IPM in the South

Many of you may have seen some of the news articles about West Nile virus in Dallas, TX. Although the virus is not prevalent in every state, I thought it might be worth sharing part of an article from the NC Pest News from Dr. Mike Waldvogel about ways you can minimize mosquitoes around your yard. Some of the information later in the article (particularly the contact information for NC Department of Agriculture) may not be relevant, but you can probably get the same information from your state’s department of agriculture.

Mosquito management techniques:

- Bird baths – simply flush with a garden hose and you flush out the mosquito larvae in the process. Plus, the birds will appreciate the fresh water. For horse owners with water troughs near stalls or out in pastures, one option is to use a product such as “Mosquito Dunks” which contain the bacteria Bacillus thuringiensis israelensis which kills the mosquito larvae (not the adults). Although, you can use them in outdoor water bowls for pets, it is far simpler (and better for your animals) if you “tip and toss” the water from the bowl and replenish it with fresh water daily.

- Old cans, tires, etc. – empty them and get rid of them (legally, not simply tossed along the highway to become someone else’s problem).

- Outdoor flower pots – empty the water from the dishes/trays underneath them. Your plants have plenty of water without the overflow. This also helps reduce fungus gnat problems in the plant soil.

- Remove all of that built-up debris from your gutters. The water and decaying material attract mosquitoes.

- Rain barrels – if you collect water from your gutters or some other system, make sure the barrel is screened to keep out debris and mosquitoes

- Tarps that cover your boat, grill, firewood, etc. also collect pockets of water that can remain for 1 to 2 weeks.

- The bed of that ’57 Ford pickup that you’ve been “restoring” for the last 25 years can collect water particularly if the tailgate faces uphill in your yard.

- Kids’ pools – if they’re not being used by kids, they’re probably being used by the mosquitoes (and maybe some toads) – empty them. The same thing applies to pools (in ground or above ground) that aren’t maintained (e.g., pools on abandoned or foreclosed properties).

- Drainage ditches – they’re meant to collect storm water temporarily. Keep them free of debris so that water flows and has time to filter into the soil.

- Decorative fish ponds can be a source of mosquitoes if they contain a lot of vegetation that provides hiding places for the mosquito larvae. “Mosquito Dunks” are an option here.

- Tree holes – when limbs fall off trees, the remaining hole in the trunk can collect water. Flush that out or put a small piece of a mosquito dunk into it.

Another critical matter – personal protection. The majority of mosquito-borne disease incidences, whether they’re human or equine, are due to a lack of personal protection. Horse owners need to spend the time and money to get their horses vaccinated against EEE. For us two-legged creatures, we simply need to take precautions when we’re outdoors for work or recreation. If it’s too uncomfortable to wear long-sleeved shirts and long pants, then cover all exposed areas of the skin with an insect repellent (see http://insects.ncsu.edu/Urban/repellents.htm). A few other important points about using repellents:

- Do not put repellent on skin that will be covered by clothing.

- Children spend a lot of time outdoors, particularly when school is not in session. The greater the amount of time spent outdoors can increase the likelihood of getting bitten by a mosquito (and potentially a higher likelihood of being bitten by an infected mosquito). Before applying a repellent to a child, read the label carefully to make sure that it contains concentration appropriate for use on children.

- When using repellents on children – you should apply the product to your hands and then rub it on their arms, legs, neck, etc. If you allow your child to rub repellent on their arms and legs, they need to wash their hands immediately afterwards because they will inevitably forget and either rub their eyes or stick their fingers in their mouths.

I’ve had a number of people ask about mosquito treatments. Some people want a “do-it-yourself” approach using liquids applied to mosquito resting areas (shrubs, etc.) or using a “yard fogger” similar to what you may have seen being used in Dallas, Texas. These are a matter of personal choice but particularly with the foggers you need to exercise caution. If you have watched the spraying in Texas, notice that the applicators are wearing personal protective equipment. If you elect to use a backpack or handheld fogger, make sure you protect yourself from accidentally inhaling the chemical, getting it in your eyes or mouth, or contaminating your skin and/or clothing. Always direct the chemical downwind. Also, remember that when you spray along your property line, you will have some drift and so you should check with your neighbor to make sure they don’t object to chemical drifting into their yard and possibly contaminating a vegetable or herb garden with a chemical that isn’t labeled for those plants.  Likewise, be aware that if you spray during the day and there are plants in bloom, you are likely to kill some pollinators (honey bees and others). Also, if you do treat your yard with a liquid or fog, make sure you cover or remove children’s toys, grills, furniture, etc. If you treat children’s yard toys (like swings and other playground-type equipment) to kill resting mosquitoes, you need to hose them down before you let kid’s play on it.

The other question is about companies that offer mosquito treatments, usually in the form of spraying yards for mosquitoes that are resting on grass and shrubs or more elaborate spray systems installed on the house (or in the yard) and are set to trigger at specific times. This is also a matter of personal preference. However, I’ve had a number of people tell me that when they ask the company what product they’re applying, the response is a somewhat vague “It’s a natural chemical” or “It’s totally safe for people and pets”. Bluntly put – I don’t care what it is. A reputable company should tell you what they are about to apply on your property. If they’re still vague about what they’re using, I suggest you shop around for another company. Also, if a company offers to treat your property for mosquitoes, make sure they hold the appropriate pesticide applicator license issued by the North Carolina Department of Agriculture & Consumer Services. Anyone representing the company should have an ID card and can provide the license number for someone in the company. If you have any questions, call the NCDA&CS (919-733-3556 or 919-733-6100).

One other point – mosquitoes have no concept of property lines.  They are simply out there looking for a blood meal whether it’s you or your neighbor. Mosquito “control” may be a matter of spraying chemicals to reduce the population below nuisance levels. On the other hand, mosquito management is what is often needed. It is a long-term proactive project that requires a community effort in order to succeed.

We have information on mosquito control on the web at http://insects.ncsu.edu/Urban/mosquito.htm.

For more information about West Nile Virus, see the CDC Factsheet.

Filed under: Insects, Pesticides, Urban IPM Tagged: | Asian tiger mosquito, mosquito control, mosquito prevention, mosquito repellents, mosquitoes, West Nile virus