Friday, April 10, 2015

Spring caterpillars

Forest tent caterpillars can be recognized by their dark-
gray to brownish body color, with pale-blue and yellow lines
 extending along each side, and a chain of distinct,
whitish shoeprint-shaped spots running down the middle of
their back.
As every PMP knows, bluebonnets aren't the only thing that emerges each spring. The annual symphony of ringing phones in pest control offices this time of year is proof that insect activity returns with warm weather.  This year is shaping up to be an active year for caterpillars in Texas, so I thought that a review of some of the more common spring caterpillar pests might be appropriate.

Forest Tent Caterpillar 
Forest tent caterpillar, Malacosoma disstria, is one of the most widespread and abundant of the tent-making caterpillars in the U.S. Like its close cousins the eastern and western tent caterpillars, forest tent caterpillars feed primarily on trees; but unlike their cousins, and the also abundant fall webworm, the forest tent caterpillar doesn't make an actual tent. Instead it aggregates between feedings on a silken mat which is spun on some area of the trunk or on large branches of the host tree. After completing its larval development in two or three weeks, the caterpillar pupates and eventually turns into a handsome, but obscure, brown moth.
Forest tent caterpillars rest between feedings on a
silken mat where they may be easily seen
and treated.  Photo via NBCDFW Channel 5 TV.

Forest tent caterpillars appear but once a year, usually in April in Texas, and sometimes in very large numbers.  They then "disappear" for a whole year until the cycle begins again.  Some years caterpillar numbers are very high, but most years they may be noticed only by the sharpest-eyed observers.  The cycles of up and down appear to be driven by a combination of environmental and natural control factors, like birds and parasitic insects.  This may be one of those abundant years, at least for some areas of Texas. Sam Houston Electrical Cooperative reported dozens of power outages this month from masses of tent caterpillars covering electrical transformers, causing fuse overloads.  I have been receiving emails over the past few days from homeowners concerned about the caterpillars massed on their silken mats.

Spring Cankerworm
Spring cankerworm can defoliate entire trees and cover plants
and sidewalks with their webbing.  This tree is losing its leaves
as quickly as they can emerge.
Another caterpillar that can completely defoliate trees in the spring is the spring cankerworm, Paleacrita vernata. When cankerworm outbreaks occur, they can produce some of the most spectacular tree defoliation events seen in this part of the country. If you have a chance to walk through an infested forest you will see millions of tiny caterpillars hanging from tree branches and blowing on the wind. After a week or two of feeding, trees can be largely stripped of leaves. Fortunately, these outbreaks normally pose little danger to trees, especially trees in woodlots and forests. Healthy trees on good soil can usually withstand total defoliation without significant damage. Trees that lose their leaves to spring cankerworms generally re-leaf and show no signs of long-term damage. However, trees that are under stress from drought or transplantation may benefit from a timely insecticide application, before the leaves are stripped. This species also has only one generation per year, so late treatment of a tree with an insecticide, or follow up sprays, are not necessary.

Cankerworms belong to the moth family Geometridae. Spring cankerworms range in color from light green to brown. Like all geometrids, spring cankerworms have fewer than normal caterpillars. Where normal caterpillars have three to five abdominal feet, spring cankerworms have only two. The result is a distinctive looping walk, giving these caterpillars their common name "inchworm". Click here to see a video of this walk.

Eastern and Western Tent Caterpillars
Tent caterpillars make their nests in the crotches of trees in
the rose family.
The eastern and western species of tent caterpillars are in the same genus, Malacosoma, as the forest tent caterpillar.  The eastern tent caterpillar, Malacosoma americanum, feeds mostly on trees in the rose family, which includes most fruit trees (apples, cherries, plum, crabapple and hawthorn).  These species, however, go beyond silk mat construction and produce protective tents in branch crotches.  These tent caterpillars are common sight throughout the country.  In addition to chewing leaves, the tents themselves, when abundant, detract from the appearance of the trees in urban landscape settings especially.  Again, these caterpillars produce only one generation per year.

Fall Webworm
Fall webworm tents extend over the tips of
branches. Feeding then occurs inside the
tent.
Even though it is called the fall webworm, in Texas Hyphantrea cunea can be found throughout the growing season, starting in the spring.  Recorded from over 400 different species of trees, fall webworm webs are a common site both in cities and along rural roadsides.  Unlike the tent caterpillars, fall webworms live full-time within their webs.  As leaves from the tree are devoured, the webworm colony simply expands its web to cover new leaves.  Silk from tent caterpillar and fall webworm "nests" likely serve to protect the insects from bird and, to some extent, insect predation.  In some years whole trees can be stripped of leaves and become covered with the unsightly webbing.  Unlike the other tent-making caterpillars, fall webworms produce 3-4 generations per warm season, and may need repeated treatment.

Non-Chemical Control Options
With fall webworms and tent caterpillars, non-chemical control might include physical removal or destruction of the nest(s).  A pole pruner can be used to cut out webs from high branches, or it can be used to physically disrupt the nest and knock caterpillars from the tree.  This is only practical for early infestations restricted to a few nests or superficial branches.

To Treat or Not to Treat
Most trees can withstand significant leaf loss without any significant reduction in sugar production and storage (a measure of tree health). A rough rule of thumb is that 20% loss of foliage (for deciduous trees) should not be harmful to a tree.  Over 20% defoliation and trees may suffer slowed growth and stress.  An otherwise healthy tree can lose all its spring leaves and will re-leaf; however this does reduce vitality. Defoliation in combination with other stresses, such as root compaction, drought, disease, or other insect attack, can push a tree into decline or die back.  For this reason, it may sometimes be worthwhile to tree a tree for caterpillars.

Other reasons to treat a tree for caterpillars include aesthetics (preventing unsightly webs, or temporary leaf loss) or prevention of nuisance factors from droppings and caterpillars falling from trees.

Every customer faces a few decisions before having trees sprayed for caterpillars.

  • Is the cost of the spray worth it for aesthetic options?  
  • Is the tree in a location where it can be treated without drift falling into a swimming pool or neighbor's yard?  If drift is inevitable, can it be mitigated by covering the pool, or getting the neighbor's OK to proceed? 
  • Can the spray treatment be done quickly enough to be worthwhile?  This is often the critical question, because most tree infestations are not noticed until caterpillars are nearly fully developed and the damage is mostly done.  


Chemical Control Options
If you and your customer determine that a spray is justified, you must determine the best active ingredient.  There are many options for caterpillar control. Spinosad and Bacillus thuringiensis are two of the better low-impact insecticides effective against caterpillars. However they are most effective against smaller caterpillars. Newer options include clothianidin (Arena®), chlorantraniliprole (Acelepryn™), and the combination product spinetoram+sulfoxaflor (Xxpire™). Pyrethroid insecticides are fast and tend to provide longer residual; however they are more toxic to non-target organisms such as beneficial insects. You should note that many of these products are toxic to bees and pollinators, so it is best to avoid spraying trees in bloom.

Lastly, it may be possible to save your customer some money and reduce drift potential and damage to beneficial insects through spot treatments. Forest tent caterpillar aggregations are easily spot-treated with a variety of insecticides including insecticidal soap and horticultural oil.  Likewise, individual nests of tent caterpillars or fall webworms can sometimes be spot treated even with a pump sprayer using a pinstream nozzle. Such applications, being very targeted, should control the caterpillars with little impact on other beneficial insects.

Thursday, March 19, 2015

Pesticides not to blame for bee woes?

According to Science Daily, new research shows that imidacloprid, an insecticide often blamed for the decline of commercially managed honey bees, is not likely to harm honey bees at field realistic levels.  The three year study, conducted by Galen Dively and associates at the University of Maryland, supports the contention by many U.S. bee researchers that proper applications of this insecticide is not likely to be the sole, or major, explanation for colony collapse disorder (CCD).

New labeling for some plants
sold by The Home Depot alerts the
consumer to neonicotinoid-treated
plants.
Despite those who claim CCD is clearly the result of dangerous insecticides, the issues surrounding CCD are complex and technical. Much of the debate in the research community recently has centered on what constitutes "field realistic levels" of imidacloprid and its cousin insecticides, the neonicotinoids. Industry representatives have contended that recent critical studies, cited by environmentalists as justifying a ban neonicotinoids, were flawed because they were based on unrealistically high levels of the insecticides. Dively and colleagues tried to allay these concerns by feeding their bees imidacloprid in protein supplement patties at doses of 5, 20, and 100 micrograms per kilogram (parts per billion).  The lowest dose, 5 parts per billion, is generally recognized as field realistic based on several studies of pesticide concentrations in the nectar and pollen of treated crops. The insecticide-laced protein supplement was provided to the bees over a continuous 12 week period. Even so this was, the authors contend, a higher exposure scenario than would likely occur in agricultural settings, where the contaminated pollen and nectar is not likely to be present continuously.

As one of the first studies to look at honey bee colony health over multiple seasons, the results were more rigorous than previous research.  They did showed a significant negative effect on colony survivorship as dosage increased; however the lowest, field-realistic dose showed no significant impact on key bee health indicators, foraging or winter survivorship.  The major impact of higher imidacloprid exposure were increased broodless periods, caused by weak queens during late summer. Such effects could lead to lowered overwintering survival, a character of CCD.

Nevertheless, the authors conclude that while short term exposure to high imidacloprid levels (represented by 100 part per billion dosages in this study) in agricultural settings does occur, it is not likely to occur continuously throughout a crop cycle.  Also, data from the study showed that bees were efficient in metabolizing imidacloprid, so that short term spikes in insecticide levels in nectar were likely to be quickly diluted and eliminated by the bees. They concluded that while imidacloprid might be a contributing factor to some overwintering losses in bees, seed treated crops in particular were likely to have negligible effects on honey bee colony health.

In the ongoing debate over bee health, this is one piece of good news for pesticide manufacturers and users; but it will not be the final word. And it should not justify anything less than the utmost caution for pesticide applicators when they use neonicotinoid insecticides.


Monday, March 9, 2015

Get updated on fire ant baiting

Fire ants remain the most prevalent outdoor ant pest in most areas of the southern U.S.  Throughout the U.S. we estimate the annual cost of fire ant control at over $6 billion.  But the cost of this pest goes far beyond measurable dollars.  Fire ants reduce the recreational value of our parks and backyards, disrupt wildlife populations, and send thousands to emergency rooms each year from their painful stings.  

So as we get ready to enter fire ant season, it may be a good time to bring yourself and your staff up to speed on fire ant control. Many people are surprised to learn that fire ants are not an especially difficult pest to manage, once the biology and control tools are understood.

One of the best places to learn about fire ant management is the E-xtension fire ant website, a place where the best information about fire ant is assembled by Extension agencies throughout the South. This information was recently summarized and presented in an informative webinar by Dr. Fudd Graham, fire ant specialist with Auburn University.   Dr. Graham focuses on fire ant biology and use of baits for fire ant control.

It's worth knowing something about how fire ant baits work because they are the most economical, ecologically friendly, and effective control methods for fire ants. The webinar will provide you or your technician with an hour of training that should pay for itself many times over.  

Friday, January 23, 2015

Winter Structural Pest Control Advisory Committee meeting

It was a cold, wet day in Austin this week as the Structural Pest Control Advisory Committee met to discuss the business of pest control regulation in Texas. Much of the meeting was going over rules drafted by the SPCS staff that will impact just about anyone who does structural fumigation, provides termite estimates, or who want to get continuing education units online.

Mike Kelly, staff member for the Structural Pest Control Service (SPCS), presented a rough draft of new document requirements for termite treatment disclosures, or as they are now called: "Subterranean Termite, Drywood Termite and Related Wood Destroying Insect Treatment Disclosure Documents" (The new name may be good for clarity, but sometimes I think government rules eat as much wood--in the form of paper--as termites).  Most of the changes are minor, designed to make the regs easier to read; however one positive significant change is that written estimates using these documents will now have to be made by a licensed technician or Certified Applicator--not an unlicensed sales person or office staffer.

Following up on industry recommendations from last meeting, Kelly also presented proposed changes for Structural Fumigation Requirements.  To anyone who is not a fumigator, fumigation requirements are about as exciting as a wait at the DMV.  But to fumigators, any change in rules can be grounds for fightin'.  Acting on our last meeting's discussion, the biggest changes to the rules included an attempt to clarify the responsibilities of fumigation contractors and subcontractors.

Danielle Dean (right) and Betty Thornton explained the new
CEU course they have developed for pest control office
managers and staff. 
Now if it were up to me, I'm not sure I would let anyone subcontract fumigation jobs. Fumigation is risky and technically complicated, and way too many things can go wrong (communications wise) between the customer and the subcontractor(s) who actually does the work.  But that's not the law, so these new rules attempt to reduce the risk of misunderstanding between fumigator and customer. As you might guess, there will be more paperwork.

One proposed rule change specified that only a registered apprentice, licensed technician or certified applicator (CA) can assist the supervising CA with introducing fumigants, or performing reentry and aeration activities. Also Kelly proposed to clarify wording on the required condition of tarps used in sealing in fumigant gases, and what the official time for a start of fumigation should be based on.  Both Brian Springer, Bevis Pest Control, and Debbie Aguirre, Elite Exterminating, commented passionately on the requirements--Springer noting the stellar human safety record of structural fumigation in Texas in recent years.  If you have anything to do with fumigation in Texas, you'll want to review these new regs carefully when they come out this spring. None of the rules are official until you get a chance to review them, and if you're a fumigator I'm sure you'll have an opinion.

We also discussed online CEU courses as supplements or replacements for face-to-face training. There have been numerous proposals over the years to allow applicators to get training remotely; but concerns about accountability, quality of courses, and security have slowed approval of this option.  The committee heard from AgriLife Communications specialist Holly Jarvis and representatives from online training provider, eStrategy Solutions.  According to Jarvis, there are now multiple ways to make these courses interactive, and accountability can be even better than live courses. Committee members felt that it was time to make electronic courses a routine way for license holders to get the CEUs they need.  In addition to the convenience of getting training on any day you need it, online CEU courses allow the applicator a choice of training topics, including difficult-to-find CEUs, like fumigation.  We recommended eliminating the proposed restriction that online CEUs be allowed only every other year.  Such changes won't mean that CEU workshops with face-to-face training are going away anytime soon, but do they mean you'll have more choices when it comes to getting your CEUs.

The highlight of this month's meeting was a presentation by Betty Thornton, Alvin Pest Control, and Danielle Dean, bwi Companies.  Thornton and Dean met earlier in the year with staff at the SPCS to educate themselves about regulations that might affect office staffers at pest control companies. It turns out that a number of laws and rules limit what advice an unlicensed staffer can say to customers over the phone. An unlicensed person, for example, cannot diagnose a pest problem or offer price quotes to someone over the phone or via email. They took lessons-learned and developed a course for office staff and technicians that includes what you can and can't say over the phone, going paperless in a pest control office, role playing, how to get a new technician registered to take their license exam, how to survive a 14-point inspection, and avoiding the top 10 non-compliance issues.  Both Thorton and Dean were engaging and enthusiastic.  They have given their (approved CEU) course several times and are willing to go on the road for groups that want to sponsor them.

Office staff are a critical, and often neglected, segment of the pest control industry.  I commend the SPCS for their train-the-trainer efforts, and hope that all these efforts result in better trained office staff throughout the state. I think bringing office managers and staff into the training picture could turn out to be one of the single most significant things we can do to improve compliance with our pest control laws in Texas.

Perhaps not many of you make it to the end of these long reports.  But the last thing I want to say is that this meeting was very significant to me in that it marks the end of my appointment to the SPCS committee.  By completing the end of my second term I am required by another one of those dern rules to step down and let someone else get to drive to Austin four times a year.  I anticipate that my replacement will be Dr. Robert Puckett, our newly hired extension urban entomologist in College Station.  I know he is excited about the chance to serve and will do a great job representing Texas A&M AgriLife.  My thanks to all the faithful committee members who have served this committee on their own dime over the years, and to the TDA/SPCS staff who take the time to listen.  It's been a pleasure.

Wednesday, January 14, 2015

Bed bugs in China

A recent article published in the Journal of Medical Entomology by entomologists at South China Agricultural University caught my eye today. The study reported on bed bug infestation rates of homes in two south China cities.  While the results were not very detailed, they do give an interesting peek inside the world's most populous country with some of the world's most crowded cities.

The size of its cities, and the potential pest control market, in China is staggering. The combined population of the two cities in this study is 18.75 million (Texas population is about 27 million), and each of the two cities in the survey support approximately 1000 pest control companies (Texas supports about 3,000 companies statewide).

In addition to dense urban populations, city residents are highly mobile.  In one of the cities, the transient population (recent arrivals from the countryside and other cities) was estimated at 78%! Such conditions seem tailor-made for bed bugs, who are easily transported in luggage.  In addition, in the winter most of the population in the two cities simply vanishes into the countryside for the very important Spring Festival.

Surprisingly, until now the bed bug has not been reported as a major, widespread pest in China; though according to this survey, that may be changing.  A preliminary survey of 11 companies from the two cities estimated that 35% of all accounts being treated involved bed bugs. In examining the records of two medium to large sized pest control companies, 29-42% of all service visits involved bed bug infestations. In the largest city, Shenzhen, 91.1% of all rooms in apartments treated were infested with bed bugs, and 56% of workers quarters were treated for bed bugs.  In the neighboring city of Dongguan, 83.7% of serviced apartments had bed bugs, and 61% of worker quarters treated were infested.

By the way, China has double trouble with both the tropical bed bug, Cimex hemipterus, and the common bed bug, C. lectularius.

With its 1.3 billion citizens, China is a huge pest control market. The same with Mexico and other Latin American countries.  I've been thinking about this recently because the U.S. is hosting the International Congress on Entomology in 2016 in Orlando, FL. This will be the largest gathering of entomologists in the world, including top experts in urban and structural pest control.  It seems to me that PMPs as well as research and extension entomologists have a lot to learn about the way pest control is conducted in other countries. So if you are ready to learn more about your global partners in pest control, consider making a trip to the ICE in two years.

Thursday, December 18, 2014

Best essential oil products for bed bugs

If you're a pest management professional in the bed bug business, I suspect the last thing you might want to hear about is a good consumer treatment for bed bugs. But the latest study published the Journal of Economic Entomology by Changlu Wang's lab at Rutgers University may hold a little good news for everyone.

In the study results recently reported in PCT magazine, Narinderpal Singh, Wang and Richard Cooper identified two low-toxicity, over-the-counter products that are surprisingly effective against both bed bugs and their eggs. EcoRaider™ and Bed Bug Patrol™ are essential oil-based insecticides available both in retail stores and via the Internet.

One of the experimental setups used in the Singh et al paper in
the Journal of Economic Entomology. Laboratory tests are
not always good predictors of what will work well under real
world conditions; but they are most useful in identifying
products less likely to work well.
The researchers looked at nine plant oil-based products and two detergents marketed for bed bug control.  In the first evaluations bed bugs were sprayed directly with the 11 products, as well as with the pyrethroid standards Temprid® SC and Demand® CS. Only two of the consumer products provided greater than 90% control.  A product called EcoRaider™ (1% geraniol, 1% cedar extract, and 2% sodium lauryl sulfate) provided 100% control of bed bug nymphs after 10 days. A second product, Bed Bug Patrol™ (0.003% clove oil, 1% peppermint oil, and 1.3% sodium lauryl sulfate) provided 91-92 percent mortality after 10 days in two trials. These essential oil products were slower than the professional insecticide Temprid® SC, but after 10 days they provided the statistically same control as Temprid®.

We all know the toughest life stage of bed bugs to kill is the egg. Singh et al. applied each of the sprays directly to exposed 2-3 day-old eggs.  EcoRaider™ controlled 86% of eggs, better than any other product, including the professional standards which gave less than 17% control.

Of course a good insecticide should not only kill on direct contact, but should leave a residue that continues to kill, and not repel, after it dries. Singh and colleagues pitted EcoRaider™ and Bed Bug Patrol™ against the two pyrethroids by confining bed bugs for five minutes on one-day old residues on cotton fabric. They then removed the bugs, placed them in clean dishes and observed. After ten days, EcoRaider™ and Bed Bug Patrol™ provided an impressive 93% mortality, equivalent to Temprid® SC, and significantly better better than Demand® CS. However when bed bugs were allowed to choose between resting on treated or untreated surfaces, the two professional products were significantly better.  

So don't dump your Temprids, Transports and Tandems just yet. Bed bugs always have a choice where to rest and walk in the real world, and these results suggest that when given a choice they might avoid spots treated with plant-oil products. And even the researchers admit that all spray exposures in this test were applied under ideal conditions. It's likely that results in the field, where bed bugs are almost always protected in cracks and crevices of furniture and bedding, will not be as good. Perhaps most importantly, even the best bed bug treatments miss directly contacting all bed bugs.  Hence residual control is very important and rightly remains the holy grail of bed bug control.  Today's modern insecticides may not always excel at long-term residual control of resistant bed bugs; but they are likely to be better than the best essential oil-based insecticide. The plant oil-based sprays in this test were only aged for a day, and given the volatility of plant oils I would not expect them to last much longer.

Nevertheless, low-toxicity "organic" pesticides have established a strong niche in the professional pest control business today. I applaud the efforts of the Rutgers researchers in sifting through the many "natural" products vying for bed bug market share. Singh et al's work may not be the last word on the subject of which green products work and which don't; but the methodology appears sound and the work thorough.  Based on what I read in the paper, if I were looking for a green insecticide to supplement my bed bug program (even one that was available to consumers), I would take a hard look at their top two performers.

The other insecticides evaluated in this study included Bed Bug Bully, Bed Bug Fix, Ecoexempt IC2, Essentria, Rest Assured, Green Rest Easy, and Stop Bugging Me. The two detergents tested included Eradicator and Bed Bug 911 Exterminator.

Please note that mentions of trade names in this article does not imply endorsement, but are included for educational purposes only.

Friday, December 5, 2014

Most common inspection failures

Inspections are never fun, but are mandated for every school
district, non-commercial applicator and commercial business
in Texas.
If you own or work for a pest control business, you know that it's no fun getting inspected. So many things can go wrong!  To make things worse, if you mess up, chances are that you'll see an inspector again soon, much sooner than if you pass with flying colors.

Fortunately, you don't need to have a bad inspection. At last month's Structural Pest Control Advisory Committee meeting, the good folks at TDA provided a list of the most common mistakes being found by regulatory inspectors during routine business and school inspections.  As you'll see, most of these mistakes relate to paperwork and record keeping--stuff that's relatively simple to correct.  So as the end of the year approaches, it might be a good time to use these  non-compliance lists as checklists to see where your team stands. Take the test and see if you pass:

Most Common Mistakes for Commercial Pest Control Businesses in 2014
Most Common IPM Rule Mistakes for School Districts in 2014
  • Are you creating and maintaining records showing approval of use of Yellow Category pesticides? (d)(6)(B)(ii)  (30% failure rate)
  • Do you maintain written guidelines defining action thresholds (a)(1)(f), at least for your key pest problems?  (24% failure rate)
  • Are you maintaining your IPM records for two years (b)(3)(B)(do you even have all your records?)? (16% failure rate)
  • Do you have a system for storing and retrieving all records (b)(3)(B) of facility inspection reports, pest-related service reports, pesticide applications and pesticide complaints?  (14% failure rate)
  • Do you keep training records for all employees approved for incidental use of pesticides?  (10% failure rate)
  • Would you be ready to provide all your IPM program records on the spot to an inspector if they were to request them? (b)(3)(B) (9% failure rate)
  • Are you creating and maintaining records showing approval of use of Red Category pesticides?  (d)(6)(C)(ii) (8% failure rate) 
  • Have you the IPM Coordinator provided the required training for any employee on the District making incidental use applications of pesticides?  (e.g., electricians carrying wasp spray for when they open electrical panels with a wasp nest inside) (8% failure rate)
  • Do you have a plan for educating your employees about their role in an IPM program? (a)(1)(E)  Note, this includes teachers, administrators and staff outside your pest control staff.  (8% failure rate)
  • Do you have a pest monitoring program in place? (a)(1)(B) Word to the wise: if you don't have properly-maintained sticky cards in your school kitchens you definitely do not have a monitoring program! (8% failure rate, and I'm surprised this isn't higher)
  • If you're a new IPM Coordinator, have you got proof of taking your 6 hour mandatory IPM Coordinator training?  BTW, we can help with that. (8% failure rate)
  • When any pesticides are applied outdoors, is your staff in the habit of posting pest control signs  (d)(2) at the time of application until the minimal reentry time?  (8% failure rate)