1. Outdoors in the Time of Zika: Nuisance Mosquito Management
July 2016
Kirsten Buhls, Extension Agent VCE Arlington County
Ingrid Werber and Kasha Helget Arlington Regional Master Naturalists

2. Living with mosquitoes without fear .
Why are we doing this?
Living with mosquitoes without fear .

3. Why is this Important? Dispel fear….
Protect pollinators, native, and beneficial insects
Understand risks and benefits of mosquito control
Respect ecological niche of all living organisms
Educate about the indiscriminate use of non-selective pesticides
Avoid false sense of security provided by pesticide usage
Educate need for personal protection tactics
Quality of Life: Enjoy the outdoors!

4. Mosquito Facts Worldwide: over 3,000 species
Virginia: about 40 different species, variety of habitats. 
Mosquitoes are largely aquatic with most of their development occurring in or near stagnant water. 
Only female mosquitoes feed on or “bite” humans and other vertebrates to obtain protein necessary for egg laying.
Mosquitoes are cold-blooded creatures and do not generally bite in temperatures below 50 F.
Mosquitoes can live as long as 2-3 months and adults that hibernate can live as long as 6-8 months.

5. #1 “nuisance mosquito” in N. Virginia:
Asian Tiger Mosquito Aedes albopictus
Vector for the transmission of viral pathogens, including the West Nile virus, Yellow fever virus, St. Louis encephalitis, dengue fever, and Chikungunya fever, and possibly Zika, as well as several filarial nematodes (heartworm).
SE Asia Native
Flies and bites only during daylight hours
Breeds in:
small and large containers
tree holes
natural rock pools
Travels 600 yds

6. A. aegypti vs A. albopictus
Aedes aegypti mosquito is the primary transmitter of Zika, dengue, chikungunya, and yellow fever.

7. CDC Estimate of potential range
Read maps with great care.

9. Mosquito breeding habitats
flood water
ditches
root-ball pools
Temporary bodies of water
Seasonal and occasional
Fresh or polluted
Natural or manmade
Lacking in predators
salt marshes
woodland pools
artificial containers
Permanent bodies of water develop resident populations of predatory species that prey upon and eliminate the mosquitoes that hatch from eggs laid in those environments.
Most mosquito species breed in shallow, temporary bodies of water (puddles, residual ditch water, or artificial containers).
Short, quick breeding cycle enables mosquitoes to complete their development before predators can become established.
permanent swamps
polluted water
grass tussocks

10. Urban mosquitoes?
Artificial Containers

11. Life Cycle of Mosquito e.g. Culex sp. ‘egg raft’ = ¼” x 1/8”
Depends on:
Longevity of the aquatic habitat
Duration of the mosquito species' life cycle
Prefers temperatures over 70 degrees but can survive in anything over 50 degrees

12. Mosquitoes as Vectors of Disease: WNV
Vector competence – a mosquito’s tendency to become infected with a virus, harbor it, and transmit it to other hosts. Mosquito species that serve as WNV vectors can only do so by having a completely disseminated WNV infection. Disseminated infections occur when the WNV virus moves from blood in a mosquito’s gut, through the gut wall, and infects tissues throughout the mosquito’s body.
The mosquito can only become a WNV vector when its salivary glands have become infected. The time required for completion of a disseminated infection may be days or weeks depending on mosquito species and environmental conditions.

13. Integrated Pest Management Techniques for Mosquito Control
IPM = Range of options with which to control an insect or disease pest problem
Public Education is a key tool
Cultural
Habitat Management
Surveillance*
Mechanical
Mosquito Traps
Personal protection
Biological
Encouraging presence of natural predators
Introducing natural predatory organisms
Chemical
Larvicides
Adulticides
Mosquito control programs should always rely on adult and larval mosquito surveillance counts

14. Dump the Bucket!

15. Biological Larval Control
Mosquito fish (Gambusia sp.) are minnow-sized fish that function well in the shallow aquatic habitats that larval mosquitoes prefer. Gambusia is particularly useful for controlling mosquitoes that breed in backyard ornamental ponds/water features
Dragonfly larvae
Frogs/Toads
Water Striders and Ground Beetles.
Biting Midge Corethrella appendiculata
Bacillus thuringiensis Israeliensis

16. Biological Mosquito Larvicides
Biological Insecticides Bacillus thuringiensis israelensis (Bti); Bacillus sphaericus (Vectolex) are only effective on early stage mosquito larvae, NOT pupal or adulthood!
Advantage – may have very long residual
effect; will bounce down through vegetation or foliage to reach the aquatic habitat; are easily carried into the field in a shoulder bag or pocket.
***Highly selective for mosquito and fly species
Disadvantage – may be too large to use on some small aquatic habitats. Requires ‘mechanical’ suspension in below ground water pools

17. Self-Protection
“Personal protective equipment” = Long sleeve, long pants, socks, shoes, hats, and neck covering.
Exclusionary tactics (Nets and screening of rooms, beds, clothing)
Repellants for application to skin
DEET %
Picaridin- 20%
Oil of Eucalyptus
IR-3535 (Merck 3535)
Details on usage

18. Mosquito Personal Protection
Physical/Mechanical
Exclusion
Chemical

19. Adult mosquito control
Should be based on:
Mosquito surveillance data
Limited to distant, sheltered, or large breeding habitats
Last Resort!
Resources:

20. Mosquito Adulticide Types and Cautions
Pyrethroids – While some have very low toxicity to mammals and birds, are toxic to fish, aquatic arthropods, and non-target insects.
Permethrin
Resmethrin (Scourge)
Sumithrin (Anvil)
Organophosphates – Have moderate to high toxicity to mammals, moderate to high toxicity to birds and fish toxicity, and very high toxicity to honeybees.
Malathion – Low to moderate mammalian toxicity
Naled (Dibrom) – Moderate to high mammalian toxicity
Resources:

21. Pollinator Protection and Pesticides
Some Guidelines to use when working with pesticide applicators: Do not ….. Apply at times when pollinators are active Apply on food crops Apply on flowering plants. Apply on windy days or before a rain event. DO: Remove mosquito-friendly plant growth Encourage natural predators Use selective, biological larvacides. Use “ultra low volume” sprays during cool parts of the day to reduce drift
Do not apply pesticides when pollinators are present or on plants that pollinating insects visit. Do not apply to food crops
Remove mosquito-friendly plant growth like dense groundcover and shrubbery
Encourage natural predators
Use selective pesticides for larval control (READ THE LABELS!)
Don’t apply pesticides during the hottest part of the day
Use “ultra low volume” sprays to reduce drift
Don’t apply pesticides before rain or on very windy days; to avoid pesticide drift from the plant surface or other property
BUT don’t apply in dead calm conditions or if there is an active temperature inversion that might cause pesticide drift

22. Hiring a pesticide applicator
DO:
Choose a VDACS licensed pest management company
Ask for proposals that incorporate multiple tactics of IPM and not adulticides alone
Get and compare several proposals for service . Ask for referrals from neighbors.
Ask about staff training in IPM and mosquito control.
Contact the Virginia Department of Agriculture and Consumer Services and its Office of Pesticide Services, at for any questions about the misuse of pesticides.
Choose a pest management company that is licensed by the state. A list of licensed, private and commercial certified applicators can be found at Virginia Department of Agriculture and Consumer Services – Certified Applicators.
Proposal should include use of Integrated Pest Management (IPM), not just pesticide application.
Choose a company by reputation for quality of service, not the price. Get several proposals for service if possible and compare them. Ask for referrals from neighbors.
Company should have a staff entomologist or access to one, and the technicians should have experience with IPM and mosquito control.
For questions about pesticide spraying and pesticide products, contact the  Virginia Department of Agriculture and Consumer Services. Its Office of Pesticide Services, at , has pesticide experts who investigate allegations of pesticide misuse.

23. Most effective control directed at the immature life cycle stages
Mosquito Controls Summary
Biological Control
Predators
Pathogens and Parasites
Mechanical (Environmental) Control
Source Reduction
Exclusion
Environmental Manipulation
Chemical Control
Oils
Insecticides
Insect Growth Regulators (IGRs)
Most effective control directed at the immature life cycle stages

24. What’s new? Male sterilization: Radiation, field testing
Ovitrap
Eggs laid near water fall into screened enclosure from which new adults cannot escape
Fabric moisture wicks, cardboard, etc.
Pyriproxyfen
WHO recommended insect growth regulator
Ovitrap cups
Male sterilization: Radiation, field testing
RNA-Interference to destroy female Aegypti
Improved chemicals and natural products like cedar oil.

25. Mosquito controls that DO NOT WORK:
Bug Zappers.
Spraying Listerine, wearing dryer sheets, VapoRub, vanilla, etc.
Wristbands, ultrasonic devices.
Aunt Ethel’s Toad pee on your wrist.
Plants on your patio don’t really repel mosquitoes.
Propane-driven CO2 emitting mosquito traps actually attract mosquitoes rather than repel them.
Bats and Purple Martins do not prefer to eat mosquitoes.
It doesn’t matter what you eat. Garlic doesn’t keep them away.
Ckikengunya and West Nile virus have been recent introductions.
Malarea was endemic as recently as the mid 19th century.
Catnip, Lemon Balm, rose geranium, Citronella, Mountain Mint, marigolds

26. What would a world without them look like?
Jittawadee Murphy, Walter Reed Army Institute of Research: “Wiping out mosquitos could leave a predator without prey or a plant without a pollinator”.
Joe Conlan American Mosquito Control Board: “If we eradicate them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take their place”.
Mosquitos are a primary food source for some birds, spiders, salamanders, and fish.
The economic effect of mosquito eradication (ex. cost of malaria fight in sub-Sahara Africa) = 1.3% of gross domestic product growth
Carlos Brisola Marcondes, Federal U. of Santa Catarina, Brazil: “A world without mosquitoes would be more secure for us. The elimination of Anopheles would be very significant for mankind”.
The ecological effect of eliminating harmful mosquitoes is that you have more people. That’s the consequence”. Daniel Strickman, Urban and Medical Entomology, Beltsville
Live on nearly every continent
More than 100 million years here on earth
A World without mosquitoes, Nature Janet Fang, 2010

27. Keep in Mind That:
The average range of an adult mosquito is 600 ft. – 1-2 miles. Work cooperatively to remove breeding and sheltering sites.
The most popular chemical control, Permethrin is non- selective (it will kill beneficial insects, too).
There is limited to no residual benefits from Permethrin.
Effective control requires appropriate timing.
Mosquitoes do not like to breed in moving water. Keep a bubbler going if you can’t change it every 3 days
Mosquitoes are not strong fliers. Keep the air moving around your outdoor dining areas.
Keep bare skin covered.

28. It’s summer. Enjoy the outdoors!
Use an effective repellent on exposed skin
DEET, Picaridin or Oil of Lemon Eucalyptus.
Always make sure to follow label directions.
Make sure door, window, and rain barrel screens are intact.
Avoid being outside during dawn and dusk.
Wear long sleeves and pants when outdoors.
Drain all sources of standing water to prevent mosquitoes from breeding:
Turn over or remove containers in yards where rainwater collects, such as old tires, potted plant trays, boats, buckets and toys.
Clean out birdbaths and wading pools once a week.
Clean roof gutters and downspout screens regularly.
Eliminate standing water on tarps and flat roofs.
Ensure that lids are placed securely on garbage cans.

29. Alexandria’s and Arlington’s Responses:
Website information for public education about:
Commitment to environmental protection AND human health
Possible upcoming mosquito surveying
Commitment to protect residents and also our mosquito population from disease!
Info on preventing mosquito bites: Use of DEET in pregnancy, most effective mosquito repellants, and best ways to prevent bites
How to hire a pesticide applicator and who can be contacted about questions.

30. Virginia Cooperative Extension (VCE) Information
Local
Daily Horticulture Help Desk at Fairlington Community Center and weekly Plant Clinics
Collaboration with VCE Master Gardeners and Master Naturalists to educate residents
Collaboration with Arlington County Environmental Health Department and Department of Parks and Recreation
Commercial pesticide applicator information and training
State
VA Tech Entomology Department and Laboratory Resources
VCE publications
Partnership with VDACS on certification and compliance.

31. Resources for Mosquito/Tick Control
Centers for Disease Control & Prevention West Nile Info
Virginia Department of Health Mosquito and Tick Disease Info
borne-disease-control/
Arlington Environmental Health Department
information-center/
Alexandria Health Department
eIllnessPreventionProgram
Virginia Department of Agriculture and Consumer Services

32. Thank you!
Virginia Cooperative Extension programs and employment are open to all, regardless of age, color, disability, gender, gender identity, gender expression, national origin, political affiliation, race, religion, sexual orientation, genetic information, veteran status, or any other basis protected by law. An equal opportunity/affirmative action employer. Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
VIRGINIA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES