. . . But not in my Backyard

    Wednesday, 29 December 2004 - Cesspools and mosquitos. With the amount of rain we've had this month, it was a constant thought whether the catch-pond behind the new theater would dry up during the warmer months just around the corner. One concern is that of it becoming a source of mosquito breeding. Following is a bit of information about that concern.

IDENTIFICATION
   Mosquito adults are small, flying, midgelike insects. Female mosquitoes can be differentiated from similar insects by the presence of a long slender proboscis that is adapted for piercing skin and sucking blood, and long slender wings that are covered with small scales. Male mosquitoes have scale-covered wings, but their probosces, or beaks, are shorter and thicker than the females', and are adapted for sucking plant juices and other sources of sugar rather than blood. In the immature stages, called larvae or wigglers, mosquitoes are usually black or dark brown and occur in nonmoving or nearly still water. Most mosquito larvae have a distinctive siphon or air tube at the rear of their bodies. The next stage is the pupal stage; pupae, called tumblers, are also aquatic and are small, roundish forms, usually black in color.

LIFE CYCLE
   The life cycles of mosquitoes vary widely from species to species. Some female mosquitoes lay single eggs on water surfaces; others lay single eggs on moist soil where later flooding is likely. Still other species lay batches of eggs, called rafts, 100 or more at a time on water surfaces. Eggs deposited on water surfaces usually hatch within a day or so, but eggs laid on soil surfaces do not hatch until flooding occurs, which may be months or even years later. Larvae, which are nearly invisible to the naked eye, hatch from eggs. Larvae molt three times to become 4th-stage larvae. Several days later, this larval form molts again to become a pupa. Adult mosquitoes emerge from pupae 1 to 2 days after that, with male mosquitoes always emerging first. In the summer the entire life cycle, from egg to adult, may be completed in only 8 to 10 days. Certainly less than it has been taking for the catch-pond to dry up.

PUBLIC HEALTH AND VETERINARY IMPORTANCE
   Female mosquitoes of nearly all species require blood from vertebrate animals to develop eggs, and many species bite people, pets, and livestock for this purpose. The most important consequence of this is the transmission of microorganisms that cause diseases such as western equine encephalomyelitis and St. Louis encephalitis. Both of these diseases can cause serious, sometimes fatal neurological ailments in people. (Western equine encephalomyelitis virus also causes disease in horses.) Western equine encephalomyelitis infections tend to be more serious in infants while St. Louis encephalitis can be a problem for older people. Some mosquitoes are capable of transmitting malaria to humans. If these mosquitoes suck the blood of a person that has malarial parasites, they may pass on the infection to the next person(s) they bite; however, malaria is currently rare in Alabama. See also an article from the Texas Cooperative Extension on mosquitos and the diseases they transmit.

ENCEPHALITIS
   Encephalitis is an inflammation of the brain caused by certain viruses transmitted by mosquitoes. Human cases of encephalitis range from unapparent or mild cases to very severe illnesses that can permanently damage the central nervous system or, in some instances, cause death. Symptoms include high fever, convulsions, delirium and other central nervous system problems. If these symptoms occur, seek medical assistance quickly.

MANAGEMENT
   Mosquitoes are best managed on an areawide basis by public agencies that are either components of local health departments or are independent districts organized specifically for mosquito control. Some are small and have responsibility for mosquito abatement in a few hundred square miles, while the activities of others may encompass one entire county or more. Mosquito control is accomplished by searching out mosquito larvae in standing water and treating the water with a material that kills the larvae. Many materials currently in use are biological in origin and are highly specific for mosquitoes, with little or no effect on other organisms.

   On occasion, mosquito abatement agencies may also apply chemical pesticides to kill adult mosquitoes, but ordinarily only when adult populations become so large that they cause extreme annoyance to many people or when the threat of disease transmission to people is high.

Around the Home
   In many areas of Cullman, efforts of public mosquito and vector control agencies keep mosquito numbers down to tolerable levels all or most of the time. However, some people in Cullman live in areas where there is little organized mosquito control. People living in these areas, or in other areas where mosquito populations become bothersome, can protect themselves from mosquitoes by using a variety of strategies that include maintaining fine mesh screens on windows and doors in good repair; checking for standing water; draining standing water or treating it with the microbial insecticide Bacillus thuringiensis subsp. israelensis or mosquito-eating fish; and wearing repellents and protective clothing outdoors during the mosquito season.

   The most effective control methods are those targeted against the larval stage. Any area (excluding wildlife habitats such as wetlands or vernal pools) or object that can hold water for more than a few days should be filled with soil or cement, drained, discarded, treated with Bacillus thuringiensis subsp. israelensis, or stocked with mosquito fish. Even small containers like cinder blocks, flower pot saucers, or crotches of trees can provide a habitat for mosquito development if they remain filled with water for more than a few days. Always combine the use of any product with good sanitation practices that reduce breeding sites. Keep in mind, however, that mosquitoes can migrate several miles from where they develop. Even successful control of mosquito larvae on your premises may not result in reducing mosquito numbers or biting activity.

   We would like to see the City of Cullman pay more attention to the catch-pond just created within a few feet of our neighborhood as well as all others in the city limits full of grass and weeds making it difficult to see whether they are holding water for extended periods of time. While these areas are great for breeding other animals other than pests, there are other methods of controling disease bearing mosquitos than bombing them with chemicals that may drain into our water system.

   One way to perform a change for the better is to yell until someone tires of hearing you and sets the wheels in motion. A much better way is to offer a more rational solution within the means of those responsible for making the change a reality. Spraying our homes with a mixture of chemicals may have long-lasting effects unaccounted for. How many of you remember our federal government saying that DDT was "harmless to humans?"

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   Further information will be made available on www.Cullman.org as it occurs.