!

Gee, I wish I had thought of that.

Caterpillars in fall not so bad

walnut caterpillar on pecan branch

Walnut caterpillars may strip leaves from portions or all of the canopy of pecan or walnut trees. However severe damage is unusual and late-season damage rarely harmful to the tree.

Finding a caterpillar on a plant or tree in your backyard can be cause for excitement. But they should be little cause for concern, especially during the fall months.

To most human eyes caterpillars are alien creatures. With their squishy, worm-like bodies, and accordion gait, they are weirdly unique among other insects. Some are large and fantastically showy.  Others have ominous-looking barbs and hairs. And some are skillfully camouflaged, nearly invisible among the leaves and shadows. When gardeners do encounter a caterpillar, reactions range from “cool!” to “yuck!!!”

Caterpillars, of course, are the larval stage of moths and butterflies.  What many good gardeners fail to appreciate, however, is the essential role they play in the backyard food chain.  Birds rely most heavily on caterpillars for food.  Without caterpillars to feed on, we wouldn’t see many of our favorite backyard birds.

But what about the damage they cause?  Most gardeners have been disappointed at finding a favorite flower or tomato plant eaten to the stems by hungry caterpillars. While it’s true that caterpillars can be devastating to crops and the occasional garden flower, most caterpillars, especially those found on trees and shrubs in the fall, pose little danger to the long-term health or beauty of our yards.

yellow bear "wooly bear" caterpillar

The yellow bear caterpillar, sometimes called a woolly bear, is a generalist feeder on weeds and low plants. This one is feeding on water lily.

Spring and summer are times of growth and productivity for plants.  Photosynthesis is at its peak during summer when the sunlight is strongest and days are long. At this time, deciduous plants can withstand 20-40% defoliation with no ill effects; though more severe defoliation can cause stress and loss of vitality.

During fall, growth slows.  Fruits like pecans and acorns fill out, and new growth halts as trees and shrubs prepare for winter.  In a few weeks, leaves will turn and drop, further evidence that plants have little use left for their greenery.

For this reason, caterpillars that feed on deciduous plants during this time of year rarely cause significant harm to our plants. Nevertheless, Extension offices get many calls from worried gardeners about caterpillars in the fall.  Walnut caterpillars are common now on pecans, walnuts and hickory trees.  Various caterpillars are active on our many oak tree species.  Hornworm caterpillars and woolly bear caterpillars are also frequently seen feeding on a variety of ground-hugging, herbaceous plants.  As a rule of thumb, however, none of these should require special attention or an insecticide treatment.

pandorus sphinx moth caterpillar and parasite cocoons

Pandorus sphinx moth caterpillar with parasite cocoons attached. This caterpillar will not successfully complete its development due to its weakened state after feeding by the dozens of parasitic larvae that have now emerged and are resting for their eventual emergence as tiny adult wasps.

Fall is also a good time to observe beneficial predators and parasites of late season caterpillars. Paper wasps and solitary wasps are active now storing up juicy caterpillars to feed their offspring. Also tiny parasitic wasps are attacking and emerging from many kinds of caterpillars.  Look for oval-shaped, white cocoons hanging from the backs of caterpillars.  These cocoons are evidence of an earlier attack by a tiny wasp that laid eggs in or on the caterpillar.  Caterpillars wearing these silken cases are doomed, having been previously weakened by the wasp larvae feeding on their insides.

Gruesome as it sounds, these parasites and the many predators keep caterpillars from being more serious pests. Most years caterpillars are rarely seen in a typical backyard, although there may be the occasional year where certain caterpillars are especially abundant, and may cause defoliation. But our trees and native plants have survived insect attack successfully for many years, long before humans were around to care and worry about them. Unless a tree is under stress from other problems, rarely do caterpillars cause much damage.

flannel moth and sting on thumb

Flannel moth caterpillars, sometimes called “asps”, hide rows of venomous bristles under their long hairs. Avoid touching these small caterpillars to avoid a painful sting (right).

Standing out from the common caterpillar crowd, are some of the stinging caterpillars.  While most fall caterpillars are harmless, a few types of stinging caterpillars deserve our respect.  Over the past month I’ve had a few inquiries about flannel moth caterpillars, known to most Texans as “asps”.  These hairy, odd-looking caterpillars feed on oaks and elms, and yaupon shrubs.  When finished eating they crawl out of trees to pupate on fences and the sides of buildings.  Asps bear a set of barbed spines under their fur coat, that can cause a painful  skin reaction.  Give these guys a wide berth, or be careful to wear heavy gloves if you must handle these critters.

Instead of worrying about caterpillars in the yard, embrace them!  They are providing food for wildlife, and in moderation are a sign of a healthy environment. And on top of that, they are fun to watch and identify.  For additional reading and identification, check out these guides for the gardener:

  • Caterpillars of Eastern North America by David L. Wagner. Princeton Field Guides, Princeton University Press, Princeton, NJ. 512 pp. Still the most comprehensive field guide to caterpillars yet published in the U.S. Beautiful photos of both adults and caterpillars of macrolepidopteran moths and butterflies. A must-have reference with lots of useful information for the serious naturalist and entomologist alike.
  • Owlet Caterpillars of Eastern North America by David L. Wagner, Dale F. Schweitzer, J. Bolling Sullivan and Richard C. Reardon. 2011. Princeton University Press, Princeton, N.J. 576 pp. I thought that Caterpillars of Eastern North America was pretty thorough until this book came out and realized how many species there were to know from just one moth family group.  The Noctuid moths constitute the most diverse Lepidoptera family, and in this guide they are covered along with three other related families now called owlet moths.  Another beautiful guide from David Wagner and colleagues, with stunning photography.  Alas, not a Texas guide, but still quite useful in helping identify moth caterpillars in the eastern half of the U.S.
  • Caterpillars in the Field and Garden: A Field Guide to the Butterfly Caterpillars of North America by Thomas J. Allen, James P. Brock and Jeffrey Glassberg. 2005. Oxford University Press, USA. 240 pp. When it rains it pours. After many years with few references to caterpillars, this book and the Wagner book both appeared in 2005. This volume focuses almost exclusively on butterfly larvae, which make up far less than half of all caterpillars; but it is well done and will be useful for butterfly gardeners and those wishing to supplement their knowledge of the lesser known life stages of butterflies.




Getting tested for Zika

doctor and patient illustration

A doctor is your best adviser when determining whether to get tested for Zika, and what tests you need (CDC).

So you and your significant other are considering whether to get pregnant; but the summer’s headlines about Zika virus and its effect on developing babies has you worried.  Or maybe you’ve just returned from traveling to an area where Zika is active.  You’ve not experienced symptoms of Zika, but you’ve been around others with the disease and you know that 4 out of 5 people who get Zika show no symptoms.  You wonder if you might be infectious to your spouse or partner (Zika can be sexually transmitted). In both cases a test to see whether you might have Zika sounds like a good idea.

So are there tests for Zika?  And if so, which one is right for you?

It turns out that there are multiple kinds of tests for Zika, although no one test is consistently definitive.  The RT-PCR test (Real Time Polymerase Chain Reaction) test is the go-to test used by doctors to see if you have an active case of Zika.  It can be used to test blood serum, saliva or urine, but generally is sensitive only to viral levels present during active infections (first 5 days of illness for blood serum, 2-12 weeks for urine).  Its primary advantages are lower cost and speed, with results available as soon as the same day.

After illness has passed, doctors must rely on tests that look for the presence of antibodies left over after the body has fought off the infection.  A test called IgM-capture enzyme-linked immunosorbent assay (MAC-ELISA) can detect whether IgM and IgG antibodies are present in the blood serum for several months after infection.  Unfortunately, these tests can also react to antibodies from other mosquito-borne viruses, like dengue fever.  So additional dengue-specific tests (PRNT) may also be needed to confirm whether the person has been exposed to dengue or Zika.  These tests are more time consuming and expensive and may require up to a week to perform.

zika rash

An itchy rash is one of the symptoms of Zika infection brought on by a mosquito bite (Photo by Jackie Thornton).

Your doctor or public health office is the best authority to determine what type of test you might need.

So should you get tested?  Unless you live in south Florida, or unless you or your sex partner have recently traveled to an area of high Zika risk, the chances that you have been exposed to the Zika virus is extremely low.  In fact, the CDC does not recommend Zika testing for asymptomatic men, children or women who are not pregnant.

Zika testing is currently being provided free by the Centers for Disease Control and regional public health laboratories, but only for the following people:

  • Those with more than one Zika symptom who have traveled to an area with Zika infection or had unprotected sex with a partner who has traveled to such an area within the past 4 weeks;
  • Pregnant women who have traveled to a Zika area during their pregnancy, or 8 weeks before conception, or who had unprotected sex with a partner who spent time in such an area;
  • Those with Guillain-Barré syndrome with Zika exposure history;
  • Infants born to a woman with a positive or inconclusive Zika test;
  • Infant born with microcephaly by mother with Zika exposure history;
  • Those with Zika symptoms and who may have had an alternative mode of acquisition like a blood transfusion or organ transplant.

Women who think they may have been exposed to Zika, and who want to get pregnant but do not meet any of the above criteria, are not being tested now by the CDC or public health agencies.  Instead, if you fall into this category you are advised to avoid getting pregnant for two months and practice protected sex for six months.  One of the reasons for excluding non-pregnant women is that testing laboratories are currently backlogged with high priority cases.  Even if you meet one of the above criteria, test results may take up to 4 weeks to be received.

There are private laboratories (Viracor, LabCorps, and QuestDiagnostics) that will test blood and urine for Zika through your private physician, with costs ranging from approximately $165 for PCR testing to $700 for IgM and IgG testing.  If you opt for this route, you will bear the cost of testing and will have to proceed through your own physician.

As of 16 September 2016, there were 79 cases of locally acquired Zika in the U.S.  All of the locally acquired cases came from the south Florida/Miami/Dade County area.  So far there has been no local (non-travel related) transmission by mosquitoes of Zika in Texas.

[Thanks to Dr. Robert W. Haley, University of Texas-Southwestern, for some of the background information for this post.]

Girding our loins for emerald ash borer

Emerald Ash borer
EAB training class screen shot

Screenshot from the new emerald ash borer online learning module.

The emerald ash borer (EAB) that has devastated ash trees throughout the Ohio River valley and Great Lakes region has finally made its way to the Lone Star State.  So far the beetle has been found in only one location in Harrison County, next to Caddo Lake; but over the next few years it will continue to spread.  As it does, it will slowly change the face of our native forests as well as our urban tree landscape.

To prepare for the inevitable changes, Holly Jarvis with Texas A&M AgriLife Extension, has recently led an effort to develop an online training tool to learn about this powerful pest.

LearnOnline is a new Extension web resource for online courses.  The classes are free, and though not yet approved for pesticide applicator CEUs, they may qualify for advanced training hours for some Master volunteer programs.  Check with your local county Extension agent or Master Naturalist chapter officers for details.

Beyond getting official credit, the LearnOnline Emerald Ash Borer module is a great way to learn about, and prepare for, this new pest. To view the course, please go to You may be asked to set up and confirm your account via a link sent to your email address. Or, for the EAB course you can simply login as a Guest.

quarantine counties Aug 2016

Counties currently under quarantine (in yellow) for the Emerald ash borer in Arkansas, Louisiana and Texas.

To find the EAB course, click the category heading “Agriculture and Natural Resources”. A list of all courses in that category will come up. From there, click “Emerald Ash Borer”.  The course is approximately 25 minutes and includes a final quiz (optional if you want a certificate of completion).

Topics covered include “why should we care about EAB?”, “how to recognize the ash trees hosts of the beetles”, “recognizing EAB damage”, “EAB biology”, “who’s at risk?”, “reasons for hope and control options” for EAB.

Let’s get out there and “gird our loins” to fight the spread of this destructive pest.  If you have a favorite tree that’s an ash tree, you will benefit from knowing the battle plan.

New Zika publications

pregnant woman silhouette

Zika Precautions for Women is the latest of several new fact sheets designed to inform Texans about this new mosquito-borne disease.

I was asked a few weeks ago if the collective “we” (meaning the whole state of Texas) were going to be ready for Zika.  My answer was a cautious, “I think so”.  If we’re not, it at least it won’t be for lack of trying.

Zika is a much different disease than West Nile virus. It has different vectors, mosquitoes that prefer to feed on humans over any other animal (unlike WNV mosquitoes, which mostly feed on birds).  It is also very difficult to detect in wild mosquito populations.  The mosquitoes are more difficult to control with spray trucks, so responding to local cases is going to depend more on public cooperation.  Unlike WNV, it’s virtually undetectable in the blood supply, as there is no approved way to screen newly donated blood to see whether it has the Zika virus in it.

If Zika does make it into the country, it will also potentially affects more people.  Any family with members of childbearing age will need to be on high alert.

The CDC recently released its response plan for Zika.  It’s assumptions are sobering:

  • Travel-associated and sexually-transmitted cases will continue to occur and are likely to increase. (we just don’t know how much!)
  • Local transmission (spread) of Zika virus in US territories and affiliated Pacific Island countries is ongoing.
  • Neither vaccines nor proven clinical treatments are expected to be available to treat or prevent Zika virus infections before local transmission begins nationwide.
  • The ability for mosquito control efforts to reduce infection risks may be limited, as has been the case with similar viruses, such as dengue and chikungunya.

The entomology department, and especially my colleague Extension entomologist Dr. Sonja Swiger, has been busy in recent weeks trying to figure out how to best arm you with the best information on how to prepare for the “Summer of Zika”.  As part of the effort, some new fact sheets are now available to answer some of the more common Zika questions.

Quick fix for mosquitoes

This year my wife and I worked all spring to turn our backyard into a flowery paradise.  We installed drip irrigation, planted new plants (including a bunch of perennials for attracting bees and butterflies) and mulched everything against the coming drought of summer.

Now that summer’s here, however, the mosquitoes have decided that since everything’s so nice, they want to be in charge.  In fact I believe every mosquito on the block knows about our backyard, making it difficult to go outside for even a few minutes without repellent.

You see, clearing your own yard of mosquito breeding sites (as I have done) doesn’t guarantee a mosquito free yard.  So how do you take back your yard?  One quick fix that a lot of people are unaware of is the thermal fogger, available through most hardware and garden centers.


A thermal fogger in use.  Apply fogs in the early morning or evening, when wind is low and bees are less active.  Focus on thick foliage, shrubbery and tall grass where mosquitoes are most likely to hide.

Thermal foggers use heat from a propane burner or electricity, to heat a coil that turns certain oil-based insecticide formulations into a dense smoke of very small particles (10-25 microns–1/10 the width of a human hair).  The small size of these particles allows them to hang in the air long enough to kill flying mosquitoes.  The small size is also effective for penetrating foliage to kill mosquitoes resting in hidden locations.

Thermal fogging is easy to do, and relatively fast.  In my experience, I get several hours to a day or more’s relief from mosquito bites when I fog my backyard–plenty of time for that barbecue, birthday party or wedding reception.

The signature smoke from thermal foggers has its good and its bad points.  On the good side, you can see exactly where the insecticide goes and direct it where needed.  On the other hand, depending on the wind, the smoke may drift beyond your yard.  It’s a good idea to alert the neighbors before fogging your yard, or you might be seeing the fire truck pull up in your front yard.  Also, not all neighbors will be pleased by unexpected mosquito insecticide drifting into their backyard.

So what are the risks of fogging? Risks to humans and pets are very low with the common over-the-counter insecticides sold for fogger use.  But I find few good studies on the impacts of consumer fogging machines on beneficial insects.  I think it’s safe to say that there likely are some temporary impacts on the smaller beneficials like parasitoid wasps, and possibly the smaller bees.  But these insects are also typically highly mobile and should be replaced by other beneficial predators and pollinators quickly.  I believe it unlikely that larger butterflies and bees will be harmed by the low exposure rates used in mosquito fogging.  Although I am still assessing, I’ve not seen any noticeable impacts of occasional fogging on the larger insects I love to see in my garden.

Mark the term “occasional”.  Fogging for mosquitoes is not something I do regularly in my yard (though my vengeful side may want to do it more often).  I reserve my fogging ventures to once or twice a summer, and only when I’m expecting guests or planning a special outdoor event.  This way I can enjoy my pollinator and butterfly gardens and get my quick mosquito fix when I need it.

The rest of the time insect repellent works well.  And I am enjoying our newly planted gardens, despite the mosquitoes.

Reminder: Mosquito season and the risk of mosquito borne diseases kicks into high gear this month.  So don’t neglect the repellent and checking your backyard to make sure you’re not the neighborhood source of mosquitoes.

Turning the tide against ash borer?

Green ash
Tetrastichus planipennisi adult

Tetrastichus planipennisi is an obscure little wasp that specializes in finding and parasitizing the larvae of emerald ash borers.

On one hand, we’ve learned a lot about how to fight emerald ash borer with pesticides in the past 14 years since it was first discovered devouring ash forests in Michigan.  But we’re still learning how nature keeps EAB in its place in its native Asian home.  Insect parasites and predators are almost certainly the reason EAB is not a major pest on the other side of the globe.

If only we could put some of those same beneficial insects to work for us!  Then maybe we could slow the spread of EAB, and save our ashes at the same time.

That’s the idea behind research being reported this month by USDA Agricultural Research Service scientist Jian Duan and other researchers with the US Forest Service and the University of Massachusetts.  They looked at a tiny wasp, Tetrastichus planipennsi, that specializes in laying its eggs in the bodies of EAB larvae feeding under the bark of ash trees.

Over the course of the 7-year study the researchers saw a 90% decline in EAB larvae in infested trees caused by both native parasitoid wasps and by T. planipennsi.  They believe that once these fighting wasps are released in an area they will reduce the population growth of EAB and perhaps prevent outbreaks in newly infested areas–like Texas.

This will certainly be among the tools that the Texas Forest Service and others will be bringing into play as EAB makes its first tentative steps into our state.  In the meantime, don’t transport cut firewood when you’re out camping this summer, especially in the Caddo Lake region of east Texas.  And stay tuned for more news concerning the spread of this devastating insect.