Bug blitz is a blast

dainty sulfur butterfly on pin

Marking perhaps the beginning of insect season, last weekend the Lewisville Lake Environmental Learning Area (LLELA) held its first ever “bioblitz”.

Collecting insects during the Bioblitz survey in Lewisville, TX.

Nets and cameras were the tools of the day for the insect bioblitz team.

In case you’ve never heard of a bioblitz, it’s a concentrated effort among volunteers, naturalists and professional biologists to go to the field and document as many species as possible over a certain time period (usually a day).  This year’s LLELA bioblitz included trees, reptiles, birds and insects.

dainty sulfur butterfly on pin

One of the cool things about bioblitz is the chance to learn new insects. This was my first time to see Nathalis iole, the dainty sulfur butterfly.

Our insect group consisted of myself and three other enthusiastic collectors/photographers (actually, mostly photographers–seems like only entomologists want to capture and euthanize insects these days).  Starting out in the prairie area of the preserve, we migrated to the very productive pollinator garden on site.  It was a lot of work, but a lot of fun too.

People often assume that professional entomologists must know a lot about the insects in the natural forests and habitats around where they live.  Of course some professional entomologists do, but many of us (like myself) are only semi-competent when it comes to sight-identifying insects outdoors.  Part of this is because there are just so many of the darned six-leggers out there, and no one can be an expert in all of them.  Part of it is because most entomologists are involved in highly specific work that doesn’t always afford the time to be naturalists.  For example, I and many of my extension colleagues usually focus on insect pests and how to control them.  Many of us are easily stumped when it comes to free-range insect life.

One of the good things that came out of the bioblitz for me was learning more about the iNaturalist tool for making biological observations. Once you establish an account in iNaturalist, you can post sightings and pictures.  The iNaturalist community will even help you identify insects.  I also learned that by adding tags to your pictures, others can search for your postings and make comments.

I’m not always a huge fan of online social networking, but this is a very useful and entertaining tool.  I found it a great way to spend some of the rainy day that followed our collecting day.

After getting home from bioblitz, the real work begins. Several hours were spent pinning insects, reviewing and culling photos, and learning how to post them online. By looking at my pictures and comparing them to iNaturalist images as well as submitting some to the more insect-oriented Bugguide.net community, I managed to identify a surprising number of insects to at least the genus level–not bad even for an entomologist.  Some of my collecting teammates were even more productive than I, having dozens of new observations posted to the web within hours of heading home.

If you want to check out some of the postings of all the LLELA blitzers on iNaturalist, try clicking here.  It might inspire you to sign up, get outside and start documenting the insect life in your own backyard.



Planting to nurture nature

white-lined sphinx moth caterpillar
white-lined sphinx moth caterpillar

Although many gardeners might shudder at the thought of caterpillars in the garden, native caterpillars are rarely serious pests to backyards trees and shrubs, and they provide an essential food source for song birds.

We all have more power than we might think.  In a world where so many things seem out of control, anyone with a small plot of land, or even an apartment balcony with room for a few potted plants can make a small but significant difference in our environment.

What we plant in our gardens can do more than just look pretty.  By selecting the right plants we can sustain native pollinators and attract butterflies.  We can create habitat for birds and reptiles and other small animals.

Imagine a songbird wanting to make a nest in your backyard.  Besides a place to weave a nest, a mother bird needs food for her young.  By far the most important protein source for song birds (including some species that are principally seed-eaters as adults) are caterpillars.  Butterfly and moth caterpillars are normally quite abundant in a natural woodlot or forest, or prairie.  But in urban areas where many of the planted trees are exotic species that sustain few native caterpillars, pickings can be scarce for nesting birds.

Many people don’t know that you can increase the carrying capacity of your backyard for birds by simply taking care to plant native trees and woody shrubs.  Dr. Doug Tallamy, University of Delaware, has documented this phenomenon in his book, Bringing Nature Home.  Tallamy also provides a useful list of woody and herbaceous plant genera and their relative attractiveness to caterpillars.  Oaks lead the list with over 500 butterfly and moth species that depend on oaks for survival.  Even though this list was compiled for the mid-Atlantic states, many of these plant genera do quite well here.  The birds will thank you.

Besides birds, bees need our help in urban areas too.  Loss of habitats, climate change and limited water are contributing to shrinking ranges and declining numbers of many unique and beautiful pollinator species.  Case in point, the rusty patched bumble bee went on the endangered species list this week, the first bumble bee to be so listed.

The Horticultural Research Institute maintains a listing of plants that bees like best.  This is a great place to start when planning a new garden.  The HRI chart is organized by bloom time, which can help you ensure that you have plants blooming throughout the growing season–an important requirement for bees and other beneficial insects.  It also lists trees and shrubs that attract few bees, like forsythia, roses, and hydrangea.

If you want to do good and feel your power multiplied, consider joining the million pollinator garden challenge a campaign to register a million public and private gardens and landscapes to support the survival and preservation of pollinators. The Pollinator Partnership even provides Ecoregion planting guides that you can download and use for even more plant ideas.  According to the website, we in north Texas and Oklahoma belong to the Prairie Parkland (subtropical) Province (though I’d just call it “hot and flat”).

So let’s get out their this summer and change something we can change–our own back yards.


Lady beetle invasion

multicolored Asian lady beetle adult


multicolored Asian lady beetle adult

The multicolored Asian lady beetle has wing covers ranging from yellow to red and with various numbers of spots. The white plate behind the head, with W-shaped markings are a good identification clue.

This year Extension offices are receiving an unusually high number of calls about lady beetles inside homes.  The culprit is an exotic lady beetle called the multicolored Asian lady beetle (MALB).  While not new, high aphid  populations in some trees last year are thought to have contributed to this year’s higher than normal number of these “naughty lady beetles”.

The multicolored Asian lady beetle is normally a helpful insect that eats aphids.  Studies of the beetle in its native Asian habitats showed that it was such an efficient predator that for many years the U.S. Department of Agriculture tried to import them.  Ironically, after repeated failures to get the beetles to establish here, the beetles mysteriously appeared on their own in a number of states during the early 1990s.  Whether these beetles were survivors of earlier deliberate importations, or whether they found their way to the U.S. on their own, no one really knows for sure.  But its one bad habit has many homeowners wishing this beetle might have stayed back in Asia.

The multicolored Asian lady beetle is unique among major lady beetles in its behavior of routinely invading homes and buildings in the fall.  In its native home in Japan, this beetle quietly disperses into the white limestone bluffs along its riverside feeding grounds.  But in the U.S. it has become a significant pest when it seeks shelter in the walls and attics and living areas of homes.

The beetles seem to become pests more often in homes surrounded by trees and forests.  They also seem to be attracted to homes of lighter or contrasting colors.  The adults enter homes through any available crack or crevice and may aggregate in attics or even living areas of the home.

Although mostly harmless, like some other common lady beetles, MALBs are occasional “nippers,” biting skin if they come in contact with humans.  They also let off a disagreeable smell when disturbed, and medical reports exist of people developing allergies to the chemicals emitted by lady beetle aggregations. But mostly these beetles are a simple nuisance, unwanted and sometimes cursed.

Although homes were invaded in the fall, this winter’s up and down temperatures have caused these beetles to get restless and move about the home in search of a way out.  When daytime temperatures reach the 80s outside, attic temperatures may reach the 90s, fooling the beetles into thinking that spring has arrived and sometimes sending them into living areas of the home or building.


There are no easy ways to prevent MALB from entering homes or controlling them once inside. Caulking and sealing outside entry points is perhaps the most effective technique.  Use of residual insecticides around areas that are not easily sealed may provide some temporary control of lady beetles attempting to enter homes.  Pyrethroid insecticides are usually good for this purpose.

Once inside the beetles are best controlled by vacuuming.  Spraying insecticides on aggregations of lady beetles will  result in piles of dead insects, and undesirable smells.  Discard your vacuum bag after use if you don’t want a smelly vacuum.  Bug bombs, light traps and lady bug houses are not effective at ridding homes of these beetles.

Once the weather completely warms up, the lady beetles will eventually find their way out of the house and on to their worthy pursuit of aphids.  Until that happens, you may have to just continue to vacuum these little guys up as long as they are found.


Benefits of cockroach baits

placing cockroach gel bait under kitchen counter

You may not have cockroaches in your home. But cockroaches remain one of the most important indoor pests of homes, especially in multifamily housing.  If you do have occasional problems with the small kitchen cockroaches, known as German cockroaches, there is good news, and it’s as close as the insecticide shelf in your grocery store.

A story

Before starting graduate school in entomology I worked as a pest control technician out of college. One of my accounts was a sprawling, multi-story public housing complex. These visits were frustrating to me, because of the difficulty (impossibility) of putting much of a dent in the well entrenched German cockroach population that scurried back and forth among these apartments.

German cockroach adult.

German cockroaches are some of the smallest cockroach pests. Their ability to reproduce quickly, however, makes them one of the most difficult to control indoor pests.

One of my visits, however, was the home of a single mom. It was a short encounter, and I’m not sure I ever saw her again; but the mother’s gratitude for my efforts to battle the cockroaches plaguing her and her daughter made an impression on me.  The apartment was uncluttered and very clean. It was obvious she was doing her part to keep cockroaches at bay–something that made my job a lot easier and more effective. Despite the feeling that I wasn’t putting much of a dent in the overall cockroach problem in those apartments, I went home that night feeling a little better about my job in pest control.

What’s changed

Two major changes have occurred in cockroach control since the early 1980s.  First, the scientific community has learned a lot more about the health impacts of cockroaches. Besides being unsanitary and capable of spreading disease pathogens, we now have solid evidence to show that cockroaches are major contributors to asthma illness, especially among children living in infested homes.  Indeed, the feces and shed exoskeletons of cockroaches have proved to be among the most important indoor asthma causes we know of.  Children who grow up in cockroach infested apartments have higher rates of asthma, more missed school days, and more doctor visits than do their more affluent classmates from cockroach-free homes.

Second, with the discovery of effective baits, we have much better tools for cockroach control today. The insecticides available to me in 1980 were mostly residual sprays and dusts that had to be applied directly to cockroach hiding places.  If counter-tops were not cleared and covered, or cupboards not emptied before I arrived, there was little I could safely do with my carbamate and organophosphate sprays and dusts.  In addition, many of these sprays were repellent to cockroaches, something that I learned later in grad school greatly reduces their effectiveness against insecticide-avoiding cockroaches.

Today’s professional and over-the-counter insecticides are safer and vastly superior to the old insecticides.  Containerized and gel baits, in particular, have revolutionized our ability to manage cockroaches.  Although sanitation is still important for cockroach IPM, baits have shown an ability to suppress cockroach numbers even in cluttered and not-so-clean homes.

A number of studies have shown over the past 20 years that cockroach control and sanitation efforts could significantly reduce the quantity of cockroach allergens in apartments.  Indeed, the National Asthma Education and Prevention Program recommends reducing cockroach exposure as a critical step to take in reducing asthma risk.

New research

A new study in the Journal of Allergy and Clinical Immunology out this week is the first to show that cockroach baiting by itself can result in measurable improvements in the health of children. The researchers looked at the apartments of 102 children (aged 5-17 years), all of whose homes had some level of cockroach infestation.  Half of the children were assigned to homes that would be treated by researchers with cockroach baits, and half of the homes were left untreated by researchers.  All of the homes were sampled for cockroaches using Victor® Roach Pheromone Traps, and health indicators were measured for all the children (such as number of school days missed, medication used, days of wheezing, number of nights where children woke up, etc.).

placing cockroach gel bait under kitchen counter

Cockroach baits come in gel form (shown) or in plastic stations. They should be placed in crevices or as close to suspected cockroach hiding places as possible.

Treatment of homes consisted of placing either Maxforce® FC Magnum, or Advion® cockroach bait gels in areas with evidence of active cockroach infestation.  Those who put out the bait were not even trained professionals. Instead, research staffers were instructed to place baits in the back corners of kitchen cabinets, behind kitchen appliances, and inside bathroom vanities.  No other control methods were used.

The median cockroach numbers were significantly lower in treated homes vs. untreated. By the end of the study none of the baited homes had evidence of cockroach activity, compared to a 20% infestation rate of the untreated homes.

Interesting to me was that after the study began cockroach numbers in the untreated homes went from 100% infested to only 20% infested.  The authors of the study attributed the drop in untreated homes to “study effects”.  People whose homes did not get treated, but were being monitored for cockroaches, took extra pains to clean up before the research team arrived, and they conducted additional cockroach control on their own, apart from insecticide baits applied by the researchers. This lead to an almost 85% reduction in trapped cockroach numbers in the control homes.

So it’s even more remarkable that, despite the cockroach reductions in homes not receiving bait treatment, researchers still noted significantly better cockroach suppression with bait-treated homes and significant improvements in children’s health.  In treated homes, for example, children had 47 fewer days a year with asthma symptoms compared to homes that were not treated with baits. Children in treated homes also had improved lung function and significantly fewer doctor visits compared to untreated homes, despite the relatively small sample size and relatively low cockroach levels in untreated homes.

When I consider how far cockroach control has come since my days with a steel pump sprayer and smelly sprays, these results are truly amazing.

So here’s the good news for anyone living with cockroaches.  A trip to your local grocery or garden center, or a visit to one of the many online DIY pest control businesses, can secure cockroach baits that are far better than anything I had 35 years ago.  For more information about selecting and using cockroach control products, see our Extension factsheet on cockroach biology and control at https://citybugs.tamu.edu/files/2016/07/E-359-Cockroach-biology-and-management-2012.pdf


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 Bugguide.net


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.]