June 8, 2005

Feature Article - for release the week of June 12, 2005

Dan Culbert - Extension Horticulture Agent

SELF Defense against mosquitoes

Unless you just arrived from another planet, you have probably noticed that summer rains have begun to fill up our local ditches canals and the chronic wet spots in our Florida Yards.  Summertime has arrived, and with it comes the “enjoyment” of seeing and feeling the effects of one of our unofficial state animals – the mosquito.

Homeowners can play a role in managing these pest populations, and today’s column will give you some tips on what you can do in self defense.  Much of this information comes to us from Extension Specialist Dr. Roxanne Rutledge of the University of Florida’s Medical Entomology Laboratory, which is located in Vero Beach.

Dump Standing Water

Most – but not all of our pesky mosquitoes – breed in standing water.  Even a small amount of still water can provide a place to a female mosquito to lay a clutch of eggs and turn it into a writhing mass of wrigglers.  Depending on the species, it may only take a few days after a good rainfall for the next generation to emerge and look for bare flesh.

There are many water-holding containers found in landscapes.  Can you get rid of them? Or, if you do not want to remove them, flush them out and replace the water every 2 - 3 days.  This will remove mosquito larvae that are in the container; larva will not live long out of water and will not develop to the adult stage.

Here is a short list assembled by Osceola County Master Gardner Nancy Pfister and some ides on how to deal with breeding mosquitoes:

·        Potted plants with pans -- Don't overwater you plants, and remove or turn the drip pan upside down so it won’t hold water.

·        Drainage ditches -- Remove vegetation and obstructions to water flow – mosquitoes don’t like moving water.

·        Low spots that hold water -- Fill and re-grade to move standing water off your property.

·        Plugged roof gutters – If they haven’t been blown away by the storms, be sure to check them and clean gutters clear of sticks, leaves and other obstructions.

·        Pet dishes -- Change water frequently.

·        Trash piles -- Remove or cover them, but be sure that covers don’t hold water in small pockets.

·        Old tires – Remove, dispose of or cover tires, which are one of the best places to grow mosquitoes.

·        Water holding containers -- Remove or cover pails, barrels, grills, or even some kinds of plastic play ground equipment.

·        Poorly maintained pools or spas -- Follow recommended maintenance and keep up with the pool chemical levels which kill mosquito larva.

·        Bromeliads -- Flush the hollow centers of these plants out with a hose.

·        Tree holes -- Fill with sand or concrete to keep water from pooling inside – or better yet, remove these trees that will have weakened trunks.

·        Debris on roofs -- Remove debris; ripped and compromised blue roof tarps can hold puddles of water.

·        Ponds -- Keep them clear of excessive aquatic vegetation, and stock with minnows or tadpoles to feed on the wrigglers.

·        Boats -- Cover or turn upside down so the hulls don’t hold rainwater.

·        Birdbaths -- Flush at least once per week.

If you must rely on chemical control of breeding areas, or insist on using pesticides to reduce adults mosquitos, please check with us for the UF bulletin on recommended, legal pesticides.

 Buying a Zapper?

 Carefully evaluate the purchase of mosquito control devices.  Dr. Rutledge has pioneered the evaluation of many of the devices that are now on the market to “eliminate” mosquitos from your Florida Yard.  Many are not effective.

Some of these devices expel carbon dioxide gas that attracts these pests into a collection bag.  Research has not shown that they actually eliminate local mosquito populations.  Other devices emit a timed spray of insecticide. These fail to consider differences in mosquitos and environmental effects, and as a result will often be too little, too late or kill a lot of nontarget organisms like birds, pets and wildlife.  They can also lead to an increase pesticide resistance among those mosquitos that survive.

There are even devices being sold that supposedly repel mosquitos by emitting ultrasonic waves.  The Federal Trade Commission has issued an order stopping their sale because they simply do not work to repel mosquitos.

Got Mosquitos? Get DEET!

If you can avoid exposing yourself to mosquitos, do so.  Limit your outdoor activities around dusk and dawn, when mosquitos are most likely to be active.  If you must be outside, wear light colored loose fitting long pants and long sleeved shirts, complete with hats, and use an effective mosquito repellent.

Repellants containing “DEET”, an abbreviation for the chemical name of the active ingredient, work the best when properly applied.  Other “natural” repellants such as citronella, eucalyptus or picaridin (i.e. Skin-so-Soft^TM) will work for 20 minutes or so; some forms of DEET can last for upwards of 5 hours.  Knowing how to apply and reapply these repellents can make all the difference in the world.  Ask for the recently revised UF bulletin, Mosquito Repellants if you want the details.

A great place for mosquito information is Dr. Rutledge’s web page; I’ve placed a link to it and more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on homeowner mosquito control, email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our County Master Gardeners from 1 to 5 PM on Tuesday afternoons.  

-30-

Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS / University of Florida.  Larry A.  Arrington, Dean.   Last update: 06/09/2005 .  This page is maintained by Dan Culbert