Tuesday, September 5, 2017

A Texas sized mosquito event

Mosquito covered shirt in Port LaVaca, TX. Photo
by Richard Murray on Facebook.
Remember last week when I warned that mosquitoes would be hurricane Harvey's final gift?  Well, mosquitoes are here as seen in this Facebook image, taken in Port Lavaca, TX this weekend.

The giant mosquitoes in this picture are probably in the genus Psorophora, (sore ROFF oh ruh) one of our largest, most painful and aggressive biters.  Psorophora mosquitoes have some impressive chops when it comes to survival.  One of the so-called floodwater mosquito species, they lay their eggs on land rather than water like most mosquitoes.  But not just on any land--eggs are laid at the edges of receding floodwaters, where they will re-hydrate and hatch during the next large rain event.

Because Psorophora are opportunists, taking advantage of brief rainstorms, they must have a quick lifespan.  The larvae of floodwater species like Psorophora are the speediest growers of all mosquitoes.  They need as little as 3 to 3.5 days of standing water to pass through the four molts common to mosquitoes. The pupal stage has even adapted to survive and complete its development on the mud surface of drying puddles.

What we see in this picture is evidence that floodwater mosquitoes were primed at the pump when Harvey hit the upper Gulf coast two weeks ago.  When the rains came, mosquito eggs hatched across thousands of square miles of coastal prairie and marsh, and billions of Psorophora larvae raced through childhood. Add to this that Harvey's rainfall impacted over 400 miles of Gulf shoreline, dumping an estimated 27 trillion gallons of water. The rainfall was epic and completely unprecedented. The city of Houston doubled it's previous all time monthly rainfall record with 39.11 inches (and Houston gets lots of rain). That's 400 miles of Gulf coast prairies producing mosquitoes, also unprecedented, I suspect.

So don't be surprised to read and hear lots of mosquito stories over the next couple of weeks.  If you have to be out and about in this part of Texas, there is protection you can carry. For extreme conditions a mosquito head net will be necessary. Wear light colored, tight knit, long-sleeved fabrics. T-shirts or short-sleeved shirts will not be enough.  Permethrin-impregnated shirts and pants may be worth their weight in gold.  And don't forget to bring DEET repellent. Lots of it.

Thanks a lot, Harvey!

Monday, August 28, 2017

Insects and floodwaters

Fire ant floating colony in Houston floodwaters.
Photo by NBC DFW  @OmarVillafranca
Many in the pest control industry find themselves in the midst of the devastating floods hitting much of south and east Texas this week.  If so, it may be a good time to remind ourselves of some unique pest challenges associated with high water.

Flooding brings all sorts of wildlife into unusually close contact with people, but few critters are more dangerous than fire ants. When floods occur, fire ants exit the ground and float, instinctively linking their legs and forming a floating mat which is nearly impossible to sink. When they inevitably bump into a dry object like a tree, a boat or a person, the ant mass "explodes" with ants quickly exiting the mass and swarming the object.

Diving underwater, or splashing water on the ants, will not help.  The best option is soapy water, which is pretty good at killing the ants and helping drown a floating ant island.  According to the Texas A&M AgriLife Extension publication, "Flooding and Fire Ants:Protecting Yourself and Your Family", two tablespoons of soap in a gallon of water, sprayed on a floating mat is effective at drowning ants.  If any of you are engaged in water rescue this week, carrying a supply of soap along with a squirt bottle would be a good idea.

You might not have thought of it, but bed bugs can also become an issue after a public emergency like a tornado or flood.  When lots of people are brought together in an emergency shelter situation, the risk of bed bug encounters goes up.  The University of Minnesota has put together a nice publication on the subject. If you are in a community hosting an emergency shelter consider offering your services to inspect shelters and treat for bed bugs as necessary.  Don't forget the diatomaceous earth and silica aerogel dusts as a means of providing significant control for shelter bedding at minimal risk.

Lastly, after the storm is long gone be prepared for mosquitoes.  The primary mosquito species in the Texas Coastal Bend area are the salt marsh and pasture-land breeding mosquitoes. These are difficult to control at their breeding sites, short of aerial mosquito control campaigns.  But to some extent, these mosquitoes can be controlled in backyards with residual mosquito adulticides. If your company does residential pest control, but hasn't yet gotten into the adult mosquito control business, this may be a good time to start. One good way to educate your customers about the mosquito threat is the Mosquito Safari website.


Thursday, August 24, 2017

Murine typhus on rise in Texas

Researchers from the Baylor College of Medicine and Texas Department of State Health Services recently reported an increase in the number of reported cases of typhus in Texas. Texas historically has had more cases of typhus than other states, but this new study published in the CDC's Emerging Infectious Disease journal  shows that numbers of cases have increased ten-fold in the past 14 years.

When rodents are present in a house, there may also be rat fleas.
The oriental rat flea is thought to be the principal vector of
murine typhus, a disease on the rise in Texas. (Image courtesy
Pest and Diseases Image Library, Bugwood.org)
In addition to a general increase in cases statewide, the data shows that what used to be solely a south Texas problem is creeping into more northerly parts of the state. Houston, for example, which had no cases of typhus as recently as 2007, reported 32 cases last year.  Nueces County, home to the city of Corpus Christi, had the highest case rate in Texas, reporting about 140 cases/100,000 population.

The causative agent for murine typhus (the term "murine" is a scientific term referring to rodents) is a rickettsial parasite called Rickettsia typhi. This parasite is always present in rodent populations, both Norway and roof rats, and to a lesser extent mice and opossums.  The primary vector that transmits the parasite from rodent to rodent, and occasionally to humans, is the oriental rat flea, Xenopsylla cheopis, though other fleas, including the cat flea are suspected to be occasional vectors.

Symptoms of murine typhus include fever, headache and rash. Left untreated, the disease can be fatal in about 2% of cases; but once diagnosed, typhus is easily treated. Numbers of cases peak during the summer months of June and July, but in south Texas there is a secondary peak in cases during the winter.

The typhus pathogen is thought to infect people when they scratch an itchy flea bite. It is present in the flea's feces, which may be rubbed into the site of the bite during scratching.

While the exact cause for the increase in typhus cases is unknown, pest control will play an important role in any solution. Experience with murine typhus in the past has shown that cases peak when flea numbers are highest, and that case frequency declines when rats are controlled, and insecticides applied for fleas.

In 54% of the cases reported in this study, fleas were reported to be present in the home, and 34% of patients recalled a flea bite.  Rodents were known to be present by the victims in about 29% of the cases, and some form of other wildlife was present in 42% of cases.

Good flea control, rodent exclusion and rodent control are among the most important public health services our industry provides. So if you didn't have enough reasons to explain to customers why they need you, you now have one more.




Thursday, August 17, 2017

New resource for ant control

Take some of the best ant experts in the country and ask them to write about their favorite ant pests. What do you get?  The new eXtension Ant Pests page.

This new addition to the eXtension (pronounced EE-ex-TEN-shun) website is the latest contribution to an information repository from Cooperative Extension Service centers across the country. The goal of the site is to provide in-depth biology and control information about important ant pests for anyone who needs it.

And who needs it more than pest management professionals?

So check us out.  And while you're there, you might enjoy exploring other pest management resource areas including fire ants, feral hogs, pests around structures (school IPM plans), and Wildlife Damage Management.

Wednesday, August 16, 2017

A life saving opportunity

How would you like to save a life today? Through pest control? It's not as hard as you might think.

In the years since Bill Gates retired his position as CEO of MicroSoft Corporation, he and wife Melinda have devoted tremendous effort to battling malaria.  Malaria and the mosquitoes that transmit it is the single greatest killer of humans in the world, accounting for most of the 700,000+ mosquito-caused deaths annually.  But unlike many of the other major problems in the world, solutions to the malaria epidemic are available now.

The Gates Foundation is partnering with the NGO World Vision to give away 100,000 bed nets. These nets protect families from mosquitoes that carry deadly diseases, including malaria. Each one is treated with an insecticide that kills mosquitoes but has a low LD50 for humans.

Insecticide-treated bed nets have played an enormous role in the fight to end malaria. But distribution is a huge logistical challenge. This is where you can help.

If you're willing to take two minutes to learn more about the fight against malaria, and take a one question quiz, Mr. Gates has pledged to donate a bed net on your behalf to a family in Inhambane province--an area in the south African country of Mozambique where malaria is common.  You can do this at the Gates Notes Bed Net Giveaway website.

On a related note, my wife and I recently watched a film about the malaria problem in Mozambique called Mary and Martha, with Hillary Swank playing an American mom who loses a son to malaria.  It's a sad but compelling and uplifting film, well worth watching.  And it shows how a simple thing like a treated bed net can make a world of difference for families in another part of the world.

Monday, August 14, 2017

A loss for Dallas Pest Control

I know that many of the readers of this blog are not from the north Texas area, so sharing news of a local nature may be a turn off for some.  But there is something universal about the loss of a colleague that should cause all of us, no matter where we live and work, to pause and reflect.

Last week the Dallas pest control community lost a friend in Ray Porter.  I knew Ray from several projects we got to do together (meaning he was willing to help me out on some field trials) well over 10 years ago. He was one of the nicest guys I've been privileged to work with, always unassuming and extremely polite. Ray was an account manager for Orkin Pest Control from 1989 -1998 and then with Bizzy Bees Pest Control in Dallas from 1998 – 2013.  He became an Orkin man again when Bizzy Bees was bought out in 2013, until 2016 when he retired. According to his friend Errol Cohen, he was "devoted to his customers beyond belief, and always delivered exceptional service... Always a top performer and a President’s Club member numerous times, Ray went way beyond the extra mile every day."

Ray also went the extra mile for his profession.  He was active for many years in our local pest control association, working to build relationships among fellow professionals and trying to raise the reputation of the industry. In this regard his life should be an example, especially to the newer pest management generation.

It's sad when a good man passes away, but Ray's passing reminds me that we all are privileged to work daily with some pretty great folks. Let's not forget to appreciate them while we have them, and to enjoy the time we are given.  So long Ray, and thanks for your example and inspiration.

I remember being told by a customer in my first job in pest control, that a company is only as good as the people it employs. By this standard, Orkin and Bizzie Bees were definitely winners.  From Ray's obituary:
Raymond Nelson Porter was born August 14, 1942 in Sand Springs, Oklahoma to Harry and Bertie Porter and died peacefully August 10, 2017 at home surrounded by family. Ray was devoted to his wife and family (especially his grandchildren and great-grandson). He was an avid golfer, loved being outdoors and working at Bizzy Bees. Survivors include his wife Yvonne of 28 years; his son Eric Porter (daughter-in-law Stacy, grandson Brandon and wife Molly, great-grandson Luke and granddaughter Tiffani); his son Christopher Porter (daughter-in-law Carol, grandchildren Claire and Nicholas); his son Jason Porter (granddaughter Lindsay); his step-daughter Andrea Hefner (son-in-law Bill, granddaughter Alexandra and husband Colman, and grandson Riley); his step-daughter Stephanie Enriquez (grandsons Steven and Christopher); his sister Sue Orendorff (brother-in-law Ellis); and, his brother Larry Porter.

A Memorial Service will be held Saturday, August 19, 2017, 10:30 am, at Williams Funeral Home, 1600 South Garland Avenue, Garland, Texas 75040.

Thursday, July 27, 2017

Chalcid wasps in homes

After identifying an unusual insect for a homeowner today, the thank you email ended with a bang. Because I was able to quickly identify her pest, which her PMP had incorrectly insisted was a "bee", she concluded, "[I guess] it's best I change pest control companies."

Brachymeria podagrica on window screen
Could you identify this insect from this picture? Brachymeria
podagrica
 is a chalcid wasp parasitoid that attacks filth flies,
like those that feed on carrion.
Ouch... I hate to hear that.

Admittedly the insect was an obscure critter. I'm guessing that not one in 100 PMPs has ever heard of a chalcid (CHAL sid) wasp before. But chalcid wasps are common natural enemies of many insect pests. Identified by their small size and giant hind femurs, the Chalcididae family makes up one of the dozen or so "parasitoid" wasp families within the bee/wasp/ant order Hymenoptera.

Parasitoid wasps are certainly one of the most fascinating and wonderful, yet horrifying, of all creatures.  So seemingly cruel in its behavior that theologians and biologists argued over the last 200 years whether the mere existence of insects like the ichneumon wasp (a cousin of the chalcid wasp) served as proof against the Christian belief in a loving Creator-God.*

Parasitoids are parasite-like predators. Like a parasite, they grow up feeding on or in a single host. But unlike true parasites, which weaken but rarely kill, parasitoids invariably kill their hosts. Parasitoids begin their lives as an egg laid by their mother on a soft part of a host's anatomy. Upon hatching the parasitoid larva burrows into the body cavity of its host and begins feeding. The larva knows instinctively to begin with the non-essential parts, prolonging the life of its victim as long as possible. Eaten alive from the inside, ultimately the host dies. Ugh.

It does sound cruel, but parasitoids are also one of nature's most effective population control agents. Without them, crops would vanish under billions of caterpillars.  Flies would breed unchecked. Even spiders would be more abundant than they already are.  Parasitoid wasps possess some of the world's sharpest "noses" (actually antennae), able to sniff out prey even when the prey are vanishingly rare. They are also smart, with some species recently being trained to sniff out illicit drugs and even bombs on the battlefield. Gardeners and farmers, especially, reap the benefits of parasitoid services every day.

The key to identifying chalcid wasps is their tiny size (this is one 
of  the larger chalcids at 5 mm), reduced veination in the wings, 
and swollen hind femurs. This Brachymeria podagrica is further 
identified by its distinctive markings. Photo courtesy Graham
Montgomery via Bugguide.net.
Admittedly we in structural pest control don't have many chances to encounter parasitic insects in our daily work.  Most parasitoid wasps live peacefully out of sight in the natural world, ill at ease in our indoor environments. Occasionally, though, parasitoid wasps make an appearance in a home or business. For this reason, it's a good idea for PMPs to know something about these insects.

The species of chalcid wasp my homeowner encountered "swarming" in her attic this spring appeared identical to other similar wasp pictures I've received recently.  These turned out to be Brachymeria podagricaa parasitoid (primarily) of flies.  Their presence indoors suggests that the source could have been a dead animal full of fly larvae somewhere in the home--a theory backed up in this case by the homeowner's report of a foul stench several days before the little wasps appeared in the attic. Likely they were drawn to the smell of the carcass in search of their blow fly hosts.

When one, or a few, unusual insects show up overnight in a structure, they are often called "accidental invaders". Accidental invaders are chance occurrences, when an insect or spider accidentally enters through an open door or window, or unsealed crack. Such accidental entries occur on a regular basis in residential accounts, but usually with a variety of arthropods.  But when several (or dozens) of the same kind of insect appear inside a home, or when the same insects show up over many days, it usually means something is afoot. Insects always have a story to tell, and they never lie.

Chalcid wasps are not likely to enter an account over and over by accident. If you find chalcids indoors, get a sample and have them identified. Brachymeria podagrica suggests the possibility of wildlife or rodents; however other species of Brachymeria and other species of chalcids are known to parasitize beetle or moth larvae, and might be evidence of a stored product pest infestation.

And remember, if you're ever unsure of the identification of an insect, don't hesitate to bring it to your in-house entomologist (if you have one), or send to your state university or other reputable insect ID authority. And don't just call something strange a "bee" unless you know for sure that it is.

* An interesting discussion of the ichneumon wasp controversy can be found in Stephen Jay Gould's essay on Non-moral Nature in the book Hen's Teeth and Horse's Toes