How fast can mosquitoes fly?
Depending upon the species, mosquitoes can fly at about 1 to 1.5 miles per hour.
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How far can mosquitoes fly?
Mosquito species preferring to breed around the house, like the Asian
Tiger Mosquito, have limited flight ranges of about 300 feet. Most
species have flight ranges of 1-3 miles. Certain large pool breeders in
the Midwest are often found up to 7 miles from known breeding spots.
The undisputed champions, though, are the saltmarsh breeders - having
been known to migrate up to 100 miles in exceptional circumstances,
although 20 to 40 miles are much more common when hosts are scarce.
When caught up in updrafts that direct them into winds high above the
ground, mosquitoes can be carried great distances.
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How much do they weigh?
Smaller species found around houses commonly weigh about 2.5
milligrams. Our largest species weigh in at a whopping 10 milligrams.
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How much blood does a mosquito take in a meal?
When feeding to repletion, mosquitoes imbibe anywhere from 0.001 to 0.01 milliliter.
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Why do mosquitoes feed on blood?
Female
mosquitoes imbibe blood so that their eggs can mature prior to laying.
It serves no nourishment function. Males do not take blood meals at
all. In order to obtain energy, both male and female mosquitoes feed
upon plant nectars - much in the same manner as honeybees.
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What good do mosquitoes do?
Mosquitoes fill a
variety of niches which nature provides. As such, placing a value on
their existence is generally inappropriate. Although the fossil record
is incomplete, they have been known from the Cretaceous Period (about
100 million years ago) in North America. Their adaptability has made
them extraordinarily successful, with upwards of 2,700 species
worldwide. Mosquitoes serve as food sources for a variety of organisms
but are not crucial to any predator species.
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How long do mosquitoes live?
Lifespan vary by
species. Most adult female mosquitoes live 2-3 weeks. Some species that
over-winter in garages, culverts and attics can live as long as 6
months.
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If mosquitoes were eradicated, how would this affect the ecosystem?
Given
that Nature abhors a vacuum, other species will fill the niches vacated
by the mosquitoes after an initial shuffling period of variable length.
Be advised, though, that species replacing mosquitoes may be even worse
- it's extremely difficult to predict. Mosquitoes' ability to adapt to
changing environments would make them all but impossible to eradicate.
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How high do mosquitoes fly?
In general,
mosquitoes that bite humans prefer to fly at heights of less than 25
ft. Asian Tiger Mosquitoes have been found breeding in treeholes over
40 feet above ground. In Singapore, they have been found in apartments
21 stories above ground. Mosquitoes have been found breeding up to
8,000 feet in the Himalayas and 2000 feet underground in mines in
India.
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Can mosquitoes transmit AIDS?
Many studies
have been conducted on this issue in the United States and abroad. To
my knowledge, there has never been a successful transfer of the virus
from an infected source to another host by bloodfeeding insects under
experimental conditions. The experts have concluded that the insects
are not capable of such transmission. Many biological reasons would
lead one to this same conclusion, but the extensive experimental
studies are the most powerful evidence for the conclusion.
- HIV DOES NOT replicate in mosquitoes. Thus, mosquitoes cannot be a biological vector as they are for malaria, yellow fever, or dengue. In fact, mosquitoes digest the virus that causes AIDS.
- There is no possibility of mechanical transmission (i.e., flying contaminated syringes); even though we all know that HIV can be transmitted by dirty needles. However, the amount of "blood" on a mosquitoes' mouth parts is tiny compared to what is found on a "dirty" needle. Thus, the risk is proportionally smaller. Calculations based on the mechanical transmission of anthrax and Rift Valley fever virus, both of which produce very high titers in blood, unlike HIV, showed that it would take about 10,000,000 mosquitoes that first fed on a person with AIDS and then continued feeding on a susceptible person to get 1 transmission.
- Mosquitoes are not flying hypodermic needles. Mosquitoes regurgitate saliva into the bite wound (the normal route for disease transmission) through a separate tube from that through which it imbibes blood.
Which mosquitoes transmit WNV?
At least 43 species of mosquitoes have been found infected with the
West Nile virus in the United States. Not all of these, however, are
capable of maintaining the virus in such a manner as to permit them to
transmit it among organisms. Many of these infected mosquitoes feed
only upon birds, thus contributing to a cycling of the virus among
avian populations. Other species feed upon these infective birds and
then will feed upon mammals, including humans. These are called "bridge
vectors" because they serve as a conduit for the virus to travel from
its reservoir in birds to its final host in humans or other mammals. In
urban settings, Culex pipiens is usually the primary vector. In rural
areas, particularly in the western part of the United States, Culex
tarsalis is the primary transmitter. As control measures for each of
these mosquitoes are considerably different, it's important to know
which is known to be in your area. Contact your local mosquito
abatement district or the Technical Advisor of the American Mosquito
Control Association (904-215-3008) for information regarding the
mosquitoes found in your area.
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Which state has the fewest mosquitoes?
West Virginia has the fewest species (26), while Texas has the most
species (85). A determination of absolute numbers of mosquitoes for
each state is extremely difficult, however, as mosquito populations
tend to be focal, depending upon amount of breeding habitat, potential
hosts and climatological factors - regardless of the number of species.
Thus, relatively dry places like Nevada, Arizona and New Mexico may
have intense mosquito activity in areas where water is present. Alaska
has a relatively short season, but biting activity during that time is
prodigious, indeed. Mosquitoes are particularly prolific in areas with
rice farming, extensive salt marsh or dredge spoil.
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What attracts mosquitoes to me?
Why some people seem to be more attractive than others to mosquitoes is
the subject of much repellent (and attractant for traps) research being
conducted nationwide. Carbon dioxide is the most universally recognized
mosquito attractant and draws mosquitoes from up to 35 meters. When
female mosquitoes sense carbon dioxide they usually adopt a zigzagging
flight path within the plume to locate its source. Once in the general
vicinity of a potential host, other cues predominate, including body
odors (sweat, lactic acid, etc.) and heat. Odors produced by skin
microflora also play a part in inducing the mosquito to land. Over 350
compounds have been isolated from odors produced by human skin. Either
singly or in combination, many of these compounds may be attractants -
and many may be repellents. As you can see, the situation is
complicated and will require many years of testing before it can be
sorted out. Visual stimuli, such as movement, also factor into
host-seeking. What can be safely stated, though, is that ingestion of
garlic, vitamin B12 and other systemics has been proven in controlled
laboratory studies to have no impact on mosquito biting. Conversely,
eating bananas did not attract mosquitoes as the myth suggests, but
wearing perfumes does. People drinking beer have been shown to be more
attractive to mosquitoes. Limburger cheese has also been found to be
attractive. Scientists have theorized that this may explain the
attractancy some mosquitoes find for human feet.
Which repellent works best?
N,N-diethyl-3-methylbenzamide (DEET) remains the standard by which
all other repellents are judged. DEET was developed by the U.S.
Department of Agriculture and was registered for use by the general
public in 1957. It is effective against mosquitoes, biting flies,
chiggers, fleas, and ticks. Over 25 years of empirical testing of more
than 20,000 other compounds has not resulted in another marketed
chemical product with the duration of protection and broad-spectrum
effectiveness of DEET although the recent additions of picaridin and
oil of lemon eucalyptus are remarkably close in effectiveness to DEET.
The American Academy of Pediatrics says that all family members over
the age of two months can use DEET-based repellents with up to 30%
concentration with confidence.
DEET-based repellents have been around for more than 50 years but that
hasn't kept the folks who make these products from innovating with new
fragrances, new formulations, new product types, and, best of all,
products that feel nice when applied. The DEET-based repellent
fragrances are pleasant to use and range from fruity to woodsy neutral
scents. Unscented products have a slight alcohol odor (there's
alcohol in the formulation) until they dry on the skin. Folks who
tend to be allergic to fragrances should try the unscented products.
Today's products start out at a concentration of 5% (lasts 90 minutes
or so) and range up to 100% (for approximately 10 hours of protection
from bites). Pick one that matches your activity. For an outdoor
family barbecue in the evenings, a 10% product is fine. It will help
protect from bites for approximately 90 minutes to two hours.
Products are available in aerosols, pump sprays, lotions, creams and
even towelettes. These are individually packaged and are also sold in
a handy plastic container that allows the towelettes to pop up one at
a time. There are water resistant and water repellent products. One
brand uses a microencapsulation process that helps the DEET release
over time after you have applied it. Another goes on dry from an
aerosol can, just as powder antiperspirants do.
For those who are in tick country, it's important to use a product
with at least a 20% concentration. Lower concentrations of all
EPA-registered repellents are not effective at warding off ticks.
Most apparent repellency failures with DEET are due to
misapplications, so care should be taken to apply it thoroughly
(avoiding the eyes and mucous membranes) and to reapply when
necessary. This is crucial to maintain the DEET vapor barrier above
the skin. New polymerized 30% DEET cream formulations provide
excellent protection not significantly exceeded by higher DEET
concentrations. Physicians recommend that a formulation of no more
than 10% DEET be used on children, but formulations of over 30% can be
used in areas of high disease incidence if label directions are
followed.
In April of 2005, the Centers for Disease Control and Prevention (CDC)
began recommending two new active ingredients as safe, effective
repellents.
The first of these is picaridin, a synthetic developed by Bayer
Corporation in the 1980s. This repellent is the most widely used
repellent in the world outside of the United States and is marketed as
Cutter Advanced. Picaridin is odorless, has a pleasant feel and doesn't
plasticize like DEET. Studies have shown it to be as fully repellent
to mosquitoes as DEET and can also be applied on infants as young as 2
months. The 15% picaridin formulation, Cutter Advanced Sport, is also
an effective repellent for ticks.
The other repellent, often the choice of those wanting a natural
product, is oil of lemon-eucalyptus, sold as Repel®. Repel is a 40%
formulation of naturally-derived eucalyptus and has a pleasant scent
and feel without any plasticizing properties. It is also effective at
repelling ticks.
How do mosquitoes get into my house?
Mosquitoes are singularly adept at entering houses through any portal
available, be it through broken window or door screens, attic soffits
or through bathroom exhaust vents. A favorite resting spot is the
garage, so take care to keep resting female mosquitoes from coming into
the house through the garage.
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What can homeowners do to reduce mosquito bites?
If possible, schedule your activities to avoid the times when
mosquitoes are most active - usually dawn and dusk. You should also
dress in light, loose-fitting clothing. If you have a deck, light it
using General Electric yellow "Bug Lights". These lights are not
repellant, per se, but do not attract mosquitoes like other
incandescent lights. Mosquitoes are relatively weak fliers, so placing
a large fan on your deck can provide a low-tech solution. Citronella
candles have a mild repellent effect, but do not offer significantly
more protection than other candles producing smoke.
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Are backyard misting systems effective?
Scheduled sprays used by these misters may needlessly broadcast
pesticides into the environment, affecting mosquitoes and non-target
insects alike. Modern mosquito control strategies emphasize an
integrated approach, based upon a profound knowledge of the target, so
that's its various vulnerabilities can be exploited by the many tools
we've developed for that purpose. Effective mosquito control requires
continual survey of adult mosquito densities to determine if certain
triggers for control are met. This reduces the use of adulticides to
only those times when they are required.
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Do Bug-Zappers Work?
Black light insect electrocution devices (Bug Zappers, etc.) are
purchased in huge quantities by homeowners due to their demonstrated
ability to attract and kill thousands of insects over a 24 hr. period.
One industry representative estimates that over 1.75 million of these
devices are purchased annually in the U.S. But do they really control
pest insects? Bug zappers do indeed kill some mosquitoes. However, the
only two controlled studies conducted to date by independent
investigators at the University of Notre Dame showed that mosquitoes
comprised merely 4.1% and 6.4% respectively of the daily catch over an
entire season. Even more important was the finding in both studies that
there was no significant difference in the number of mosquitoes found
in yards with or without bug zappers. What is particularly
disconcerting, however, is the number of non-pest insects that comprise
the vast majority of trap catch. Many of these insects are beneficial
predators on other insect pests. They in turn constitute a major part
of the diet of many songbirds. Indeed, reduced numbers of moth and
beetle prey species have contributed significantly to the decline of
songbird populations in many affluent suburbs. Insect electrocution
devices undoubtedly bear some responsibility for this phenomenon.
Mosquitoes continue to be more attracted to humans than to the devices.
One study conducted in homeowners' backyards showed that of the insects
killed by these devices, only 0.13% were female mosquitoes. An
estimated 71 billion to 350 billion beneficial insects may be killed
annually in the United States by these electrocuting devices.
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Do Ultrasonic devices work?
At least 10 studies in the past 15 years have unanimously denounced
ultrasonic devices as having no repellency value whatsoever. Yet,
consumers flock in droves to hardware stores to purchase these
contraptions. Why? The discovery that mosquitoes locate mates in mating
swarms via wing beat frequency generated a great deal of research into
ultrasound as a potential source of environmentally-friendly control.
Yet, all attempts to affect mosquito behavior by ultrasound have
fizzled, despite enormous amounts of money spent upon research and
development. To be sure, the clever, high-tech, and imperceptible (by
humans) use of ultrasound proved to be an exceedingly effective
marketing tool for the repeller manufacturers. Homeowners were urged to
buy ultrasonic repellers and the like to rid their houses of pests
without the need to inhale "even one breath of poisonous spray". This
appeal to the public's chemophobia, while extremely effective in
diverting attention away from proven preventive and control measures
(and toward their repeller products), has undermined an unbiased review
of the subject by consumers desperate for a clean, effective,
nonchemical means of mosquito control. Unfortunately, no such miracle
cure exists. A pioneering study testing five different ultrasonic
devices against four mosquito species convincingly demonstrated that
ultrasound in the 20-70 kHz range used by these devices had no effect
on reorienting flight by female mosquitoes either toward or away from
human subjects. Additional tests have shown that sound generators
capable of a wide range of frequencies were also ineffective in
repelling mosquitoes. The fact is that these devices just do not work -
marketing claims to the contrary.
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Do mosquito traps work?
An enormous amount of
consumer interest has been generated by the marketing of new devices
designed to attract, then either trap or kill, mosquitoes. The general
idea is to reduce the number of questing mosquitoes that would
otherwise be afflicting the homeowner. Many products even claim to
significantly reduce or even collapse local mosquito populations by
decreasing the number of egg-laying females through their capture. All
of these traps utilize some form of attractant that lures the
host-seeking female mosquitoes to a capture or killing device. In some
cases, mosquitoes are captured via an impellor fan that suctions them
into a net, where they desiccate while other trapping systems use a
sticky surface to which the mosquitoes adhere when they land. Still
others utilize an electric grid to electrocute mosquitoes drawn into
contact.
These are not set-and-forget devices. Each requires some level of
maintenance, i.e. propane tanks need replacement, capture nets need
emptying, adhesive boards require replacement and grids require
cleaning to ensure their continued effectiveness, particularly in areas
of high catch. The process of a mosquito questing for a blood meal
involves a complex, interconnected cascade of behaviors, each probably
having its own cues, be they visual, thermal, or olfactory. The
complexity of these questing behaviors may account for the bewildering
variations in trapping efficiency noted for certain species of
mosquitoes at different times, seasons and places. With 174 species of
mosquitoes currently recognized in the United States, this is no small
issue and will require many years before research can provide a
clarification. There is some anecdotal evidence that these baited
traps, indeed, capture more females of some species than others,
depending, to some extent, on the concentration of carbon dioxide
emitted and the mosquito species present. There may also be seasonal
and circadian variables that affect mosquito responses to certain
attractants. Nonetheless, these devices will trap and kill measurable
numbers of mosquitoes. Whether this will produce a noticeable reduction
in the mosquito population in each case will depend upon a number of
factors, e.g. individual tolerance level, absolute mosquito population
size, proximity, size and type of breeding habitat producing
re-infestation, wind velocity and direction, and species of mosquito
present, and others. Thus, the homeowner must still use repellents and
practice source reduction methods as adjuncts to realize any measure of
relief.
Please be cautioned against putting too much faith in traps as your
sole means of control. These traps represent an evolving technology
that is a most welcome addition to our mosquito control armamentarium.
Their potential is great, but shouldn't be overestimated. It's highly
unlikely that these devices, whatever their improvements, will ever
fully supplant organized community-wide mosquito control programs, for
there is no single silver bullet that will prove to be the ultimate
answer to mosquito problems.
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Do bats serve as an effective mosquito control?
Recently the public has shown increased interest in the value of
insectivorous species of bats in controlling mosquitoes. Although
untested lately, this is not a new idea. During the 1920's several bat
towers were constructed near San Antonio, Texas, in order to help
control malarial mosquitoes. Mosquito populations were not affected and
the project was discontinued. Bats in temperate areas of the world are
almost exclusively insectivorous. Food items identified in their diet
are primarily beetles, wasps, and moths. Mosquitoes have comprised less
than 1% of gut contents of wild caught bats in all studies to date.
Bats tend to be opportunistic feeders. They do not appear to specialize
on particular types of insects, but will feed on whatever food source
presents itself. Large, concentrated populations of mosquitoes could
provide adequate nutrition in the absence of alternative food. However,
a moth provides much more nutritional value per capture than a
mosquito. M.D. Tuttle, a world authority on bats, is often quoted for
his anecdotal report that bats effectively controlled mosquito
populations at a popular resort in New York State. While there is no
doubt that bats have probably played a visible, if not prominent, role
in reducing the mosquito problems in many areas, the natural abatement
of mosquito populations is an extremely complex process to study,
comprising poorly known ecological relationships. Tuttle attempts to
underscore the bats role by citing an experiment in which bats released
into a laboratory room filled with mosquitoes caught up to 10
mosquitoes per minute. He extrapolated this value to 600 mosquitoes per
hour. Thus, a colony of 500 bats could consume over a quarter of a
million mosquitoes per hour. Impressive numbers indeed, but singularly
unrealistic when based upon a study where bats were confined in a room
with mosquitoes as their only food source. There is no question that
bats eat mosquitoes, but to utilize them as the sole measure of control
would be folly indeed, particularly considering the capacity of both
mosquitoes and bats to transmit diseases.
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Do Purple Martins help reduce mosquitoes?
It has been known for many years that bird species like purple martins
consume large numbers of flying insects. Proponents of their use in
mosquito control are quick to cite J. L. Wade, an amateur
ornithologist, who reasoned that an average 4 oz. adult purple martin,
due to its rapid metabolism, would have to consume its body weight
(14,000 mosquitoes) per day in order to survive. Wade recognized that
the purple martins diet includes many other types of insects, but this
appears to have been lost on many individuals searching for a natural
means of control. In fact, during daylight, purple martins often feed
voraciously upon dragonflies, known predators of mosquitoes. At night,
when mosquitoes are most active, purple martins tend to feed at treetop
level, well above most mosquito flight paths. Ornithologist James Hill,
founder of the Purple Martin Conservation Association (PMCA), writes,
"The number of mosquitoes that martins eat is extremely insignificant,
and they certainly don't control them. In-depth studies have shown that
mosquitoes comprise no more than 0 to 3 percent of the diet of
martins". They eat only flying insects, which they catch in flight.
Their diet is diverse, including dragonflies, damselflies, flies,
midges, mayflies, stinkbugs, leafhoppers, Japanese beetles, June bugs,
butterflies, moths, grasshoppers, cicadas, bees, wasps, flying ants,
and ballooning spiders. Martins are not, however, prodigious consumers
of mosquitoes as is so often claimed by companies that manufacture
martin housing. An intensive 3-year diet study conducted at PMCA
headquarters in Edinboro, PA, failed to find a single mosquito among
the 350 diet samples collected from parent martins bringing beakfuls of
insects to their young. The samples were collected from martins during
all hours of the day, all season long, and in numerous habitats,
including mosquito-infested ones. Purple Martins and freshwater
mosquitoes rarely ever cross paths. Martins are daytime feeders, and
feed high in the sky; mosquitoes, on the other hand, stay low in damp
places during daylight hours, or only come out at night. Since Purple
Martins feed only on flying insects, they are extremely vulnerable to
starvation during extended periods of cool and/or rainy weather. Rather
than erecting martin houses to specifically attract insect-eating birds
for mosquito control, we should at least promote them for their
aesthetic and educational value.
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How do mosquito control districts control mosquitoes?
The
integrated mosquito management methods currently employed by organized
control districts and endorsed by the CDC and EPA are comprehensive and
specifically tailored to safely counter each stage of the mosquito life
cycle. Larval control through water management and source reduction,
where compatible with other land management uses, is a prudent pest
management alternative - as is use of the environmentally friendly
EPA-approved larvicides currently available. When source elimination or
larval control measures are clearly inadequate, or in the case of
imminent disease, the EPA and CDC have emphasized in a published joint
statement the need for considered application of adulticides by
certified applicators trained in the special handling characteristics
of these products.
A successful mosquito management program should include the following elements:
- larval and adult mosquito sampling;
- source reduction;
- biological control using native or introduced predators and parasites of mosquitoes,
- larviciding and adulticiding, when indicated by surveillance;
- resistance monitoring;
- disease surveillance in mosquitoes, birds, horses and humans, and
- public education.
Are pesticides used in mosquito control safe?
Since
its inception, the Environmental Protection Agency (EPA) has regulated
mosquito control through enforcement of standards instituted by the
Federal Insecticide, Fungicide, and Rodenticide Act. This legislation
mandated documentation of extensive testing for public health
insecticides according to EPA guidelines prior to their registration
and use. These data requirements are among the most stringent in the
federal government and are met through research by established
scientists in federal, state and private institutions. This process
costs a registrant several million dollars per product, but ensures
that the public health insecticides available for mosquito control do
not represent health or environmental risks when used as directed.
Indeed, the five or six adulticides currently available are the
selected survivors of literally hundreds of products developed for
these uses over the years. The dosages at which these products are
legally dispensed are at least 100-fold less than the point at which
public health and environmental safety merit consideration. In point of
fact, literature posted on the websites of the EPA Office of Pesticide
Programs, Centers for Disease Control and Prevention (CDC), American
Association of Pesticide Safety Educators and National Pesticide
Information Center emphasizes that proper use of mosquitocides by
established mosquito control agencies does not put the general public
or the environment at unreasonable risk from runoff, leaching or drift
when used according to label specifications. (For the federal
government's position on risks associated with mosquito control
insecticides, visit http:/www.epa.gov/pesticides).
The safety profiles of public health insecticides are undergoing
increasing scrutiny because of concerns with how the specialized
application technology and product selection protect the exposed public
and environment. In fact, well over 200 peer-reviewed scientific
studies in various national and international refereed journals since
1980 have documented the safety and efficacy of these public health
insecticides at label rates in addition to their application
techniques.
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How do mosquito districts avoid spraying chemically-sensitive persons?
Organized
mosquito control agencies often go to extraordinary lengths to
accommodate individuals who, for varying reasons, prefer their property
not be sprayed with approved public health insecticides. When surveys
indicate the need for adult sprays, they are approved, planned and
conducted with special regard to the concerns of chemically sensitive
persons. Personal notification of chemically-sensitive individuals of
spray times in addition to using Global Positioning Systems
(GPS)/Global Information Systems (GIS) technology to reduce the
likelihood of drift over unauthorized areas are but a few of the means
utilized to ensure mosquito control serves the entire public spectrum.
Should you desire that your property not be sprayed, please notify your
local district.
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The extremely small droplet aerosols utilized in adult mosquito control are designed to impact primarily on adult mosquitoes that are on the wing at the time of the application. Degradation of these small droplets is rapid, leaving little or no residue in the target area at ground level. These special considerations are major factors that favor the use of very low application rates for these products, generally less then 4 grams active ingredient per acre, and are instrumental in minimizing adverse impacts.
