By Lisa Lupo, Pest Control Technology, July
2006
It’s a fact that fleas are reemerging across
most of the U.S., but it’s pure speculation as to why this
is happening.
Ten to 15 years ago, fleas were a significant piece
of business for most residential pest control companies.
Then in the 1990s on-pet application with actives such as fipronil,
imidacloprid and the IGR methoprene, were introduced, due in part
to the research of Dr. Michael Dryden, professor of veterinary parasitology
at Kansas State University (KSU). Dryden and others found that dog-
and cat-infesting fleas cannot survive apart from their host and
need constant host relationship for reproduction. The breakthrough,
says Dryden’s KSU website, led to the development of topical
and systemic flea treatments “which can be applied directly
to the pet without having to treat its environment.”
As a result, the slice of the service pie allocated
to the pest management industry steadily shriveled to virtually
nothing. It stayed that way for years, with companies getting calls
now and again for fleas, but veterinarians and their on-pet products
taking over the bulk of the business. Gradually pest management
companies quit training on flea treatments; flea products disappeared
from inventory; and a generation of service technicians was raised
with no flea service experience.
Even the Ninth edition of the Mallis Handbook of
Pest Control, a virtual bible for PSOs, stated, “In the last
decade, flea control products killing virtually 100% of on-host
populations have been developed…Using these host-targeted
products has minimized the necessity for environmental treatments,
switching flea control out of the professional pest management market.”
During the last few years; however, these revolutionary
on-pet products seem to be losing control of the fleas. The industry
is once again getting calls, buyers are scrambling to research and
stock product, and technical directors are rewriting training programs.
The amount of resurgence, however appears to vary by area:
Florida. “We’ve seen
an increase in fleas population; we’ve also had increasing
difficulty in controlling them,” says Ron Box, director of
education and scientific affairs for Hulett Environmental Services,
which has 10 Florida offices.
Minnesota. Though the season starts
a bit later, Jay Bruesch, technical director of Fridley, Minn.-based
Plunkett’s Pest Control, says they have been seeing more fleas
in recent years, “not…this spring, but late last summer
things were really hopping.”
Illinois. McCloud Services, Hoffman
Estate, Ill., is primarily a commercial service company, but in
both the apartment buildings and residences they service, they are
experiencing increases in calls, says McCloud Technical Director
Pat Hottel.
Flea service requests seem to be picking up again
for Peter Schopen, president, Schopen’s Pest Control, McHenry,
Ill. “Fifteen to eighteen years ago, I remember that I used
to do three or four flea jobs a week,” he says. “Now
I do maybe only ten over the whole summer; although in the last
couple years, it seem that it’s a little on the rise.”
John Forbes, who is now a sales representative
for Univar in Illinois, previously worked as a pest control technician.
“We were doing flea jobs several times a week,” he says,
then the spot-on products came along. “When that happened,
the flea market dropped probably 75 percent.” But two years
ago, he says, the market began to revive.
Texas. Bart Foster, technical
director of Bill Clark Pest Control, Beaumont, Texas, says calls
have been fairly steady the past three years. “We are getting
calls,” he says. “It’s a pretty constant challenge
for us.” A challenge, which that very morning had been the
subject of a training meeting and for which the company is still
seeking an effective product.
California. The story is a bit
different on the West Coast, where some companies are reporting
no increase in flea calls at all. Keith Willingham, technical director
of Anaheim, Calif.-based Western Exterminator, reports that Western
actually had fewer flea jobs in 2005 than it did in 2004, and its
calls continue to be low this year. Scott Crowley, technical director
of Lloyd Pest Control, San Diego, concurs, stating that the few
calls they receive are typically from pet owners who are not familiar
with available products or are having problems with wild animals.
Why the resurgence in most states? We spoke with
more than a dozen industry specialists, including researchers, manufacturer
reps, technical directors and PSOs, asking for their thoughts and
speculation on what might be the reason. The most common
answer: “I just don’t know.” But once assured
that the speculation would be positioned as just that, as a guess
as to what may be happening – They gave it more thought
and provided some fairly consistent theories.
 RESISTANCE.
By far, product resistance was the most frequently proposed theory,
with the researchers tending most toward this view. “We always
think of insect resistance,” says Dr. Nancy Hinkle, entomologist
at the University of Georgia and author of the Mallis flea
chapter. “We’re never surprised, when an insecticide
is used intensively and extensively, to see insect’s resistance.”
The “general chatter” in the research
community is that it is resistance, agrees Dr. Gary Bennett, professor
at Purdue University. All the on-animal products came out at about
the same time, he explains, and flea control shifted from the pest
management industry to the veterinarian. As a result, “I think
we’re starting to see resistance, “he says. “I
wouldn’t be surprised because most of the components being
used are reaching the points in their lifetimes that you see resistance
cropping up.”
“The suspicion is that there may be some
kind of resistance,” Forbes agrees, adding that manufacturers
are working on some product formulation changes. “They are
still being used, but I think the problem is that they sold so much
and used so much that fleas started developing a resistance.”
The lesser problem in California could even be a result of the state’s
strict regulations and aversion to pesticides in general, Forbes
speculates as a “best guess.” As eco-friendly as the
state is, the on-animal products may have been used less heavily,
with California retaining instead a stronger emphasis on an integrated
pest management approach to flea control.
Bruesch says that during the last few years, “I
heard predictions that we were going to start seeing flea control
work again because fipronil would start seeing failures.”
The increased work for the pest management industry would be, he
says, “due to an expected development of resistance to the
products being used by veterinarians.”
However, there are those who disagree with resistance
as a cause. In a 2004 presentation at the Western Veterinary Conference,
Dryden stated, “While insecticide resistance may cause organophosphate-
and pyrethroid-based flea products to fail, no one knows the extent
of insecticide resistance to fipronil, imidacloprid, lufenuron,
methoprene, pyriproxyfen, or selamectin in cat flea populations.
Even today, if a product containing fipronil, imidacloprid, lufenuron,
methoprene, pyriproxyfen, or selamectin fails, some veterinarians
cite resistance as the cause. But in my experience, true product
failures are rare, and most problems stem from poor compliance,
application or administration errors, and a lack of understanding
of important biologic and epidemiologic parameters in the flea life
cycle.” Dryden’s research has been recognized for its
significance in modern veterinary dermatology.
Jeff Smith, Univar’s e-business content manager
who coordinates pestweb.com and deals with PCOs across the nation,
says he has not had a huge surge of question on fleas, but he has
noticed a gradual reemergence of the pest. He has not really thought
much about why, he says, but “I am loathe to say, ‘there
must be some resistance.’ That’s an easy cop out.”
WILDLIFE. With excessive growth
and expansion common to cities across the U.S., our wildlife is
being increasingly pushed from its established habitat – evidenced
in many areas by the increasing number of animals lying dead on
roadsides. Are some of these animals resisting the push, or even
moving further in to seek home, and bringing with them parasites
– such as the resurging flea?
Box, for one, has seen an increase in feral and
nuisance animals in Florida. “We’re always constantly
destroying their normal areas of habitation,” he says.
Hinkle cites a study by Dryden showing that raccoons,
opossums and such feral animals in urban areas support more fleas
than those in rural areas. The animals are attracted by the cities’
safe living conditions as well as accessibility of food, such as
particles found in open dumpsters or pet bowls left outside, which
results in more wildlife per area in the city than in rural areas.
Thus, she says, “they have increased opportunity to interact
with one another and share their fleas,’” and to interact
– and share fleas – with house pets as well.
This interaction is, according to Dryden’s
KSU biography, an area of cooperative research. “As a result
of continual urbanization, displaced wildlife often finds refuge
and seeks food in suburban areas. Interactions with some of the
most common species of urban wildlife, such as raccoons, skunks
or opossums may pose serious health risks to humans and their pets.”
LACK OF AN INTEGRATED APPROACH.
The industry has seen it with both cockroaches and bed bugs: The
efficacy of cockroach bait brought with it an over-reliance on that
product to the neglect of integrated management, and the industry’s
departure from baseboard treatments is suspected as enabling bed
bugs to regain a hold in hotels and residences. Has the homeowner’s
concentration on on-pet applications and neglect of integrated treatment
enabled fleas to rebuild their populations?
In PCT’s November 2005 article “Back
to the Future,” Medical Entomologist Jerome Goddard, of the
Mississippi Department of Health in Jackson, was cited as noting
the reemergence of fleas. At that point he stated that the cause
was uncertain, but theorized that it could be products not working
as well as they used to, pet owners using over-the-counter products
and making inadequate applications, fleas becoming resistant, or
owners not taking an integrated approach. Today, Goddard affirms,
the cause is still uncertain. It may be possible that there is some
resistance developing, but there is no evidence of this, he says,
adding that, rather than speculating on causes, “I’d
stick to the facts. Flea problems are getting worse again,”
he says. He advises technicians: “Pay attention to what you’re
doing and do it right. Don’t get sloppy. Don’t depend
on veterinarian products to take care of it.”
While the on-animal products were revolutionary,
they are not the whole answer. “I think we saw that a little
bit with baits for cockroaches. People think, ‘That takes
care of it so I don’t have to do anything,’ “he
says, “but the basics of pest control have not changed.”
An integrated approach including sanitation and physical measures
is needed. “You have to still do those things.”
INADEQUATE APPLICATION. Perhaps the homeowner is
getting lax, a few experts speculated. They haven’t seen flea
problems in a while and, as a result, have become less diligent
with their applications or veterinarian visits. Pet owners may not
be bothering to apply flea products at all or neglecting to reapply
the product at regular intervals, and with even a few of the pet-owning
experts of this article admitting to slipping in this area, this
could be an implicator for the fleas’ comeback.
As with most pesticides, there are definite limits
to the efficacy of flea products. “You have to reapply it
every month on an animal,” says Michael Chapman, technical
service and field development representative, Bayer Environmental
Science, Placentia, Calif. “That’s a limitation of the
product. There’s a constant potential for re-infestation.”
DIMINISHING EXPERTISE. With fleas
in virtual remission for more than a decade, there is an entire
generation of pest control technicians who have never dealt with
the pest, and a host of others who have not conducted the treatment
in so long that the finer points have been relegated to some far
corner of the mind - if retained at all.
“When I was a technician, that was my route,
doing flea work,” Chapman says. “Then the on-animal
stuff came along and that market really dropped off to almost nothing.
You still had calls, but it wasn’t like it used to be.”
As a result, he adds, technicians are no longer getting trained
in flea control, they’re not aware of flea biology, they’re
not communicating with the customer to find out where the pet travels
and spends its time, they’re not integrating adulticides and
insect growth regulators, so they’re ending up with hit-and-miss
service, which doesn’t result in effective control.
“A lot of new people have come along who
have not had to do many flea jobs,” Hinkle says. And the fact
that the newer technicians have not been trained in flea work could
be a reason we are seeing an increase in populations. “We
need to go back to what we were doing 15-20 years ago,” she
says. Technicians need to understand the pest biology and life-cycle
as well as its relationship with its host and how to effectively
target the flea.
“It’s really more re-educating them
on the flea biology,” Chapman says. “We have some good
products to target that as long as you know the biology.”
Thus, it’s not just the homeowner who may
have become lax in treatment or even an understanding of fleas and
proper control methods. Forbes provides an example of a visit he
made to a dog track with a customer. “The fleas out there
were beyond belief,” he says. The primary reason was that
the dogs were being kept in a sandpit next to the track. “Fleas
and sand go hand in hand,” and with the greyhound’s
thin skin and low body fat, they were suffering. The track did have
a pest control service, but it was obvious that a great deal more
product was being used than should have been, Forbes said. Though
it is a singular incident by an individual PCO, the situation does
provide a concrete example of the need for training, not only on
service practices but on flea biology as well.
Unfortunately, though, it is a training that many
companies gradually eliminated over the last decade because of the
lack of need. As flea calls now become more and more numerous, management
is dusting off old programs, taking a look at updated techniques
and products and reintegrating fleas into training programs while
working on-on-one with newer technicians who are getting calls that
they’d never had to deal with in the past.
“We took flea training out, literally because
there were no fleas to control,” Bruesch says of Plunkett’s
training. Now the company is rewriting its SOP (Standard Operating
Procedures) on fleas.
OTHER THEORIES. Here are some
other theories behind the flea resurgence from various experts contacted
by PCT.
Weather. Until recently, it had
been extremely dry in Florida, Box says, a condition that helps
promote the growth of fleas.
Subterranean Crawlspaces. Perhaps
it is because of the increased in-city wildlife, but Hulett now
makes treatment of subterranean crawl spaces mandatory for any flea
job. This has become an essential step to gaining control, Box says.
Placebo Effect. Smith wonders
if homeowners who used the on-animal applications actually overlooked
the fact that they still had fleas. He cites a study in which ultrasonic
flea collars were used on pets. Although ultrasonics have been proven
to have no effect on fleas, pet owners in the study swore that the
fleas were eliminated. “Maybe it was a placebo effect {with
the application}, and reality is just catching up.”
BEYOND THE ‘WHY’.
With all the suppositions, thoughts and theories on Why?, the fact
remains that fleas are back and, once again, are a pest that technicians
are being asked to understand and control. Though many companies
are having to dust off and re-introduce their flea training manuals,
the positive aspect is that they are able to do just that with very
little change. The steps for control are essentially the same as
they were 15 years ago. And most experts expect the reemergence
to continue. “I think we will continue to see these pests
as a problem,” Hinkle says. “We never completely eliminate
anything. There’s always a reservoir.”
The best part about the flea reemergence is most
consider it a boon for the industry. Bruesch agrees that “there
has to have been a whole reservoir of fleas” to have spurred
the resurgence, and he expects it to continue and increase, adding,
“I’m glad about it actually. Fleas were one pest that
if you knew you did a good job, and covered all your bases, you
could always get control.”
Smith concurs, adding that he hopes fleas continue
to increase. “We didn’t cause it,” he points out,
but it certainly is good for the industry. “Fleas are my favorite
pest!”
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