Several diseases are found in lawns at this time. Brown patch, dollar spot, and helminthosporium are some of them. It is not recommended to treat lawns for diseases since it a never ending proposition. Sprays are generally applied every 10-14 days forever. It is recommended to let diseases run their course, and reseed in the early fall if needed.

Evergreens are not looking the best. Most evergreens don't do well for long periods of time in central Illinois. Scotch, red, and Austrian pines get several needle diseases. White pines have weather and environment related problems that can lead to sudden death. Spruces have needle diseases, spruce spider mites, and canker diseases. Spider mites and bagworms can be treated, but we may have to look at the other problems. Most evergreens don't like the Illinois extremes for moisture and temperature. Many are even found as understory trees in natural settings, rather than specimen trees. Take care when selecting evergreens for landscape use.

Cucurbits are basically everything in the squash and melon families. There are several potential insect problems with them, and today's column attempts to help minimize or prevent these problems. The first group of insects is the cucumber beetles. These can be green, black and yellow striped, or black and yellow spotted. These are also called corn rootworm beetles when they are in corn fields. When these insects are in cucurbits, they are usually called cucumber beetles. The importance of the beetles is not that they eat small holes in the leaves, but that the striped and spotted beetles can transmit a bacterial wilt to the plants as they eat. The first thing you see is you have a plant that suddenly wilts on various runners, or the entire plant. The best means of controlling this disease is a good beetle control program. Current homeowner recommendations would include these products with the days to harvest restrictions in parenthesis: carbaryl (0), bifenthrin (3 days), or rotenone (1 day).

Of course, Japanese beetles love cucurbits as well. Their damage is direct leaf feeding. Remember they feed in groups, so once they get started you will have a battle on your hands. The carbaryl and bifenthrin are both good control measures.

Squash bugs are the next problem to discuss. Squash bugs are usually dark gray to black in color and like a long stink bug. Their eggs usually hatch mid-June to mid-July. Best control timing is when the eggs first hatch. Non-restricted products are sabadilla (1 day), which is an organic product that might be a little hard to find, and bifenthrin (3 days to harvest). One last note, if the squash bugs get past their early growth stages then physically removing them is about the only

control method available.

If you haven't checked for bagworms yet, now would be a good time. Small bags have been noticed in the county for the last few weeks. Re-treatment may be necessary in some cases. Sevin will work on the smaller sized bagworms, while the B.t. products may be required for the larger ones.

Remember bagworms frequently start in the tops of trees. Bagworms are the larvae of clearwing moths that don't fly too well. If you control the bagworms well, you may not have high populations for a few years.

Logan County Extension Office

After three years of heavy numbers in the Mt. Pulaski, Chestnut and Latham areas, the rest of Logan County is becoming acquainted with the Japanese beetle. Japanese beetle adults have a 1/2 to 3/4 inch long body with copper colored wing covers and a shiny metallic green head. A key characteristic is prominent white tufts of hair along their sides.

They also have an overwhelming appetite for your favorite rose. Adults feed in herds on many deciduous trees, shrubs and vines such as linden, Japanese maple, sycamore, birch, elm, and grape. They generally do not feed on dogwood, forsythia, holly and lilac.

Japanese beetle adults feed on flowers and fruits and skeletonize leaves by eating the leaf tissue between the veins. Feeding is normally in the upper portions of trees. Beetles prefer plants in direct sun, so heavily wooded areas are rarely attacked.

Adults can be with us until mid August. The life cycle is similar to a June bug. After mating females lay eggs in turf which hatch into grubs in August. Grubs feed on plant roots until cold weather drives than deeper into the soil. Adults emerge in summer of the following year.

The bacterial control, milky spore sold as Doom or Grub Attack, is frequently recommended to control Japanese beetle grubs. In our area milky spore is generally not recommended, since it controls only Japanese beetle grubs and not our predominate lawn grub, the annual white grub. Also Japanese beetle grubs must already be infesting the turf for milky spore to work effectively. Pesticides commonly used for lawn grub control will also control Japanese beetle grubs.

Controlling Japanese beetle grubs does not significantly reduce the number of adult beetles the following year. The beetles are good fliers and easily fly a couple miles in a single flight. Evidence suggests that adult beetles are attracted to previously damaged leaves. Therefore reducing feeding damage now can result in less feeding damage in the future.

Generally pesticide sprays of cabaryl sold as Sevin can reduce damage for up to two weeks, but four to seven days is more likely. Sevin is toxic to bees. Synthetic pyrethroids can also be effective, but tend to break down quickly with extreme heat. These would include permethrin and bifenthrin. The Japanese beetle repellent made from Neem has not been shown to be effective. Picking beetles off by hand every couple of days may be just as effective as spraying. When disturbed, the beetles fold their legs and drop to the ground. Covering plants with floating row covers can protect prized roses and ripening fruit. Japanese beetle traps are not recommended since they can actually increase damage by attracting more than they kill.

Logan County Extension Office

A lot has happened in a week with our trees. The maples continue to show increasing leaf drop. Sycamores have been hit with a vengeance, and leaves have been falling like rain for the last week. Other good quality hardwoods, such as ash, are also showing symptoms.

The symptoms are dead material between the leaf veins, along the leaf edges, or dead tips of leaves. There are also times when the disease affects buds and twigs. In the leaf stage, the disease only affects leaves currently out. If damage to leaves results in enough dropped leaves, the tree will shoot another set within four to six weeks. All we're out is the energy the tree spent in pushing out another set of leaves. Of course, we also had a freeze that caused the loss of leaves on many trees. What I'm getting at is trees have spent quite a bit of energy already this year. We need to do what we can to replace nutrients and keep moisture available.

Moisture will be needed to with keep those affected trees in a vigorous growing condition. Usual watering rates are an inch a week, and rainfall can supply part or all of that. Fertilizer applied to lawn area or trees is the other part of the equation. Fertilizer should be applied at the lawn rate (supply one pound each of nitrogen, phosphorus, and potassium per 1000 square foot of drip area), if you haven't fertilized the lawn area around the trees. This would translate to about 10 pounds of 10-10-10 fertilizer or eight pounds of 12-12-12 or 13-13-13 per 1000 square feet.

Anthracnose is usually the first leaf spot fungus to affect trees each spring. That means the others can't be far behind. One the more common ones is apple scab. This disease affects apples and crabapples in much the same way as anthracnose does the shade trees. It starts as spots on leaves between the veins of the leaves, and ends with leaves dropping at a rapid rate. This is the reason for so many "naked" crabapple trees late in the summer. Traditional spray programs for production apples (used on the apples or crabapples) should prevent the problem. Samples of apple scab have been coming in for a week now, so expect some acceleration of the disease on susceptible varieties.

It is time to take action against the notorious oystershell scale, because the eggs are now hatching into young crawlers that are extremely susceptible to insecticide applications. However, as the scales mature later in the season, they are more difficult to control because they form an impenetrable protective covering. Oystershell scale has a wide host range, including ash, birch, dogwood, elm, hemlock, maple, poplar, privet, walnut, and willow.

Eggs hatch into young, creamy white to brown crawlers that are active from May through June. The crawlers locate a place to settle and then use their piercing–sucking mouthparts to remove plant fluids, which causes leaf yellowing, plant stunting, and possibly death. Branches or twigs totally encrusted with oystershell scale eventually die.

Insecticides recommended for managing oystershell scale include acephate (Orthene), bifenthrin, carbaryl (Sevin), malathion, insecticidal soap, and horticultural (summer) oil. All these insecticides should be applied when the crawlers are most active, which increases their overall effectiveness in controlling oystershell scale populations. Repeat applications may be needed 10 to 12 days later, as the eggs don't all hatch at the same time. Lilacs and maples should also have a repeat spray in early August.

It's that time of year when iron chlorosis has started to show up again as the yellowing of leaves with a darker green color immediately around the veins in a leaf. This usually shows up on the younger leaves first. This yellowing is particularly noticeable on pin oaks and sweet gums, but may be seen on other species.

The cause is the lack of available iron for the plant. Manganese is another element that can cause these symptoms. There can be tons of iron in the soil, but if the soil pH is not acid enough the plant cannot take the iron up. Possible solutions include: altering the soil pH with either nitrogen or sulfur (be careful since it may take a truckload to alter the soil around a large tree), spraying leaves every 2-4 weeks with a foliar iron compound, or implanting iron tablets in the trunk which would last from 2-4 years.

Injury from iron chlorosis is the eventual decline of the plant, and it may lead to plant death over a period of time. Also, don't expect treatments to green leaves up immediately when applied now. In fact, many times the implanted iron tablets don't show green leaves until the following year when the sap begins to rise. Many people have been using the iron tablets in the dormant period of the tree and have had good results.

After some very severe infestations of bagworms the past few years, the calls have been coming in all year on the correct treatment times for bagworms this year. Year-in and year-out, the correct treatment time for bagworms is June 15. You can mark this date on your calendar for

next year and be within a few days of the correct treatment time. With a very cool spring, a week later may be a possibility. The opposite is true for a very warm spring. The idea is to have all the eggs hatched before treatment, but not wait until the bagworms are almost mature.

The next problem is what to use. The traditional standby has been Sevin, but the B.t. products such as Dipel and Thuricide have really taken their share of the market the past several

years. The B.t. products have several good points including safety to mammals and toxicity to larger bagworms. Since they are bacteria that affect only the larvae of moths and

butterflies, it does take a while for the bacteria to build up to the point where they can kill the bagworm. I won't get into the discussion about Monarch butterflies lighting in the tree just after treatment (actually these products don't kill the butterflies – only the larvae would be killed).

If you are in doubt about whether you have bagworms, check your trees and shrubs around June 15. You can actually see the small bags as the larvae build them. They become very noticeable at about 1/16 of an inch long. Treat bagworms early, since larger ones are more difficult to control. The spring we have had is probably going to zero out the timing, meaning the last two weeks of June should be ideal.

Most people think that bagworms only affect evergreens. True, that is their preferred host group, but bagworms have a huge number of potential hosts. Through the years I have seen them on oak trees, grape vines, apples, and about any other growing thing you can think of. Make sure to check the tops of tall trees. An infestation may get started in a tall tree simply because you can't reach the top when applying a control. In that case, you'll have to use a taller ladder.

Logan County Extension Office