Tuesday, March 17, 2020

Coronavirus strikes training classes

The strategy behind today's protective measures of hygiene, social
distancing, and reducing human interaction is called "flattening
the curve".  This is why Extension programming is being
temporarily suspended.  Adapted from CDC/The Economist.
Who would have believed, even one week ago, that coronavirus would dominate our lives so quickly and severely?  This sort of thing is something that happens to other countries, not ours.  Yet here we are.

The reality of coronavirus hit home to me last week when we realized that we couldn't follow through with our plans to offer a long-planned mosquito control class as part of our IPM Experience House class curricula.  Texas A&M AgriLife and our local campus have moved to emergency mode, effectively shutting most training classes down for the foreseeable future.

In addition to IPM House classes, upcoming school IPM coordinator training courses are similarly affected.  We are cautiously considering whether we may be able to offer classes in May and June.

It took me a while to grasp the significance of the coronavirus shutdown strategy; but for what it's worth, here are a few facts and links that turned me around this week.

  • Understanding that the COVID-19 is not just another seasonal flu.  It's a disease with 4 to 7X higher mortality rate than the flu and longer persistence in the environment than the flu (up to 3 days on stainless steel and plastic).  Maybe worst of all, people (especially children) who catch it can be contagious without even realizing they are sick. 
  • We don't hear a lot about the plight of those who catch this virus and recover (not as gripping in headlines), but this is not a virus to take lightly. Early reports suggest the possibility of chronic lung impairment in some recovering COVID-19 patients
  • Yeah, it sounded bad in China, but look at Italy.  In Italy, where health care systems are more similar to our own but where quarantine actions were slow to be adopted, a crisis situation developed with lightning speed in emergency rooms of afflicted areas.  And if you think Italy's health care is inferior to our own, consider one statistic.  In hospital beds per 1,000 people, Italy leads the US 3.2 to 2.8.  Anyone thinking that our doctors and hospitals could do better in the face of overwhelming numbers of cases as in Italy would be wrong. 
  • Thankfully, there is a strategy behind the "stay at home" message we are hearing so much about. It's called flattening the curve, and it's based on the impact that self isolation and social distancing can have on the speed of spread of COVID-19.  While it may seem inevitable that some of us will get the virus, by reducing our exposure to others we can slow the rate of virus spread.  And if we do this, we might be able to spare our health care system the tsunami of cases seen in Italy. 
  • Our country rightly invests billions of dollars each year in science and health care.  It's time to listen to those smart folks who have dedicated their lives and their intellects to understanding health and illness and the spread of disease.  They don't know everything, of course, but they know a lot more than us non-health professionals know.  
So for all these reasons, I am working this week in an empty building with plenty of social distance around me. We use hand sanitizer, wash our hands regularly and stay away from large gatherings including, unfortunately, classes where we might otherwise be training some of you.  

Let us pray for our communities and our nation, and look forward to celebrating a return to face to face interactions in a matter of weeks.  Be assured that our IPM training classes will resume as soon as possible. 

Loving it with fleas

I love my job--especially when I get to identify tiny insects that no one else wants to look at. I recently received an insect from a gentleman whose daughter had been bitten at home. I could tell immediately we were dealing with a flea--usually a routine identification to confirm that the tiny insect was a cat flea.  But this specimen was different, and prompted a closer look. What fun!

Before I let the "cat flea" out of the bag, one of the fleas below was the flea I saw this week. Can you identify which is the one that was not a cat flea? (Hint: it doesn't have anything to do with the color, length of the body, or shape of the flea)

Two adult fleas.  Human flea on left, cat flea on right.
Click on image for a better view.  Photos by M. Merchant.

If you guessed the flea on the left was my mystery flea, you'd be correct.  But did you guess right for the right reason? 

First, it wasn't the legs.  Both fleas are "host fleas", which means they live most of their adult lives on a host.  Host fleas must have strong jumping legs to gain access to this host.  Nest fleas, on the other hand, live in the nests of their hosts (usually rodents or birds), only living on the host long enough to take a blood meal and returning to the nest after dinner.  Nest fleas rely less on jumping and and more on crawling within the nest to feed, so the third pair of legs is more like the second pair in size. 

The big difference between these two fleas is the presence or absence of dark, comb-like bristles on the face and behind the head.  The cat flea has combs both above the mouth (called a genal comb) and on the tail-edge of the first thoracic segment (pronotal comb) behind the head.  Fleas with both genal and pronotal combs are relatively rare, narrowing down their probable identity considerably.  Most fleas found indoors with two combs like this in homes are either cat fleas, Ctenocephalides felis, or dog fleas, Ctenocephalides canis

The flea on the left lacks both a genal and a pronotal comb, ruling out cat flea.  This flea is a human flea, Pulex irritans.  The human flea, like the cat flea, has many potential hosts including small mammals, canines, pigs, humans, and even burrowing owls. 

Entomologists have identified over 2,500 different kinds of fleas from around the world.  Most of these fleas are highly fussy about their food, feeding on the blood of only one or a few closely related kinds of hosts.  These two fleas are exceptions.  Besides cats, the cat flea gladly feeds on dogs, opossums, raccoons (two frequent wildlife hosts that can bring fleas into homes when pets are not present), foxes, skunks, cattle, rats and rabbits, to name a few. [Curiously, squirrels do not seem to be a listed host of cat fleas, so are not likely to be the source of fleas in homes with no cats or dogs.]

Why worry about flea identification?  Because flea ID may provide clues to a possible source of a flea problem. If fleas found in a home or on a pet are not cat fleas, it's possible that the fleas are coming from rodents or other wildlife.  For example, rat fleas may suggest a rat or mouse infestation.  Rat fleas may pose greater risk for the homeowner from flea-borne illness such as murine typhus, or even (more rarely) plague, though the cat flea is not without its own risks. Cat fleas on opossums have been associated with increased cases of murine typhus in California and Texas and other areas.  Cat scratch disease may also be carried by cat fleas.

The following key is provided by the Centers for Disease Control (reprinted in the Mallis Handbook of Pest Control) and can help you identify some of the more common fleas found in structures or on pets. Combs can usually be seen by the practiced eye with a good 10X handlens.  If you want to see other features in this key, however, you'll need a microscope.  A 12X magnification will show genal and pronotal combs; but 25X to 50X is needed to see smaller characters shown on the key. 

If you do not see pronotal and genal combs on a flea collected in a home, and do not have a good microscope, it's best to save some specimens in either 70% ethanol or rubbing alcohol.  Specimens can then be sent to an entomologist for positive identification. Five or more pointed teeth on both the genal and pronotal sites will narrow any flea found on a pet or in a building down to a cat or dog flea, both of which have similar host ranges and control measures. 

CDC Pictorial key to adult fleas
Click on key for a better view. 

 Next time you get your hands on some fleas, take a closer look. Check for combs and use the key. I predict you'll get that same thrill of satisfaction entomologists get when being able to put a name on something that most people can barely see. Your customers will be impressed too.

Wednesday, February 12, 2020

Termite season (and training needs) around the corner

Dr. Davis suggests tips for better termite barriers
with participant at the 2019 termite class.
It doesn't take a PhD to predict that termite season is likely to arrive early this year. Record warm temperatures and abundant rain are already stirring the pots of pest activity in Texas, so all pest control companies should be gearing up now for a busy and early year.

If your company is hiring new staff this spring, or needs to get existing technicians cross-trained for termite season, this class is for you.  IPM House will be offering a one-day, 2020 Termite Training for New Technicians class on February 28. Dr. Bob Davis, BASF Corporation, and Kevin Keim of Corteva, will be assisting our team with an interactive course in termite biology and control.

If you've not yet attended an IPM Experience House course, this is a great opportunity to get involved. All IPM House classes are an interactive mix of both classroom and field training. The training day includes lecture and Q&A with top experts, microscope exercises and hands-on activities at the IPM House itself.

We especially welcome PMPs from other parts of Texas and out of state to attend and become part of the IPM Experience House alumni.

At $55 for the day, including lunch, this course is a bargain. To learn more about this month's class, please check out our registration page at https://agriliferegister.tamu.edu/productListingDetails/3076

Thursday, January 23, 2020

Spring IPM Conference registration opens

For anyone who needs structural or ag CEU credits in the area of turf and ornamental pest management, 2020 Spring IPM Conference registration is now open.

This year's program will focus on how pesticides accomplish the challenging task of controlling pests. It's not as easy or as simple as you might think!

Dr. Christopher Bibbs with Central Life Sciences will talk on how insecticides work. Our Dallas turfgrass extension specialist, Dr. Chrissie Segars, will cover modes of action of herbicides.  And Scott Smith, Bell Labs, will review rodents and how rodenticides work. In addition, Janet Hurley, our school IPM program specialist, will be providing the latest updates on what's going on with re-certification rules and pesticide regulations.  And I will review those common, and not-so-common insects associated with turfgrass.

Our challenge every year is to make sure when you attend an IPM Conference, you leave with at least one useful piece of knowledge. There will be lots to learn at this meeting, so register now by going to https://agriliferegister.tamu.edu/IPM.  As usual, a great lunch will be provided.

Thursday, January 16, 2020

Pavement ant gets a new name

Tetramorium immigrans nest. Photo by Alex Wild.
A few years ago I was called to a home in the Dallas area to look at a stubborn "fire ant" problem.  Indeed the numerous mounds did look much like fire ant mounds, and the red ants like fire ants; but closer inspection showed the ants to be pavement ants. 

The name "pavement ant" comes from its preference for nesting in open, well-drained gravelly soil typical of sites under sidewalks and other pavement. By building roads and laying concrete throughout our cities it seems we have created the perfect habitat for these ants. 

Temperate climates, like those of the Northern and Midwestern states, are especially favorable to  pavement ants.  In some states, pavement ants are the most common household ant, foraging for crumbs and swarming indoors like termites or carpenter ants. Though less common in Texas, I suspect pavement ants are more common than we realize, often being mistaken for fire ants. 

According to BugGuide.net, there are seven native and introduced species of Tetramorium in the U.S. and 455 species worldwide. By far the most common and widespread species has, until recently, been referred to as Tetramorium caespitum or, more mysteriously, "Tetramorium species E".  This is the only Tetramorium that is a common urban nuisance pest.

It's not common to have an important pest insect whose identity remains a mystery for almost 100 years since it was first recorded. It turns out that the genus to which pavements ants belong is a real "brier patch" of related and difficult-to-tell-apart species. Taxonomists who have studied the group have realized as much and out of frustration have been calling our pest pavement ant "species E" within the T. caespitum "brier patch".  That has now changed. 

Two recent papers clarified the identity of these common ants, and they required some ingenious sleuthing to do it. A paper by Herbert Wagner and colleagues used a combination of two kinds of DNA, numerous body features and ecological observations to untangle the briers obscuring the Tetramorium species in Europe.  When they finished they (in a very scientific way) said "Phew!" and noted that it took six types of analysis to solve the "highly intricate" problem of identifying the European Tetramorium.  Without both molecular (DNA) studies and studying the morphological features of the ants, they never would have solved the puzzle. 

The new name of the American pest pavement ant is Tetramorium immigrans, an appropriate name since our pest turns out to be an immigrant from Europe.  Very similar in appearance to the Tetramorium caespitum first described and named by Carl Linnaeus in 1758, a group of researchers based in Florida and led by Yuanmeng Zhang recently studied the genetics of Tetramorium immigrans populations in the U.S. In Zhang's study, molecular evidence was taken from 90 samples collected across the country by mostly school children using Pecan Sandies® cookie crumbs to attract the ants.  The lack of genetic diversity among all the samples collected suggests strongly that all of today's ants came from a one-time introduction, perhaps as long as 200 years ago. 

What's in a Name?

Why is knowing the name of an insect important? Because IPM is important.  Integrated pest management is the definition of modern, effective pest control. One of the key principles of IPM is that control methods should be based on knowledge of the biology and behavior of the pest.  Without knowing what pest you are facing, its impossible to know with any certainty the lives and behaviors (and weaknesses) of any pest.  

Knowing the right species of ant will also help in selecting an appropriate bait. In the case of pavement ants, the Advion® Fire Ant Bait has a label that includes pavement ant. In the case of the Dallas home with fire ants, Advion® performed well against that infestation. 

Recognizing Pavement Ants

Pavement ant. Note the two node segments between thorax and gaster, two
small spines toward the end of the thorax, and parallel grooves on
the head and body.  Color ranges from light brown to black. From the
Ant Identification Guide by Bayer Environmental Science.   
So how do you recognize pavement ants? Determining Tetramorium ants to an exact species can be a challenge and requires a very fine microscope.  Fortunately, the genus is not hard to identify with a hand lens or modest microscope.  And most Tetramorium found in urban settings and as indoor pests in the U.S. will be T. immigrans.  

Pavement ants are in the ant subfamily Myrmycinae.  Like all myrmycines, pavement ants have stingers (rarely used) and two small nodes (bumps) between the thorax and gaster (tail segment). In addition, look for two small spines on the last segment of the thorax.  Color may range from light brown to black, and all the workers from a given nest will be the same size (monomorphic).  Pavement ants may superficially look like fire ants but they are generally slower, less aggressive when their mound is disturbed, and do not sting. 

Knowing what kind of ant, or any insect, you have in hand is essential to everything we do in pest control.  And having taxonomists working behind the scenes to figure out what pests we have is a real benefit to our industry.