Written by
Dawn H. Gouge, Assistant Specialist, Entomology
Carl Olson, Associate Curator, Insects
Kirk A. Smith,Assistant Research Scientist
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Introduction
Mosquitoes, biting flies, chiggers and ticks can be
annoying and sometimes pose a serious risk to public health. In certain
areas of the United States, mosquitoes can transmit diseases like
equine and St. Louis encephalitis. More recently transmission of West
Nile Virus has become a major concern. Biting flies can inflict a
painful bite that can persist for days, swell, and become infected.
Ticks can transmit serious diseases like Lyme disease (the north western
corner of Arizona is classed as a low risk area, it is only in this
part of Arizona that the vector exists at all) and Rocky Mountain
spotted fever. When properly used, arthropod (insects, ticks, mites,
etc.) repellents can discourage biting arthropods from landing on
treated skin or clothing.
Choosing Insect Repellents
Insect repellents are available in various forms and
concentrations. Aerosol and pump-spray products are intended for skin
applications as well as for treating clothing. Liquid, cream, lotion,
spray, and stick products enable direct skin application. Products
with a low concentration of active ingredient may be appropriate for
situations where exposure to insects is minimal. Higher concentration
of active ingredient may be useful in highly infested areas or with
insect species which are more difficult to repel. Where appropriate,
consider non-chemical ways to deter biting insects — window
and door screens, bed netting, long sleeves, and long pants.
Browndogtick
Tabanus
Using Insect
Repellents Safely
The Environmental Protection Agency (EPA) recommends
the following precautions when using insect repellents:
- Apply repellents only to exposed skin and/or clothing (as directed
on the product label). Do not use under clothing.
- Never use repellents over cuts, wounds, or irritated skin.
- Do not apply to eyes and mouth, and apply sparingly around ears.
When using sprays do not spray directly onto face; spray on hands
first and then apply to face.
- Do not allow children to handle the products, and do not apply
to children’s hands. When using on children, apply to your
own hands and then put it on the child.
- Do not spray in enclosed areas. Avoid breathing a repellent
spray, and do not use it near food.
- Use just enough repellent to cover exposed skin and/or clothing.
Heavy application and saturation is generally unnecessary for
effectiveness; if biting insects do not respond to a thin film
of repellent, then apply a bit more.
- After returning indoors, wash treated skin with soap and water
or bathe. This is particularly important when repellents are used
repeatedly in a day or on consecutive days. Also, wash treated
clothing before wearing it again. If you suspect that you or your
child are reacting to an insect repellent, discontinue use, wash
treated skin, and then call your local poison control center if
symptoms persist. If you go to a doctor, take the repellent with
you. Reactions to repellents usually take the form of burning
or irritated skin where the repellent has been applied.
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Get specific medical information about the active
ingredients in repellents and other pesticides by calling the
National Pesticide Information Center (NPIC) at 1-800-858-7378.
NPIC operates from 6:30 a.m. to 4:30 p.m. (Pacific Time), 9:30
a.m. to 7:30 p.m. (Eastern Time), 7 days a week. The NPIC Web
site is: http://npic.orst.edu/
Important
Information on Using Repellents
EPA recommends the following precautions when using
an insect repellent:
- Check the container to ensure that the product bears an EPA-approved
label and registration number. Never use a product that has not
been approved for use by EPA!
- Read the entire label before using a pesticide. Even if you
have used it before, read the label again - don’t trust
your memory.
- Follow use directions carefully, use only the amount directed,
at the time and under the conditions specified, and for the purpose
listed. For example, if you need a tick repellent, make sure that
the product label lists this use. If ticks are not listed, the
product may not be formulated for that use.
- Store repellants away from children’s reach, in a locked
utility cabinet.
Types of Repellents
DEET
DEET (chemical name, N,N-diethyl-meta-toluamide)
is the active ingredient in many insect repellent products. DEET’s
most significant benefit is its ability to repel potentially disease-carrying
insects and ticks. Products containing DEET currently are available
to the public in a variety of liquids, lotions, sprays, and impregnated
materials (e.g., wrist bands). Formulations registered for direct
application to human skin contain from 4 to 100% DEET. DEET is designed
for direct application to human skin to repel insects, rather than
kill them. After it was developed by the U.S. Army in 1946, DEET was
registered for use by the general public in 1957. Approximately 230
products containing DEET are currently registered with EPA by about
70 different companies. Skin sensitivity to DEET can develop after
repeated use. EPA is no longer allowing child safety claims on product
labels. These claims currently appear on certain products containing
a DEET concentration of 15% or less. Use lower levels (<6%) of
DEET on children and apply to clothing not onto skin. Do not use DEET
on infants or if you are pregnant.
Amount |
DEET Approx. Hours of Protection |
30% |
6.5 |
15% |
5 |
10% |
3 |
5% |
2 |
| Off
Deep Woods
(SC Johnson)
23.8% DEET
301.5 minutes of protection time
Off Skintastic for Kids
(SC Johnson)
4.75% DEET
88.4 minutes of protection time |
IR3535-based repellent
A chemical repellent that has been used in Europe for
over 20 years, IR3535 was approved for use in the United States in
1999.
Skin So Soft Bug Guard
(Avon) IR3535
22.9 minutes protection time |
BOTANICALS
It is recommended that personal insect repellents
such as citronella and oil of lavender not be used on children under
2 years of age.
Registered citronella oil repellents protect people
against mosquito bites for less than one hour. The registered lavender
oil repellent protects for half an hour or less.
The citronella-based repellents tested protected
for 20 minutes or less. Slow release products do not provide significant
added benefit.
Based on animal studies, citronella-based products
appear to be potential dermal sensitizers. Therefore, allergic reactions
may occur in some individuals .
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Products containing eucalyptus oil were the
most effective herbal repellents tested and lasted as long as low
concentrations of DEET!!
Repel Lemon Eucalyptus Insect Repellent
(WPC Brands)
120.1 minutes protection time
Fite Bite Plant-Based Insect Repellent
(Travel Medicine)
120.1 minutes protection time |
-
Bite Blocker for Kids
(HOMS)
soybean oil
94.6 minutes protection time |
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Skin-So-Soft Bath
Oil
(Avon)
9.6 minutes of protection |
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As a treatment for clothing only.
Use by itself or with skin applied repellents. Permethrin is a contact
insecticide. That is, it kills ticks or other insects when it comes
in contact with them. It is used on clothing and materials only.
It uses the same active ingredient used in hair shampoos for head
lice. Skin contact should be avoided and deactivates Permethrin
within fifteen minutes. As a clothing, tent or sleeping bag application,
Permethrin is very effective at keeping ticks from attaching to
you and at reducing mosquito bites. Permethrin is an effective repellent
against mosquitoes and flies and can be used in conjunction with
a skin based repellent. Spray applications of Permethrin can remain
effective up to 14 days of exposure to light or oxygen, or through
two aggressive washings. By storing the treated clothing in black
plastic bags between uses the fourteen days of protection can be
extended considerably. If necessary a heavier application can remain
effective even longer. Bed nets can be treated with permethrin.
Reference
Product data has been taken from:
Fradin MF, Day JF. Comparative efficacy of insect
repellents against mosquito bites. New England Journal of Medicine.
2002. 4;347(1):13-8.
Triatoma protracta dorsal
Triatoma protracta ventral
Triatoma recurua dorsal
Triatoma recurua dorsal
Triatoma rubida dorsal
Triatoma rubida ventral
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review by a Washington, D.C.-based team. The reviewers suggested
that CALS use the same equal opportunity/affirmative action statement
(or indicia) as the University. Therefore, as of October 1, 2002,
the new statement reads: “The University of Arizona is an
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Shirley O’Brien, CALS Affirmative Action Officer (621-7145).
Issued in furtherance of Cooperative
Extension work, acts of May 8 and June 30, 1914, in cooperation
with the U.S. Department of Agriculture, James A. Christenson, Director,
Cooperative Extension, College of Agriculture & Life Sciences,
The University of Arizona.
The University of Arizona is an equal opportunity, affirmative action
institution. The University does not discriminate on the basis of
race, color, religion, sex, national origin, age, disability, veteran
status, or sexual orientation in its programs and activities.
The University of Arizona is an Equal
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Document located
http://cal.arizona.edu/pubs/insects/az1223/
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