“WHAT’S HAPPENING

MOSQUITO FACT SHEET AVAILABLE

by Darrell Hensley

The Environmental Protection Agency (EPA) has a new Web fact sheet on outdoor residential misting systems, also known as mosquito misting systems. This fact sheet should help consumers decide if residential pesticide misting systems are appropriate for their home, understand safety precautions

for using outdoor misting systems, find related information on a variety of methods for mosquito control, and understand the role of the EPA and state agencies in regulating mosquito misters.

The EPA developed this fact sheet because an increasing number of households have purchased timed-release outdoor residential misting systems to control mosquitoes and other insects around the home. However, advertisers, the media, and other sources sometimes provide information about misting

systems that is difficult to understand or might conflict with other information. The new Web page describes outdoor residential misting systems and discusses the pesticides used in the systems, their safety and effectiveness, and the regulatory authority of EPA and state governments regarding misting

systems. The Outdoor Residential Misting Systems fact sheet is available on EPA's Web site at http://www.epa.gov/pesticides/factsheets/misting_systems.htm.

ODOROUS HOUSE ANTS: THE MOST COMMON STRUCTURE- INVADING ANT IN TENNESSEE

by Karen M. Vail

The odorous house ant (OHA) is one ant species that can be driven indoors by rain or changes in temperature. OHA has been ranked as the number two pest ant in the U.S. and is probably the most common structure- invading ant in Tennessee. This small black ant, about 1/8 inch long, is easily distinguished from other dark ants by its one-segmented waist with a very flat, barely noticeable node or bump hidden by the abdomen. There is another way to distinguish this ant. Crush an ant between the fingers and if it smells of a “disagreeable, rotten-coconut like” odor possibly mixed with pine, then it’s the odorous house ant. Nests are shallow and often found in shady, moist areas such as in or under mulch, pine straw, leaves, stones and logs. If given the opportunity, small satellite colonies may exist indoors too and are often located near a moisture, food and/or heat source. In many cases, a connection is maintained with the outdoor colony as evidenced by the movement of dyed food from the indoor colony to outdoor ants. Thus management efforts can often be conducted on the outside of the structure and still affect the indoor ants. More information on OHA and other ants can be found in PB1629, Managing Structure-Invading Ants (http://www.utextension.utk.edu/publications/pests/default.asp) .

If these indoor ant populations do not recede with the rains or weather change, they are best managed by a pest management professional (PMP) because PMPs have access to baits and slower-acting, nonrepellent insecticides that are generally unavailable to the homeowner. We have been conducting research on this ant since 1998. To date, our successful results for reducing indoor and outdoor odorous house ant populations around homes were obtained with a slower-acting, nonrepellent spray of 0.06% fipronil (Termidor SC), applied to the outdoor foundation base 1 foot up and out, the outdoor entry points and outdoor trails combined with a bait in the landscape or another slower-acting spray to the interior. Baits or sprays that have performed well in combination with Termidor include the following:

• a 1.3% borax experimental liquid bait (now registered as PT381B Advance Liquid Ant

Bait) applied in stations in the landscape near the structure where ants were active; OR

• a 0.5% chlorfenapyr (Phantom) spray applied to interior cracks and crevices with an

NPD sprayer where ants were seen or were likely to enter; OR

• a 5.4% borax experimental gel bait (now registered as PT388B Advance Ant Gel Bait)

applied crack and crevice on the outside of the structure or on landscape elements

near the structure where ants were active; OR

• an interior pyrethroid spray (Suspend SC containing deltamethrin) and/or dust

(DeltaDust containing deltamethrin) applied to a crack and crevice where ants

were seen. The interior pyrethroid applications by themselves did not

satisfactorily control the OHA found inside or outside.

Other insights gleaned from our research include the following:

• Termidor alone at label rates did not eliminate OHA indoors very quickly from all houses, so it should be applied in combination with an exterior bait or with an interior Phantom spray to kill OHA indoors and out!

• When heavy rains occurred, baits in stations provided longer control than sprays applied at low volumes, such as 1.5 gallons/1000 sq. ft.

• Bifenthrin (pyrethroid) applied, without a bait in the system, to the exterior foundation at more than 1.5 gal/1000 sq. ft and to areas greater than 1 ft up & out effectively controlled OHA outside, but not inside.

• Gel baits can be difficult for the ants to manipulate and results are often inconsistent. Gel baits may work better when applied in a station. An experimental bait worked in a outdoor station, but failed when applied outdoors as a crack and crevice treatment. A gel bait may work outdoors, but fail indoors or vice versa. The same experimental bait that worked in the field in a station was not effective in the laboratory. Also, Gourmet gel had worked in the lab in previous years, but recently it did not work outdoors in the field or in the lab. Manufacturers may change formulations and what we tested in the lab several years ago may not be the same product being used today. We have evaluated gel baits that look very promising, but cannot release the information at this time.

In our laboratory, we have evaluated many baits for use against small laboratory colonies of odorous house ants. However, one should be cautioned about making the assumption that the results of a small laboratory colony will reflect the results of a bait applied to a structural infestation or even to a large laboratory colony. We just don’t know how well any of these baits would be transferred around a large odorous house ant colony. Baits that have proven effective against our small laboratory colonies of OHA, i.e., killed all odorous house ant colony members within 8 weeks of bait introduction and are still registered for use in Tennessee, include gel-type baits such as Terro Ant Killer II (5.4% borax) which is more like a syrup than a gel, Gourmet Ant Bait Gel (6% disodium octaborate tetrahydrate),Whitmire Micro-Gen experimental gel bait (now registered as PT388B Advance Ant Gel Bait, 5.4% borax), and PRO-JOE-S Ant Bait/Gel Formula 4.5 (4.5% boric acid); granular baits such as Maxforce Fine Granule Insect Bait (1% hydramethylnon), the NEW Niban baits (5% orthoboric acid), and liquid baits such as Terro Ant Killer II or Terro-PCO (diluted to 2% or 1 % borax), Whitmire Micro-Gen experimental liquid bait (now registered as PT381B Advance Liquid Ant Bait, 1.3% borax), and Gourmet Ant Bait Liquid (0.5% or 1% disodium octaborate tetrahydrate).

If a homeowner insists on attempting control themselves, they may try baiting with Terro Ant Killer II or other baits that have a sweet or protein attractant and a slower-acting toxicant such as hydramethylnon, boric acids, borax, disodium octaborate tetrahydrate, etc. Typically, baits with an oil attractant, such as those produced for fire ants, are not fed upon by OHA. After baits are placed, they should be observed for feeding. If the ants won’t feed on the bait, it doesn’t matter how effective they are, they aren’t going to work and you’ll need to try another bait. There’s a trick to using the Terro Ant Kiler II. This bait’s carrier and attractant appear to be corn syrup which tends to dry with time and crust over. Dry, crusty baits may not be as attractive to ants as a liquid bait. Therefore, replenish the bait as it dries. The manufacturer has overcome this problem by also distributing this bait in prepackaged stations. Terro Ant Killer II may take 5 to 8 weeks to completely eliminate a colony.

Pyrethroid (bifenthrin, cyfluthrin, permethrin, etc.) sprays are usually fast-acting. If a perimeter application of a pyrethroid was made to the outside foundation and entry points, and ants were nesting indoors, ants may remain in the home, thereby causing further annoyance to the residents. Homeowners have easy access to pyrethroids and therefore must be very careful to prevent this from happening. If a pyrethroid perimeter treatment has already been applied and ants have been “sealed” in the home, adding a bait indoors may help.

Rain is a precursor to mating flights in many ant species and subterranean termites, so not only are we bothered by the wingless worker ants, but the winged reproductive forms may become a nuisance too! After spring rains, I would expect to see mating flights on calm, warm, sunny days. Male odorous house ants usually fly from about mid-May to the end of June in Knoxville. If you receive winged ants, please ask the client for specimens of the wingless workers. Most identification keys are written for the major workers. While I am familiar with many ants found in Tennessee, it is difficult to distinguish between some species because the shape of the thorax has been modified to accommodate the wings. For example, the shape of the workers’ thorax is needed to distinguish the wood-destroying carpenter ant from the nuisance field ant. The winged female of the large yellow ant is also difficult to distinguish from the carpenter ant and field ant, but fortunately, it smells like lemons when crushed. So, the next time you receive an ant for identification (as long as it does not have a stinger!), give it a squeeze and add the description of the emitted odor to the specimen submission form.

Combination treatments are the key to controlling odorous house ants inside and outside of structures. Combine a slower-acting insecticide, such as Termidor, as a perimeter treatment with an effective bait, preferably in a station, in the landscape or with a Phantom crack-and-crevice spray to the interior. We still need to test the efficacy of combining a wide pyrethroid perimeter spray in combination with an effective bait to see if this combination can reduce OHA numbers both indoors and out.

The Environmental Protection Agency (EPA) has posted on its Web site three documents that are designed to communicate the role of EPA's National Pesticide Field Program more clearly. The documents explain the vital importance of a strong field program to help the Office of Pesticide Programs accomplish its goals. EPA's National Pesticide Field Program is made up of the frontline implementation activities carried out by states, tribes, and EPA Regional pesticide experts and associated partners. Among other activities, this program helps protect agricultural workers; provides certification and training for users of some of the more hazardous pesticides to enhance competence and insure safe use; promotes protection of endangered and threatened species; collaborates in protecting the nation's water supplies from pesticide risk; and promotes comprehensive protection programs, such as Integrated Pest Management.

The three documents they have posted are:

“a short question and answer piece that addresses the key questions related to the National Pesticide Field Program”;

“an expanded discussion of the field program's contributions to national pesticide program public health and environmental protection goals”;

and “a description of the goals of the national program, and the contributions of the field programs, including examples in which the interaction between regulatory partners has proved beneficial.”

These documents are available on EPA's Web site at http://www.epa.gov/pesticides/about/fieldprograms/fieldprograms.htm.

COLD WEATHER AND INSECTS: WHAT CAN WE EXPECT

by Frank A. Hale

Can there be a silver lining to this freezing dark cloud? Many insects become active each spring as the new spring growth occurs. There have been a number of reports this spring of spring and fall cankerworm feeding on many types of trees in the landscape. There was definitely the potential for partial or even complete defoliation on some trees in Nashville and other areas. I checked trees here at the Ellington Agricultural Center on Monday and Tuesday to see if the cankerworms were alive or dead. I found them on branches of trees with blackened foliage, alive and well although definitely well chilled. I do not know if these caterpillars will starve before new foliage is produced, but that is a possibility. We will just have to see. Many trees such as maples and elms did not loose their foliage and foliage feeding on those trees should continue as expected.

Red maples are attacked each April by a maple shoot borer that attacks the developing shoots. The window of opportunity for applying a protective spray of Talstar is very narrow and the proper spray timing is determined by the tree phenology. Growers need to spray the foliage with when the first two pair of leaves emerge in order to kill the tiny caterpillar before it tunnels into the shoot. Once inside, the caterpillar is safe from contact insecticides and its tunneling quickly kills the shoot. This phenological

stage on red maple has already occurred here in Nashville and live maple shoot borers can be found within wilting shoots. While it might have been even colder in some of the nursery growing areas in the state, we need to assume that the maple shoot borers are alive and well. Apply a protective application of Talstar soon when the shoots produce the first two pairs of leaves.

Euonymus scale crawlers emerge should have emerged prior to the freeze and moved to the new spring foliage. Since this new foliage has been killed, most of the crawlers should die also. Some will possibly survive on the older leaves and stems. After pruning off the dead leaves, you can either apply a clean-up foliar spray of summer horticultural oil, TriStar 70 WSP, or Safari 20 SG or just wait and watch. You will have a couple more generations this growing season to target crawlers with a spray. Note that Safari 20 SG can also be applied to the soil as a drench for long lasting control.

Eastern tent caterpillars were apparently unfazed by the cold. These fuzzy caterpillars often group together in the protective nest and they are apparently able to deal with fluctuating spring temperatures. Some mature larvae have already begun to move to the ground where they will spin a silken white cocoon. If you see a fuzzy grey caterpillar walking across the road in the next few weeks or so, it is probably eastern tent caterpillars.

While these are just a few examples, it appears with such a mixed bag, that we should assume that the insects are still ticking, unless there is evidence to the contrary. Note that the latest edition of the on-line UT newsletter, Fruit Pest News, addresses maintaining reduced insect and disease control programs for fruit crops that have been devastated by the freeze.

SOME COLD INJURY MAY BE HIDDEN ON ORNAMENTAL PLANTS IN LANDSCAPES

by Alan Windham

Most cold injury to ornamental plants and shade trees is readily apparent to the laymen. However, some gardeners may mistakenly think they have dodged a bullet when examining their azaleas. Damage to flower buds and blooms of azaleas is fairly easy to detect, but what may go unnoticed for weeks is damage to the main stem. I have seen several azaleas with healthy looking foliage with bark splitting on the main stem. The cambium layer of the stem was killed over the weekend; the result is a splitting and pulling away of the bark from the stem. This is considered catastrophic damage to an azalea and is usually fatal although death may not come for several weeks. You may have clients coming to your office in early June with dead azaleas, that may not react well to a diagnosis of cold injury. So be advised and examine any azaleas to be purchased for symptoms of cold injury. No doubt there will be azaleas in the retail market this spring and summer that will have this injury. Buyer beware.

SOYBEAN FUNGICIDE SEED TREATMENTS FOR 2007

by Melvin Newman

Several plant pathogenic fungi attack soybeans in the early seedling stages of growth VE to V4. In wet, cool soil Phytophthora sojae, Pythium spp. and Rhizoctonia solani can be very destructive to seed and seedlings. Symptoms of Phytophthora and Pythium infection may include soft decay of the seed, missing seedlings in the row, chlorotic and wilting leaves followed by necrosis with leaves remaining attached. Rhizoctonia may cause reddish-brown lesions on the taproot, hypocotyls and lower stems, wilting and death of the leaves and stunting of the whole plant.

Some soybean varieties may have full are or partially resistance to Phytophthora and that may help, but there are many races of this fungus. There is no research available in Tennessee on resistance to Phytophthora. So, fungicide seed treatments are important. Especially useful are the products with the fungicides metalaxyl or mefenoxam (apron) as a premix with other fungicides. (see table below)

It is recommended that all soybean seed be treated with a fungicide for best yields, especially when planting early into no-till or into killed wheat debris. Follow recommended rates stated on the labels. But remember that treated seed can not be sold for feed or food. So, treat only enough for planting purposes for this year.

PLANT & PEST DIAGNOSTIC HIGHLIGHTS

by Bruce Kauffman

We received 45 samples from March 28 to April 9, 2007 including 18 samples via the UT Distance Diagnostic Web Site.

TOBACCO and FIELD CROPS :

Cold damage to corn; powdery mildew on wheat; wheat spindle streak virus.

ORNAMENTAL :

Winter drying and/or injury of boxwood, camellia, holly, dwarf Colorado blue spruce, arborvitae, magnolia; excessive irrigation of yew and boxwood; volutella leaf and stem disease of pachysandra; kabatina twig blight of cedar; botrytis blight of vinca; stigmina needlecast disease on spruce; heterosporium leaf spot of iris; smooth patch disease of ash bark; canker and winter injury to Japanese holly; root rot and xanthomonas leaf spot of English ivy; Phomopsis twig blight, iron deficiency of azalea; leaf spot of pieris; phyllostica leaf spot of rhododendron; tar spot of Chinese holly leaves; cedar-hawthorn rust of Washington hawthorn; procerum root disease of eastern white pine; decline of daylily due to poor site conditions.

TURF :

Bermudagrass decline caused by gaeumannomyes blight of stolons; root knot nematodes and gaeumannomyces blight of zoysiagrass; non-fungal leaf tip burn, scorch and death of older leaves on bentgrass.

INSECTS and MITES :

Cinara aphids, elongate hemlock scale, and circular armored scale on fir; lacebug eggs on azalea; xyela sawfly larvae on pine staminate flowers; mite damage on Virginia pine needles; aphids on tomatoes; alfalfa weevil; red-necked cane borer on blackberry; fungus gnat root damage on vinca; thrips leaf damage to petunia.

In and around the house:

Varied carpet beetle, ants, American dog tick, dark-winged fungus gnats, anobiid beetles in old hardwood flooring; termites, clover mites, and ground-nesting solitary bees.

ANIMAL DAMAGE :

Woodpecker damage to viburnum, apple and eastern white pine; meadow voles girdling holly.

AQUATIC :

Spirogyra filamentous algae in prawn pond.

OTHER UT NEWSLETTERS WITH PEST MANAGEMENT INFORMATION

Fruit Pest News

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 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.

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