The following new ENTFACTS are being added to the Entomology Department Web site as PDF files. County offices should use these to produce camera-ready copies for distribution. Other camera-ready copies will not be sent to the offices.
See "Insect Management Recommendations" for insecticide recommendations on crops and livestock.
Upgraded ADVISORY : We still have no reports of blue
mold activity from Kentucky or adjacent states, but the
potential has increased recently for blue mold to develop
in east Tennessee and eastern Kentucky. The region
experienced a weak exposure event late last week and the
wet weather expected this week will provide highly
conducive conditions for development if viable spores did
contact unprotected tobacco.
Blue mold remains active in northern Florida and southern Georgia. It is our understanding that the level of activity there is very low.
Exposure Event: Some airborne spores may have been deposited in southeast to eastern areas of Kentucky and east Tennessee on Thursday evening/night (May 1). This occurred in association with a band of storms coming from the west that contacted southeastern air masses that probably had picked up spores as they passed over the Georgia/Florida activity. The national forecast (made in advance of the weather system) did predict movement and some possible deposit into east Tennessee, but not as far north as Kentucky. However, an analysis of the actual route and timing of events after they had developed last Thursday, supports the idea that viable spores may have arrived and been deposited on that system as far north as eastern and southeastern Kentucky, as well as, in east Tennessee. Basically, it appears that the main band of showers/thunderstorms encountered the trajectory more during the evening hours, rather than during the late afternoon, because the storm front moved along slower than models predicted. Consequently, we believe there has been a better chance of Kentucky receiving some viable spores from that system than had been predicted in advance of the system's move.
Furthermore, we believe the level of risk was low, because of the following factors limiting the amount of viable spores in the system:
1.) The spore-load in the system should have been low, because the level of disease activity in Georgia and Florida was low.
2.) Also, there was some solar exposure (UV) in both the release area and along the route of travel, which should have killed many, but not all, of the spores.
3.) And, there is a very low probability that spores actually landed on tobacco with this event, because very little tobacco has been transplanted into the field in our area. This is important, because transplanting spreads the crop out over a much larger land areas increasing the chance that viable spores will encounter tobacco.
In contrast, if viable spores landed in an unsprayed or poorly spray tobacco float system, conditions would have been ideal for development and spread. Furthermore, many growers have plants ready to set, and will be attempting to hold plants under a variety of conditions conducive to blue mold development. Therefore, increased scouting and control efforts are warranted in eastern and southeastern Kentucky.
Tobacco growers in the Tennessee River Valley and Ohio River Valley are urged to keep fungicide spray programs for blue mold control in place in ALL transplant production systems, especially those in the east. Transplanting is underway in both states in this region, but that will be slowed with the wet weather. I do not recommend fungicide sprays in the fields at this time, rather put scouting efforts in place and remain alert to regular updates.
Also, I urge all to appreciate the risk blue mold in the southeast may present to transplants being produced there and moved to our region. Avoiding movement of blue mold on transplants is a key to controlling blue mold in the northern states. We need to focus on not introducing it with transplants from outside the region and keeping local plants free of the disease with regular fungicide sprays. In addition, operate the ventilation and heating systems in transplant production systems such that the foliage is always dry, especially at night. Growers should also be equally concerned about transplant movement from within our region if they become contaminated with blue mold, so remain in contact with the Kentucky Blue Mold Warning System for regular updates on the status of blue mold within our region. County agents need to report the first cases of blue mold in their county to the system and keep the system updated at least weekly once blue mold is present in their county.
Application guidelines for the fungicides labeled for blue
mold control in transplant production systems and in the
field in Kentucky have been presented in recent issues of
Kentucky Pest News:
Transplants fungicides in the March 24, 2003 issue number
978 at web address-
http://www.uky.edu/Agriculture/kpn/kpn_03/pi030324.htm
Field fungicides in the April 28, 2003 issue number 983 at
web address -
http://www.uky.edu/Agriculture/kpn/kpn_03/pi030428.htm
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
The following is reprinted from an article by Dr. Dean
Malvick, Extension Plant Pathologist at the University of
Illinois. It is the UI Pest Management and Crop Development
Bulletin for May 1, 2003, and sums up the situation well for
Kentucky producers (the only exception being that
nematodes are an even lower risk to corn seedlings in
Kentucky than in Illinois)
This article will provide a brief review of corn seed and seedling diseases and the fungicidal seed treatments (including one new product) that are used to manage these diseases.
Corn planting is off to a good start in Illinois, with about 47% in the ground on April 27 versus 24% last year on this date (estimates from the National Agricultural Statistics Service, USDA). Much of the state has good conditions for corn germination and seedling growth, while some areas have wet conditions. Where conditions are relatively warm and dry, seed and seedling diseases will have minimal impact, and seed/plant loss may not exceed the 5 to 10% loss that we may normally expect at this stage of crop development. However, conditions can become favorable for disease if they turn to prolonged cool and/or wet conditions, as we saw in May 2002.
How can seed and seedling diseases affect the corn crop? We can probably generalize and say that seed and seedling diseases may have a minor impact on corn in many fields during an average year in Illinois. Partly, this is due to widespread use of corn fungicidal seed treatments along with average conditions that don't favor seed and seedling diseases. But when soil is cool and wet after planting and emergence and growth is "delayed," these diseases can be a problem. Their main effects may be reduced plant populations and stunting. In addition, it is possible that nonlethal infection at the seedling stage may cause damage through the growing season. Not as much data as is desirable exists to document potential damage from seed and seedling pathogens, but results from two seed treatment studies provide some indication of damage caused by soilborne corn fungal pathogens. Studies from Iowa (G. Munkvold, 1998) suggested Captan+ Allegiance and Maxim+ ApronXL can provide a yield increase of 10 to 15 bushels per acre compared to nontreated seed, and results from Illinois (W. Pedersen, 2000) were similar with these same products (10- to 15-bushel-per- acre increase over nontreated check).
How can you recognize a problem with corn diseases that affect seeds and seedlings? Disease damage may appear to be similar to some environmental stress, but general and specific symptoms can help you diagnose a disease problem. General effects of corn seed and seedling disease are reduced emergence, slow growth and stunting in a random or circular pattern, wilting, chlorosis/yellowing, and postemergence damping-off. Specific symptoms of seed and root infections include rotted seed and seedlings before or after emergence; red/yellow discoloration of leaves; complete or partially rotted roots with firm or soft brown reddish to gray lesions or decay; discolored and soft coeleoptile; death of leaf tips; wilting; and sunken, discolored lesions on mesocotyl. Leaf spots and streaks can also occur, resulting from anthracnose and Stewart's wilt infections.
What are the pathogens/diseases that affect corn seeds and seedlings, and what is the source of these pathogens? Some common genera of "fungal" pathogens that cause one or more of the preceding symptoms are Diplodia (Stenocarpella), Pythium, Rhizoctonia, Fusarium, Colletotrichum, and Penicillium. Two bacterial pathogens that can affect corn seedlings are Erwinia [=Pantoea] (Stewart's wilt) and Pseudomonas (holcus spot). In addition, don't forget about nematodes, which also damage corn seedlings, especially in sandy soils. The source of these pathogens is typically the soil-infested residue remaining from previous years' crops and infested seed. Recently, we checked 10 seed lots for fungal infestation, and we frequently isolated Fusarium, Aspergillis, and Penicillium from surface-disinfested seed.
What conditions favor these pathogens? The frequency of infection and importance of these pathogens will vary and depend in part on location, seed quality (cracked or infected seed), soil temperatures less than 55ø F, wet soil, soil compaction, slow emergence and growth, hybrid/inbred, fertilizer burn, herbicide injury, crusted soil, high temperatures (Penicillium infection), and high populations of flea beetles (Stewart's wilt). Common favorable conditions for seedling diseases are cool, wet, and compacted soil and poor seed quality. For example, Pythium is a common soil fungal-like pathogen that causes seed and seedling rots, and is favored by damaged seed and wet and cool soil conditions.
Which fungicidal seed treatments are most commonly used on corn, and are any new products available? Most corn seed sold in Illinois is treated with fungicides to provide protection from seed and seedling diseases. However, these chemicals are most effective for only about 2 weeks after planting, depending on soil water content and temperature. The primary fungicidal seed treatments used are of two main groups. The first group (ApronXL, Allegiance, and Apron) is most effective against Pythium. The second group of fungicides (Maxim and Captan are common examples) protect against the other fungi.
A new fungicidal seed treatment was labeled for corn in February 2003. The U.S. EPA approved the Syngenta Protege label as a seed treatment for field, seed, and sweet corn. Due to the late registration, treatment of commercial seed has been limited in 2003. The active ingredient in Protege is azoxystrobin, the same active ingredient in Quadris foliar fungicide (Syngenta) and one of the active ingredients in SoyGard soybean seed treatment (Gustafson). Azoxystrobin is reported to have greatest activity against Rhizoctonia, Fusarium, and Penicillium, and research is under way in Illinois and elsewhere to improve our understanding of its activity and efficacy against various corn seed and seedling diseases."
There have been a few reports of cutworm activity in corn
in western Kentucky. That's to be expected at this time of
the year, however, this has surprised several growers who
thought that their preventive controls should have done the
job. Many growers now use preventive controls for
cutworms, these can be at planting treatments, broadcast
sprays or seed treatments. Some of these do a good job,
others only control a portion of the cutworms. They help to
reduce cutworm levels, but will not be effective enough by
themselves if cutworm pressure is moderate to high.
Growers need to understand the level of control that can be
expected with these controls. For example, some of the seed
treatments help with cutworm control b ut are not stand
alone strategies. These fields still need to be scouted for
cutworms and if populations are moderate to high, the fields
may require an additional rescue treatment for cutworms.
For more information about corn pests, visit "Insect Management Recommendations".
Some alfalfa fields in Central Kentucky are exhibiting patches of yellowing, stunting, and death of shoots. Upon close inspection, one may notice that crown buds are commonly breaking on these; many of the plants are diseased but not dead, at least in samples I have seen. Crowns and lower stems may exhibit a reddish brown discoloration, which is due to infection by the very common soilborne fungus Rhizoctonia solani.
High humidity and moderate to warm temperatures can favor Rhizoctonia infection. An abundant supply of fresh organic matter often is also a contributing factor, since Rhizoctonia grow well on such a substrate. Organic matter that enhances Rhizoctonia activity may include: fresh manure applications, plowing of plant residue prior to seeding, or herbicidal "burndown" of a pasture prior to a no-till seeding. In the last case, we had quite a bit of humid weather last autumn, which might have favored an onset of disease activity that is showing up now.
Unfortunately, there is little a producer can do about this disease. It would be desirable to cut the alfalfa as soon as is possible, to allow air circulation and light penetration into the crown area. Maintain the crop at the recommended pH of 6.5 to 7.0, maintain adequate P and K fertility, and cut on a regular 30-35 day schedule. There are no resistant varieties, although choosing well-adapted varieties that have consistently performed well in UK Agronomy Department variety trials can result in more vigorous stands that are more resistant to Rhizoctonia infections.
Spittlebug are annoying pests of strawberries that can stunt
plants and reduce berry size. More important to some
producers, particularly u-pick growers, is the annoyance that
spittle masses cause pickers. Although the spittle is harmless,
pickers object to being wetted by the insect excretion.
Initially the nymphs feed at the base of the plants, but later
move up to the tender foliage. Feeding may cause leaves to
become wrinkled and dark-green. While fruit may be
stunted, significant yield loss seldom occurs. High
spittlebug populations are often associated with weedy
fields, so proper weed control along with other practices
encouraging healthy plants are important. Fortunately,
there is only one generation per year.
Prebloom sprays are rarely necessary for spittlebugs, but u-pick growers should keep populations less than one spittle mass per square foot through prebloom to appease customers. Begin estimating spittlebug density at 10% bloom by inspecting five to ten 1-square-foot areas per acre of strawberries at two week intervals. It will be necessary to spread plants and inspect the crowns as well as leaves and stems. Control is considered at one spittlebug per square foot (u-pick) up to four to five per square foot.
Another serious preharvest pest of strawberry is tarnished plant bug. It can cause considerable damage to strawberries by puncturing young fruits before receptacles expand. These damaged areas do not develop along with the rest of the berry, resulting in misshapen "catfaced" fruit. The damage may range from slight deformation to complete loss of market value of the crop.
Most damage takes place just after petal fall. Early June bearing varieties can escape most tarnished plant bug injury because pest populations are small and consist of less damaging early instars. Late maturing cultivars are more susceptible to damage. Plantings near alfalfa fields, woods, or weedy areas are more prone to damage. Alternative hosts, especially weeds and seed-producing plants should be eliminated around the planting. Regular mowing or weeding may help, but should be avoided during the blossom period. From pre-blossom until harvest, shake blossom or fruit clusters from ten to fifteen plants per acre over a light colored pan. Treatment is suggested when levels reach an average of 0.5 nymphs per cluster.
Crane flies come in all sizes and closely resemble mosquitoes.
Fortunately, they're not blood feeders because some appear
to be large enough to drain small dogs. There are two
relatively easy characters that can be used to identify this
large group of flies that range in size from gnats to large,
long-legged types.
The first characteristic involves tools for the job. Crane flies do not have the long sucking mouthparts of a mosquito. Secondly, crane flies and other non-biting gnats do not have small scales along the veins in the wings. A hand lens is needed to see this characteristic.
Crane flies are scavengers as larvae, feeding on decaying organic matter in moist to wet areas. The adults only mate and lay eggs. They do not feed at all. They can breed in low- lying areas and are becoming more common where in- ground irrigation systems are used extensively and keep the soil much wetter than normal.
The most obvious and visible diseases of trees are those affecting the leaves. The effect of each leaf spot disease on tree health varies with the disease and tree affected. In general, those leaf spots that result in premature defoliation will cause the most harm to the tree, and those that appear late in the season or that cause very little death of leaf tissue will only slightly harm the tree. Thus, it is important to diagnose leaf spots correctly and to know how a particular tree is going to respond to the disease.
Symptoms. Leaf spots are usually thought of as well-defined lesions or dead areas on leaves or needles. They may be circular or angular on broadleaves, or band-like on needles. Because there are so many different fungi and bacteria that cause leaf spots, and there are so many different ways that tree species and cultivars react to the diseases, the symptoms will vary considerably.
---Scab disease spots are somewhat circular, superficial and sometimes roughened lesions. Flowering crabapple scab spots are visible now on susceptible crabapples in Kentucky. Crabapple leaves often respond by turning yellow and falling from the tree.
---Conifer needle spots often appear as yellow or brown bands on the needle. Infected needles usually fall from the
---Leaf blisters are swollen or raised blister-like spots on the leaf surface. Oak leaf blisters may become dead but they rarely cause much harm to the tree.
---Anthracnose leaf spots tend to spread into surrounding tissues so it may be referred to as a blotch. These spots- turned-blotches finally may progress to extensive dead areas that involve the whole leaf and shoot. Anthracnose can also cause shoot dieback because the causal fungus can attack small twigs and branches. Such anthracnose symptoms are being seen now on sycamores, for example.
---Phyllosticta and other fungi cause leaf spots with dark margins and tan centers. On maple, dark fungal pycnidia can often be seen in these spots.
---Bacterial spot of ornamental Prunus species may cause shot hole symptoms which develop in leaves when the dead tissue of the leaf spot drops out. Cherry leaf spot, caused by a fungus, also causes shot hole symptoms.
---Tar spots appear as smooth, thick black tar-like fungal stromata dropped on the leaf surface.
---Spots caused by rust fungi often have a rusty orange color provided by the masses of spores produced in the infected spot. Hawthorns and crabapples will be showing rust spot symptoms within a few weeks here.
---Cristulariella leaf spots usually appear as zonate concentric circles on the leaf, often with black fungal structures in the same arrangement.
---Powdery mildew often begins as a small spot with visible signs of the fungus on the leaf surface. The initial powdery spots often expand and cover the whole leaf.
Cause. Many fungi, most of them ascomycetes or imperfect fungi, are parasites of tree leaves and cause spots. Fungi such as Ascochyta, Cercospora, Cylindrosporium, Elsinoe, Marssonina, Microsphaera, Mycosphaerella, Phyllosticta, Rhytisma, Septoria, Taphrina, and Venturia can each cause leaf spot diseases of several different trees. Leaf spot symptoms may also be caused by powdery mildews, and rust fungi. Bacteria such as Pseudomonas and Xanthomonas also cause leaf spots. Determining the exact pathogen causing the the leaf spot by microscopy or special laboratory tests is sometimes necessary to develop effective control strategies.
Control - biological and cultural.
---Use sanitation to reduce pathogen levels. For the vast majority of leaf spot diseases, raking up and destroying or thoroughly composting diseased leaves is sufficient for control. Some of the leaf spot fungi, e.g., Septoria leaf spot of poplar and many of the anthracnose diseases, also cause cankers on the twigs, and pruning out cankered wood is needed to reduce inoculum.
---Manage the growing environment. Avoid sprinkler irrigation which wets the foliage. Thin out crowded branches and prune away overhanging vegetation from nearby trees to improve ventilation and sunlight penetration.
---Provide good growing conditions for trees in the landscape. Some leaf spot diseases such as Actinopelte leaf spot of oak attack trees under stress.
---When available, use disease resistant cultivars. There are many excellent cultivars of flowering crabapple that are resistant to scab (Kentucky Pest News # 978, March 24, 2003), for example.
Control - chemical. If the tree is a valuable specimen and despite the use of good cultural practices the leaf spot disease continues to be detrimental to the health of the tree, fungicide sprays should be considered. Professional landscapers have access to a wider range of effective chemicals than do homeowners.
---Use protectant fungicides such as Captan, Chipco 26019, Daconil 2787, fixed copper, Fore, Manzate, Syllit, and Ziram to control a wide range of leaf spot diseases.
---Use systemic fungicides such as Banner Maxx, Bayleton, Benomyl, Cleary's 3336, Eagle, Immunox, or Rubigan to target certain specific diseases.
---Fungicide mixtures may include active ingredients with both protectant and systemic activity which may be advantageous.
---Bacterial leaf spot diseases are more difficult to manage, but fixed copper chemicals such as Kocide, Champion, or Bordeaux mixture are most often used.
Choose fungicides and bactericides that have the tree and
the disease listed on the label. The timing of sprays for leaf
spots is critical, and applications often will need repeating.
It is almost always better to control the disease early rather
than later in the season. Be sure that the spray equipment
that is being used thoroughly covers all surfaces of the
foliage.
Galls are irregular plant growths which are stimulated by
the reaction between plant hormones and powerful growth
regulating chemicals that can be produced by some insects or
mites. Galls may occur on leaves, bark, flowers, buds, acorns,
or roots. Leaf and twig galls are most noticeable. The
inhabitant gains its nutrients from the inner gall tissue. Galls
also provide some protection from natural enemies and
insecticide sprays. Important details of the life cycles of many
gall-makers are not known so specific recommendations to
time control measures most effectively are not available.
Gall makers must attack at a particular time in the year to be
successful. Otherwise, they may not be able to stimulate the
plant to produce the tissue which forms the gall. Generally,
initiation of leaf galls occurs around "bud break" or as new
leaves begin to unfold in the spring.
Oaks are susceptible to many gall makers. The woolly fold
gall, caused by a small fly, is a striking example. A fuzzy
white pubescence appears on the leaf and is associated with
a pouch that contains the maggots larval stage of the fly.
Galled leaves are deformed but overall tree health is not
affected adversely.
Information on several common shade tree galls is available
in Entfacts 403, 404, and 408.
Many calls have been received in recent weeks about ants.
Ants are the most frequent and persistent pests encountered
around homes and buildings. Besides being a nuisance,
they contaminate food, build unsightly mounds on clients'
property, and cause structural damage by hollowing out
wood for nesting.
To most people, all ants look alike and "an ant is simply an ant." In truth, dozens of different species may be found within homes, each having unique characteristics which may influence the method of control. Throughout Kentucky, the most common household-invading ants include pavement ants, carpenter ants, acrobat ants, and odorous house ants. The latter ant species has become a huge problem of late, causing fits to householders and pest control professionals alike. Knowing which ant(s) you have often requires the help of an entomologist or knowledgeable pest control firm.
Ant control can be really frustrating. Repeated attempts often are needed to eradicate or at least maintain them at tolerable levels. This column will help you control ants with more success, or at least know when it may be time to call a professional. Recommendations pertain to all common structure-invading ants found in Kentucky except carpenter ants, which will be discussed in a subsequent newsletter (or see 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 is 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. Species nesting inside, or foraging indoors for food or moisture, tend to be the most challenging to control.
Ants Active Indoors - Buildings contain many favorable hiding and nesting sites for ants. Preferred sites include spaces behind walls, cabinets, or appliances; behind window and door frames; or beneath floors and concrete slabs. Most of these areas are hidden, making it difficult to determine their precise location. When the location of the nest(s) cannot be determined or are 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. If all goes well the colony is destroyed.
Ant baits are easy to use. Most homeowner products are pre packaged with the insecticide and food attractant contained within a plastic, child resistant station. Three of the more effective versions sold in grocery, hardware and retail stores are Combat Quick Kill and Combat SuperBait for ants, and Raid Ant Bait Plus with Mettastop . Another bait that often works well is Terro , a sweet liquid bait dispensed from a tube that certain ants including hard-to-control odorous house ants often prefer.
Place baits 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 baited locations 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 hopefully will subside in a matter of days as the number of ants in the colony declines. Continue to place other baits wherever ants are seen.
Ants are rather finicky in their food preferences and may alter them throughout the year. If one bait isn't attractive, try another. Optimal results usually require a sustained period of feeding, not just a brief visitation by a few ants. Retail baits usually will not control carpenter ants, although the Terro bait may be worth a try.
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. Ants usually prefer to trail along lines and edges. 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. Nests often will be located in the ground, marked by a mound or anthill. Other times, the nest will be concealed under stones, mulch, landscaping timbers, pavement, or beneath grass abutting the foundation wall. Some kinds of ants prefer to nest behind siding, or beneath wood trim that has been damaged by moisture. While it takes patience to locate an ant colony outdoors, results will be more permanent than if you spray only where ants are seen trailing. One way to entice ants to reveal the location of their 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 often be eliminated by thoroughly spraying or drenching the nest location with a liquid insecticide such as Sevin or a pyrethroid product such as Spectracide Triazicide , 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 insecticide dilution 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 some species of outdoor and indoor-nesting ants is the granular bait product, Combat 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 the bottom outside edge of thresholds), windows, and openings where utility pipes and wires enter the building. Chronic ant problems can further be reduced by spraying one of the above-mentioned liquid insecticide products 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 2-to 6-foot swath along the ground adjacent to the foundation, and a few feet up the foundation wall.
Broadcast spraying or applying insecticide granules to the lawn or yard seldom, if ever, solves an indoor ant problem. In Kentucky, such applications are a waste of time and a potential polluter of streams, lakes, and municipal water systems. They also eliminate beneficial ants which are important allies in suppressing other pests on your property.
BATTLING ODOROUS HOUSE ANTS
The odorous house ant has become the most common and difficult ant to control in Kentucky and throughout much of the United States. The ant is small, darkish in color, and forms distinct trails along floors, counter tops, sidewalks, foundation walls, etc. It is often mistaken for the pavement ant, which can easily be controlled with most baits. The most accurate diagnostic difference (requiring a good quality hand lens or ideally a microscope) is the absence of a noticeable "bump" (node) along the constricted area between thorax and abdomen. Pavement ants have two obvious nodes and fine grooves or striations along the head and thorax. (Pavement ants are also more likely to "kick out" bits of dirt or debris from their typical nesting location under slabs or along walls. Odorous house ants, in turn, give off a rotten coconut or pine-like scent when crushed.)
Odorous house ant colonies can be large, numbering in the tens of thousands, with multiple nesting sites in just about every imaginable location. The ants commonly nest outdoors under pavement, rocks, mulch, woodpiles, flower pots, siding, etc., and forage indoors for food and moisture. Nests also may occur behind brick veneer, or indoors within wall voids, potted plants, appliances, and especially near sources of moisture. OHA nests tend to be mobile - colonies relocate fast and often in response to changes in weather, disturbance and other factors. The colonies usually have multiple, egg-laying queens, and the primary colonies may split into smaller ones for no apparent reason. Ants foraging indoors feed on all manner of foods, ranging from the trash can to the cereal bowl, but generally prefer sweets.
This particular ant is VERY DIFFICULT to control, especially by householders. The better baits to try are often the sweet ones, e.g., Terro, mentioned above. Activity indoors can sometimes be alleviated by eliminating ready food sources, such as spillage or pet food dishes. Sealing obvious ant entry points may also be helpful, along with trimming back shrubs and limbs that afford untreated 'bridges' to the building (in nature, this ant feeds extensively on plant nectar and honeydew excreted by plant-sucking insects such as aphids).
When odorous house ants are the culprit, many clients will be better off calling a professional, although they, too, are often challenged by this ant. Some of the newer professional products (e.g., Termidor/Phantom sprays, certain bait formulas) are showing promise but are not available to the general public.
On April 2, EPA released the revised human health and ecological effects risk assessments for the carbamate pesticide carbaryl and announced a 60-day comment period closing June 2, 2003 during which the public may submit risk mitigation ideas and proposals. EPA plans to complete an Interim Reregistration Eligibility Decision (IRED) for carbarylby June 30, 2003. To be most useful to the Agency in completing this risk management decision, comments should be submitted as early during the comment period as possible. Comments should suggest measures to reduce risks of concern and/or focus on needed uses and associated benefits of carbaryl, including the timing of applications, target pests, available alternatives, and the cost and efficacy of alternatives.
Carbaryl is one of the most widely used insecticides in agriculture, professional turf management and ornamental production, as well as in residential pet, lawn, and garden markets. Carbaryl also is used as a mosquito adulticide.
EPA has concerns regarding residential and agricultural and other worker exposures to carbaryl. Around the home, the Agency is concerned about exposures of people using carbaryl lawn, garden, ornamental plant, and pet flea control products, as well as adults performing yard work and toddlers playing on treated lawns. Many occupational handler and post-application worker exposure scenarios present risks of concern, even assuming that workers use maximum personal protective equipment and clothing.
The carbaryl risk assessments and related documents explain these exposures of concern in detail. These documents are available from the pesticide docket or from EPA's website at http://www.epa.gov/pesticides/reregistration/carbaryl
During the last week, we have received samples of tobacco seedlings with Pythium root rot, Sclerotinia collar rot, decline from saturated media ("wet feet") and cold injury. On greenhouse ornamentals we have seen Botrytis blight on geranium; black root rot on vinca and Pythium root rot on snapdragon. On landscape ornamentals, we have seen black spot on rose, rust on hollyhock; herbicide drift injury on tulip; Verticillium wilt and winter injury on magnolia; and freeze injury on tuliptree and maple.
UKREC-Princeton, KY, April 25 - May 2 | Black cutworm
| 8
| True armyworm
| 25
| European corn borer
| 3
| Southwestern corn borer
| 0
| Corn earworm
| 6
| | |
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
