Kentucky Pest News: November 3, 1997 Kentucky Pest News: November 3, 1997


795...........November 3, 1997




    November 5, 1997
    1997 Wood Preservative Workshop
    Hardin Co. Cooperative Extension Office
    Elizabethtown, KY

Remaining 1997 Commercial Pesticide Applicator Training and Testing Dates (Categories 1, 2a, 3, 4, 10, 12)

Categories 2a: 8:30 AM - 12:20 PM, Testing at 1:00 PM;
Cat. 3, 10. 12: 8:30 AM - Noon, Testing at 1:00 PM;
Cat. 1, 4, 10, 12: 9:45 AM - 2:00 PM,Testing at 2:00 PM

    November 11, 1997
    McCracken Co. Extension Office
    Paducah, KY

    November 18, 1997
    Fayette Co. Extension Office
    Lexington, KY

    December 22, 1997
    419 Reed Hall
    Morehead State University



by William Nesmith

A limiting factor in the control of blue mold in burley tobacco is adequate coverage of susceptible tissues. Plant pathologists have advised growers that the most likely way to achieve good coverage with foliar fungicides is through the use of high-pressure spray equipment. During the past summer, the following fungicide regimes were evaluated for blue mold control at the Robinson Substation, University of Kentucky, Quicksand, Ky. All fungicide treatments were made weekly from on-set of disease on the farm until near topping using a tractor-mounted, high pressure sprayer delivering a spray solution of Acrobat MZ at 2.5 lbs/100 gallons, volume adjusted for crop stage. Plots consisted of 8-row blocks, 25 feet long, replicated 4 times.

The following treatment regimes were evaluated:

High = Acrobat MZ, 250 psi, using disc-core nozzles, six applications, delivering 28, 28, 46, 65, 84, and 100 gallons/acre. (total 8.8 lbs/acre for the season). The number of nozzles/row also varied by rate with 3, 3, 5, 7, 9, and 9, respectively.

Moderate = Acrobat MZ, 80 psi, hollow-cone nozzles, Tx-series, six applications, delivering 20, 20, 40, 60, 60, and 80 gallons/acre. (total of 7.0 lbs/acre for the season). The number of nozzles/row also varied by rate with 3, 3, 5, 5, 5, and 7, respectively.

  Treatments     % Leaf surface  
  % Systemic**  
High 0.8c*** 4.2c
Moderate 18.8b 37.5b
Check (unsprayed) 49.7a 74.4a
* % leaf surface diseased with blue mold rated at harvest time.

** % stems with systemic infections of blue mold at harvest time.

*** Value in the same column sharing any letter in common are not significantly different as determined by the Tukey's Multiple Range Test at P= 0.05.

Subjective evaluations judged the coverage to be superior with the higher pressure all season, but obvious differences in disease control were not observed until the canopy closed about the time of the last two applications. As is clearly evident from these data, greater blue mold control was achieved with the delivery system involving higher pressure and more nozzles.



by Doug Johnson

It's raining its snowing the north wind is blowing- Do you know how lucky you are? The weather is absolutely miserable outside, and just right for keeping down the spread of aphids in small grains! But don't get too smug for the forecast is for a warm up later this week.

Yes its November and time for the great aphid hunts. Most of the wheat is planted and a bunch of it is up. So from now until we are frozen over (If that ever occurs) you need to watch out for aphids on the crop. A cool fall could make your search fruitless which should make you quite happy. However, don't for get on those nice warm clear days which always show up in late Nov and early Dec to check your fields. The most important time is the first 30 days following emergence followed by the next 30. BUT even in mid winter if the weather is warm aphids will move if they are there.

Right now check AT LEAST five locations in each field. At each location check all of the top growth right down to the soil level for the presence of aphids. Count all of the aphids you can find in one foot of row length. If on average after sampling the entire field you find and average of 10 aphid per row foot you should consider an insecticide application. Check ENT-47 for the appropriate insecticides.



by John Hartman

Some stone fruits such as peach, plum and cherry in Kentucky have shown symptoms of gummosis in which an amber gum is exuded from the tree trunk or branches and deposited on the bark. Gummosis most commonly occurs as a result of perennial canker disease, but the gum also flows in response to any wound, whether it is due to insects such as peach tree borer, mechanical injury such as that resulting from winter cold or spring frost, or other diseases such as bacterial canker.

Perennial canker is a destructive disease and is caused by a fungus that tends to invade winter-damaged woody tissues. The cankers develop a roll of callus at the margins and gradually enlarge until infected limbs are girdled and then die. Gummosis is usually associated with the cankers. Perennial canker must be prevented if peaches, plums and cherries are to thrive in the garden and orchard. Disease control practices must reduce ports of entry for the canker fungi, minimize tree stress, and reduce levels of the causal fungi.

Avoid the temptation to prune out dead and diseased branches now. Pruning activities should be delayed until growth starts in the spring. Fall pruning can severely weaken and stress trees and can predispose them to winter injury and subsequent infection. Branch stubs and very close flush cuts should be avoided. When training young trees, narrow angled crotches should not be left because these are potential sites of infection.

Prune out and destroy badly cankered limbs. Late fall fungicide applications to control peach leaf curl and plum pockets, and spring sprays for brown rot may help suppress perennial canker. Fruit trees should be fertilized according to soil test results, and unnecessary injury including those caused by insect pests should be avoided.



by Lee Townsend

During the fall female twig girdlers are laying eggs in lateral or terminal twigs of many trees, including hickory, pecan, oak, and many others. After depositing a single egg, the female chews a continuous notch around the twig, girdling it. These twigs, usually over a foot long, die quickly and fall to the ground. The egg in the broken twig hatches and the legless white larva feeds some before winter. Development resumes in the spring and the adult emerges in early fall. Sanitation is the key to managing this pest. Pick up and destroy the fallen twig to kill the developing generation.



by John Hartman

Pansy growers in Michigan, Georgia and perhaps other states have been noticing elongated, twisted and streaked leaves on plants affected by what has been called mottled pansy syndrome. Affected plants have been studied carefully and plant pathologists have so far ruled out, microbes such as bacteria, fungi, and commonly occurring viruses as well as nutritional deficiencies and chemicals as causes. One common factor in the cases observed so far is that pansy seedlings have been exposed to high temperature, high light, or dry soil conditions. Fortunately, this problem has not yet been reported in Kentucky.

If you see this problem, contact your County Extension Agent who can bring it to our attention and we can work with researchers in nearby states for identification assistance and possibly research on the problem. Growers can reduce the chances for this malady to appear in their pansy planting by reducing heat stress, water stress, and excessively high light levels on their plugs and newly transplanted plug plants.



by Mike Potter

As expected, our phones began ringing last week with complaints of lady beetles congregating on the sides of homes and infesting buildings. This phenomenon has become a recurring fall event in Kentucky and throughout much of the U.S. The culprit is the Asian lady beetle, Harmonia axyridis, in search of protected places to overwinter. In Kentucky, movement into buildings begins in mid to late-October, continuing through mid-November.

Detailed information on this challenging problem is contained in ENT-64, Asian Lady Beetle Infestation of Structures. Key points include:

1. Lady beetle flights are heaviest on warm sunny days, when temperatures climb above 60 degrees F. They tend to initially congregate on the sunnier, southwest sides of buildings in mid-afternoon. Structures that are shaded and not brightly illuminated by afternoon sun are less likely to attract the beetles.

2. Once the beetles have alighted, they attempt to enter cracks and other dark openings in search of hibernation sites. These locations may be anywhere on the structure, but especially beneath exterior siding, around window and door frames, soffits, fascia boards, and through weep holes and attic or crawl space vents. Sealing exterior cracks and openings with caulk, screening, weatherstripping, etc., is the most effective long-term, preventive measure against beetle entry. (See KPN 10/21/97 or ENTFACT-641 How to Pest-Proof Your Home.)

3. Once the beetles are indoors, the best way to remove them is with a vacuum cleaner. Insecticides tend to be less effective and may stain or leave unwanted residues on walls, counter tops, and other exposed surfaces.

4. While sealing openings is the more permanent way to deny beetle entry, pest-proofing is time-consuming and impractical for many clients. If a household or business continues to be troubled by lady beetles, owners may want to enlist the services of a professional pest control firm. Some companies offer pest proofing services and many offer insecticide treat-ment of the building exterior, which helps to prevent pest entry. Fast-acting, "professional strength" synthetic pyrethroid formulations (e.g., Demand, Demon, Commodore, Optem, Saga, Tempo) tend to be most effective, and can be applied around eaves, attic vents, windows, doors, underneath siding, and other likely points of pest entry.

Homeowners bent upon performing exterior treatment themselves will probably get the most for their efforts using either Spectracide Bug Stop (permethrin), Enforcer Overnight Pest Control Concentrate (cypermethrin) or microencapsulated (slow-release) Dursban, sold by some hardware/lawn and garden shops. The key is to apply the treatment before the beetles enter buildings to overwinter.

5. Finally, concerned clients should be reminded that lady beetles play an important role in nature, and that their entry into buildings is a sporadic and short-term event. Lady beetles do not injure humans, nor can they breed or reproduce indoors like fleas or cockroaches, i.e., they constitute a nuisance only by their presence.


by Mike Potter

Several people have called recently about small flies or gnats flying about in their kitchen. These are probably fruit flies. Fruit flies can be a problem year round, but are especially common this time of year because they are attracted to ripened or fermenting fruits and vegetables. Tomatoes, melons, squash, grapes and other perishable items brought in from the garden are often the cause of an infes-tation developing indoors. Fruit flies are also attracted to rotting bananas, potatoes, onions, and other unrefrigerated produce purchased at the grocery store. This column will explain how infestations originate and how they can be prevented in your clients' homes and businesses.

Description and Habits- Fruit flies are common in homes, restau-rants, supermarkets and wherever else food is allowed to rot and ferment. Adults are about 1/8 inch long and usually have red eyes. The front portion of the body is tan and the rear portion is black. Fruit flies lay their eggs near the surface of ferment-ing foods or other moist, organic materials. Upon emerging, the tiny larvae continue to feed near the surface of the fermenting mass. The surface feeding behavior of larvae is significant in that damaged or over-ripened portions of fruits and vegetables can be cut away without having to discard the remainder for fear of retaining any developing larvae.

The reproductive potential of fruit flies is enormous; given the opportunity, they will lay about 500 eggs. The entire life cycle (egg to adult) can be completed in about a week.

Fruit flies are especially attracted to ripened fruits and vege-tables in the kitchen. They also will breed in drains, garbage disposals, empty bottles and cans, trash containers, mops and cleaning rags. All that is needed for development is a moist film of fermenting material. Infestations can originate from over-ripened fruits or vegetables that were previously infested and brought into the home. The adults can also fly in from outside through inadequately screened windows and doors.

Fruit flies are primarily nuisance pests. However, they also have the potential to contaminate food with bacteria and other dis-ease-producing organisms.

Prevention- The best way to avoid problems with fruit flies is to eliminate sources of attraction. Produce that has ripened should be eaten, discarded or refrigerated. Cracked or damaged portions of fruits and vegetables should be cut away and discarded in the event that eggs or larvae are present in the wounded area. A single rotting potato or onion forgotten at the back of a closet, or fruit juice spillage under a refrigerator can breed thousands of fruit flies. So can a recycling bin in the basement that is never emptied or cleaned.

People who process their own fruits and vegetables, or make wine, cider or beer should ensure that the containers are well sealed; otherwise, fruit flies will lay their eggs under the lid and the tiny larvae will enter the container upon hatching. Windows and doors should be equipped with tight-fitting (16 mesh) screens to help prevent adult fruit flies from entering from outdoors.

Eradication- Once a structure is infested with fruit flies, all potential breeding areas must be located and eliminated. Unless the breeding sites are removed or cleaned, the problem will continue no matter how often insecticides are applied to control the adults. Finding the source(s) of attraction and breeding can be very challenging, and will require persistence on the part of the client -- guided by your suggestions as to where these areas might be. Potential breeding sites that are inaccessible (e.g., garbage disposals and drains) can be inspected by taping a clear plastic food storage bag over the opening overnight. If flies are breeding in these areas, the adults will emerge and be caught in the bag.

After the source of attraction/breeding is eliminated, a pyrethrum-based, aerosol insecticide may be used to kill any remain-ing adult flies in the area. A better approach, though, is to construct a trap by placing a paper funnel (rolled from a sheet of notebook paper) into a jar which is then baited with a few ounces of cider vinegar or a slice of banana. This simple but effective trap will soon catch any remaining adults. Faster results can be achieved by installing additional traps. Since more fruit flies will be caught in traps closest to the breeding source, the technique can also help pinpoint the source of the problem. Adult fruit flies caught in traps can be killed or released outdoors.

Lee Townsend
Extension Entomologist