TRUE ARMYWORM THE NEXT GENERATION
By Doug Johnson

The second generation true armyworm moth flight appears to have peaked here at Princeton. Last Friday (01Jun) we captured 220 moths / trap-week, up from 68 moths / trap-week the Friday before (29May). This most recent Friday (08Jun) we captured 121 moths / trap-week. So the population appears to be in decline and the week of 01Jun was the peak flight.

First a warning. The week of the flight had some bad weather for moth flights. So, it is possible that we are little bit premature and that the flight will actually increase next week. I don't expect this to happen but it could.

What does this data tell us? First, it gives us an indication of when we might begin to see the worms appear. More on that later. Second, it may give a general idea of the size of the population but that is a very tricky question to answer. However, we do know two things about the size of the moth flight. First, it is smaller than the spring flight (1st generation) that caused all the problems ( 220 vs 398 moths / trap- week). Second, it is larger than the "normal" 2nd generation peak flight (220 vs ca.150 moths / trap- week). This may mean absolutely nothing. Moth flight data is notoriously variable. However, given the problems we had with the 1st generation I think we have to take a look at possible problems caused by the 2nd generation.

If indeed the peak flight was the week of 01Jun, we can estimate worm arrival using last year's temperatures (2000) to power our Degree Day model. Using this:

Peak of eggs hatching (worm appearance) should occur on about: 09 -10 June, peak of larvae completing development (worm disappearance) about: 28-29 June

These are only estimates and from data for Princeton, KY be sure to remember that 1.) this will occur earlier where it is warmer and later where it is cooler, and 2.) this only helps you know WHEN not IF or WHERE.

I would advise you to look for worms:1.) first, where you had problems with the first generation, 2.) in small corn, 3.) other small grass crops (new seeding, regrowth, etc).

With any luck at all we will not have a problem with this generation, and that would be the normal situation. But it won't hurt to be on the look out.

To see recent armyworm trap counts, click here.

NEW INSECTICIDES FOR ARMYWORM CONTROL IN PASTURES
By Lee Townsend

(Frankfort) The U.S. Environmental Protection Agency has granted special registration for two insecticides to combat armyworms in pastures and hayfields in Kentucky, the Ky Department of Agriculture has announced.

The insecticides are Pounce 3.2 EC (FMC Corp.) and Confirm 2F (Rhom and Haas Co.). Both are Restricted Use pesticides. Cattle can be present during application, if necessary, when Pounce is applied and they may graze fields after treatment. However, pastures sprayed with Pounce cannot be cut for hay during the remainder of the season. Pastures sprayed with Confirm 2F can be harvested for hay after a14-day wait.

Applicators must have a copy of the appropriate state (24-c) label for Pounce or the Crisis Exemption label (Section 18) for Confirm. These are available from the pesticide dealer when the products are purchased.

WORKSHOP ON MICROSCOPIC IDENTIFICATION OF GRAY LEAF SPOT OF PERENNIAL RYEGRASS
By Paul Vincelli

Most readers who work with perennial ryegrass are aware of the emergence of gray leaf spot in the past decade as one of the most destructive turfgrass diseases known. Those of you with experience against gray leaf spot know how rapid and destructive the disease can be.

Fungicides remain our first line of defense against gray leaf spot, because all commercial varieties are susceptible and cultural practices can provide only limited control under high disease pressure. Because of the high cost of fungicides, many turf managers are interested in ways to use these important products more wisely and economically. My opinion is that at this time, there is no better way to optimize the use of fungicides than to scout your own swards for the disease and to microscopically verify the presence of the causal fungus in diseased tissues. Experienced turfgrass pathologists agree that microscopic verification is important because it is often not possible to positively identify this disease based on symptoms alone.

Proper scouting can help you decide:

• when to spray
• when to switch to more costly, but more effective, fungicides
• when you can cut back on spraying
• whether to treat roughs

The University of Kentucky Cooperative Extension Service will hold a workshop for turf managers and other interested professionals on microscopic identification of gray leaf spot of perennial ryegrass. Details are as follows:

Date & Time: June 20, 2001, from 1:00-5:00

Location: The University of Kentucky campus in Lexington

Cost: $900, Registration must be received by Monday, May 7
While the cost may seem high at first glance, registrants will actually be getting a lot for their money. Each registrant will receive a high-quality compound binocular light microscope (40-1000X magnifications, with halogen illumination and high contrast lenses), which you will learn to use during the workshop. In addition, each registrant will receive dissecting kits, lense cleaning supplies and other laboratory materials, a notebook including color images, a 2X desk magnifier with built-in illumination, and a field magnifying glass.

Learning Objective: As a result of this workshop, you will be able to detect Pyricularia grisea (the causal fungus of gray leaf spot) in diseased turfgrass tissue. This skill will provide the foundation for a scouting and monitoring program for gray leaf spot.

If interested in attending, please contact Pat Yancey at pyancey@pop.uky.edu pyancey@pop.uky.edu for a registration form. Registration is limited in order to provide a high- quality learning experience for those who attend. Interested Kentuckians should act soon, since out- of-state registrants will be accepted on April 20. Registration and payment must be received by Monday, May 7.

CURRENT BLUE MOLD STATUS
By William Nesmith

Situation: The blue mold situation has changed sufficiently for the better, such that I am down-grading the blue mold status in Kentucky. The blue mold warning that has been in place for Clark and Fayette counties since Memorial Day has been reduced to a watch. There may still be low levels of blue mold present, but aggressive and timely disease control action by the growers in the communities involved have the disease under control at this time, as best we can determine from grower reports and pathologists visiting the area. Aggressive action was taken by growers in the warning area, and it appears that it was in time to greatly reduce spread to the surrounding counties (Bluegrass and Ft. Harrod), and to those north and east of this area (Northern Kentucky, Northeast Kentucky, Licking River, Southern Ohio and Western West Virginia). With the weather this region has been experiencing, blue mold should be active if it moved! But, it has not been reported to date from counties previously under a watch. Consequently, the watch for the counties in those areas has been reduced to an advisory - which is the status the remainder of the commonwealth is under at this time, except for Clark and Fayette. Should blue mold develop anywhere in the state, please report its status to County Extension Offices immediately, but especially any finds in the former watch or warning areas.

In other states, blue mold is occurring in Florida, Georgia, North Carolina, Virginia and Pennsylvania. The North American Blue Mold Forecast System is monitoring and forecasting spore transport from those areas. Changes in weather events could place spores into Kentucky from any of those areas at any time - so remain alert to the changing status of blue mold. Our website is: www.uky.edu/Agriculture/kpn/kyblue/kyblue.htm

Under a watch or warning, spray programs should be in place in the fields. However, under an advisory, spray programs in the field should not be necessary, if the community is regularly scouting the fields and remaining in daily communication with the Kentucky Blue Mold Warning System. However, cultural controls should be incorporated into production. Spray programs should remain in place in the watch areas, and in transplant production statewide. Aggressive action should be taken to eliminate all transplants that are not needed. Either keep them protected or kill them!

For the latest blue mold status and other tobacco disease information, check the KY Blue Mold Warning System.
http://www.uky.edu/Agriculture/kpn/kyblue/kyblue.htm

FOLIAR SPRAYS FOR APHID CONTROL
By Lee Townsend

Foliar sprays for aphid control include Orthene (acephate) (also available as Acephate and Bracket), Fulfill, Thiodan (endosulfan) (Golden Leaf, Phaser) and Provado (imidacloprid). These insecticides can provide good aphid control if applied at the treatment guideline of 20% infested plants, using at least 25 gallons of water per acre.

Provado contains the same active ingredient as Admire but is a 1.6 pound per gallon formulation while Admire is a 2 pound per gallon product. Admire is applied as a transplant water or tray drench at the rate of 1 fl oz per 1,000 plants and provides 80 to 90 days of systemic aphid control. Provado is applied as a foliar spray at the rate of 2 to 4 fl oz per acre. It does not give the systemic control that is seen with Admire.

For more information about tobacco pests, visit "Insect Management Recommendations".

BLISTER BEETLES AND HAY
By Lee Townsend

Blister beetles are a concern of hay producers because of the toxicity of these beetles to horses. Generally, we see these insects in early July in Kentucky and numbers are rarely high enough to cause concern.

Blister beetles commonly feed on flowering plants so they should be considered if alfalfa is showing significant bloom or weeds are abundant and flowering. These insects will leave the field once the hay has been cut and wilts. If blister beetles are present or suspected and the hay needs to be cut, harvest without crushing, crimping, or conditioning the hay. The beetles will leave and the cured hay can be baled and used without worry. More information on this group, including identification and management alternatives is available in Entfact 102

See Insect Recommendations for more alfalfa pest recommendations.

TIMELINESS OF POSTEMERGENCE HERBICIDES AND SOYBEAN YIELD
By James R. Martin

The "critical period of weed presence" refers to the period when weeds emerge and grow with the crop without causing yield loss. This period for soybeans is approximately 4 to 8 weeks after planting and depends on a number of factors such as environmental conditions, emergence patterns, competitiveness, and density of weed species, and row spacing. Examples of conditions where timeliness of control is important in order to limit the risk of soybean yield loss include:

1. dry weather
2. heavy weed pressure
3. competitive weeds such as giant ragweed and common cocklebur
4. weeds that tend to emerge early in the season such as giant ragweed or Pennsylvania smartweed
5. row spacings that exceed 15 inches in width.

FORE RAINSHIELD NT AND GRAY LEAF SPOT CONTROL IN PERENNIAL RYEGRASS
By Paul Vincelli

Recent announcements have circulated about the label change allowing the use of Fore Rainshield NT (active ingredient mancozeb) for control of gray leaf spot of perennial ryegrass, caused by Pyricularia grisea. The product is labeled for use at 8 oz/1000 sq ft biweekly as a preventive spray.

This is not a particularly strong product against gray leaf spot; in fact, it is probable more accurate to say it is rather weak when used alone. See, for example, accompanying data from a test conducted last year at the UK Turf Research Center. Disease pressure in that test was light (and any product that cannot reliably control the disease when disease pressure is light should not be counted on when disease pressure is severe). Studies conducted by colleagues in other states have been mixed, although there are several where control with mancozeb was poor to non- existent.

The greatest potential of this product for gray leaf spot control probably is as a tank-mix partner with other fungicides. For example, the premix of myclobutanil and mancozeb (sold as MANhandle 62.25WP) has provided control equivalent to other "three-star" products and tank-mixes (see table). To put this in a context, according to my personal efficacy rating system, anything receiving three stars is acceptable and has a place for managing the disease; however, four-star products and tank-mixes provide better, more reliable control under moderate to high disease pressure. So mancozeb does have a place as a mixing partner, but I would not really on mancozeb alone for controlling gray leaf spot.

Table 1. Control of Gray Leaf Spot of Perennial Ryegrass, 2000*
		% plot affected by gray leaf spot			% dead tillers
Treatment and rate/1000 sq ft	Spray interval (weeks)	8-Aug	21-Aug	5-Sep	21-Aug
Water		0.7 ab*	28.3 a	27.7 a	2.7 a
Heritage 50WG 0.4 oz	3	0.0 b	0.0 i	0.0 i	0.0
Fore Rainshield 80WP 8 oz	2	0.0 b	15.0 bcd	20.0 ab	1.3 abc
MANhandle 62.25WP 10 oz	2	0.0 b	3.7 f-i	7.0 c-g	0.7 cd

*Data abstracted from a full reported published in Fungicide and Nematicide Tests, 2001. Means within a column followed by the same letter are not significantly different, Waller-Duncan k-ratio t-test (k=100, p=0.5).

BROWN PATCH ACTIVITY ENHANCED BY RECENT WET WEATHER
By Paul Vincelli

Wet weather with moderate temperatures over the last several weeks has been very favorable for brown patch activity in susceptible grasses, although dry weather over the week-end may have slowed disease activity. Although all grasses are a potential host, we most commonly see this disease on tall fescue and perennial ryegrass; it also sometimes occurs on Kentucky bluegrass.

Tall Fescue
Leaf lesions are irregular in shape; they are olive- green when fresh, and dry to a tan color with a thin reddish-brown border. On humid mornings, look for gray fungal weblike threads (mycelium) growing from diseased leaves. The disease sometimes causes very discrete, circular patches; in certain varieties or conditions, affected patches are irregular.

Maintain a moderate mowing height of 2-2.5 inches. Don't let the turf get too tall in order to minimize leaf disease activity, yet don't mow so close that the root infections that sometimes occur result in tiller death. When irrigating, do so in the early morning hours and avoid evening watering when possible. A recent study at Kansas State University found that clipping removal had no effect on disease development, providing a justification for leaving clippings in place even during an active outbreak of brown patch.

Although we generally don't recommend fungicide use on home lawns, newly established lawns of tall fescue may need protection during high disease pressure. If so, Heritage 50WG applied at 0.2 oz at 35- day intervals has worked well under high disease pressure in studies at Kansas State University and the University of Georgia. One note: the Kansas State study found that Heritage applications predisposed the turf to outbreaks of Pythium cottony blight in both years of the study when the turf was also under daily irrigation (but not when irrigated on alternate days) this was possibly the result of suppression of naturally occurring antagonistic microorganisms. Prostar 70WP is also another very good choice for fungicidal control of brown patch in tall fescue. For either fungicide, preventive applications are more effective than curative applications, in cases where disease progress is rapid. Be reminded that fungicides that were previously commonly used against this disease notably chlorothalonil and iprodione are no longer labeled for use in residential lawns.

Perennial Ryegrass
Diseased leaves initially appear dark green, watersoaked, and somewhat slimy, much like the appearance one would expect from frost damage. On humid mornings, one can see grayish, weblike threads (mycelium) growing from diseased leaves. This mycelium is usually in the lower half of the canopy, but under unusually disease-conducive weather, the Rhizoctonia mycelium can grow all the way up to the top of the foliage, and can look very much like Pythium cottony blight. As diseased leaves dry, they take on a light brown color and may appear matted. Outbreaks usually occur in discrete patches one to several feet in size, but under highly conducive weather, most of the grass can have active mycelium.

Fungicidal and cultural management options are described in the UK Extension publication, Chemical Control of Turfgrass Diseases, available from county Extension offices or at http://www.ca.uky.edu/agcollege/plantpathology/PPAExten/pppublin.htm#Ornamental - Turfgrass.

Kentucky Bluegrass
Although rather uncommon on Kentucky bluegrass, some varieties are very susceptible. These will develop circular patches of straw-colored turf that appears depressed in the middle. Examine leaves for leaf lesions that appear very similar to those described for tall fescue. The disease is rarely destructive enough to warrant treatment on Kentucky bluegrass.

WARM WEATHER FAVORS AJUGA CROWN ROT
By John Hartman

Ajuga, or Bugleweed, is valued as a ground cover in Kentucky landscapes because it forms a dense mat- like cover. Ajuga is subject to one major disease, crown rot, caused by the fungus Sclerotium rolfsii. Crown rot is favored by our warm, humid Kentucky summer weather. The most obvious indicator of crown rot disease is the appearance of somewhat circular patches of dead plants, especially in poorly drained beds.

In early stages of the disease, infected ajuga may show yellowing of lower leaves. Plants soon wilt and die because the causal fungus has invaded the roots and crown and cut off the water supply. Badly infected plants may be easily pulled up because the roots and crown have been destroyed. The most revealing diagnostic feature is the presence of small spherical tan to reddish brown sclerotia of the fungus, often embedded in a mat of white fungal mycelium. The sclerotia, about the size of a mustard seed, survive winter or other unfavorable conditions, allowing the fungus to resume infections of nearby susceptible plants next season.

The crown rot fungus has a wide host range including most common vegetables, perennial and annual ornamentals, and young woody plants in nurseries. Ajugas should not be planted where the disease is already present in other hosts. Soil from infected beds can be removed and replaced with "clean" or sterilized soils, and then replanted. The fungicide Terraclor, containing PCNB, can be used as a drench to prevent new infections.

ANT WARS
By Mike Potter

Many calls have been received, in recent weeks, about ants. Ants are the most frequent and persistent pests encountered around homes. At least a dozen species may be found indoors, including pavement ants, carpenter ants, odorous house ant, acrobat ant, and pharaoh ant. Besides being a nuisance, they contaminate food, build unsightly mounds on clients' property, and cause structural damage by hollowing out wood for nesting.

At certain times of the year, ant colonies produce winged individuals which are often mistaken for termites. Winged ants have a constricted (pinched) 'waist' and antennae which are bent or elbowed; winged termites have a body which is not constricted in the middle and the antennae are straight. The role of the winged individuals is to mate and establish new colonies fortunately, the success rate for accomplishing this inside a home is low. Winged ants do not feed, and can be removed with a vacuum cleaner. However, they are an indication that a nest is present within the structure which may require additional effort to eradicate.

Ant control can be very frustrating. Repeated attempts often are made to maintain ants at tolerable levels. This column will help you eliminate pestiferous ants with more success and less effort. Recommendations pertain to all of the common ant species found in Kentucky except carpenter ants, which are discussed in entomology Entfact-603 or ENT-57.

THE BATTLE PLAN

The mistake most people make when attempting to control ants is only spraying the ones they see. This approach usually fails because the ants seen foraging over exposed surfaces are only a small portion of the colony. Typically, there will be thousands of additional ants, including one or more egg-laying queens hidden somewhere in a nest. The importance of eliminating queens and other colony members within nests cannot be overstated and is the key to effective ant control.

Ants build their nests in many different locations, both inside and outside of buildings. Control of indoor-nesting ants requires a somewhat different approach than for ants nesting outdoors, because indoor nests usually are hidden or inaccessible.

Ants Nesting Indoors- Buildings contain many favorable nesting sites for ants. Preferred sites include spaces behind walls, cabinets, light switches and receptacles, behind window and door frames, and beneath floors. Most of these areas are hidden, making it extremely difficult to determine the precise location of the ant colony. When the location of the nest cannot be determined, or the nest is inaccessible, insecticide baits are the preferred solution for homeowners. The advantage in using baits is that foraging ants take the insecticide back to the nest and feed it to the queen(s) and other members of the colony. In a relatively short period of time (often within a week) the colony is destroyed.

Ant baits are easy to use. Most homeowner formulations come pre-packaged with the insecticide and food attractant confined within a plastic, child-resistant station. Three of the more effective containerized bait products which can be purchased in most grocery, hardware and discount stores are Combat Quick Kill and Combat SuperBait for ants, and Raid Ant Bait Plus with Mettastop® . Place the baits next to wherever ants are seen, preferably beside ant "trails" invisible odor trails that worker ants follow between food and the nest. Do not spray other insecticides or cleaning agents around the bait stations as this will keep ants from feeding on the bait. Initially, you should see an increase in the number of ants around the bait station. Do not spray them. This indicates that the ants are feeding on the bait and transporting the insecticide back to the nest. Ant activity around the bait station should subside in a few days as the number of ants in the colony declines. Continue to place other baits wherever ants are seen.

Two other baits that often work well are Terro Ant Killer II and Dr. Moss's Liquid Bait System. Both are formulated as sweet, liquid baits which certain types of ants often prefer. When placing liquid ant baits indoors, the bait can be confined in a shallow film or pill container cap, inside 1-inch lengths of cut plastic straws, or on the back (non-sticky side) of masking tape placed along ant trails, but away from children and pets. Replenish daily until activity ceases.

Ants are rather finicky in their food preferences and may alter them throughout the year. This is especially true of the odorous house ant, a small blackish ant found on the inside and outside of structures. If one bait product isn't attractive, try another. Optimal results usually require a sustained period of feeding not just a brief 'visitation' by a few ants. Retail ant baits will not normally control carpenter ants.

Ants Nesting Outdoors- Ants noticed inside the home may actually be nesting outdoors in the yard. Trace the ants back to the point where they are entering from outside, such as around a window sill, beneath an exterior door, or where the exterior siding meets the foundation wall. When tracing ant trails outdoors or indoors, pay particular attention to seams and edges created by mortar joints, foundation/siding interface, baseboards, carpet tack strips, etc., as ants usually prefer to trail along "lines" and edges. Nests often will be located in the ground, where they may be marked by a mound or anthill. Other times, the nest will be concealed under stones, mulch, landscap-

ing timbers, pavement, or beneath the grass adjacent to the foundation wall. Some kinds of ants prefer to nest underneath siding or behind wood trim that has been moisture damaged. While it takes patience to locate a nest outdoors, results will be more rapid and permanent than if you spray only where ants are seen. One way to entice ants to reveal the location of their outdoor or indoor nest(s) is to place small dabs of honey or maple syrup next to where ants are observed. After the ants have fed, they soon will head back to the nest.

When a below-ground nest is discovered, the colony can be eliminated by thoroughly spraying or drenching the nest location with Sevin, Dursban, or a synthetic pyrethroid such as contained in Spectracide Bug Stop , Ortho Home Defense System® , or Bayer Advanced Lawn & Garden Multi-Insect Killer® . Large colonies will require greater amounts of liquid to move the insecticide throughout the network of underground galleries within the nest. Using a bucket to apply the diluted insecticide is an effective method. Follow label directions for treating ant mounds, paying attention to precautions for mixing and application.

Another effective and convenient way to control outdoor and indoor-nesting ants is the granular bait product, Combat® Outdoor Ant Killing Granules. Sprinkle the bait in small quantities beside outdoor ant mounds, along pavement cracks, and other areas where ants are nesting or trailing.

Ant entry into homes can be reduced by caulking around doors (especially along bottom outside edge of thresholds), windows, and openings where pipes and wires enter the building. Chronic ant problems can further be reduced by spraying one of the above-mentioned liquid insecticide formulations around the outside perimeter of the building. Pay particular attention to likely points of entry, such as around doors and where utility pipes and wires enter from the outside. Also consider applying a 3-to 6-foot swath along the ground adjacent to the foundation, and a 2-to 3-foot band up the foundation wall.

Broadcast spraying or applying conventional (non-bait) insecticide granules (e.g., diazinon or Dursban) to the yard seldom, if ever, solves an indoor ant problem. In Kentucky, such applications are a waste of money, effort, and a potential polluter of streams, lakes, and municipal water systems. They also eliminate beneficial ants which may be important allies in suppressing other pests on your property.

Difficult or persistent ant problems are often best managed by a professional pest control firm.

DIAGNOSTIC LAB - HIGHLIGHTS
By Julie Beale and Paul Bachi

Field and forage crop samples seen in the Diagnostic Lab last week included nutritional problems on corn (general and zinc deficiency); Pythium root rot on alfalfa; Fusarium root rot on oat; tomato spotted wilt, blackleg, black root rot, Pythium root rot, blue mold, target spot, flea beetle feeding, transplant shock, sunscald, cold injury (field symptoms), nitrogen, potash and temporary phosphorus deficiency, and manganese toxicity on tobacco.

On fruit, vegetable and herb crops we have seen freeze injury on blackberry; black rot on grape; fireblight on apple and pear; cold injury on cherry; tarnished plant bug injury, plum curculio, and sunscald on peach; bacterial soft rot on broccoli; bacterial spot and Pythium root rot on pepper; bacterial wilt on cantaloupe; Phytophthora root and stem rot on squash; bacterial spot/speck, acterial canker, Pythium root rot and walnut wilt on tomato; fertilizer burn and Botrytis blight on rosemary; and Alternaria leaf and stem blight on ginseng.

On ornamentals, we have seen powdery mildew on rose and monarda; rust on hollyhock; Pythium root rot on liriope; Cladisporium blotch on peony; rust on Kentucky bluegrass; Pseudonectria canker on boxwood; Phytophthora root rot and Kabatina twig blight on juniper; and rosette disease on rose.

By Patty Lucas, University of Kentucky Research Center

Insect Trap Counts

To see recent moth trap counts, click here.

Lee Townsend
Extension Entomologist

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