Vector Management

2818 Neuse Boulevard
New Bern, NC 28561
E-mail: envhealth@cravencountync.gov Phone: (252) 636-4936
Fax: (252) 636-1474



As of July 1, 2011, the Craven County Vector Control Program has been discontinued due to budget constraints.



Mosquito
Biology
Mosquito
Viruses
Protective
Measures
Protecting
Your Horses
Control
Measure
What Can You Do?
Mosquito
Facts
Mosquito
Links
Other
Vectors
Mosquitoes
After the Storm
Contact Us  

Mosquito Biology

Mosquitoes are members of the insect order Diptera, meaning two wings. Mosquitoes undergo complete metamorphosis. This means they have a life cycle that includes four stages of growth. This begins with an egg stage and progresses through a larval stage, pupal stage and finally the adult stage. When the optimum environmental conditions exist for a particular species their eggs will hatch and the larval stage begins. The larvae require water to live and if the source dries they will die. These larvae go through four growth periods called instars. This is when the larvae are growing and feeding. They then enter the pupal stage where they no longer feed and energy is directed towards production of the adult mosquito. The adult mosquito then emerges from the water. The males emerge first and hover around the site waiting to mate with the females. The male mosquito does not bite; only the female does. The blood a female mosquito acquires though its bite is not a source of food, but a source of protein for egg production. The females may take several blood meals during its two to three week lifespan and may lay hundreds of eggs. Mosquitoes can occupy a variety of habitats such as woodland pools, brackish marshes or artificial containers, depending on the species.

Mosquito Larvae Mosquito Pupae
Click here for detailed pictures and illustrations of the mosquitoes life cycle and habitats.

Mosquito Viruses

Mosquitoes are capable of spreading a number of viruses. These viruses are called arboviruses, which stands for arthropod-borne virus. The two arboviruses we are mainly concerned with here in eastern North Carolina are Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV). Both of these viruses involve a complicated transmission cycle between mosquitoes and birds. Certain mosquitoes can acquire the virus from an infected bird and potential bridge it to the mammal population such as humans. The transmission cycle of EEE and WNV are shown below. For detailed information on these viruses click on the links given.

EEE Fact Sheet WNV Information
EEE Transmission Cycle West Nile Virus Transmission Cycle
Click here for detailed pictures and illustrations of the mosquitoes life cycle and habitats.

Protective Measures

Protection from mosquito bites requires responsible decisions on the part of every citizen. The following guidelines should be followed to lessen the risk of mosquito bites.

Keep all screens in good repair so mosquitoes cannot get inside.

Protecting Your Horses

While there currently are no vaccines available to protect humans from mosquito borne viruses, there are vaccines available to protect horses. These vaccines are available for both EEE and WNV. It is recommended that you get your horses vaccinated annually. Check with your veterinarian on the proper procedure for getting them vaccinated.

Click here for additional information about mosquito diseases in horses and how you can prevent them.

Control Measures

A variety of control measures are available to suppress mosquito populations. Craven County used integrated pest management in its vector control program. This means a variety of control is employed depending on a number of factors. The various control measures included education, source reduction, larviciding, and adulticiding. Surveillance techniques were in place to determine the optimum time to implement these control measures.

Vector control personnel were available to perform site evaluations in relation to requests from the public. Many of these requests were handled by simply eliminating the source of the problem. Many times the problem mosquito found was the Asian Tiger Mosquito. The only way to control this mosquito is to eliminate its breeding source. Education is a key component of this. Click here for more information on the Asian Tiger Mosquito.

Through active larval mosquito surveillance, mosquito breeding sites were found. The sites were mapped and monitored for breeding mosquitoes. When breeding was observed the sites were treated using biologicals that  specifically targeted the larval mosquitoes. This is known as larvaciding.

CDC Mosquito light traps were used to catch adult mosquitoes. They were collected and the various mosquitoes identified as to each species. This told us which species were present and in what numbers. This also told us if these species populations were on the increase or the decrease. When adult mosquitoes reached elevated levels adulticiding, or spraying measures, were implemented. Spraying for adult populations is the least cost effective control measure, but it is often necessary to control adult mosquitoes at an acceptable level.

Surveillance methods were also in place to monitor mosquito disease activity within the county. A key component of this was the use of sentinel chicken flocks. This consisted of placing flocks of chickens throughout the county in prime habitat locations for mosquito development.  Disease activity in the bird population was measured from antibodies produced and found present in blood samples taken from the birds every two weeks. The detection of these diseases antibodies when other factors were also present would often trigger the need adult spraying activities.

EPA: Pesticides And Mosquito Control

Control Products Formerly Used By Craven County Vector Control

Product Active Ingredient Kind of Control Product Info
Altosid (30Day Briquette) Methoprene Larvacide Label MSDS
Altosid XR (150 Day Briquette) Methoprene Larvacide Label MSDS
Altosid (30 Day Pellets) Methoprene Larvacide Label MSDS
Vectobac 12AS Bacillus thuringiensis subsp. Israelensis Larvacide Label MSDS
Vectolex CG Bacillus sphaericus Larvacide Label MSDS
Vectolex WDG Bacillus sphaericus Larvacide Label MSDS
Summit bti Briquette Bacillus thuringiensis subsp. Israelensis Larvacide Label MSDS
Agnique MMF POE ISOOCTADECANOL Larvacide Label MSDS
Abate   Larvacide Label MSDS
Biomist 3+15 Permethrin Adulticide Label MSDS
Anvil 2+2 Sumithrim Adulticide Label MSDS
Flit Permithrin Adulticide Label MSDS

What Can You Do?

Mosquito control begins in your immediate environment. The vast majority of mosquito problems are the result of them being bred in one's own yard. The list below details many of the important practices to perform to keep mosquitoes from breeding around the home.

  • Remove and discard old tires and drill drainage holes in tires used for playground equipment.
  • Remove or turn over clay pots and plastic containers.
  • Clean rain gutters so water can flow freely.
  • Store plastic wading pools inside or turn them upside down when not being used.
  • Check tarps such as those for boats and pools for areas holding water and arrange these to drain the water.
  • Pump out bilges in boats and store canoes and small boats upside down.
  • Remove unused pet food and water dishes.
  • Replace birdbath water at least twice a week.
  • Flush water in the bottom of plant holders at least twice a week.
  • Flush livestock troughs at least twice a week.
  • Turn wheelbarrows upside down when stored outside.
  • Clean and discard any trash or debris.
  • Do not leave trash can lids upside down and look for water standing in the bottom of trash cans.
  • Repair dripping outside faucets.
  • Inspect construction sites and do-it-yourself projects to ensure there is proper backfilling and grading to allow drainage.
  • Keep ditches free of debris so they can properly drain.
  • If you have ornamental ponds, tree holes or other low water holding areas contact Craven County's vector program for assistance.

Mosquito Facts

Mosquito control begins in your immediate environment. The vast majority of mosquito problems are the result of them being bred in one's own yard. The list below details many of the important practices to perform to keep mosquitoes from breeding around the home.

  • Mosquitoes are not capable of spreading AIDS. Click here for a detailed explanation why they cannot.
  • People are not always the primary blood hosts for mosquitoes. Many prefer to seek blood from birds and other mammals. The Arctic circle has very few people, but millions of mosquitoes.
  • Most mosquitoes do not like to travel and will stay within a 1 mile radius of their breeding site.
  • Mosquitoes locate their blood hosts through scent, sight and heat. They can detect our scent, especially the carbon dioxide we are exhaling, from up to 100 feet (30 meters) away. They can see you at a distance of about 30 feet (10 meters).
  • Bug zappers kill very few mosquitoes, but kill numerous beneficial insects.
  • There are over 3,300 mosquito species worldwide.
  • Mosquitoes are responsible for more deaths throughout the world than any other living creature.
  • Studies have shown that while bats consume a large number of insects, mosquitoes are a very small proportion of their diet.
  • The itch of a mosquito bite is due to chemicals it injects to keep the blood from clotting.

Mosquito Links

North Carolina Mosquito and Vector Control Association
Mid-Atlantic Mosquito Control Association
Mosquito Bytes
Mosquitoes and DEET
West Nile Virus and Wildlife
West Nile Virus and Pets
Heartworm Disease In Dogs and Cats

Other Vectors

Ticks

Like mosquitoes, ticks are a part of life in Craven County. They also have the potential to spread diseases as well. Protecting yourself from them is the key to avoiding their diseases. Below are some important links to a variety of information about ticks.

Tick Prevention tips
Tick Diseases
 
     
Rodents

Rodents can be a potential problem. At the heart of rodent control is the maintenance of sanitary conditions. To exist rodents require food, harborage and water. Elimination of these requirements is the key to controlling them. Below is an important link to information about rodents.

Rodent Control
 
     
Roaches and Flies

Roaches and flies can also be pests of concern. Like rodents, maintaining sanitary conditions is the key to controlling them. Eliminating their food, water or harborage is the way to prevent them from becoming a problem. Below are links to important information on them.

Safer Roach Control
Roaches and Asthma
Flies and Fly Control
     

Other Pests

Go to the links provided below for information on additional public health pests with the potential to cause problems.

Flea Management Guidelines
Bedbugs
www.ncbedbugs.com
Lice
Red Imported Fire Ant
   

Mosquitoes...After the Storm

Effects of Mosquito Populations From Flooding
Flooding can be one of the most devastating components of a storm. Inch after inch of rainwater can be deposited quickly.  These flooding waters fill numerous ditches, depressions, artificial containers and other water holding areas across the landscape. Also, wind-blown tidal waters can be pushed to high levels bringing flooding waters to areas that are normally dry. These elevated water levels provide the essential element for mosquitoes to complete their life cycle and can suddenly lead to heavy populations of them.

Why So Many Mosquitoes in Such a Short Time Period?
Many species of mosquitoes deposit their eggs in mud at the reaches of ditches, depressions, artificial containers and other mosquito breeding areas. They lay these eggs here in anticipation of an eventual high water event that will bring the essential ingredient to the eggs: WATER. These eggs can remain viable for many years after they are laid. This is why a storm producing high levels of rain water can quickly elevate mosquito levels.

Why Should We be Concerned with Mosquitoes?
As we know, mosquitoes can be a substantial nuisance, especially during recovery efforts. More importantly, they have the potential to spread diseases such as Eastern Equine Encephalitis and West Nile Virus. The possibility of one of these viruses to vector to the human population can increase substantially with elevations in the mosquito population which occurs with flooding. This is why we should be concerned with mosquitoes and should take action to control as many as possible.

What Can You Do to Help Alleviate the Mosquito Problem?
After the store has passed, it will take time for clean-up efforts to begin. There likely will be debris scattered that needs to be cleaned up. While this clean-up is ongoing, every attempt at removing mosquito breeding sites around the home should be made. Look for any water that has accumulated in artificial containers all around the household. Any standing water should be removed from these as soon as possible. Clean any debris that may be blocking the flow and drainage of ditches and low lying areas. Mosquito control briquettes such as those found in hardware stores can be placed in standing water to help control larval mosquitoes.

Common Mosquito Breeding Areas

  • Toys
  • Roof gutters
  • Water features
  • Uncovered boats
  • Potted plants
  • Bird baths
  • Dripping spigots
  • Puddles – natural or under A/C units
  • Neglected pools/hot tubs
  • Drainage ditches
  • Items in recycle bins

How Can You Protect Yourself From Mosquito Bites?
Personal protection from mosquito bites will be important as clean-up activities continue. Repair any damaged screens to keep mosquitoes out of the household. If high levels of adult mosquito are encountered, wear protective clothing that prevents you from getting mosquito bites. Apply repellents to prevent bites. Always use repellents with care and follow the labels, especially when applying to children.

Contact Us

Craven County Health Department
Division of Environmental Health
2818 Neuse Boulevard
New Bern, NC 28562
envhealth@cravencountync.gov
(252) 636-4936


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