Outdoors in the Time of Zika:

Nuisance Mosquito Management April 2017

Kirsten Buhls, Extension Agent VCE Arlington County

Ingrid Werber and Kasha Helget Arlington Regional Master

Naturalists

Living with mosquitoes without fear .

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!

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.

#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

A. aegypti vs A. albopictus

Aedes aegypti mosquito is the primary transmitter of Zika, dengue,

chikungunya, and yellow fever.

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CDC Estimate of potential range

Read maps with great care.

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artificial containers woodland pools salt

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Mosquito breeding habitats

- Temporary bodies of

water

- Seasonal and

occasional

- Fresh or polluted

- Natural or

manmade

- Lacking in predators

Artificial Containers

Life Cycle of Mosquito

e.g. Culex sp.

‘egg raft’ = ¼” x 1/8”

Mosquitoes as Vectors of Disease: WNV

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

Dump the Bucket!

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

Biological

Larval Control

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

Biological Mosquito Larvicides Biological Insecticides Bacillus thuringiensis israelensis

(Bti); Bacillus sphaericus (Vectolex) are only effective

on early stage mosquito larvae, NOT pupal or

adulthood!

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 25- 30%

• Picaridin- 20%

• Oil of Eucalyptus

• IR-3535 (Merck 3535)

Mosquito Personal Protection

Physical/Mechanical

Exclusion

Chemical

Should be based on:

• Mosquito surveillance data

• Limited to distant, sheltered,

or large breeding habitats

• Last Resort!

Resources:

http://www.arlingtonva.us/Departmen

ts/HumanServices/HumanServicesW

esNileVirusSpraying.aspx

Adult mosquito control

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

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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

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 804.371.6560 for any questions about the misuse of pesticides.

Most effective control directed at the immature life cycle stages

• Biological Control

• Predators

• Pathogens and Parasites

• Mechanical (Environmental) Control

• Source Reduction

• Exclusion

• Environmental Manipulation

• Chemical Control

• Oils

• Insecticides

• Insect Growth Regulators (IGRs)

Mosquito Controls Summary

What’s new?

• 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.

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.

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

• 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.

Keep in Mind That:

•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.

It’s summer. Enjoy the outdoors!

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.

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.

Resources for Mosquito/Tick Control

• Centers for Disease Control & Prevention West Nile Info

• www.cdc.gov/westnile

• Virginia Department of Health Mosquito and Tick Disease Info

• www.vdh.virginia.gov/environmental-epidemiology/vector-

borne-disease-control/

• Arlington Environmental Health Department

• https://health.arlingtonva.us/environmental-health/mosquito-

information-center/

• Alexandria Health Department

• https://www.alexandriava.gov/EnvironmentalHealth#VectorBorn

eIllnessPreventionProgram

• Virginia Department of Agriculture and Consumer Services

• www.vdacs.virginia.gov

Thank you!

VIRGINIA DEPARTMENT

OF AGRICULTURE AND

CONSUMER SERVICES

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.