“WHAT’S HAPPENING?”
The University of Tennessee/Agricultural Extension Service
Entomology & Plant Pathology - EPP #60
September 8, 2006
FIRST WEST NILE VIRUS HUMAN DEATH OF 2006 OCCURS IN RUTHERFORD COUNTY
Karen M. Vail
On August 31, 2006 the Tennessee Department of Health announced that a middle Tennessee resident had died of West Nile Virus (WNV) earlier in the week. This is the first Tennessee human WNV death recorded in 2006. The patient was 70 years old. Last year, one Tennessean died of West Nile Virus while 17 others survived.
West Nile Virus, a mosquito-borne virus, was first recorded in the US from New York in 1999 and has since been found in most of the continental US. Most infected people, about 80% of the WNV cases, will be unaware they are infected and will remain symptomless. The other 20% may develop flu-like symptoms such as fever, headache, muscle aches and pains, stiff neck, nausea, weakness, vomiting, and rash. Some of these cases may become severe and the patient may experience confusion, convulsions and brain swelling. The elderly are most at risk with those over 50 yrs of age more likely to develop a severe case and those over 70 with compromised health at the greatest risk of death.
How do you reduce the risk of becoming infected with West Nile Virus?
Protect Yourself by Reducing Exposure to Mosquitoes
• Wear repellent when outdoors. This is especially important at dawn and dusk
when Culex spp. , the primary vector of WNV, is active.
Of the repellent active ingredients registered with the EPA, products containing DEET (N,N-diethyl-m-toluamide) or Picaridin (KBR 3023) typically provide longer-lasting protection than others. Repellents containing oil of lemon eucalyptus [p-menthane 3,8-diol (PMD)], typically provided protection similar to repellents with low concentrations of DEET. More information on repellent use can be found at the CDC web site http://www.cdc.gov/ncidod/dvbid/westnile/qa/insect_repellent.htm
• When possible, wear long sleeve clothing, pants and socks.
• Avoid areas where adult mosquito populations are high.
• Avoid shaded locations and locations with overgrown vegetation where mosquitoes may be resting or waiting for a meal.
• Repair window and door screens if they are torn.
Reduce mosquito larval habitat around your home
• Remove containers or similar objects such as soda cans, tires, buckets, plastic sheeting and others from areas surrounding your home.
• Do not allow water to remain in flower pot bases or pet dishes for longer than a week.
• Clean gutters, downspouts, roofs, etc. to remove leaves and other debris that may hold
standing water.
• Water in bird baths and children’s wading pools should be changed at least once a
week.
• Tree holes or stumps often contain water. Drain them or fill them with sand or mortar.
• Water the landscape so standing water cannot accumulate for more than a few days.
• Inspect animal water troughs and surrounding ground for larval mosquitoes and
change water if necessary.
• Fill or drain depressions left by tires.
• Stock a small garden pool or ornamental pond with mosquito-eating fish such as
• native top-feeding minnows or goldfish.
• Make sure covers on pools and boats do not retain water.
• Cover rain-collecting barrels with a 16-mesh screen.
The Tennessee Department of Health does not typically recommend spraying adulticides as the only means of mosquito control. Counties, municipalities and other entities do not usually have the needed budget and trained personnel to conduct an effective abatement program (http://eppserver.ag.utk.edu/personnel/Vail/TNDOH_Co_Dirs_Mtng.pdf). For these reasons, an emphasis is placed on personal protection and reducing larval habitat.
For more information on Tennessee mosquitoes and their management see:
Vail, K. K. Gottfried, and R. Gerhardt. 1998. Mosquito Control Around Homes http://www.utextension.utk.edu/publications/pests/default.asp#home
Vail, K. 2006. Home Insect Control in the UT E&PP PB 1690 Insect and Plant Disease Control Manual http://eppserver/redbook/sections/structural.htm (Lists current pesticide suggestions)
Vail, K., G. Burgess, R. Gerhardt and C. Jones. 2002. Public Health Pest Control: the Tennessee Mosquito Control Handbook
http://eppserver.ag.utk.edu/psep/secondlevel/thirdlevel/PHC/PHCindec.htm
Vail, K.M., E.E. Burgess, R. Gerhardt, C. Jones, J. Skinner and C. Harper. 2003. PB1733. Public Health Pest Control (Certification Category 8). University of Tennessee Extension
http://eppserver.ag.utk.edu/psep/secondlevel/thirdlevel/C08/C8index.htm
Anonymous. 2006. First Human West Nile Virus Death of 2006 Confirmed
Tennessee Department of Health Press Release. http://www2.state.tn.us/health/newsreleases/083106.htm
Anonymous. 2006. Repellents are an important tool to assist people in protecting themselves from mosquito-borne diseases. http://www.cdc.gov/ncidod/dvbid/westnile/RepellentUpdates.htm
Barnard DR, Xue RD. Laboratory evaluation of mosquito repellents against Aedes albopictus Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). J Med Entomol. 2004 Jul;41(4):726-30.
Fradin MS, Day JF. Comparative efficacy of insect repellents against mosquito bites. N Engl J Med. 2002;347(1):13-8.
DOZENS OF LARVAL LONE STAR TICKS ATTACHING TO PEOPLE
Karen M. Vail
I’ve been receiving calls about numerous large mites biting people. Upon further inquiry and an occasional specimen submission we assume that most of these calls have been referring to larval or seed ticks of Amblyomma americanum, the lone star tick. Larval or seed ticks have six legs as they hatch from the egg mass which may contain thousands of eggs. Upon hatching the 1/40-inch long seed ticks seek a host, thus a person can walk through this area and be attacked by dozens or more seed ticks. The bite site may itch for about 10 days or even longer if the area is scratched and becomes infected. All three stages of the lone star tick can attach to people. In other ticks, such as the American dog tick, it is usually the adult stage that attaches to humans.
High tick populations tend to be found in areas of tall grass or overgrown vegetation and are less likely to be found in open, sunny areas with low humidity because they tend to dessicate or dry out. To reduce the risk of tick attack when outdoors,• wear light-colored clothing so ticks are easier to see;.
• tuck pants into socks and tape over the pant/sock interface and tuck shirt into pants to keep ticks on the outside where they can be more easily detected;
• use repellents such as DEET on the skin and permethrin-based clothing treatments (Permanone) on lower pant legs; and
• use the buddy system to regularly inspect you and any companions and remove ticks as they are found (if a buddy isn’t available, a mirror can help to see difficult to reach areas).
Upon arriving home, remove clothing and wash in hot water and detergent and dry. If washing immediately is not an option, put the potentially tick-contaminated clothing into a plastic bag and seal until it is washed. Ticks may climb off your clothing onto furniture or disperse from the laundry pile if clothing is not washed or sealed immediately.
At least one of the callers mentioned that they had been finding ticks in the home for several weeks. In this case, vacuuming and steam cleaning may help remove ticks from the indoor environment. However, if the problem persists, insecticides will need to be applied into cracks and crevices.
Protect pets from tick attack by using products labeled for tick control on pets and regularly inspecting them for ticks too.
Pesticide suggestions for pets, homes and outdoor environments can be found in the UT E&PP PB 1690 Insect and Plant Disease Control Manual (http://eppserver.ag.utk.edu/redbook/pdf/homeinsects.pdf)
What is the best way to remove a tick?
1. Grasp the tick as close to the skin surface as possible with fine-tipped tweezers and pull upward with steady, even pressure.
2. Do not squeeze, crush, or puncture the body of the tick because its fluids (saliva, hemolymph, gut contents) may contain infectious organisms. Don’t use petroleum jelly or lit match sticks to attempt tick removal.
3. After removing the tick, treat the bite site as any other skin wound and wash your hands with soap and water.
4. You may wish to save the tick for identification in case you become ill within 2 to 3 weeks. Your doctor can use the information to assist in making an accurate diagnosis. Place the tick in a plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag.
Lone star ticks are not believed to be vectors of Lyme disease; however, they are the primary vector for human ehrlichiosis caused by Ehrlichia chaffeensis (http://www.cdc.gov/ncidod/dvrd/ehrlichia/Index.htm) and have been attributed to the condition known as Southern Tick Associated Rash Illness (STARI). STARI is estimated to be in about 1% to 3% of Lone star ticks. The rash is a red expanding bulls-eye area (similar to Lyme disease) that develops around the site of a lone star tick bite. The rash appears within about 7 days of the bite and expands to a diameter of about 3 inches. This rash is much bigger than the red area at the bite site. STARI may include fatigue, fever, headache, muscle and joint pain. The cause of STARI is not known but the rash and symptoms respond to treatment with oral antibiotics (http://www.cdc.gov/ncidod/dvbid/stari/index.htm)
It is unlikely that a bite from a lone star seed tick, which has not fed upon a host, could transmit any disease-causing organisms.
Modified and excerpted from:
Townsend, L. 2006. LONE STAR TICKS ACTIVE AGAIN. Kentucky Pest News Number 1106, Aug 21, 2006. http://www.uky.edu/Ag/kpn/kpn_06/pn060821.htm#humlon
ENVOKE HERBICIDE
Gene Burgess
TDA has recently approved a Section 24c, Special Local Need Registration, for Envoke (trifloxystrobin) herbicide for the control of winter weeds in cotton, including glyphosate-resistant horseweed.
FALL ARMYWORMS MAKE AN IMPACT
Frank A. Hale
A week ago Thursday at the Turfgrass Field Day in Jackson, I had many questions about fall armyworms. Besides bermudagrass pastures, many home lawns had been attacked over the last three weeks or so. The last instars (larger size caterpillars) can strip a lawn in 2-3 days. Several of the turf managers noted that lawns with sod laid this spring or summer had been attacked. Dr. Scott Stewart called me a few days ago from Jackson and conveyed the same observation. In addition to turfgrass, a large milo field was reported to have been severely attacked in Warren County in Middle Tennessee.
I queried fellow turfgrass entomologists for further insight into this pest. Dr. Steve Bambara from NCSU has a nice information note on fall armyworms at: http://www.ces.ncsu.edu/depts/ent/notes/O&T/lawn/note128/note128.html
Steve said that this year most of the fall armyworm reports have been in western North Carolina. In past years, he has also seen most of the damage on new sod, especially near outside lighting. Damage often starts near the house or porch lighted areas or along the street light area. The moths are attracted to the lights and lay the majority of their eggs on shrubs, fences etc. near the houses. The damage usually is not as bad on established turf, possibly because it is a more balanced ecosystem (more pathogens, predators, parasitoids present) and generally more resilient. Dr. Robert Bauernfeind at Kansas State University states that established turf mowed down by fall armyworms quickly responds to an irrigation and looks fine after10 days or so. Newly laid sod is less able to bounce back/tolerate fall armyworm feeding.
Dr. Eileen Buss at the University of Florida noted that fall armyworms tend to prefer feeding on newly fertilized turfgrass and most newly laid sod receives some fertilizer. A general rule of thumb used in Florida is to not fertilize warm season turfgrass in late summer to reduce the chance of having fall armyworm outbreaks in the late summer and fall.
RISK MANAGEMENT AND TOLERANCE REASSESSMENT DECISIONS ANNOUNCED FOR METHYL BROMIDE COMMODITY USES
Gene Burgess
EPA has completed its review of the commodity uses of the fumigant methyl bromide. To reduce potential risks of concern to workers and bystanders from acute inhalation exposure, the Agency is requiring a number of mitigation measures, including site-specific fumigant management plans,
respiratory protection, buffer zones, posting, and notification. Combined with the methyl bromide phase-out mandated by the Montreal Protocol, many of these measures will further reduce potential health risks from ozone depletion, such as skin cancer. EPA has determined that methyl bromide's
commodity uses are eligible for reregistration and its tolerances meet FQPA safety standards, provided that risk mitigation measures identified in the methyl bromide decision document are adopted and product labels are amended accordingly.
Methyl bromide is a broad-spectrum fumigant with a variety of pest control uses. Its use is being phased out under the Montreal Protocol; however, critical use exemptions will still be available under special
circumstances. While most often used as a soil fumigant, methyl bromide also is used as a structural fumigant and for post-harvest treatment of commodities. The current decision document covers methyl bromide uses that have accompanying food residue tolerances for post-harvest fumigation
of food commodities in chambers at ports, or specialized structural fumigations at food processing facilities. Although some methyl bromide uses such as fumigation of timber, wood products, and industrial equipment do not require a food residue tolerance, the Agency has included them in
the current decision since they are performed in similar facilities and were assessed using a similar risk assessment methodology.
EPA is currently assessing risks and will be developing risk management decisions for five soil fumigant pesticides: chloropicrin, dazomet, metam sodium, methyl bromide, and a new active ingredient, iodomethane. Risks of a sixth soil fumigant, 1,3-D (Telone), will be discussed for comparative purposes; the Telone risk management decision was completed in 1998. The Agency is evaluating these soil fumigants concurrently to ensure that human health risk assessment approaches are consistent, and
that risk tradeoffs and economic outcomes can be considered appropriately in reaching risk management decisions. A decision on the reregistration of methyl bromide's pre-plant soil fumigation uses is scheduled to be completed in 2007 with the other soil fumigants.
RISK MANAGEMENT AND TOLERANCE REASSESSMENT DECISION ANNOUNCED FOR METALDEHYDE
Gene Burgess
EPA has completed its review of the supported uses of metaldehyde, a molluscicide used to control snails and slugs on a wide variety of sites including turf, ornamentals, berries, citrus, and vegetables. The Agency has determined that all of metaldehyde's supported uses, except turf and dichondra lawns, are eligible for reregistration; and, its sole tolerance meets the FQPA safety standard, provided that risk mitigation measures identified in the Metaldehyde Reregistration Eligibility Decision (RED)
are adopted and product labels are amended accordingly. Registrants also must submit confirmatory data and domestic animal incident monitoring results to help the Agency determine whether the risk mitigation
adequately reduces pesticide poisonings among domestic animals.
Metaldehyde poses no dietary, residential, or worker human health risks of concern. To further deter children and toddlers from accidental ingestion, a bittering agent currently in some products will be included in all residential use products. However, incident information suggests that many domestic animals, mainly dogs, are poisoned after ingesting metaldehyde pellets applied to home lawns and gardens as snail and slug baits. Birds and animals are also assumed to be at risk. To reduce risks
to dogs, other domestic animals, and wildlife, the Agency is requiring a number of mitigation measures for residential use products, including:
* reduce numbers of applications and application rates
* add minimum retreatment intervals
* prohibit broadcast and foliar applications
* update product warnings and use directions
* provide information on cultural practices to reduce damage from snails and slugs
* always include bittering agents
* to discourage animals from mistaking metaldehyde pellets for food, formulate granular products at a rate of fewer than 35 pellets per gram
* submit data on the efficacy of metaldehyde products formulated with non-food-based inerts and bulking agents
TAKEN FROM EPA PESTICIDE UPDATES
ACIDIC SOIL, MANGANESE TOXICITY IN TOBACCO
Darrell Hensley
Manganese is an essential plant nutrient, but when available in excessive amounts within the soil, tobacco plants may not function properly. Manganese toxicity is greatly affected by soil acidity (low pH). Growers and production specialists often use either term (manganese toxicity or low pH) to explain poor growth due to manganese toxicity. As soil becomes more acid, greater amounts of manganese are available, and tobacco plants take up more manganese than they need for normal growth. Symptoms of
manganese toxicity occur early in the growing season soon after plants are transplanted or established in the field. Severely affected leaves develop a light green or yellowish color (chlorosis) between veins while the midrib and lateral veins remain dark green. These symptoms are very similar to those for iron deficiency. Plants grow slowly and the chlorotic spots on the older leaves turn brown and eventually die and fall from the leaf. Such leaves become less sound, weigh less at harvest, and are trashy and of low quality after curing. Under moderate conditions, plants recover from the disease about mid-season and only leaves on the plants' lower portions are affected. However, the disease may be so severe under
some conditions that plants become badly stunted or die. The disease is less severe in years with above normal temperatures. Generally, this problem is observed sporadically across the field or may be observed in areas skipped by fertilizer spreaders or in low or high areas of the field. Often low soil pH may be confused with other production problems such as herbicide injury caused by Spartan. Tomato spotted wilt virus (TSWV) a disease, may also be confused with low pH due to its stunting nature, however additional symptoms can help visually identify it from manganese toxicity.
The best way to control manganese toxicity is to lime soils to pH 6.5 for burley or to 6.0 for dark tobacco. Soil test recommendations are based on these target levels. Avoid over-liming, as higher pH levels encourage black root rot disease. Summer and fall are good times to apply lime since the soil is dry, dealers in agricultural lime are not as busy and the lime applied can react over the winter. Avoid using higher than recommended rates of fertilizers, as the acidifying effect of fertilizers lowers the soil pH. When manganese toxicity is observed, do not add fertilizer to try to correct the problem, as this will only make it worse.
In past years, the Nashville diagnostic laboratory has received many tobacco samples which have tested with low soil pH. So if growers have noticed any problems with irregular growth within the field this year, they may want to take soil samples this fall to avoid problems and prepare for next season.
EPA FINDS ORGANIC ARSENICAL HERBICIDES INELIGIBLE FOR REREGISTRATION
Gene Burgess
EPA has announced its decision that all uses of the organic arsenic herbicides -- MSMA, DSMA, CAMA, and cacodylic acid -- are not eligible for reregistration. The Agency's primary concern is the potential for applied organic arsenical products to transform to a more toxic inorganic form of arsenic in soil and subsequently be transported to drinking water.
The Agency's risk assessment, supported by field monitoring data in both surface and ground water, estimates levels of inorganic arsenic in drinking water from the pesticide use that raise a concern for cancer risk. Given this risk, EPA has determined that the tolerances for the organic arsenic herbicides do not meet the safety standard of the Federal Food, Drug, and Cosmetic Act (FFDCA). In addition, because there are readily available alternatives, EPA believes continued registration of the organic arsenic herbicides will pose an unreasonable risk under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).
The element arsenic is found naturally in the environment. Through erosion and industrial activities, arsenic is transported into water, air, food, and soil. As a result, people are exposed to small amounts of
arsenic every day. EPA and other federal and state agencies have regulations in place that aim to reduce or limit arsenic exposure to individuals. In light of these facts, and given that alternative herbicides are readily available, EPA believes additional exposure to arsenic from the organic arsenic herbicides is unnecessary.
The organic arsenic herbicides are used primarily on cotton and turf, including golf courses, home lawns, recreational areas such as school yards and athletic fields, and rights-of-way. Overall, use in the U.S.
appears to be declining, and alternative weed controls are available for each of these uses.
TAKEN FROM EPA REGISTRATION REVIEW
OTHER UT NEWSLETTERS WITH PEST MANAGEMENT INFORMATION
http://web.utk.edu/~extepp/fpn/fpn.htm
Tennessee Crop and Pest Management Newsletter
http://www.utextension.utk.edu/fieldCrops/cotton/cotton_insects/ipmnewsletters.htm
This and other "What's Happening" issues can be found at http://web.utk.edu/~extepp/whatshap.htm
Disclaimer
This publication contains pesticide recommendations that are subject to change at any time. The recommendations in this publication are provided only as a guide. It is always the pesticide applicator's responsibility, by law, to read and follow all current label directions for the specific pesticide being used. The label always takes precedence over the recommendations found in this publication.
Use of trade or brand names in this publication is for clarity and information; it does not imply approval of the product to the exclusion of others that may be of similar, suitable composition, nor does it guarantee or warrant the standard of the product. The author(s), the University of Tennessee Institute of Agriculture and University of Tennessee Extension assume no liability resulting from the use of these recommendations.
Precautionary Statement
To protect people and the environment, pesticides should be used safely. This is everyone’s responsibility,
especially the user. Read and follow label directions carefully before you mix, apply store or dispose of a pesticide. According to laws regulating pesticides, they must be used only as directed by the label.
Persons who do not obey the law will be subject to penalties.
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