Due to the unprecedented severity of the West Nile virus outbreak in North Texas last year, individuals and towns are already planning their strategic defenses to the disease bearing mosquitoes.
On Thursday, March 21, from 7 to 8:30 p.m., the Town of Copper Canyon will host a public information meeting on West Nile virus response plans for area towns at Crossroads Bible Church on the southwest corner of FM 407 and Chinn Chapel Road in Double Oak.
Residents of Copper Canyon, Double Oak, Canyon Oaks, Bartonville and Argyle are especially welcome to attend (but we will certainly not turn away any residents from Flower Mound, Highland Village, or Lantana- however, those three governmental entities are reliably capable of developing and funding their own effective mosquito control programs for their own respective residents.) Coffee and light refreshments will be offered courtesy of Copper Canyon volunteers. Our sincere thanks to Crossroads Bible Church for once again making their facilities available gratis for a public education meeting.
Municipal Mosquito.com is the presenter. MunicipalMosquito.com is the largest private mosquito contractor in North Texas and is operated by Entex Pest Solutions of North Texas. In its regular pest control operations, Entex uses only natural organic products. However, effective mosquito control products are usually not organic.
West Nile Virus Response Plan
This official document outlines consistent response regarding virus positive mosquitoes or disease positive individuals. Listed below are guidelines and trigger points for each stage of an Integrated Mosquito Management (IMM) program. Each municipality can develop its own West Nile Virus Response Plan.
Texas Commission on Environmental Quality Compliance (TCEQ) for National Pollutant Discharge Elimination System (NPDES) of the
Clean Water Act: The recent policy changes enacted in the fall of 2011 of the EPA Clean Water Act require new and additional procedures for municipalities to follow regarding applications of mosquito control materials in and around bodies of water. NPDES compliance is mandatory for any municipal mosquito program.
Surveillance includes (a) Field Inspections, (b) Trapping, (c) Virus Testing (by Reverse Transcriptase Polymerase Chain Reaction RT-PCR for accurate uniform data,) and (d) Geocoding of sites.
“Surveillance” was the critical area of mosquito control that was least available to small towns last year. There were simply not enough existing Mosquito Traps available to supply the demand. Personnel experienced in collections in the field and testing labs were overwhelmed by requests for their services.
Mosquito trapping usually runs from May 1st through October 31st – or six straight months. Last year Dallas County had its first trapped mosquito testing positive for the West Nile Virus on June 4th and Tarrant County on June 6th. (However, there were mosquitos still testing positive for the virus in December of 2012.) But a caveat: the location of mosquito traps can be manipulated, so that disease-bearing mosquitoes will, or will not, be found.
The cost to rent a Florida produced mosquito trap is an estimated $105 per trap per week; plus $50 per trap per week for testing. Testing for West Nile Virus is a very labor intensive procedure. The traps need to be put out each evening between 4-6 p.m. and picked up the next morning preferably between 6-7 a.m., no later than 10 a.m. Traps cannot simply be left in place between weekly testing, as they are an attractant to raccoons and other wildlife who will simply destroy the traps.
Each trap needs to be baited with what is graphically called in the industry – “stink water”. Alfalfa hay and rabbit pellets and sometimes other ingredients are placed in water in a 55 gallon poly drum. The drum is sealed and placed in the sun, so that the concoction can brew for about two weeks and eventually stagnate.
(NOTE: Individuals can also purchase the traps and training is available to learn how to collect the mosquitoes for testing. A trap cost $130, plus $25 for batteries, plus shipping costs from Florida. The vial that transports the mosquitoes for testing costs $6 per vial. The handmade retrieval net costs $28. Professionals will train the individual in trapping procedures. The professionals will also walk the individual’s land and suggest areas for placing the traps. The individual will need to prepare “stink water”, place and bait the trap, aspirate the mosquitoes, and transport them to a third party private lab for testing. The nearest such lab is in Addison. Traps should not be left out overnight and will need to be stored safely between weekly overnight testing sessions.)
Municipally rented traps need to be placed on public land (for legal liability reasons), but in concealed places where mosquitoes may be naturally attracted and birds are roosting nearby. Mosquito traps in public road right-of-ways are often vandalized or stolen. Suggested test areas for Copper Canyon are the acre around Town Hall and under the bridges at Poindexter Creek and in Hidden Creek.
Retrieval of Mosquitoes from the Traps
The mosquitoes are retrieved from the trap by a $28 handmade net. The mosquitoes are aspirated from the net and then “knocked down” by a chemical or frozen. A typical trap will catch 150 mosquitoes. It takes approximately 15 minutes for a technician to “speciate” per trap. This reveals the varieties of mosquitoes in the trap and the diseases they carry.
The Culex quinquefasciatus mosquito is associated with two diseases: St. Louis Encephalitis and West Nile Virus. It is easy to distinguish blood-infested female mosquitoes. They have recently bitten bird, animals or humans and the resulting protein they have ingested from the blood enables them to have the strength to produce and lay eggs. A standard sample from a mosquito pool will have only 50 retained mosquitoes. Otherwise, more than one sample of 50 mosquitoes each will be retained. Culex mosquitoes only fly 500 yards maximum. They stay very close to where they are hatched.
Determining the percent of male and female mosquitoes is also important. For example, if 60% of the mosquitoes trapped are males, there will be an exceedingly high fertilization rate of the females resulting in a very large production of larvae. Normally, it takes 7-10 days for an adult mosquito to mature, if climate temperatures are mild. However, if day time summer temperatures are 105 degrees Fahrenheit, and night time temperatures are as high as 90 degrees Fahrenheit, the maturation of an adult mosquito may only take 3 days.
If the traps are set on a Tuesday night, mosquitoes are collected Wednesday morning, and by Thursday or Friday the results of the testing is known. (Third party labs offer same day, 24 hour, and 48 hour results for entities that desire more rapid processing than public health labs may provide. Bird testing is also available upon request.)
The Cost of Testing
Copper Canyon is 4 square miles in area and would require 3 to 4 “static trap” locations. Static traps are not moved from week to week and provide more reliable comparison information. “Roving traps” can be moved each week, as a response to specific complaints of locations discovered with heavy mosquito concentrations.
For Copper Canyon alone the cost of 3 static and one roving trap per week with weekly testing for six months would be an estimated $620 per week, or approximately $2666 per month or $15,996 for six months. Or the costs could be halved with only 2 static traps per week with testing. It is recommended that the traps are tested weekly for reliable resu
lts and NOT every two weeks. Or the testing schedule could begin timely May 1st, but be shortened by several months if the West Nile Virus infections are considerably less frequent and milder this year. (This testing cost does not include the cost for any treatment by larvicides or fogging.)
Standardized Testing and Effective Intergovernmental Communication
One serious problem last year was the lack of standardized testing procedures. Sometimes test results were comparing “apples to oranges”, instead of “apples to apples”. The State and the Center for Disease Control (CDC) are attempting to remedy that defect in 2013. Also, last year some adjacent governmental entities did not communicate effectively with each other (i.e. the City of Dallas and Dallas County). Hopefully this issue will be resolved in 2013 with all North Texas governmental bodies using identical testing standards AND timely communicating test results and planned actions with each other.
Usual Areas of Standing Water that become Mosquito Breeding Areas
Larviciding concentrates on eliminating the shallow, stagnant water that is a favorite breeding place for mosquitoes; and using larvicide dunks to destroy existing mosquito larvae before they can hatch. Favorite mosquito breeding places are in standing water in: saucers under outdoor plants, outdoor pet food bowls, shallow water troughs for livestock, tires stacked outside, roof gutters and down spout areas that don’t totally drain, bird baths, toy or yard wheel barrows and wagons that hold water, shallow outdoor fountains, ruts in roads and lawns that hold excess sprinkler and rainwater run off for several days, upright buckets left outside – even sandbox toys and trucks. Ponds with aerators and chemical and salt treated swimming pools generally are not mosquito breeding grounds. But a bottle cap holding stagnant water for a couple of days can breed mosquitoes. As can a landscape drain, which grass clippings fall into, that holds 1-2” stagnant sprinkler water for a few days. This stagnant water will attract female mosquitoes looking for undisturbed breeding sites. Larvicide pellets need to be pulverized and pushed through the landscape drain into the shallow standing water to eliminate a potential mosquito breeding ground.
Larvicide Dunks – the Easy and Effective Way to Eliminate Mosquitoes
Larvicide dunks are inexpensive and effective ways to destroy mosquito larvae. They can be placed in all the above locations for standing water. However, they are often under applied. One dunk will service a 16 foot square area by one foot deep. (But, that dunk is under-applied if the water depth is more than one foot deep.) The dunks are available at feed stores, plant nurseries, and in the yard sections of home improvement stores like Lowe’s and Home Depot. Beginning May 1st Copper Canyon will provide free dunks at Town Hall to Copper Canyon residents. (Just show your driver’s license with home address to identify yourself as a Town resident.) Many other towns also provide free dunks for their residents, as did Denton County last year for county residents.
Larvicide dunks placed in a stream with moving water may need to be replaced after every serious rain event. Or, the dunks can be put in mesh bags, that are anchored to the stream bed and do not flow away with rain events.
Vacant homes-lots-and acreage were a problem last year, if they had standing stagnant water or “green” unmaintained pools. Senator John Corona has sponsored a legislative bill that would allow municipal and county health officials to drain stagnant water and provide larvicide dunks where needed on vacant property without having to first locate and notify the absentee property owner. The prompt passage of Senator Corona’s bill would immediately alleviate these potential mosquito breeding sites before they become active.
If every homeowner and landowner will take individual responsibility for their property and eliminate any potential stagnant water mosquito breeding areas, the battle against West Nile Virus is predominantly won!
Adulticiding – Ground Fogging
Ground fogging can include personal backpacks for misting areas usually inaccessible to the fog from trucks. All-Terrain Vehicles (ATVs) can also be used to fog in wooded areas, large pastures, and other remote areas not served by paved or gravel surfaced roads. To be effective, fogging trucks usually need to move at a speed of no more than 2 to 3 miles an hour. (10-12 miles per hour vehicle speed does not allow the fog to drift in enough concentrated amounts to effectively kill flying mosquitoes.) A slight wind in the right direction is also a benefit in dispersing the fog. (MunicipalMosquito.com will not travel over private roads, unless the landowners sign a waiver of any potential liability claims.)
In addition, storm sewers can be thermal fogged and natural organic solutions can be used in environmentally sensitive locations.
“Resistance Testing” is invaluable prior to fogging. The City of Dallas did a little “resistance testing” last year through the federal Center for Disease Control. Dallas area mosquitoes were found to be 80% resistant to the #2 fogging material that Dallas had originally planned to use. Basic pesticides (that have long been used in an urban area on lawns, landscape areas, and parks) can leach into ponds, streams, reservoirs, and any standing water where mosquitoes breed. Area mosquitoes that are routinely exposed to these pesticides, over time, develop an in-bred resistance to that specific pesticide’s active ingredients.
Resistance testing for Copper Canyon’s 4 square miles would require 8 test sites and currently cost approximately $3,000. Mosquito contractors are actively trying to reduce the standard cost of resistance testing. Because, whatever toxin is included in fogging materials needs to have a high percentage of effective kill rate – especially for the species of flying mosquitoes prevalent in that specific geographical area.
This last option is one that we can only hope Denton County Commissioners will offer, and only if it is needed. Individual small towns can simply not afford the cost of aerial spraying. Last year Copper Canyon residents were overwhelmingly in favor of aerial spraying, by an over 4 to 1 ratio. And in retrospect, fears about contamination of pet water bowls and livestock troughs, animals harmed and bees and other beneficial insects killed, and fields and forests contaminated – simply did not happen. But, we don’t want to spray even diluted toxins into our air unless necessary to preserve human health and save lives.
However, if each individual systematically eliminates any standing stagnant water on their property that could provide a mosquito breeding area or larvicides it – and religiously protects themselves and their family members with mosquito repellant and wearing protective clothing at dawn and dusk when mosquitoes are flying – maybe we can prevent the potential of a West Nile Virus epidemic BEFORE it happens. Together, let’s try.
Public Education and Consulting
Overwhelmingly public education is the recognized cornerstone of an effective campaign against the West Nile Virus. There ARE things that each person living in North Texas can do to protect themselves and each of their family members. And each citizen can inform themselves about more details of how the disease spreads and how to combat it by learning from consultants.
NOTE: A “vector entomologist” is one who specializes in diseases that “vector” into humans from animals and insects. Vector entomologists from MunicipalMosquito.com offer general public education presentations on mo
squito control to Town staffs, Town Councils, and at Town Hall Events for residents. The firm also consults with a Town for developing a specific Integrated Mosquito Management (IMM) program and in-house training of the Town’s staff.
This article was first published in Copper Canyon Mayor Sue Tejml’s March 2013 column in The Cross Timbers Gazette.