An odd "pest"

Even when not an insect, if an object is small and mysterious, it will often be called a "bug" and end up on the desk of an entomologist.  Such was the case with some specimens I received last week.  They were described by a pest management professional as "tiny bugs" that appeared on the south side of a customer's house every year.  No mulch or trees or shrubs were reported nearby.

I thought at first that these tiny (1.3 mm length) objects might be spores from the artillery fungus, in the genus Sphaerobolus.  Artillery, or shotgun, fungus is a type of primitive plant that grows as a saprophyte on wood mulch.  It has tiny black spores that it can shoot for several yards.  The spores are sticky and adhere to a variety of surfaces, like walls of homes, sometimes leaving a stain when removed.  But, according to the submitter there was no mulch nearby, and according to my plant pathologist friend, Dr. Kevin Ong, the specimen I was looking at under my microscope was not smoothly round as typical for Sphaerobolus.  

These tiny, 1.3 mm, seeds from the Oxalis plant are sometimes
ejected from the plant and stick to man-made surfaces, like
exterior walls, where they may be confused with "bugs".

My sample of 20 or so objects were teardrop-shaped and ridged/segmented.  Under the microscope they looked vaguely insect-like but appeared to lack legs and mouthparts.  Fortunately I network with many experienced entomologists around the country, several of whom kindly informed me that the sample was actually the seed of Oxalis, a common garden weed or plant.

One entomologist who wrote back noted that he once got a series of calls from a commercial greenhouse grower who was doing his best to "kill" these "pests" "crawling" all over his greenhouse, but with little success.  This is another example of why it is so important to identify the pest before reaching for the insecticide sprayer.

As it turns out, Oxalis seeds are pretty cool.  They are borne by the plant in a cylindrical pod.  When mature, or when the rip seed pod is touched, it shoots out the small seeds three to five feet.  The rough coats on the seeds helps them stick to some surfaces (like a hardy-board exterior wall, in this case). For a good video showing how Oxalis seed dispersal works, check this out.  The plants themselves are attractive, if sometimes difficult to eradicate from your yard.  The plant leaves are sour-tasting because of the presence of oxalic acid; but in small quantities are good in salads.

So let's not be quick to blame insects for those strange objects that customers are prone to find around the home.  If you don't know what something is, have it checked out by me (if you're in Texas) or one of the other fine entomologists most states (and many pest control companies) are blessed with.  There are enough real insects in the world to keep all of us entomologists busy full-time.

Good grooming

Thanks to Wizzie Brown for alerting me to the recent, very cool video on cockroaches by NPR's Science Friday.  Like cats that lick their feet and fur, cockroaches continually groom their feet and  antennae.  I've watched cockroaches groom themselves, but never in magnified HD with a lucid narration by North Carolina State University entomologist Coby Schal.  Dr. Schal reports on recent research by his laboratory to answer the question about why cockroaches groom, and he's well worth listening to.

One thing the video does not mention is that we take advantage of this grooming behavior in pest control when we use certain insecticides.  Boric acid is a relatively low risk pesticide that can be used around the home.  Boric acid, it turns out, is ONLY toxic to insects (and coincidentally, people) when it's ingested.  When we apply boric acid as a dust, and a cockroach walks through the dust layer, a small amount of the insecticide is picked up on the roach's feet, body and antennae. It's because of the grooming behavior documented so elegantly in this video, that the cockroach is poisoned by such dusts.  This may also be the case with other insecticides and other insect species, according to the news release by North Carolina State. 

One caveat about using boric acid in the kitchen--don't use too much.  Cockroaches avoid heavy deposits of any dust, including boric acid.  They are not repelled, however, by light dust deposits of boric acid.   So if you use boric acid, take it easy. You should not be able to see more than the slightest dusting of white residue after an effective application of boric acid.   

Mosquito season upon us

Spring rains and warmer weather usually spell mosquitoes.  To prove this to myself, I've been watching my backyard fountain slowly fill with recent rains, leaves and catkins from nearby oak trees. Last week I was rewarded(!?) with my first mosquito wigglers.

Mosquito "wiggler" and "tumbler" are informal terms for the larval and pupal (immature) life stages of a mosquito.  Mosquito wigglers live in water, and as soon as temperatures get warm enough to drive their development, they quickly mature and emerge from pools and containers wherever they may be found. After last summer's record West Nile virus season, any news about mosquitoes is bad news to us in Texas, and especially the Dallas area.  But the species emerging right now are not likely to be the disease-carriers of last summer.

According to Scott Sawlis of the Dallas County Health and Human Services Department, in north Texas we are now more likely to see  Culex restuans, or one of the other early mosquito species that do better in cool weather.  These cool season mosquitoes are not considered important in the spread of West Nile virus or other encephalitis diseases.  Nevertheless, these mosquitoes still bite and are not welcome around your customer's home.

My backyard observation site gave me the chance to photograph and put together a short video about what to look for if you see a suspicious puddle of water around your yard.  Mosquito larvae are not all that easy to see unless you know what you are looking for.  Any water-holding container, regardless of whether you see mosquitoes or not, should be considered a potential breeding site. Early in the season is a good time to scout out these water traps and treat or eliminate them before the REALLY bad mosquitoes show up.

I advised in my last post to take advantage of your residential service calls to check your customer's backyards for mosquito breeding sites. If you do find a suspected breeding hole, advise your customer to drain it, or fill it in with sand, gravel or soil.  This will immediately kill any mosquito larvae breeding there.  If the source is too deep or impossible to drain, mosquito dunks or granules, containing Bacillus thuringiensis or S-methoprene are available through pest control distributors. Ask your distributor, but typically these professional products can last from 30-90 days.

I betting that, at least for some of your customers, a little good will in the form of pointing out a potential mosquito problem is likely to earn some customer-retention brownie points.

New interest in mosquitoes

A simple bucket with leaves and compost becomes a
mosquito breeding site (see inset) after a rain. Photo
by M. Merchant in his own backyard (oops).

After last summer's West Nile virus epidemic in north Texas there is a heightened awareness of mosquitoes and mosquito issues around the state.

Every pest management professional, especially anyone involved with residential pest control, should think of mosquitoes as an opportunity to provide another valuable customer pest control service.

In my experience, few people imagine that they might be the culprit when it comes to breeding  mosquitoes.  Most folks believe that mosquitoes come from someone else's property--especially the creek across the street, or the neighbor's fish pond.

While this might be true, especially in the case of an abandoned pool or marshy area, we are often our own worst enemy. Most creeks, ponds and lakes are not major sources of disease-carrying mosquitoes.  Any body of water with fish, or with running water that is not stagnant, is not likely to be an important breeding site for the worst mosquito species--most of which are "container breeders". Rather, small containers or human structures that collect dust and debris along with water that sits for more than a couple of weeks, are the most likely source for our worst disease transmitting mosquitoes like the urban-dwelling Aedes and Culex species.

A few years ago, Dallas County did an evaluation on the properties of citizens who reported severe  mosquito problems in their backyards.  They found that 25% of citizens who complained about mosquitoes were  breeding mosquitoes in containers found in their own yards.

Green pools are common in neighborhoods with
foreclosed homes, and should be drained or
treated. Photo by M. Merchant

As a PMP you approach every property with trained eyes to see pests and to see conditions that are conducive to pest infestation. This skill can serve you well when inspecting a backyard for mosquitoes, and provide value-added to any pest control visit.  Here are some of the common problem areas to be alert for in residential yards:

• Water- and leaf-filled bird baths.  Bird baths should be emptied or cleaned weekly to minimize risk of mosquito breeding.  
• Gutters that fail to drain properly.  This can be difficult to see, but your extension mirror can help. Check gutters, especially after a rain, to make sure they are draining properly.  Leaves and dirt that build up in gutters provide the organic matter, all they need is water to make a mosquito breeding spot.
• Tires. Rubber automobile tires, it seems, are designed to hold water.  They are one of the worst sources of mosquito breeding in some areas.
• Buckets, plant pots and wheelbarrows without drain holes. These items should be inverted or hung to ensure that water is not held.
• Landscape and gutter drain lines that catch and hold water.  Poor installation of underground drain pipes allow water to stand.  Mosquitoes are adept at finding their way in and out of underground holes that we may not notice.  All underground drain lines should be fitted with a pop-up drain emitter that opens only when water is flowing.
• Water catch basins/septic tanks.  Catch basins in French drains and municipal storm sewers are designed to keep debris from clogging drain pipes.  But these same boxes can catch and hold water for extended times. Flush out catchment basins or apply a larvicide like Bacillus thuringiensis or methoprene.  Poorly closed or maintained septic systems can provide many breeding sites for Culex mosquitoes.
• Uncapped steel fence posts are often overlooked, but may hold water for long times after a heavy rain. Point out fence posts without covers and explain how any container that holds water can breed mosquitoes.
• Plastic or canvas covers on boats or trailers.  Tarps or plastic sheets used to cover vehicles or boats can easily hold water for a week or more.  Boat covers should be pulled taught to force water to drain.
• Rain barrels and cisterns. With most areas in Texas water is increasingly precious. Drought and water restrictions have encouraged many homeowners to install cisterns and rain barrels to capture and store rain water. While most commercial rain storage systems come with drains to keep mosquitoes out, screening on intakes and overflow plumbing can become damaged, and needs regular inspection.  
• Unmaintained swimming pools.  So called, "green pools" are unchlorinated pools that can become breeding sites for large numbers of mosquitoes.  If you notice such a pool and the homeowner is absent or unwilling to respond to complaints, these sites should be reported to the local health department as a public health threat.

Let's all do our part to keep our communities safer and mosquito free. Let your customers know when they have a dangerous situation.  Chances are that they will thank you for it.  For more information on mosquitoes in backyards, see the Mosquito Safari website.  

Legislative Note

Last week the Texas Senate gave thumbs up (28-3 vote) on a measure (SB 186) introduced by Sen. John Carona (R-Dallas) that would give municipal health officials authority to enter empty or abandoned properties to treat mosquito breeding sites that pose a public health nuisance. It can be difficult for health authorities to gain access to such properties without a search warrant.  This bill would allow a "public official, agent or employee charged with the enforcement of... laws" to enter the premises at a reasonable time to inspect or treat the nuisance stagnant water.

David Oefinger, with the Texas Pest Management Association, feels that chance for passage of the bill in the House is pretty good given the lack of opposition in the Senate.

Spring Pest Management Training 2013

Skunk and armadillo control is one of the topics covered in
this spring's pest management training.

I thought I would share an upcoming training opportunity that might be of interest to Insects in the City readers around north Texas. Next week, March 7, is the Spring Pest Management Seminar at the Texas A&M AgriLife Center at Dallas. This year's program should be a good one, and (if you need it) will provide you with all the CEUs you need for another year, whether you are a certified non-commercial applicator through TDA, or licensed through the Structural Pest Control Service with categories in pest control, turf and ornamental, and weed control.

This year's speakers include Janet Hurley, providing an update on the new pyrethroid rules, Charles Adams with Sherman ISD speaking on skunk and armadillo control, Ross Eckstein from Syngenta covering weed control, Dr. John Rowland with Bayer Environmental Science talking about insects of urban landscapes, and me, talking about mosquito control.  Three of our speakers are new to the seminar series, so this will be a great opportunity to get fresh insights and new IPM information.  I'm especially interested in the skunk and armadillo talk from Charles Adams.  Charles has many years of experience in school IPM and running his own wildlife control business. I've listened to Charles teach, and he really knows his wildlife.

Registration is online and can be accessed here--type in keywords "Spring IPM".  For a copy of the program brochure, click here.  Cost is $70 if you get your application in by March 4, otherwise it's $85 at the door.  Lunch (brisquet and chicken BBQ) is provided.  Hope to see you there.

Tawny crazy ant name proposal hits streets

Tom Rasberry points out one of the early known
infestation sites of Nylanderia fulva close to the
Houston ship channel in Houston, TX (2004)

The crazy ant first discovered in Texas by PMP Tom Rasberry, may be getting a new common name.  As I reported in an earlier post, the way for a new name was opened with the recent publication of research firmly identifying the ant variously known as the Rasberry crazy ant, hairy crazy ant or Caribbean crazy ant (depending on what state you are from).  As it turned out, the ant was decidedly NOT the Caribbean crazy ant, Nylanderia pubens, but another species originally described from Brazil, Nylanderia fulva.

This week the Entomological Society of America's (ESA) committee on common names approved a new common name which has received lukewarm support.  The last step before formal acceptance of the official common name (which I and most entomologists will likely start using) is for the proposal to go before ESA membership for comment.  The proposal is located at http://www.entsoc.org/PDF/2013/names/tawny-crazy-ant.pdf, and does a pretty good job of detailing the background of the controversy and listing authorities who both support and oppose the new name.

If you are an ESA member, this is your last chance to let your voice be known. Please submit any comments by March 13, 2013 to Greg Dahlem, the committee chair, at dahlem@nku.edu.

Interestingly, there are colleagues of mine from Texas A&M who both support and oppose the new name.  Dr. Bart Drees (Texas A&M AgriLife Extension) supports the name change, and Dr. Roger Gold (Texas A&M University) opposes it, along with (not surprisingly) the Rasberry family.  Dr. Gold thinks "tawny" a little dull, and argues that a more descriptive name is needed.  He suggests "Brazilian crazy ant," to commemorate where the ant was first discovered.  I think I like Brazilian crazy ant better than tawny crazy ant; but I have another name to propose.  I suggest we call it the "troublesome crazy ant".  I'm sure that's one name most of the people who encounter this tiny invader could agree on.

Pyrethroid label requirements tweaked again

Last year I posted a story about the new pyrethroid insecticide label requirements being sent to pesticide manufacturers by the U.S. Environmental Protection Agency. The requirements were designed in 2009 to reduce the risk of drift (wind carried contamination) and runoff (stormwater-carried contamination) of these commonly used insecticides. Since last spring, when pesticide manufacturers were officially informed of the new standards, the EPA has continued to dialog with both regulators and the pest control industry.  The results of this dialog are now out, and the final product is a big improvement, in my opinion.

The new EPA label requirements will
continue to allow pyrethroid applications
to eaves and protected sites around homes
where mosquitoes and other pests
may be resting.

At issue were applications needed to control certain overwintering insects like brown marmorated stink bug and kudzu bug, both of which aggregate on the sides and eaves of structures prior to entering the home or other building.  Under the 2009 rules, outdoor applications to the sides of structures were limited to crack and crevice applications or building foundations up to a height of three feet only.  In addition, all outdoor applications to impervious surfaces such as sidewalks, driveways, patios, porches and structural surfaces (such as windows, doors, and eaves) were to be limited to spot and crack-and-crevice applications, only.

After consultation with the National Pest Management Association (NPMA), the Association of Structural Pest Control Regulatory Officials (ASPCRO) and the State FIFRA Issues Research and Evaluation Group (an EPA advisory group also comprised of regulatory officials), the EPA agreed to make further changes to the original label requirements to allow for better control of overwintering insects.

While restrictions on insecticide applications to impervious surfaces and prior to expected rainfall have not changed, there are some big changes on applications to structures, as published in a January 10 letter to pesticide manufacturers.  The three changes are summarized as follows:

• Now applications of pyrethroids may be made to the exterior of buildings where the treated surfaces are underneath eaves, soffits, windows or doors that are protected by coverings, overhangs, awnings or other structures that protect the residues from rainfall;
• application bands up to one inch-wide may be applied to cracks or other potential pest entry points;
• and applications may be made using a coarse, low-pressure spray to portions of surfaces that are directly above bare soil, lawn, mulch or other vegetation.

The purpose of these requirements is to prevent pyrethroid pesticides from entering storm water and getting into streams, something that is most likely when pyrethroid sprays land on impervious surfaces like asphalt or concrete.

In addition to giving back to PMPs the ability to use pyrethroids against overwintering pests these new regulations should help applicators control nuisance and public health mosquitoes that frequently rest on the sides of buildings and around doorways.  This was, in my view, a potentially serious public health issue with the 2009 rules.

So what will be the big change to the way your company applies pyrethroids after the dust is all settled? The new labels will prohibit power spraying driveways and over sidewalks, garage doors and any vertical building surfaces over pavement. Assuming the manufacturers follow these guidelines closely, labels should allow low-pressure sprays to the sides of structures over vegetation or soil and in sites protected from the rain, in addition to cracks and crevices.

Congratulations to the EPA and to those regulators and NPMA experts who took the time to look for ways to keep the pyrethroid label requirements reasonable while continuing to protect the environment. This is one of those examples of how the system sometimes works in everyone's favor--except, in this case, the pests'.