Tuesday, December 29, 2015

Bracing for Zika

Will Zika be the next mosquito-borne disease to capture headlines in 2016?  Or will it be the little disease that few (at least in the U.S.) have heard of?  That's the question being debated by public health officials this year.

Current (2015) worldwide range of zika virus. Central and South
American countries were first reported with the disease in
2015 (U.S. Centers for Disease Control).
For many years it seemed like new things happened relatively slowly in public health in Texas. In the mid-1980s entomologists reported the Asian tiger mosquito in Texas for the first time--a daytime-flying mosquito from Japan that is not shy about biting humans. Then in 2002 the first cases of west Nile virus hit our state.  Carried by the southern house mosquito, WNV affected a couple of hundred people or less each year. This was the case until the blazing hot summer of 2012 when over 1800 cases were reported, including 83 deaths. Health departments throughout the state are still reeling, in some ways, from the impact.

Now health officials are bracing for another mosquito-borne disease caused by Zika virus (abbreviated ZIKV by epidemiologists).  A cousin of west Nile virus and dengue fever, ZIKV has been thought of as a less severe form of these flavivirus.  Most people who get ZIKV show no, or very mild symptoms.  Others exhibit a rash, conjunctivitis (inflammation of the eye), and flu-like symptoms.  Most people do not get as sick with ZIKV as with dengue fever or chikungunya, and recover relatively quickly.

For this reason, since its discovery in 1947 until 2007, it was not on the radar of many public health experts. But in 2007 ZIKV cases started to spread throughout Micronesia French Polynesia, and eventually Easter Island. There it was thought to possibly be the cause of a twenty-fold increase in cases of Guillain-Barre syndrome--an autoimmune disease of the central nervous system that can be highly disabling, at least temporarily.

In 2015 the disease made its appearance in Brazil and has since spread to at least nine other member states of the Pan-American Health Organization (PAHO/WHO), and prompting that organization this month to issue an alert to all of member public health agencies.

So here's where things get a little scary.  Since the arrival of ZIKV to Brazil, the virus has been detected in babies born with a condition known as microcephaly.  Microcephaly is a relatively rare condition where the brain fails to develop normally. It may result in miscarriage or in babies being born with under-sized brains.  There is no cure for the condition.  The PAHO/WHO alert noted that the number of diagnosed cases of microcephaly has increased to 2700, a 10-fold increase, in Brazil this year.  Health officials there are worried that there might be a connection between this unprecedented increase in microcephaly and the arrival of ZIKV.  And last month, unusual nervous system birth defects were also reported in Polynesian mothers who tested positive for flavivirus antibodies.

Public health officials guess that these cases may result when a pregnant woman who is bitten by an infected mosquito contracts the virus.  The virus then infects the developing fetus, resulting in this serious condition.

So far there is no hard proof of a connection between ZIKV and microcephaly or Guillain-Barre syndrome, but medical researchers are rushing to learn more about the virus and its possible effects on human health.  According to one expert, quoted in the New York Times, it could be that the risk of microcephaly is increased among people who have previously contracted dengue fever or chikungunya, neither of which diseases are common to Texas or the U.S. If this hypothesis proves correct, the risks to the unborn in this country would likely be negligible.

Currently, ZIKV is thought to be transmitted by the yellow fever mosquito, Aedes aegypti.  This mosquito, along with its close relative, Aedes albopictus, the Asian tiger mosquito, are both very common throughout Texas and the southern U.S.  Unlike west Nile virus, which is primarily a disease of birds, ZIKV is solely a disease of primates.  To be spread among people, it must be picked up from another infected human.

Dengue and chikungunya are similar, human-only, viruses that have not been quick to spread in Texas or other U.S. locations.  This may be the result of lower rates of mosquito biting in the U.S., perhaps due to our more indoor lifestyles, or more common use of repellents.  Some experts argue that for similar reasons ZIKV is likely to be slow to establish in the U.S.  Nevertheless, Brazil shows that given the right conditions, this virus is capable of establishing itself very rapidly, with 85,000 known infections in its first year of spread.

A few U.S. cases of ZIKV have been reported in 2015, but all from travelers who contracted the virus elsewhere.  Mexico has also seen a few cases this year.  There are still no known cases of ZIKV, however, contracted within the U.S.

So be prepared to hear more about the zika virus this year.  It may turn out to be a big event, or it may not.  Even if we didn't need more reasons to dislike biting mosquitoes, now we have one more reminder of the importance of residential mosquito control, and putting on the insect repellent when venturing outdoors.  

Wednesday, December 23, 2015

Managing bed bugs in multifamily housing--insights from ESA

The Minneapolis, MN Convention Center hosted this year's
annual conference of the Entomological Society of America
It's been almost 15 years since bed bugs started as a hot symposium topic at the annual conference of the Entomological Society of America. And following this year's meeting in Minneapolis, it seems like solutions are still elusive, especially when it comes to multifamily housing.

As usual for me during these marathon meetings, I attended as many talks about bed bugs as I could.  But this year I was especially attracted to discussions about bed bug management in multifamily housing, a.k.a. apartment complexes.  There were several interesting papers related to the topic, but three of them seemed to do an exceptional job of illuminating the issue and possible solutions.

Virginia Tech and Apartment Managers

I know of no one who exhibits more passion about bed bug management in multifamily housing than Dini Miller of Virginia Tech University.  In fact, to keep up with the overwhelming education demands in this area, her group recently established a Bed Bug and Urban Pest Information Center to better educate Virginians (and especially apartment managers) about bed bug control.

According to Miller, a big part of the reason that bed bugs are such a problem in apartment complexes is that they are not just a pest problem. Bed bugs are also a social problem with a unique human dimension. In her ESA talk Miller observed that in her experience the worst bed bug infestations seem to occur with individuals who have problems that are much worse than bed bugs (e.g., health issues, finances, safety and security).  Such tenants, for a variety of reasons, are less likely to complain to management about bed bugs.  On the other hand, the most vocal complaints often come from those with relatively small-scale bed bug problems. Therefore, when an apartment complex bed bug control program is primarily complaint-driven, the program is doomed to miss what should be the highest priority units.

Miller believes that good apartment management is key to an effective bed bug program. To be successful, she argues, (1) managers must be committed to solving the problem, (2) the response needs to be proportionate to the problem (less money and time on small infestations and more effort on finding a eliminating heavy infestations), (3) apartment preparation requirements must be reasonable (with assistance provided for the elderly), and (4) managers must be better informed and involved with the pest control company in the IPM process.

For managers who don't feel that bed bugs are that big an issue, Miller notes that one 4,000 unit complex she works with spends $500,000 annually on bed bug control.  And liability is also a big issue. In Iowa in 2014, residents of a public housing complex successfully sued management for $2.45 million for an uncontrolled bed bug infestation.

Rutgers and Bed Bug IPM

Climbup interceptor cups were effective at detecting bed bug
infestations 95% of the time in the Cooper study. Pitfall traps
like the Climbup detect 3X as many low level infestations
than would otherwise be reported by tenants.  
Another leading bed bug researcher, Changlu Wang from Rutgers University, offered his own perspective on reasons for the ongoing bed bug crisis in multifamily housing.  He said that the biggest challenges come from (1) heavy infestations associated with clutter, (2) widespread resistance to insecticides among bed bugs, (3) the small size and difficulty in finding bed bugs (thus determining whether an infestation is eliminated), and (4) the need for cooperation from residents.

As background, Wang and his laboratory have undertaken some ambitious field trials in the past few years.  I say ambitious because it is extraordinarily difficult to do large scale control studies in apartments.  Not only do researchers have to work with the same unpredictable clients you work with daily, they also have to get approval from a group called the Institutional Review Board (IRB).  Each University has an IRB that oversees any research done with humans or animals, ensuring that the research is done ethically and without harm to its subjects. Getting through the process requires lots of paperwork and is enough to make you crazy.

In a study just published by Wang's recent Ph.D. student, Rick Cooper, an IPM program was pilot tested at a four building complex with 358 units housing elderly and disabled residents.  The IPM program consisted of resident education, initial monitoring with ClimbUp® interceptors to determine which units were infested, encasements, vacuuming, steam, laundering assistance, and insecticide applications with diatomaceous earth and chlorfenapyr.  Units with less than 5 bed bugs received non-chemical treatment only.  Units that continued to be infested with more than 5 bed bugs after the first treatment received spot treatments with Transport GHP.  Followup treatments in all originally infested units were continued every two weeks until no bed bugs were captured in interceptors, seen, or reported by the residents for three consecutive visits.

Relationship between the initial number of bed bugs in a treated
apartment and the number of treatment visits needed to eliminate
the problem.  An initial infestation of 100 bed bugs required  ca.
10 visits to verify elimination. From Cooper et al. Jan. 2015.
Pest Management Sci.
Cooper's experiment is the first research to document the success of a bed bug IPM protocol in an entire apartment complex. Key findings of the study were:

  • Management was aware of only 29% of the infestations before Climbup interceptors were used.
  • It took an average of 2 to 4 minutes (they got faster throughout the study) to install approximately 10 interceptors per apartment.
  • It took less than 4 minutes to inspect Climbups compared to over 15 minutes to conduct a visual inspection of an apartment.
  • Because of the difficulty in detecting low levels of bed bugs, the authors defined "elimination" as three consecutive visits with no live bed bugs detected by Climbup counts, visual inspections and resident reports. The authors considered the stringent elimination protocol an essential part of the IPM program.
  • Researchers estimated the overall infestation rate of the apartment complex was reduced from 15% to 2.8% at 6-months and to 2.2% at 12-months, an 85% improvement. 
  • In infested apartments the mean number of bed bugs trapped was reduced by 96% and 98% after 6- and 12-months, respectively. 
  • Heavily infested apartments at the beginning of the study required the most visits to achieve control, hence costing the complex more. 
  • 62% of residents with bed bugs were not aware that they had bed bugs, including one oblivious resident whose apartment had over 4,000 bed bugs, many of which were openly crawling on the bed during inspection.
  • 76% of residents who thought their bed bug problem was solved through treatment still had bed bugs detectable with Climbups, supporting the idea that customer satisfaction should not be the sole criterion for determining when treatments can be stopped.
  • Average labor and chemical costs for the 12 month treatment for 66 apartments was $456 per apartment, a figure in line with other programs and which the authors believe can be reduced in subsequent years of a contract.
A full copy of Cooper's excellent study can be accessed here.

University of California Survey

In contrast to what ought to be done about bed bugs, Andrew Sutherland of the University of California's Statewide IPM Program, reported on what is being done for bed bugs in the western region of the U.S.  He surveyed 114 PMPs in California and other western states and provided some useful insights into current industry bed bug practices.  His study confirmed Miller's observation that compared to hotels and single-family homes, multifamily housing was rated by respondents as having the worst infestations, the most-difficult to control infestations, and being the most often treated kind of account.  When asked about monitoring methods used for bed bugs, 98% of respondents employed visual inspections "most of the time".  Pitfall traps were used at least once by about 75% of respondents; but only 20% said they used this tool "most of the time".  About 40% of respondents used canine detection at least once.  Surprisingly, glue boards had been used by about 75% of respondents, at about the same frequency as the far superior pitfall traps.  

Regarding control methods, insecticides were used "most of the time" by 94% of respondents. Desiccants were used to some extent by 85% of respondents, but only by 57% "most of the time". Encasements were used "most of the time" by 50% of respondents.  And 53% of respondents never used volumetric heat treatment--not surprising given the relatively high initial cost of the equipment. 

Among liquid sprays, the insecticides used "most often" by respondents were neonicotinoid+pyrethroid combination products (53%), followed by chlorfenapyr (20%), followed by pyrethroids (17%). Among dusts, pyrethrins (surprise to me) were most commonly used, and least used were the highly promising silica aerogels.  A copy of the PMP portion of his survey results has been published in PCT magazine.

In addition to PMPs, Sutherland surveyed 167 housing management professionals, and the results were also revealing. Eighty-seven percent of respondents said that bed bug service in their facilities was complaint-based, just what the Rutger's and Virginia Tech entomologists said doesn't work. Also, 72% of respondents make their tenants responsible for preparing for a bed bug treatment--not a good idea for elderly and disabled who are often unable to perform prep tasks.  And 69% of respondents said they used a bed bug addendum as part of their lease agreement.  Such addenda generally put responsibility for bed bugs back on the tenant, discouraging many from reporting infestations when they are small and easily treated. These latter results, especially, suggest that the pest control industry, and we in Extension, have some work to do.

These three talks for me illustrated why bed bug management, especially in multifamily housing, remains a challenge.  Within the industry better IPM protocols are needed, especially protocols that rely on proactive monitoring and early intervention, sanitation, physical and mechanical controls, and conservative, targeted use of carefully chosen pesticides. I think we also need to take a closer look at desiccant dusts, perhaps an underused, low toxicity tool in the bed bug tool kit.  Within the apartment industry, managers and tenants need to be educated about the importance of monitoring-based protocols, minimum prep models, and reversing the "blame the tenant" mindset. All research shows that the sooner a bed bug infestation is detected, the better the prognosis for a quick and less-costly response.

Given that approximately 26 million households reside in multifamily rental housing (2014 data from National Multifamily Housing Council), there is hardly any pest control issue in the U.S. today that affects more people in a more personal way. The way that pest management and multifamily housing businesses respond to the challenges of bed bugs in the coming years will say a lot about the character of these two industries.

Monday, December 21, 2015

Changes in the rules of the game for Texas PMPs

New rules start as laws passed by the Legislature under
the Texas Capitol dome.  Laws become enforceable only
after rules are drafted and published for public comment by
the lead agency, like Texas Department of Agriculture.
New rules governing the pest control industry in Texas were published last week and are now in effect.  While none of the changes in the "rules of the game" are major, there may be a few things that affect your business or school district.

The rules governing pesticide use in Texas can be complicated, and are passed down to us through two sets of documents.  First, the Texas Occupations Code (TOC) contains  the official list of laws as passed by the legislature pertaining to different occupations, including structural pest control. If you go to this code online, the chapter having to do with pest control is Chapter 1951. Chapter 1951 lists all the state law as passed over the decades that relate to the business of structural pest control.
The second, and probably most relevant set of rules to our industry is the Texas Administrative Code (TAC).  The TAC records how the various state agencies choose to interpret and administer the laws. For example, Section 1951.212 of the TOC directs the Texas Department of Agriculture to establish standards for an IPM program for public school districts.  The TAC Sections 7.201-7.205 spell out what the standards are, including requirements for IPM coordinators, pesticide categories, posting requirements, etc.

But wait a minute. How can non-elected bureaucrats in a state agency write rules outside the legislative process?  The answer is that legislators don't have the time or the expertise to write detailed regulations, so they pass their rule-making authority on to Executive branch agencies like the Department of Agriculture.  Of course the rules have to fairly interpret the law, and they must be published ahead of time in the Texas Register so that all of us can review and comment.

Publication of several new or revised sections of Subchapter H of the TAC (Texas Department of Agriculture) marks the end of this process for pest control rules this year.  On December 18 the Texas Register published the results of public comment and listed the final versions of proposed rules originally published on September 18. With this final version, the rules are now considered to be in effect.

Most of the changes were made simply to clarify wording of the old rules.  There was also some reorganization of section numbering, so that old rule citations may no longer apply.  Here are the essential changes:

  • Sec. 7.122 Changes in wording that include giving power to the Department to deny a license to anyone who holds a similar license that has been revoked, suspended, probated or denied within the last five years by another state or by the federal government.
  • Sec. 17.127 There are no more fees for providing a continuing education course.
  • Sec. 7.141  Rewording of rules pertaining to ID that must be carried at all times by license holders.  Basically, if you have a license you must carry it on your person at all times and show it to any customer or relevant government employee who asks. If it's not legible, then its not a legal ID.  Also, language on vehicle signage has slightly changed to require all marked or unmarked vehicles being used for customer contact or service must have the business license number prominently displayed (magnetic signs are not OK).
  • New Sec. 7.150 requires all pesticides be used consistent with the pesticide labeling, and prohibits use of any pesticide missing a complete label when the identity of that pesticide is unknown.
  • New Sec. 7.151 prohibits anyone from hurting people or the environment, and making the pesticide owner, the applicator and/or the mixer equally responsible for proper storage and disposal of pesticide containers and contents. It also requires all pesticide containers to be labeled with the name of the pesticide.  And it specifies that hard copies of all pesticides being stored shall be available for inspectors visiting the storage site.
  • Sec. 7.152 states that no one may advertise to perform structural pest control services without a license, and that all advertising must include the same business name as is on the license.  This rule was rewritten to ensure that companies not use multiple business names under the same business license, and to clarify that pest control advertising includes online ads such as might appear on sites like Facebook, Craigslist and Angie's List.  
  • Sec. 7.193 is a new section number which clarifies who may qualify as a member of the Structural Pest Control Advisory Committee from an institution of higher learning (the position I formerly held, and now is being held by Dr. Robert Puckett).  
  • Sections rules for the IPM program for public school districts have been moved to a new Division (7) and renumbered from Sec. 7.150-7.154 to 7.201-7.205.  The biggest changes in this section relate to CEU requirements for IPM Coordinators.  
  • Sec. 7.202  School IPM coordinators no longer are specifically required by rule to personally conduct periodic inspections of their school district.  While this remains desirable, taking away this rule frees the coordinator to rely on other trained inspectors to provide inspection reports.
  • Sec. 7.204 includes slight wording changes to clarify that outdoor areas treated with a pesticide may be posted at all entry points with a sign in lieu of a lock, fence or barrier tape until the reentry time is over.  This section also allows IPM Coordinators, or their supervised employees, to use non-pesticide containing monitoring devices like sticky traps, to monitor pests without a license.
Perhaps the most significant change heralded by these rules is that expanded CEU requirements for school IPM Coordinators (IPMCs) are now officially in place.  Over four years ago, as a result of Sunset Commission recommendations, the legislature decided that ongoing CEUs would be required for school IPMCs.  Until now, the only CEU requirement was that IPMCs have six hours of department-approved training at the beginning of their appointment.  Under the new rule IPMCs must have six hours of verified, approved training every three years.  While most of these CEU requirements can come from any approved, relevant pesticide CEU class, at least one of the hours must be related to school IPM rules and regulations.  The countdown for existing IPMC's three years will start this January, or for new IPMCs at the date whenever their initial training is completed. Pesticide CEUs obtained in support of a pesticide applicator's license can be double-counted toward the CEU requirements for IPMCs.

After seeing how long it can take the TDA to publish its rules, I don't feel nearly as bad about the stacks on my desk.  

Friday, December 11, 2015

Earthworms gone wild

Nearly everyone loves earthworms. I don't remember my first childhood encounter with earthworms, but I imagine it had something to do with wet sidewalks after a rain, and rescuing "wormies" from the hot sun. As I grew older I learned to respect earthworms less for their delightful slimy "squirmy-ness" and more for their practical roles in helping gardeners and farmers, and providing food for wildlife... and other good things like fishing.

No one denies that earthworms provide hefty environmental services in the form of improved soil aeration and water penetration, and composting.  But it turns out that there are some bad guys in the earthworm community. And sometimes earthworms just show up in the wrong places at the wrong time.

Extreme earthworm excavation can lead to boggy soil and weak
turfgrass stands. 
Let me explain. Some types of earthworms are notorious for leaving excessive amounts of castings on the soil surface. The spongy soil and excess castings produced by these worms can make it difficult to mow, or even walk across an infested lawn. Earthworm tunneling can also disrupt grass roots and reduce turf quality. And don't talk to golf course superintendents about earthworm castings on putting greens. Besides disrupting play, earthworm activity dulls mower blades used to keep greens short and fast.

Also, it turns out that earthworms are not very welcome at airports. With the number of reported bird strikes increasing over six-fold between 1990 and 2013, airport managers are eager to look for ways to reduce bird activity around airport runways. Therefore, high earthworm populations, which attract birds, are not desirable close to airplane landing and takeoff sites.

Of course the overall benefits from earthworms on turf is great, but there are places and times where earthworms are pests.  Until now, there has been little to be done about earthworms.  A few insecticides and fungicides are known to be highly toxic to earthworms; but there are currently no pesticides (vermicides) registered for earthworm control in the U.S. And by all accounts the U.S. EPA, which regulates such things, does not appear eager to register worm-killing pesticides.

Research reported in 2010 from the University of Kentucky documented that an organic, plant-produced mixture of natural soaps called saponins could effectively be used to control earthworms for at least five weeks. The best commercial source of saponins turns out to be a byproduct of tea manufacturing called tea meal.  While the research has not resulted in anyone registering tea meal as an insecticide, a company called Ocean Organics has started importing tea meal from China and using it as a base for a new organic fertilizer.

Early-bird 3-0-1 organic fertilizer, described by some as "a fertilizer with benefits", uses a tea seed base.  Though not sold as a pesticide, it happens to be toxic to some earthworms. It is labeled for application at 6 lbs/1000 ft sq or 5 bags per acre. A 50 lb bag retails for around $55, and cost of application is around $275/Acre (it can be found at Winfield Solutions--Land O Lakes in Texas, and possibly other suppliers).

I know that any suggestions on ways to kill earthworms will be viewed with alarm by many, but there will be situations when at least short term control is desirable. On the other hand, as one researcher thoughtfully concluded, earthworms are highly adaptable creatures that are difficult to manage, and to some extent we will have to learn to take their bad along with the good.  Think about that the next time you go fishing.