CORN ROOTWORM egg hatch begins soon; PLUM CURCULIO egg laying begins; WOOD COCKROACH incursion into homes; Signs of Four-Lined Plant Bug feeding; EUROPEAN PINE SAWFLIES feeding on old needles; DOGWOOD BORERS and Bronze Birch Borers flying.
Captures of true armyworm moths in pheromone baited traps are decreasing, as expected. There will be a second generation, but historically it has not been a problem in Kentucky. By the time the second generation worms appear, our wheat is made and corn is far enough along that true armyworms don't bother it too much. NO guarantee, but that is the usual outcome.
The current (1st) generation of worms is out and active. I have had recent reports of small numbers of worms in both wheat and corn from agents and consultants in KY and IN. I want to thank those individuals that took time to call and let me know what they were seeing in their areas. Fortunately; the populations have remained quite small, not at all like what happened in 2001. BUT the 1st generation is not complete, and wheat and corn are in stages that can definitely be damaged. Everyone needs to remain on the alert for large populations of this pest at least through the end of May.
This is beginning to look like one of the most dramatic illustrations of the importance of natural control that we have seen in a long time. There is little doubt that the moth flights in 2006 are larger and of longer than 2001. Yet as of this date, it appears that a large outbreak of worms will not occur. That can only happen because the agents of natural control (predatory and parasitoid insects and diseases) have reduced the worm population. This is typically what happens in Kentucky, but we often forget how important this is because we do not see it in action. However, when natural control is breached, like it was in 2001, one sees what can happen when it does not work!
Remember don't be lulled into a premature sense that nothing will happen. We still have at least two weeks for a large population to develop.
As of 12 May 2006, blue mold is known to be active in western Cuba and western Mexico. The North
American Plant Disease Forecast Center projects a low threat to U.S. production areas for the next
few days from the known sources of the disease in Cuba and Mexico. No blue mold has been reported
in the U.S.
We are continuing to see quite a few cases of Pythium root rot and target spot in our diagnostic labs and during visits to transplant facilities around Kentucky. Sclerotinia collar rot has been found in a few locations, but has remained a minor problem to date. Reports of plant injury resulting from environmental stress have increased. We are hearing that a number of growers have lost a significant amount of their production. The consensus around Kentucky is that plants may be in short supply this spring - increases in field production and losses due to disease and environment have placed heavy demand on the number of seedlings available.
Injury from Terramaster, applied to control Pythium, is also a common problem this season. Loss of water roots immediately after application seems to be the most common symptom. Roots damaged by Terramaster take on a translucent, "greasy" appearance and will slough off within a week after treatment. Root re-growth should take place 4-7 days following application of Terramaster, but this process may be delayed during cool weather. It is not uncommon to see some slight yellowing as plants recover from "Terramaster shock", likely due to root injury; however, this should improve as new roots form.
A number of cases of heat injury have been reported over the past week. One of the most common side-effects of excess heat in the float system is delayed germination. During our recent heat wave, back in April, it is likely that the air temperature in some float systems was excessively high and either killed germinating seedlings or delayed germination in parts of the bed. The end result of delayed germination is uneven stand. I saw two outdoor beds that had not been ventilated properly and nearly all the plants in both cases failed to germinate. In situations such as this, re-seeding is the only option. These types of cases illustrate the importance of temperature control and adequate ventilation. Temperatures around Kentucky are expected to rise into the mid-to-upper 70's by the end of this week, so encourage growers to raise side curtains or uncover beds to prevent heat-related problems.
For the latest blue mold status and other tobacco disease information, check the KY Blue Mold Warning System online.
For more information about tobacco pests, visit "Insect Management Recommendations".
Growers need to be scouting of armyworms in corn as there have been numerous reports from scattered areas across the state. This follows the intense true armyworm moth flights that were reported by Doug Johnson last month in western KY. Growers need to monitor their corn throughout the rest of the month of May. We have had cool and wet conditions which tend to favor true armyworm and the cool temperatures have slowed corn growth.
When scouting for armyworm, watch for feeding on the leaf margins. Feeding is usually confined to leaf margins, but occasionally they may strip the entire plant leaving only the midrib of the leaves. During the day, armyworms are found in the soil or underneath ground cover. Corn can usually recover from light to moderate feeding by armyworm without significant yield loss. However, severe damage, particularly if the growing bud is injured, can cause significant loss in yield. Bt corn will provide some protection, but large numbers or large larvae migrating from grassy areas may cause some loss.
Scouting is used to determine if armyworms are present (identify hot spots) and to evaluate if they are worth treating. Survey field edges that border small grains or large grassy areas, and watch for damaged plants. If the characteristic armyworm damage is observed while scouting, look on the ground for armyworms or their black pepper-like droppings littering the ground. To sample for armyworms, examine 20 consecutive plants in each of at least 5 random locations in the field. Note the number of plants with the characteristic damage and the size of the larvae.
Scout the field margins of conventional fields first, particularly adjacent to small grains or grassy strips. If armyworms or damage is found, then determine how far the infestation extends into the field. Often armyworms can be controlled by treating just a portion of the field.
Before deciding whether to treat for armyworms with an insecticide, there are a few things to consider. First, what sizes are the armyworms. If the armyworms are longer than about 1-1/4 inch they have completed most of their feeding. Controlling larvae of this size is not profitable because the damage is already done. Control actions in corn are recommended when armyworms average between 1/2 and 3/4 inches and the entire field averages 35% infested plants or 50% or more defoliation is seen on damaged plants.
For information about corn pests, visit
"Insect Management Recommendations".
The University of Kentucky (UK) Corn/Soybean working group, in partnership with UK-Integrated Pest Management (UK-IPM) program have joined in the regional effort to monitor and explore the flight biology of the very important soybean aphid. An aphid suction trap, located at the UK-Research and Education Center in Princeton, (Caldwell Co.) Kentucky (KY) has been set up and is functioning. This trap is the most southerly of a forty trap network that stretches from Kentucky to near the Canadian border, through the heart of the area of major soybean aphid infestation. Hopefully, in the near future the network will also contain traps run by our friends in Ontario and Quebec in Canada.
Although the soybean aphid has been present in Kentucky every season since its discovery in 2000, it has yet to develop into the serious pest that it is in the upper Midwest. While we hope that the aphid never develops as a serious pest in Kentucky, we can not count on that outcome. While we are sensitive to the dulling affect of "crying wolf", we are never the less compelled to keep up with this pest as it develops and changes in the US. Although it is not currently an important pest in KY, aphids are well known for their ability to adapt to new conditions. We do not want the aphid to show up in Kentucky at some future date, as a very ugly surprise.
In addition to the soybean aphid project, our aphid trap has potential to payback on other crops. For example we may finally be able to get flight information on the grain aphid complex which infests our winter wheat crop. Like the Corn/Soybean working group's interest in the soybean aphid, the UK Wheat Science group, also partnered with UK-IPM will gain knowledge on the flight biology of the grain aphids that move Barley yellow dwarf virus in our wheat crop.
An aphid suction trap is a relatively simple device which allows the capture of aphids while they are flying. The trap is essentially a set of pipes, with a fan that draws in air at one end and exhausts it out the other. Inside the pipe is a funnel shaped screen that concentrates insects into a small "jar" which containing a preservative. Set up vertically to a height of about 24 feet, the trap sucks insects in at the top, pulls them through the funneling device into the collecting jar, then exhausts the air out the bottom of the pipe.
Perhaps more important than the trap, is the ability to get these tiny insects identified. Critical to our trapping efforts is the cooperation of Dr. David Voegtlin. Dr. Voegtlin is an aphid biologist with the Illinois Natural History Survey. Dave and cooperators received a grant from the North Central IPM Center to support this project. Kentucky's contribution in part, will be to supply information on these aphids from the edge of their major distribution.
This project is a good example of cooperative work among states, a regional IPM Center and the National IPM program.
For more information about soybean pests, visit
"Insect Management Recommendations".
Kentucky grape growers are observing and reporting symptoms and signs of black rot disease on grape leaves. Most grapes are still in bloom, so fruit decay is not yet evident, but with high fungal inoculum present and as the fruits enlarge and mature, there will be fruit spotting and decay on them as well. The current wet and cloudy period in early and mid May, although cool, has nevertheless been favorable for infections and new infections will continue to occur just about any time there is more rain.
Black rot disease, was first recorded on this continent in 1804 - in Kentucky. The pathogen, Guignardia bidwellii, infects leaves, and then fruits, generating the typical hard, black, shriveled mummies which produce crop losses ranging from 5% to 80%. Leaf petioles, pedicels, and shoots can also become infected. Management of black rot requires an integrated approach involving cultural practices and chemical controls. If the disease is already present in the vineyard, additional attention to fungicide applications will be needed. Growers with already infected foliage will want to protect the still-emerging new growth and the just-developing fruit clusters from infection.
Fungicides for disease control. Leaf wetness requirements for black rot infections have been worked out and although infection may occur at 75║F with as little as 7 hours of leaf wetness, infection may also occur at 55║F with only 12 hours of leaf wetness. Given that some vineyards have been wet for 24 hours at a time, there have been many opportunities for infection in recent weeks. Be aware that chemical controls need to be integrated because there are other fungal diseases in addition to black rot that need managing. Examples of fungicides for grapes follow:
A variety of insecticides are available for use on shade trees and ornamentals. Many can be used on flowers, also. This is a list of common names of market shelf products along with some example brand names. The information is for educational purposes only. References made to commercial products or brand names is with the understanding that no discrimination is intended and no endorsement is implied. The user is responsible for determining that the intended use is consistent with the label of the product.
Organophosphates and Carbamates - nerve poisons, broad spectrum, not very persistent on plants
Acephate Systemic Insect Control Concentrate, Orthene Turf, Tree & Ornamental Insecticide, Ortho Bug-B-Gon Japanese Beetle Killer Carbaryl Sevin Dimethoate Dragon Cygon 2E Systemic Insecticide, Southern Ag Cygon 2E Home & Garden Malathion Ortho Mosquito-B-Gon Tree & Shrub Spray, Bonide Malathion Insect Control, Ortho Malathion Plus
Pyrethroids - nerve poisons, moderately broad spectrum, relatively persistent on plants, may be less
effective on sap feeding pests.
Bifenthrin Ortho Bug-B-Gon MAX Lawn & Garden Insect Killer Concentrate Cyfluthrin Bayer Advanced Garden Multi-Insect Killer Concentrate l-cyhalothrin Spectracide« Triazicide« Soil & Turf Insect Killer Concentrate Esfenvalerate Ortho Bug-B-Gon Garden & Landscape Insect Killer Concentrate Permethrin Ortho Mosquito-B-Gon Tree, Shrub & Lawn Spray, Spectracide« Bug Stop« Multi-Purpose Insect Control Concentrate, Bonide Borer-Miner Killer, Gordon's Bug-No-More Yard & Garden Insect Spray, Eight Vegetable, Fruit & Flower Insect Control, Dragon Lawn & Garden Protector
Nicotinoids - nerve poison, systemic insecticide applied to soil, for sap-feeding insects, borers
Imidacloprid Bayer Advanced Garden Tree & Shrub Insect Control Concentrate
Microbial insecticides - toxins produced by bacteria
Bacillus (Bt) Thuricide, Dipel caterpillars only, best against smaller stages, must be eaten thuringiensis Spinosad Conserve Naturalyte Insecticide - caterpillars, sawflies
Botanicals - produced from plants, modes of action and pest control activity varies with products
Azadirachtin Olympic Azatin XL, Gordon's Garden Guard Liquid Insecticide, BioNeem, Bon- Neem (neem + insecticidal soap) Extract from neem tree acts as a growth regulator for many insects Pyretrins Many products - quick knockdown, broad spectrum, no residue. Extract from certain Chrysanthemum flowers Rotenone Dragon Rotenone Pyrethrins Spray, Rotenone Pyrethrins Stomach poison Extract from roots of a legume plant. Control of chewing insects
Physical insecticides - contact insecticides, may physically block breathing pores or be absorbed
into the body and interferes with physiological processes. For soft-bodied aphids, scale crawlers, mites, etc. Insecticidal Bonide Insecticidal Soap, Safers insecticidal soap soap
Horticulture SunOil, All Seasons Horticultural Spray Oil, Ortho Volk Oil Spray Oil
Forest tent caterpillars (FTC) have been very abundant in Ohio River counties from Trimble through Boone over the past few years. Here is some update information from Tim McClure, Forest Health Environmental Scientist (KDF). FTC defoliation in Carroll County near the river is not as bad this year as in past years, there are many dead caterpillars with a fungal growth on them plus hanging dead caterpillars. It appears that this population is dwindling and entompathic fungi and a polyhedral virus are active. From all indications the FTC population is heading eastward from Trimble and Carroll counties. There has been complete defoliation of ash, and chinquapin oak, and feeding on maple, multiflora rose and elm.
According to Mike Klahr, Boone Co agent for horticulture, FTC are defoliating oaks and sugar maples throughout the county. The population there is considered to be greater than last year.
What is the potential impact of FTC feeding? A single complete defoliation rarely kills a tree but growth is affected. A study of aspen in MN showed a 70% reduction in basal area growth from a single defoliation. Growth was down by 90% after a second defoliation the following year. There was a 15% reduction during the third year, which was a recovery year. Consequently, growth was reduced an average of 58% over the three years. This stress affects susceptibility to insect borers and can account for problems seen in subsequent years.
FTC outbreaks usually last for 3 to 4 years years then decline due to environmental conditions, extreme competition for food, or diseases. This may help to reduce numbers along the western boundary of the infestation but there appears to be a slow spread to the east. Moths will fly in June and will lay masses of 100 to over 300 eggs on twigs a variety of hardwoods. These eggs will hatch next spring to produce the 2007 brood.
Several calls have been received about tiny red, mite-like "specs" crawling over pavement, patios, foundations and other outdoor surfaces. Oftentimes the critters make their way indoors and wander over floors, walls, counter tops, computer monitors, etc. When crushed they leave reddish stains, further elevating their status as pests.
Technically speaking, these are mites in the family Trombidiidae - a large group of outdoor, free-living mites that prey on insect eggs and other tiny soil arthropods. They breed outdoors in moist, organic, vegetative environments such as occur around the foundations of buildings. The mites cannot breed indoors, nor will they bite pets or humans. They are often mistaken for clover mites, which have similar outdoor origins and habits. (Clover mites tend to be reddish, orange or olive-brown in color and when viewed under magnification, and the front pair of legs extend much farther forward than the others). Some people also mistake the mites for chiggers.
Control- Most clients will not tolerate the mites once they have made their way indoors. Tremendous numbers often appear on foundations, patios, and other adjoining surfaces. Given their abundance and very small size, it's virtually impossible to prevent their entry by caulking and sealing alone. The most efficient and immediate solution is an outdoor perimeter application of insecticide around the base of the foundation in a 2 to 6-foot-wide band along the ground, and 2-3 feet up the foundation wall. Also spray along the base of exterior doors, beneath the bottommost edge of siding, along the crack where brick veneer meets foundation wall, and around framework of windows and doors. Several different homeowner products are effective when applied with a pump up or hose end sprayer, including Sevin, Ortho HomeDefense, Spectracide Triazicide, and Bayer Advanced Lawn & Garden Multi-Insect Killer Concentrate. Professional pest control firms also perform treatments around building exteriors.
Mites occurring indoors are best removed with a vacuum to minimize red smears and stains. Indoor insecticide applications are not needed or recommended. The occurrence of this mite around structures is a temporary event. For clients who opt to do nothing, the problem usually corrects itself in a matter of days or weeks.
Two hay samples from different parts of the state arrived in the Insect ID lab over the past few days. Both contained 5/8 inch long black beetles and came with the fear that the hay was infested with blister beetles. The culprits in both samples were darkling beetles. These insects are relatively common stored grain and feed pests that feed on cracked kernels and fines. The adults have shiny dark brown to black bodies and the head is narrower than the segment immediately behind it (thorax). In contrast, the head of blister beetles is noticeably wider than the thorax. The larval stage of a darkling beetle, often called a mealworm, has a hard cylindrical yellow to brown body like that of a wireworm. The larvae may be seen with the adults in feed or hay.
Darkling beetle adults and larvae feed on broken seed and fines. They may move from stored feed or grain into stored hay and can find food and shelter there. Neither the larvae nor the adults are toxic and they should pose no threat to livestock.
The blister beetles that we are concerned about as contaminants in horse hay are not live and active during the winter. They live for a relatively short time in late summer. The immature stages occur in the soil so the insect cannot complete its life cycle in stored hay or feed.
For more information livestock pests, visit "Insect Management Recommendations".
Agronomic samples received in the PDDL this past week included barley yellow dwarf virus, wheat streak mosaic virus and powdery mildew on wheat; Pythium root rot, Rhizoctonia damping off, target spot, Sclerotinia collar rot, and injury from cold (rapid temperature change) and heat on tobacco.
On fruit and vegetable samples we have diagnosed fire blight, powdery mildew, cedar-apple rust, frogeye leaf spot and Botryosphaeria dieback on apple; black knot on plum; iron deficiency on blueberry; Rhizoctonia fruit rot on strawberry; nitrogen deficiency on kale; and early blight and thrips injury on tomato.
Ornamental samples included anthracnose on ash and maple; Botrytis blight on rose; leaf miner on hawthorn and birch; petiole borer on maple; spot anthracnose and freeze injury on dogwood; Botryosphaeria dieback on rhododendron; stress and transplant shock symptoms on numerous species of woody ornamentals.
|UKREC-Princeton, KY, April 28-May 5, 2006 ||True Armyworm
||European Corn Borer
||Southwestern Corn Borer
View Princeton trap counts for the entire 2006 season at - http://www.uky.edu/Ag/IPMPrinceton/Counts/2006trapsfp.htm
Fulton County trap counts are available at -http://ces.ca.uky.edu/fulton/anr/Insect%20Counts.htm
For information on trap counts in southern Illinois visit the Hines Report at - http://www.ipm.uiuc.edu/pubs/hines_report/comments.html The Hines Report is posted weekly by Ron Hines, Senior Research Specialist, at the University of Illinois Dixon Springs Agricultural Center.
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.
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