Moby Rat

A pretty hefty roof rat in a picture send by Keller
ISD impressed me, but not so much the expert
from New York City.

I can tell you that fishermen aren't the only ones to exaggerate when it comes to biggest-catch stories. I've heard lots of tales. "I swear that cockroach that flew at me was 6 inches long!" "That rattlesnake was as big as my leg!" And, maybe most impressive, "The rats in our neighborhood are as big as cats!"

Nearly everyone and their brother's got a story about the biggest rat.  "Moby rats" they might be called.  Or "super rats".

A picture of one big roof rat sent recently by one our Texas school districts got me thinking.  What is a really big rat?  And what would it take to impress someone who has worked most of his life with rats?  Someone like Dr. Bobby Corrigan, the rat expert who consults on rodent control for New York City?

I decided I would send the school picture to Bobby and see what he thought.  He did not disappoint.  In his methodical way, he analyzed the image, and shot back a series of questions:

• "Is that a scrotal sack under the tail, or possibly enlarged female genitalia?  Hmmm...don't see any teats." [This blog post is going to get lots of strange Google hits]
• "Was the tail long enough to be pulled back over and beyond the head?" [Knowing what species is critical for the Guinness world record book--roof rat tails are generally longer than the body... otherwise it would be a Norway rat.]
• "How long was it dead?" "If it was dead for a few days in a ceiling," he explained, "...the body begins to decompose, the skin gets stretchy when held by the tail, and they can appear much larger than what they really are. Too, the body gases inside will begin to bloat the cavity and the whole end result is a very large-appearing rat." [Never thought of that!]
• Last but not least, he asked, "How much did it weigh?" [It takes more than a picture... you gotta have real data to impress a rat expert.]

Of course the upshot of all this was that I felt a little sheepish.  I should have thought to ask those questions before I even sent the picture. Duh! And who knew that you could rig a big rat competition by letting Fatty stew in his own juices a few days?

My last question to Bobby was, "What would it take to impress you?  What's a really big rat?"  

He answered quickly. "Any rat 2 pounds or over." "But it has to be fresh," he added.

According to Bobby, the heaviest live Rattus norvegicus on record is 1.8 lbs (29 oz) or about 820 g. Most “big boys” weigh in the 775 g range, he said.  And according to his book on rodent control, wild Norway rats over the years have been measured up to 19 inches.

By the way, compare these stats to what might be the world's fattest cat weighing in at 39 pounds. And an average healthy cat, I'm told, runs 8-12 pounds. No contest between rats and cats there. And chances of seeing a rat as big as a full grown cat is nil.

Of course Dr. Corrigan couldn't leave things gentlemanly.  He had to add, "Texans claims that everything is bigger in Texas.  You guys should own up to the bragging."

I'd say those are fighting words, Texas PMPs. So here's a challenge. The next time you find what you think might be an impressive rat, check the sex and species (lots of sites online for how to sex rats), weigh it, measure the length, and take a photo and send to me.  If you come up with anything approaching 1.5 lbs for a Norway Rat, or or 3/4 pound for a roof rat, I'll post  your catch on Insects in the City. And if it's a really big, record rat, and your office manager or spouse allows it, throw your double-bagged catch in the freezer--for proof. Bobby says he's waiting. Are we going to let him get away with that?

New pest on crape myrtle

Texans (and many other southerners) love their crape myrtles! And why not? Crape myrtle (Lagerstroemia species) is one of the few trees that bear colorful flower displays through much of the summer, come in a variety of stunning colors, is easy to grow, and until now has been relatively pest free. Unfortunately, the pest-free reputation is changing with the advent of a new exotic scale pest.

Crape myrtle trees infested with CMBS in Richardson, TX.  Black sooty mold
 deposits on the branches and trunks of infested trees are often the first
sign of an infestation.  Note the white, scale encrusted upper branches. 

In 2004 I received a call from a local lawn maintenance company that was having a difficult time controlling an unusual scale on crape myrtle at a commercial property in Richardson, TX. After examining it I thought this scale might be something new, and sent samples of the insect off to experts for identification. Under the microscope it appeared to be a Eriococcid scale called azalea bark scale, Eriococcus azaleae.  Azalea bark scale is a common pest of azaleas in the eastern U.S.,  but had never been recorded as occurring on crape mrytle before. A suggestion by a retired USDA scale specialist led us to change our minds and believe that the scale might actually be a closely related scale known as Eriococcus lagerstroemia. This scale is an important pest of crape myrtles in China, Japan and Korea.  The difficulty was that no one knew how to tell these two scales apart.  And because the only place that the scale occurred was in the Dallas and Fort worth metroplex, it was difficult to interest others in investigating the problem without some financial backing.

After several years of slow spread through several north Texas counties, last year the scale made its move. In 2013 the scale appeared in several locations in Arkansas, Louisiana and Tennesee.  As a result, this winter researchers from the University of Arkansas and the USDA's Animal and Plant Health Inspection service agreed to lend a hand and take a closer look at these tiny insects.  

Molecular and new microscopic examinations now appear to confirm that our new scale is likely to be a recent import from Asia, probably Eriococcus lagerstroemia.  Last year Dr. Mengmeng Gu, Extension Horticulture specialist with Texas A&M AgriLife, had a chance to see these scales in their native Asian environment in a trip to China. The messy crape myrtles she saw there stimulated her interest in the scale, and led us to coauthor two new publications with the University of Arkansas. Both Texas and Arkansas now have fact sheets on this pest.

Crape myrtle branch with a heavy infestation of scale.

A scale-encrusted crape myrtle branch. Note
the pink blood from crushed scales where a
finger has been dragged across the infested
stem. Photo by M. Gu.

Many pest control professionals provide IPM services for landscape and turf pests, so it will be important to be able to recognize and identify it when you see it. Crape myrtle bark scale (CMBS) is a small white scale that bleeds pink when crushed. No other insects found on crape myrtle share these characters.  They can be found on the trunks branches and twigs of crape myrtle. Don't be surprised to find this scale in Arkansas, Louisiana, southern Oklahoma, Germantown, Tennessee, and possibly South Carolina. In Texas the Dallas/Fort Worth area is widely infested and it may also be found in Tyler, Longview, and College Station. Based on the current rapid spread, within the next ten years this scale will likely be common in many communities throughout the South.

If you are interested in learning more about CMBS, Dr. Gu asked me to talk about this pest this week in a Webinar, which is now posted on YouTube. In the webinar I discuss the appearance and damage caused by CMBS, how it is spread, and what is known about control.

The best control methods that we currently have involve soil injections of neonictinoid insecticides. Control recommendations are also listed here and in the fact sheets mentioned above. If you encounter this scale in areas outside Texas, or in areas of Texas I did not list, I would be interested in knowing about it. Leave comment on this site or drop me an email.  We hope to eventually have a website where sightings can be more easily reported.

Bee protests are cute, but...

A recent protest by organic activists outside a Chicago Home Depot highlighted something of the current debate over pesticides and bees.  It also reminded me that no one wants to go on record as being "against the bees".  Check out the video above.

The folks in the bee costumes in the above video are protesting the retail sale of "bee-killing" insecticides called neonicotinoids. They represent groups demanding that these insecticides not be sold, and that stores begin selling only nursery plants that have not been treated with these insecticides. I've blogged about this issue in the past, and reported on some recent urban incidents that could affect the pest control industry.

Over the past few days there has been some interesting discussion on this subject in a chat group that I belong to. I thought I would share some of the more interesting comments and new studies on the subject.

• Bee experts are mostly in agreement that Colony Collapse Disorder (CCD) in honey bees is not as simple as "bad" pesticides. In fact pesticides may have little to do with bee declines in some areas.  Australia may be instructive in this regard. Australia uses neonicotinoid insecticides like the rest of the world, but Australian honey bees are not in decline. A new Australian government report out this month confirms as much, and concludes that take as a whole, neonicotinoid use has led to an "overall reduction in the risks to the agricultural environment from the application of insecticides." 
• A recent collaborative paper in the journal mBio, by Chinese and U.S. scientists, found a virus that has been known for many years, tobacco ringspot virus (TRSV), that is infecting honey bees.  This virus is the first known plant virus that has mutated and adapted into an animal-infesting virus.  It appears to be transmitted to bees via pollen, and also by varroa mite. And its presence in bee colonies appears to be associated with gradual declines in bee colony vitality.
• In fact, varroa mites in combination with viruses are currently under close scrutiny as a major explanation for CCD.  According to Dr. Richard Cowles, with the Connecticut Agricultural Experiment Station, "When combined with work on Israeli Acute Paralysis Virus and a demonstration that irradiation of hive equipment from CCD could prevent nukes from succumbing to CCD, the strongest evidence for the cause of CCD is the varroa/viral combination."  An interesting side observation is that Australia does not yet have varroa mite, which lends strength to the argument for a mite-vectored virus explanation for the disease.
• Most studies that have found neonicotinoids in pollen have been on herbaceous plants. In one study on red maple trees, a dissertation by Dr. Josephine Johnson at the University of Maryland, no imidacloprid was found in tree nectar and only extremely low levels in pollen (bees feeding on these trees had no evidence of insecticides, nor in hive collected nectar).  So if you do neonicotinoid root applications on trees per label instructions, there is no evidence right now that such applications pose any risk to pollinators.
• Two new Washington State University Extension publications are now available on CCD and neonicotinoids.  The first publication by Lawrence and Sheppard, provides an overview of the problem with an explanation of the various factors thought to contribute to CCD.  How to Reduce Bee Poisoning from Pesticides is a thorough overview of practical ways to reduce the risk of bee poisoning due to pesticides, and includes a table of most commonly used pesticides with their potential risks to bees. 

None of this is to say that there are no legitimate concerns about the toxicity of neonicotinoids to pollinators. These products are certainly toxic to bees, and at levels lower than previously recognized. But research in this area is ongoing, and our understanding of the possible factors that might be hurting bee populations is much better than it was a few years ago. Despite what you might hear, both EPA and the pesticide industry is taking pollinator concerns seriously and is acting to make sure that you have safe tools to control pests effectively. After all, who wants to be "against the bees"?

A reminder about rat bite fever

"Rat bite fever" does not refer to the latest Hollywood horror film.  Rather it is a little known infection sometimes mentioned when listing to prospective clients the reasons why a good rodent control program is so important.  In a sad story this week, however, rat bite fever has gotten some media attention.

USA Today reports that a San Diego family is suing Petco [the national pet retailer] after their 10-year old son died from rat bite fever allegedly contracted after handling a new pet rat. Results of testing by the Centers for Disease Control have apparently confirmed that the purchased rat was indeed infected with the pathogen.

Rat bite fever is caused by a bacterium known as Streptobacillus moniliformis. According to the CDC, people can contract rat bite fever from bites or scratches from infected rodents, such as rats, mice and gerbils, or even just by handling an animal with the disease without a bite or scratch. It can also be contracted by consuming food or drink contaminated with the bacteria. It is not spread from person to person. Antibiotics, such as penicillin, are highly effective at treating rat bite fever, and it is rarely fatal, according to the CDC.

Nevertheless, as the story implies, rat bite fever is not to be taken lightly. Although this case relates to a domesticated rat, it is no less relevant to pest control on the street.  It would be interesting to learn how the pet rat contracted the disease, perhaps from a Norway or black rat infestation in the store or breeding facility.

How many other serious human diseases are there that we glibly recite as associated with the ants, cockroaches, flies and rodents we control?  Until a personal story like this comes along, it's easy to downplay the importance of our profession. But I'm reminded today how important this work really is.

Running from Little Brown Moths

Little brown moths, like this meal moth,
Pyralis farinalis, can pose an identification
challenge to untrained PMPs.

Skill at insect identification is one of the little things that distinguishes the well-trained from the not-so-well trained pest control technician. And one of the pest problems that stop many a technician in their tracks is the so-called, "little brown moth".  Even entomologists are disposed to run the other way when a little brown moth shows up--so much so that bug experts often use the acronym LBM when sorting these insects from other, more interesting creatures.

But it's really not fair to the moths, or your customers, to give up so quickly on little brown moth identification--especially when the moth is an indoor pest. Household moths are pretty distinctive when examined carefully, and with a little practice identification decisions about indoor moths are not that difficult to sort out.

First a little background.  Moths, along with butterflies, are insects in the Order Lepidoptera--one of the largest insect groups, with almost 175,000 known species. Perhaps the most distinctive lepidopterous feature is the membranous wing surface covered with flattened, modified hairs, called scales.  Scales are what give each species of moth or butterfly their distinctive body and wing color pattern. 

All Lepidoptera go through a complete metamorphosis as they develop.  This metamorphosis starts out with the egg and larval, or caterpillar stage.  After the caterpillar is fully developed there is a pupal stage, then the adult emerges. In moths, it is typically the caterpillar stage that causes the most damage to plants or to stored products; although in pest control the adult stage flying indoors can also be a problem. 

The most common indoor pantry
pest is the Indian meal moth, shown
here resting in its characteristic
push-up position.

Your first job when faced with an indoor LBM problem is to determine the source. Is the moth coming indoors from outside, or is there an indoor source of the infestation?  And secondly, is this a food-infesting pest, or is it a clothes moth?  The first question can be answered to some extent by considering the numbers of moths present (outdoor moths should not be common indoors), but also by familiarity with the important indoor moth pests.  The second question is answered by familiarity with the appearance and behavior of the two major species of clothes moths.

Comparison of sizes and wing
shapes of Indian meal moth (top),
Angoumois grain moth, and
clothes moth (bottom).

The most common types of moths found in residential or commercial interiors are pyralid moths. Pyralid moths include the Indian meal moth, Mediterranean flour moth, almond moth, raisin moth and others. These moths all have a relatively short fringe of hairs on the hind wing.  The Angoumois grain moth is a smaller moth with a 1/2 inch (13 mm) wingspan and a long fringe of hairs on its hind wings shaped like a pointing finger (see right).

Clothes moths are the smallest of the moths likely to be found indoors (3/8-inch or 5-7 mm wingspan). They are covered with light brown to golden scales and have a tuft of hairs on the forehead. The hind wings lack a pointing finger shape. Clothes moths do not readily fly, and prefer to scuttle or run. For this reason, clothes moths can usually be ruled out as the culprit when a client reports seeing flying moths commonly indoors.

If in doubt as to the source of an indoor moth problem, pheromone lures can help. Pheromone lures contain copies of the sex pheromones that these moths use to locate mates. Pheromone lures can be placed throughout an account to help pinpoint moth hot spots. Some pheromone formulations for moths are even available as confusing agents to prevent males from finding female hosts (this approach is not effective for clothes moths, as explained in an interesting article just out in Fumigants and Pheromones newsletter).  Pheromone traps are available for many species and Insects Limited is an excellent source for information on selection and technical aspects of pheromone use.  Another commercial source for pheromones is Trécé Inc.

For anyone with deeper interests in stored product pest identification, including detailed keys to stored product pests, an excellent resource is the USDA Agriculture Handbook 655, Insect and Mite Pests in Food, now accessible online.

With all the great resources available there really is little reason to run from those Little Brown Moths.

Mosquito Training for Cities

AgriLife Extension will be hosting four Mosquito Training workshops this spring in Fort Worth (Mar 10), Longview (Mar 14), San Antonio (Mar 17), and Round Rock, TX (Mar 24).  The program is designed to help orient municipal employees who need to learn more about setting up a mosquito control program, but some of the information could be useful to pest management professionals involved in mosquito control.  These workshops are being held along with the Texas Department of State Health Services, and will include DSHS speakers at some locations.

The programs have been developed by AgriLife extension entomologist Dr. Sonja Swiger. I will be helping with the first program in Fort Worth, and Wizzie Brown and Molly Keck will be assisting with the San Antonio and Round Rock location trainings, respectively.  For a copy of the flier, click here.

Topics being covered include:

• Vector Borne Disease in Humans & Testing 
• West Nile Virus: Summary of the 2012 Outbreak 
• Mosquito Identification, Biology & Ecology 
• Integrated Mosquito Management 
• Putting Surveillance Data to Work 
• Properly Treating Mosquito Oviposition Sites
• Developing an Effective Vector Education Program

Cost for the program is $50 in all locations except Fort Worth, which is free. To register for the Fort Worth program only, click here.  For the other programs contact Dr. Swiger using information on the flier linked above.

It's not easy finding green

Occasionally I get a request from someone seeking a listing of green insecticides. Of course this is a difficult question to answer without knowing exactly what someone means by a "green insecticide".  Green means different things to different people.  To some it means something natural or organic, overlooking the fact that many highly toxic compounds are found in nature. Others might not restrict a list of acceptable insecticides to only products that occur in nature, but might include some man-modified compounds if they were sufficiently easy on the environment.

Personally I prefer the concept of low impact pesticides. I define "low impact" to include any pesticides (man-made or natural) that pose low risk to humans and to beneficial organisms (including wildlife, pets and beneficial insects).  Using this definition, it's not too hard to find products that fit the description from both the organic and the synthetic side of things.

Examples of man-modified or produced insecticides that meet the low impact criteria include soaps and oils, insect growth regulators, microbial-based products, and reduced risk pesticides identified by the U.S. EPA. If the properties of such products were understood properly, most of these insecticides would be acceptable to most people.

So are there any lists of low-impact, or green pesticides?  A few resources come to mind.  First, Texas has a loose definition of green pesticides in its Green Category products that schools are encouraged to use.  For a summary of these pesticides, see http://citybugs.tamu.edu/factsheets/ipm/ent-4003/.

Another resource is the U.S. EPA list of reduced risk products.  This list is tucked away online in an obscure, online EPA cubbyhole on the Conventional Reduced Risk Pesticide Program.  While this is a regulatory concept and not intended as a list of the lowest risk pesticides, it does list some interesting insecticides that might not be otherwise noted by people seeking lower impact alternatives to more conventional products.  For a list of RR pesticides, click here.

One of the frequently cited sources of "acceptable" pesticides in green circles is the City of San Francisco's Reduced Risk Pesticide list.  The list is designed around professional products that can be used by city employees, and is not intended for consumer reference (click here for consumer low-impact options).  It is, however one of the few sites that has some scientific review and is continually updated with new products--a lot of work.  Municipalities and LEED building architects frequently refer to Tier III pesticides on this site as the standard for acceptable pesticides.

Lastly, the EPA's list of Minimum Risk (or 25b) compounds that are considered exempt from standard label requirements bears mention. This list contains ingredients that are "generally regarded as safe" by the EPA.  Unfortunately, being safe doesn't always make for an effective pesticide; but manufacturers continue to roll out new products with these ingredients because of the economic advantages of not having to register with the EPA.

None of these lists are perfect and all are highly arbitrary in some respects. They all have their uses and limitations.  All of them leave out some very useful pesticides that can solve otherwise intractable pest problems at reasonable risk to the environment. Some "green pesticides" may be very green, but not make very good pesticides--a common problem.  For these reasons, my advice would be to not commit oneself to a course of saying that "only these (select, green, organic, etc.) pesticides will be used" in our city, or our school, or our place of business.

Pesticides are power tools.  Like any power tool, along with their advantages, they have potential hazards. That doesn't mean we shouldn't use them, but that we should choose them and use them with caution.  If you're committed to using pesticides from a green list for your school, city or business, give yourself options. The Texas school regulations and the San Francisco program have both been relatively successful.  But they both allow for exemptions or exceptions for using pesticides not on the preferred lists.  The worst mistake any green pest control program can make is to limit itself so that it cannot effectively or economically respond to all pest problems. That's the quickest way to discredit any green program as impractical.

As Kermit the Frog would tell you, "it's hard to be green".  It's also hard to find the perfect green list of pesticides that will cover all pest problems. Keep this in mind, and these lists might actually help you.