“WHAT’S HAPPENING?”

The University of Tennessee/Agricultural Extension Service

Entomology & Plant Pathology - EPP #60

June 27, 2005

TENNESSEE MOSQUITOES TEST POSITIVE FOR WEST NILE VIRUS

by Karen M. Vail

On June 16, two mosquito pools positive for West Nile Virus (WNV) were recorded from Shelby County and became the first 2005 records of WNV in Tennessee. Fourteen other states have found the virus in mosquitoes, horses, birds, or sentinel animals. Human cases don’t usually start occurring until July; however, this year's first human case was reported from Kansas on June 22.

West Nile Virus is a mosquito-borne virus. Mosquitoes become infected when they feed on infected birds. They can then transmit West Nile Virus to humans and horses through mosquito bites. The virus is not spread from person to person, so prevention emphasizes reducing exposure to mosquitoes.

To reduce the risk of being bitten by a mosquito and of a subsequent mosquito-borne illness:

• Use a mosquito repellent that contains DEET, picaridin or oil of lemon eucalyptus and follow label directions.

• Reduce outdoor activities between dusk and dawn or wear protective clothing such as long pants, long-sleeved shirts and socks.

• Empty any receptacles that allow water to collect around your home and provide mosquito larval sites.

• Close windows and doors or cover them with screens to prevent mosquito entry.

In an earlier article I discussed the two products, picaridin, or oil of lemon eucalyptus,

that CDC is suggesting, in additional to DEET, as mosquito repellents. Here are some “dos” and “don’ts” associated with repellent use:

• Do not use DEET or picaridin on infants younger than 2 MONTHS.

• Children younger than 2 YEARS of age should not be exposed to oil of lemon eucalyptus.

• Do not placed repellents around the mouth or eyes at any age.

• Do not apply more than 30% DEET to children and infants more than 2 months of age.

Birds are often the first indicators of WNV in an area. Recently deceased crows and blue jays that have been kept cool after discovery are being tested for WNV in Tennessee. To find out more about testing procedures, contact your LOCAL health department to determine if they are conducting tests and for instructions on how to handle the birds. In the U.S. last year, 2,535 West Nile Virus human cases and 98 deaths were reported. In Tennessee, 14 human cases with no deaths and 15 equine cases were reported in 2004. In the past, most areas of Tennessee have had reports of WNV.

Most people, about 80%, that contract WNV are asymptomatic. Others may have fever, headache, and body aches, which may last only a few days. Less than 1% of those infected will have the severe form in which case the virus may cause meningitis or encephalitis and result in high fever, neck stiffness, stupor or disorientation. Some degree of muscle weakness or paralysis may be also be present.

For more information about West Nile Virus, visit the Department of Health’s Web site at tennessee.gov/health and access the “Featured Topics” section.

Form information on managing mosquitoes, see:

Mosquito Control Around Homes http://www.utextension.utk.edu/publications/pests/default.asp#home

Home Insect Control in the UT E&PP PB 1690 Insect and Plant Disease Control Manual

http://eppserver/redbook/sections/structural.htm

Public Health Pest Control: the Tennessee Mosquito Control Handbook

http://eppserver.ag.utk.edu/psep/secondlevel/thirdlevel/PHC/PHCindec.htm

Excerpted and modified from

Turner, A. 2005. June 16, 2005 Media Release: Tennessee Prepares for West Nile Virus Season; Two additional products provide protection from the disease. Tennessee Department of Health.

DARK SOUTHERN SUBTERRANEAN TERMITES ARE SWARMING

by Karen M. Vail

The cool, rainy spring kept the number of termite swarms to a minimum, but things have picked up the first two weeks of June. With temperatures rising and rains still occurring, Reticulitermes virginicus or the dark southern subterranean termite, a native to Tennessee, started making its presence known. Unusually large swarms were reported. R. virginicus is expected to fly through June and possibly into July.

Inquiries from Extension agents and pest management professionals (PMPs) indicate they are not as familiar with the dark southern subterranean termite as they are with the most common subterranean termite, Reticulitermes flavipes also known as the eastern subterranean termite. Both Extension agents and PMPs indicate they think this is a termite, but something about it is different and they can’t be completely sure.

As with other subterranean termite alates or winged forms, R. virginicus has 2 sclerotized veins in the foremargin of wing visible the entire length of the wing and a net-like wing membrane between veins. The alates body is dark brown to black which is the same as R. flavipes. However, there are several ways to help distinguish the alates of R. virginicus from R. flavipes:

• A R. virginicus alate is slightly smaller (7.0-9.5 mm from the front of the head to the tip of the wing) than R. flavipes (8.5 to 10.5 mm ).

• The distance between R. virginicus’ simple eye or ocellus and its compound eye is less than the width of the simple eye.

• R. virginicus’ veins in the costa region are whitish and R. flavipes’ are light brown.

• R. virginicus’ wing membrane is nearly transparent and R. flavipes may be considered slightly yellow brown. This character may not be as reliable as the others.

Images of these and other termite alates can be found in Chapter 2 and Appendix B Color Image References of the Wood-destroying Organisms Licensing manual at http://eppserver.ag.utk.edu/psep/secondlevel/thirdlevel/WDO/WDOindex.htm

Control options for our native subterranean termites are similar. See the WDO manual mentioned above or PB1344 Subterranean Termite Control (http://www.utextension.utk.edu/publications/pests/default.asp#home) for control options. A current list of pesticides to be used against termites can be found in the PB1690 E&PP Insect and Plant Disease Control Manual under Home Insects (professional), http://eppserver.ag.utk.edu/redbook/sections/structural.htm.

FIELD CROP UPDATE

by Russ Patrick

Corn :

No serious problems have been reported to date. Probably, the European Corn borers will find homes in non-resistant corn. Bt corn varieties do a very good job controlling corn borers, including Southwestern Corn Boreres which attack late season corn.

Wheat:

With wheat harvest underway, it looks as if there have been no problems with armyworms this year.

Soybeans:

Aphids, no real problems with soybean aphid at this time. However keep looking for them, as well as for stinkbugs which can cause a great deal of damage if they are left untreated.

Stored Grain:

Hopefully, most of the grain bins were pretreated before the grain went in the bin. See the previous issue of What's Happening for more information.

Disclaimer Statement

Pesticides recommended in this publication were registered for the prescribed uses when printed. Pesticide regulations

are continuously reviewed. Should registration or a recommended pesticide be canceled, it would

no longer be recommended by the University of Tennessee.

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.

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.

Visit the UT Extension Web site at http://www.utextension.utk.edu

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