ASIAN LADY BEETLE flights to structures, early reports indicate large numbers of
beetles in some areas (See KPN 1108, Sept 11, 2006 for latest information);
PANTRY PESTS, such as drugstore beetles and flour beetles are common submissions to the
Insect ID lab;
GIANT BARK APHIDS twigs of sycamore and other deciduous trees;
fallen twigs from TWIG GIRDLERS;
nuts infested with PECAN WEEVILS.
A number of field trials aimed at evaluating various fungicide products for management of disease were
onducted around Kentucky this past growing season. We focused on the "big three" of tobacco diseases
- black shank, blue mold, and target spot. Fungicides currently labeled for use on tobacco were
tested, as well as a few experimental compounds. The following is a brief summary of what we learned
from these trials.
Black shank
Mefenoxam (Ridomil Gold EC) was evaluated in an on-farm trial to evaluate the effects on incidence of
black shank where tobacco varieties with low, moderate, and high resistance (NCBH 129, TN 86, and KT
204 respectively) to the black shank pathogen, Phytophthora nicotianae, were planted. In this trial, Ridomil Gold EC (RG) was applied prior to planting, at 1st cultivation, and at layby; the application rate was 1 pt/A, and a non-treated control was included for comparison. The field where the trial was conducted had a history of severe black shank. Where low host resistance to black shank (NCBH 129) was utilized, losses to black shank exceeded 90% at the end of the season without RG, and around 70% when RG was applied. Despite the application of fungicide, little tobacco was harvested from plots planted to NCBH 129. Disease incidence in TN 86 averaged around 80% without RG and approximately 35% when treated with RG. With KT 204, non-treated plots had about 35% incidence and this was reduced to roughly 18% where RG was applied. Tobacco from these plots was harvested at the beginning of October and housed; yield data will be available early in 2007. Although we don't have data for yield by which to gauge the success of the trial, it's clear that KT 204, with its relatively high resistance to races 0 & 1 of the black shank pathogen, performed as well without RG as the moderately-resistant TN 86 that had received three applications of RG. Under severe disease pressure, choosing a high level of resistance to black shank seems to be a sound decision.
Blue mold
Trials were conducted in Fayette, Jackson, Jessamine, and Woodford counties to evaluate a number of
fungicides for management of blue mold. Currently labeled materials such as Actigard, Acrobat +
Dithane DF, Aliette WDG, and Quadris were tested (all at labeled rates), along with experimental
compounds from Bayer, Syngenta, and Valent. All materials were applied as foliar sprays when tobacco
had reached a height of 18 in. and up to two additional applications were made at 14-day intervals.
In all trials, the combination of Acrobat plus Dithane DF performed as well as, or better in some
cases, than Quadris, which gave reasonably good control of blue mold. Actigard also performed well
in our trials, but Aliette WDG (which received a tobacco label in 2006) showed high levels of disease. New compounds from Bayer gave excellent control of blue mold; it is hoped that one or more of these products will be available to tobacco growers in the coming years.
Target spot
Target spot is fast becoming a serious problem for many tobacco growers in Kentucky. Of the products registered in Kentucky for disease management, only Quadris includes target spot on its label. Dithane DF is believed to have modest activity against target spot. Trials conducted on target spot in 2006 focused on determining the optimal rate and application timing of Quadris. Results from our tests indicate that, in general, 8 fl oz/A of Quadris is adequate for suppression of target spot (2 applications, applied early and late-season); however, 12 fl oz/A might be necessary in situations of higher disease pressure. In a separate trial, we found that a single application of Quadris (8 fl oz/A), applied when tobacco had reached 36 in. in height, was as effective at suppressing target spot as two or three applications (14-day schedule) begun at the same time. Disease was evaluated immediately prior to harvest in these trials. In all trials, Quadris-treated plots had significantly less disease than those treated solely with Dithane DF + Acrobat at labeled rates.
Full reports of all fungicide trials conducted in 2006 will be made available in early 2007 on the KY Tobacco Disease Information page (http://www.uky.edu/Ag/kpn/kyblue/kyblue.htm). Please visit the page for these results and other disease-related information for tobacco.
For the latest blue mold status and other tobacco disease information, check the KY Blue Mold Warning System online.
http://www.uky.edu/Agriculture/kpn/kyblue/kyblue.htm
For more information about tobacco pests, visit "Insect Management Recommendations".
Fifteen insecticide treatments were evaluated for control of wireworm larvae, primarily
Melanotus depressus. The test plot was planted following soybeans the previous year on the
UK Spindletop Research Farm, on April 18 as a randomized complete block with 4 replicates. There has
been a history of wireworm damage in this particular field. The corn hybrid used for all treatments
was N67-D6 at a seeding rate of 34,500 kernels per acre. All insecticide treatments were applied at
planting except the seed treatments which were custom applied prior to the seed before planting.
Stand counts from the center 18.3 m were recorded on May 2, 8, 18, and Jun 8 June. Extended leaf
heights were recorded from 10 plants in each plot on June 18. Data were subject to ANOVA and treatment
means compared by LSD.
| Treatment | Rate | Stand Counts | Leaf Height 6/18/06 |
|||
|---|---|---|---|---|---|---|
| 5/02 | 5/08 | 5/18 | 6/08 | |||
| Untreated | 25,700 h | 26,281 gh | 25,047 gh | 24,611 f | 142.2 bcd | |
| Fortress 5G SB | 1.0 oz / 1000 ft (infurrow) | 26,136 gh | 26,063 h | 25,047 gh | 24,539 f | 139.9 bcd |
| Fortress 5G SB | 1.5 oz / 1000 ft (infurrow) | 26,789 efgh | 26,862 fgh | 26,209 efgh | 25,918 ef | 144.5 abcd |
| Fortress 5G SB | 2.0 oz / 1000 ft (infurrow) | 27,225 efgh | 27,080 efgh | 25,555 gh | 25,846 ef | 139.9 bcd |
| Aztec 4.67G SB | 1.0 oz / 1000 ft (infurrow) | 24,974 h | 26,136 h | 24,974 h | 24,394 f | 139.9 bcd |
| Aztec 4.67G SB | 1.5 oz / 1000 ft (infurrow) | 26,739 efgh | 27,225 efgh | 25,918 fgh | 26,572 def | 142.7 abcd |
| Aztec 4.67G SB | 2.0 oz / 1000 ft (infurrow) | 28,024 defg | 28,750 def | 27,370 defgh | 27,443 cde | 146.7 abc |
| Poncho 250 | 0.25 mg/kernel | 31,000 abc | 31,218 abc | 30,710 abc | 30,202 abc | 138.3 cd |
| Capture LFR 1.5 Poncho 250 |
3.4 fl oz / acre 0.25 mg/kernel |
28,387 defg | 28,677 defg | 28,822 bcd | 27,951 bcde | 148.5 ab |
| Capture LFR 1.5 | 3.4 oz / acre | 28,604 def | 28,677 defg | 28,532 bcde | 28,024 bcde | 148.2 abc |
| Cruiser | 0.25 mg/kernel | 29,621 bcd | 29,113 cdef | 28,750 bcde | 28,532 bcde | 136.0 d |
| A14115 Cruiser |
0.125 mg /kernel 0.125 mg/kernel |
31,291 ab | 32,089 ab | 31,073 ab | 30,637 ab | 147.5 abc |
| Force 250 GA/L | 8 fl oz/a | 26,426 fgh | 28,024 efgh | 27,588 defg | 26,935 def | 152.6 a |
| Poncho 1250 | 1.25 mg/kernel | 33,178 a | 33,541 a | 32,960 a | 31,944 a | 143.0 abcd |
| Force 3 G | 4 oz/1000' | 28,967 cde | 29,330 cde | 28,314 cdef | 29,330 abcd | 140.7 bcd |
| Cruiser | 1.25 mg /kernel | 29,911 bcd | 30,565 bcd | 29,766 bcd | 29,185 abcd | 142.5 bcd |
In general, the higher rates of Aztec and Fortress improved stands when compared to the below labeled rates. We do not ever recommend using pesticides at rates above or below those listed on the label, but we may include those for research and demonstration purposes. The other treatments in the study all improved stands when compared to the untreated control. The higher rates of Poncho and Cruiser also improved stands and vigor.
This study indicates that producers need to match the technology for wireworm control with their specific field needs (the potential for stand loss in that field) and with their available equipment.
For more information about corn pests, visit
"Insect Management Recommendations".
Asian soybean rust (SBR) was detected in soybean for the first time in Kentucky on Friday, October 6, 2006. The find was in a sample collected from the corner of an otherwise mature sentinel plot located at the University of Kentucky Research and Education Center in Princeton. Disease incidence was about 25% (i.e., 25 leaves out of 100 had some infection) and infection severity was around 10% affected leaf area. Our new laboratory technician, Carol Nash, spotted the infections first. SBR was confirmed from this site by multiple people in four different labs, using four different methods, in three different states. This site no longer has any green leaves.
Between Sunday October 8 and Friday October 19, SBR was detected at various levels in 15 additional counties: Ballard, Calloway, Christian, Fayette, Fulton, Hardin, Hickman, Hopkins, Lyon, McLean, Marshall, Todd, Trigg, Union, and Webster Counties. All of the finds are in west Kentucky except for the ones in Fayette and Hardin, which are in central Kentucky. Finds were in commercial fields (mostly doublecrop soybeans) except for the Caldwell, Fayette, Union, and Webster County finds, which were in sentinel plots. Incidence was generally low (<1-15%) and severities ranged from 1-10%, except for Fayette and Union, which were about 15-20% severity. As of October 21, recent samples from Carlisle, Daviess, Graves, Henderson, Livingston, Logan, and Muhlenberg Counties in west Kentucky and Bracken, Larue, Oldham, Magoffin, and Nelson Counties in central or northeast Kentucky were negative for SBR.
All of the finds in Kentucky, plus numerous recent finds in Arkansas, southern Illinois, southern Indiana, southeast Missouri, Mississippi, and Tennessee are more than likely the result of a large number of spores moving into the Midsouth from Louisiana during the latter part of September. I believe we are now probably seeing evidence of infections that occurred in the period immediately following spore movement, which was apparently highly conducive to infection.
Finding soybean rust at this time will have absolutely NO impact on the 2006 soybean crop in Kentucky. In fact, soybean rust will "go away" from Kentucky as soon as there is hard frost. It simply cannot survive this far north. However, these finds are of great importance for refining the soybean rust predictive models.
Continue to monitor the FREE SOYBEAN RUST HOTLINE: 1-888-321-6771 for updates on new soybean rust finds this fall. I will also update the hotline during the winter to reflect information on the overwintering status of soybean rust. During the remainder of the fall, I will update the hotline on Mondays and Friday's. During the winter, I will update the hotline on Mondays only. This hotline is funded by your check-off dollars through the Kentucky Soybean Promotion Board.
For more information about soybean pests, visit
"Insect Management Recommendations".
Our current below average temperatures are providing an excellent way to shut down stored grain insect activity. Reducing the temperature in your stored grain to below 50oF will for the most part stop all insect activity. Certainly, you should continue moving air through the grain to reduce the temperatures into the 40o's F as the weather permits. It is not necessary to get the grain to the freezing level for insect control. Additionally, it is probably ill advised to get grain temperatures too low at this time of year, due to the risk of condensation if we hit a period of warmer, moist weather.
Notice that I said the insect activity would cease, I did not say they would die. Although prolonged storage at low temperatures will aid in reducing insect populations, these insects are adapted to the life in a cold bin. When warm up occurs you should once again be looking for insect activity.
Even when your grain is cooled to the preferred temperature it is advisable to take an occasional look into the bins. Though not overly common, very large insect populations in small highly concentrated areas within the bin can generate enough heat and moisture to remain active. You should be on the lookout for this situation. Use of temperature cables within the grain may sometimes alert you to this problem. Otherwise, taking temperature probe samples where possible is advised. Discovery may be a simple as sticking your head into the bin hatch, looking around and giving it the "sniff" test. It is surprising how often this simple technique will discover a problem before it gets out of control.
For more information about crop and livestock pests, visit
"Insect Management Recommendations".
Chrysanthemums are grown in Kentucky as a greenhouse crop and also in field plantings. White rust, caused by the fungus Puccinia horiana is a destructive disease of chrysanthemums and related plants. The disease is indigenous to east Asia, but has since spread to Europe, Australia, South America and Africa. This disease has the potential to be extremely damaging to the commercial horticulture and florist industries if it becomes established in the United States. Chrysanthemum white rust has been accidentally introduced several times in the United States in recent years. For example, it was found in 2004 in New York, New Jersey, California, Pennsylvania, Delaware, and Maryland and again this past September, 2006 in Pennsylvania. In the past, aggressive eradication programs have successfully prevented establishment of this pathogen in this country.
Hosts. Twelve species of chrysanthemum (Dendranthema ) have been shown to be hosts for the rust. Major susceptible varieties include C. morifolium x C. spp. hybrids (Florists chrysanthemum and Garden or Hardy mums), Nippon daisy, High daisy and C. pacificum. Species that have not developed symptoms when inoculated include the Annual chrysanthemums, the Crown, Pyrethrum, Marguerite, Ox-eye and Shasta daisies, Dalmatian pyrethrum and the Corn marigold.
Symptoms. The top surface of infected young leaves shows small light green to yellow spots, which sometimes contain raised bumps. Eventually the leaf spots turn brown and become necrotic. Spore forming pustules appear on the lower surface of the leaves and are buff to pink color at first but as these pustules mature, they become white in color. Flower bracts, petals and other green tissue may also become infected. Hot, dry weather or fungicide applications will suppress symptoms.
Disease progress. The disease is moved long distance by movement of plants and cuttings from one country or state to another. Locally, splashing water moves spores from diseased plants to healthy ones nearby. Cool, wet weather favors disease and leaf wetness of about 2-5 hours is necessary for spore germination and infection. Symptoms appear a week or two after infection. The pustules which develop on the leaf undersides contain teliospores which in turn yield basidiospores. Basidiospores of P. horiana may travel 1/4 mile under high humidity conditions or during a rain storm. The pathogen can also be spread on contaminated soil, litter, dead leaves, gardening equipment, clothes, shoes and hands. Teliospores can remain viable for up to eight weeks on contaminated objects.
Disease management.
Twig girdlers are species of longhorned beetles that have a very distinctive approach to laying their eggs. Females select twigs about the diameter of a fat pencil and chew deep, narrow grooves that leave about a 2 foot-long section attached by only a slender piece of heartwood. The brown beetles crawl along the terminal portion and make small notches in which the eggs (about 5 to 20) are placed. Girdled twigs, which contain eggs and white legless larvae, soon break and fall to the ground. The results of this handiwork can be seen littering the ground under a variety of trees including hickory, pecan, and oak. Twig pruning produces growth deformities that affect the shape and appearance of small trees.
Collection and destruction of fallen twigs is the most effective means of reducing the potential infestation for next year. Application of insecticides to control these insects has not been very satisfactory.
Now is the time when clients begin calling about fabric pests infesting items unpacked from storage. Signs of infestation often are subtle - a few small holes chewed in a sweater, skirt or blanket. These likely were inflicted by clothes moths or carpet beetles. They will feed on any item composed of animal fiber, e.g., wool, fur, silk, feathers, felt or leather. Items commonly infested include wool sweaters, coats, blankets, rugs, upholstered furniture, toys and animal trophies. Cotton and synthetic fabrics such as polyester and rayon are rarely attacked unless blended with wool, or heavily soiled with food stains or body oils. Serious infestations of clothes moths and carpet beetles can develop undetected in a home, often causing irreparable damage to household articles.
THE CULPRITS
Carpet beetles - Carpet beetles are common in buildings, and can infest many items in addition to fabrics. Larvae are about 1/8 to 1/4-inch long, tan to brownish in color, slow moving, and densely covered with hairs or bristles. This is the life stage likely to be encountered now, since only the larvae feed on fabrics and cause damage. Oftentimes, only the shed (molted) skins of the larvae are present on the damaged item. Adult carpet beetles feed mainly on flowers and usually appear indoors during the springtime. The adult beetles are small (1/16 to 1/8-inch), oval-shaped, and range in color from black- to various patterns of white, brown, yellow and orange. They often appear around windows, indicating that an infestation is present somewhere within the home.
Clothes moths- Clothes moths are small, 1/2-inch, buff-colored moths with narrow wings fringed with hairs. Like carpet beetles, they damage fabric only in the larval stage. Adult clothes moths are seldom seen because they avoid light, preferring to hide in dark places such as closets. Clients who report seeing tiny moths in the kitchen and other well-lighted areas are probably seeing grain moths originating from stored foods, e.g., cereal, dried fruit, nuts, or pet food. Clothes moth larvae spin silken feeding tubes or patches of webbing as they move about on the surface of fabrics. They also deposit tiny fecal pellets similar in color to the fabric.
THE SOLUTION
Current infestations- Controlling an existing problem requires a thorough inspection to locate all infested items and locations. The primary source may be an old woolen scarf at the back of a closet, a fur or felt hat in a box, an unused remnant of wool carpeting, or an abandoned bird or squirrel nest up in the attic. Larvae prefer to feed in dark, undisturbed areas where woolens and other susceptible items are stored for long periods. When inspecting clothing, pay attention to seams, folds, and creases (e.g. cuffs and collars) where larvae often prefer to feed. Larvae also may be found along and beneath edges of rugs and carpeting. Use needle-nose pliers to lift the outer edge of wall-to-wall carpet from the tack strip along baseboards. Other possible locations include beneath/within upholstered furniture or inside heat ducts and floor vents with accumulations of pet hair and lint. Occasionally, infestations may originate from bird or animal nests in an attic, chimney, or wall cavity. Carpet beetles, in particular, will also feed on pet food, birdseed, and grain/cereal products associated with kitchens, basements or garages.
Infested items should be laundered, dry-cleaned or discarded. Laundering (warm cycle) or dry-cleaning kills any eggs or larvae that may be present. Vacuuming floors, carpets, and inside heating vents effectively removes larvae as well as hair and lint, which could support future infestations. Be sure to vacuum along and beneath edges of carpets, along baseboards, underneath furniture and stored items, and inside closets and quiet areas where carpet beetles and clothes moths prefer to feed.
Insecticides applied to infested rugs and carpets may be helpful as a supplement to good housekeeping. Sprays containing active ingredients labeled for flea control (e.g., permethrin) or with fabric insects listed on the label are effective. When treating, pay particular attention to carpet edges, floor/wall junctions, beneath furniture, and bottoms of closets. Infested clothing or bedding should not be sprayed with insecticides and should instead be laundered or dry-cleaned.
Avoiding future problems- The best way to avoid future problems with fabric pests is prevention. Woolens and other susceptible items should be dry-cleaned or laundered before being stored for long periods. Cleaning kills any eggs or larvae that may be present, and removes perspiration odors that tend to attract pests. Articles to be stored should then be packed in tight-fitting plastic bags or containers. Customers choosing to use mothballs or flakes should be encouraged to read and follow label directions. The vapors from these materials are only effective if maintained at sufficient concentrations. Effective concentrations can best be achieved by sealing susceptible items (with the manufacturers' recommended dosage of moth crystals) in large plastic bags within in tight-fitting trunks, boxes or chests. Contrary to popular belief, cedar closets or chests are seldom effective by themselves because the seal is insufficient to maintain lethal or repellent concentrations of the volatile oil of cedar.
Conventional household insecticides should not be used to treat clothing. Valuable garments such as furs can further be protected by cold storage - a service offered by some furriers and department stores.
Additional tips on fabric pest prevention, control, and repair of damaged items can be found in entomology publications Carpet Beetles and Clothes Moths, or IP-50, Fabric Insect Pests. Elimination of persistent infestations in a home or business may require the help of a professional pest control firm.
Recent agronomic, fruit and vegetable samples in the PDDL have included Asian soybean rust and charcoal rot on soybean; anthracnose stalk rot and charcoal rot on corn; Rhizoctonia root rot on alfalfa; bacterial leaf spot on pepper; and POTY virus on pumpkin.
On ornamental and turf samples, we have seen powdery mildew, bacterial leaf scorch, Xylaria root rot and actinopelte leaf spot on oak; rose rosette virus on rose; Phytophthora root rot on cherrylaurel; Phytophthora collar rot on spruce; black root rot on holly; Botryosphaeria dieback on leucothoe and yellowwood; anthracnose on walnut; pine wood nematode on Scotch pine; Rhizoctonia crown and root rot on cinnamon fern; and rust on bluegrass.
NOTE: Trade names are used to simplify the information presented in this newsletter. No endorsement by the Cooperative Extension Service is intended, nor is criticism implied of similar products that are not named.
Lee Townsend
Extension Entomologist