Managing a Menace: Japanese Beetles

pests , japanese beetle

I had a call this morning from a customer wanting to know what all the beetles were on her roses. “There are about 10 per blossom. They are eating the flowers and have eaten a lot of leaves already. They weren’t there the last time I looked! What do I do?”

The Peoria area is becoming infested with Japanese Beetles, an insect that wasn’t around 3 or 4 years ago. It has been around other parts of the country for years. We knew it was coming, but nothing could be done to stop it. Now it is here to stay and is likely to increase in population over the next few years.

The beetle is a 3/8 to 1/2 inch, greenish-bronze metallic color with white spots on its hind end. Japanese Beetles will be here into early August but are peaking now. It starts as a white grub in the lawn; don't confuse it with the grub of the June Beetle. There are now two white grubs to deal with. Fortunately, they can both be controlled with Merit, and NOW is the time to apply it. So it will be effective when the eggs hatch and the grubs start feeding.

Controlling the Beetles

You are thinking, “But what do I do NOW to keep the Japanese Beetles from feeding on my plants?” You can always knock them off the plant into a bucket of soapy water. That’s the safest control and the one that raises the fewest concerns about effectiveness or ecological impact.

If it isn’t the best option for you, the sprays you can use are:

• Sevin (Carbaryl)
• Permethrin
• Ortho Systemic Insect Killer (Orthene, or acephate)
• Ortho Rose and Flower Insect Killer (bifenthrin insecticide)
• Ortho Max Garden and Landscape Insectic Killer (esfenvalerate)
• Bayer Rose and Flower Insect Killer (cyfuthrin and imidacloprid)

Multiple applications are needed. The beetles are great flyers and will come in from other places. They live for about 6 weeks. Insecticides with Merit or imidacloprid provide very good control as a soil drench. But this takes awhile to be taken up into the plant. It needs to be used before you see the beetles.

Japanese Beetle Traps

There are differences of opinions on the use of the Japanese Beetle traps; some scholars feel that they may end up drawing more beetles to your garden than they will actually catch. Although we have heard reports of horticulturists who used them last year and had good success with them.

These beetles feed on a lot of different plants (over 400!). They really like roses, Linden trees, and crabapple trees. While they won’t do long term damage to the plants, they do make it look bad. You can find a lot of information on the web about these pests. For the most reliable information, stick to the ones published by professionals, such as the universities, arboretums, or nurseries.

Best of luck in keeping them controlled.

--Dave

 

Emerald Ash Borer

pests , trees , emerald ash borer

With all the news regarding the Emerald Ash Borer, we are getting many inquiries. Ranging from beetle identification to panic about what to do, we get calls and visits daily regarding this exotic pest. I’ll try to summarize the highlights about this insect.

The Emerald Ash Borer is considered exotic, because it is not native. Since it isn’t native, it doesn’t currently have any natural controls to keep it in check. The frightening aspect of the pest is that it can attack healthy trees. Most other borers attack only stressed trees. The good news is that it doesn’t appear to be a problem in the Peoria area yet.

The Illinois Department of Agriculture has taken aggressive steps to determine the actual status of this pest in our state. 5,000 traps were placed throughout Illinois to determine where the borer is active. The traps are being taken down now, but it will take a couple of months to analyze the large volume of traps.

The insect found in Bloomington appears to be isolated at the moment. They were not able to find an infestation in the area around where the beetle was located. They believe it was brought in from someone who transported the pest in firewood. However, there was an infestation found in Chenoa, IL that appears to have been there for awhile.

What does this mean to homeowners?

1. Don’t bring firewood in from other areas. The borer cannot travel far on its own, so hitching a ride on a load of firewood is the most effective way to transport exotic wood boring insects.
2. The adult EAB is a mall, slender, green beetle that can fit on a penny.
3. The larval stage feeds under the bark of the tree; you won’t see it unless you cut into the tree.
4. The borer is very slow moving unless it is aided by humans.
5. You don’t need to treat your ash yet. The University of Illinois insists there is no need to treat until the insect is verified within 15 miles of your home. Some companies are advertising that you must treat your ash trees now, we do not consider this prudent. First of all, as we mentioned, the EAB is not yet present in Peoria, so chemical treatment is premature.
6. Stressed and weakened trees will most likely be attacked first. Keep your tree healthy for the best control.
7. If the insect becomes numerous, it is then that healthy trees become infected.
8. Once confirmed in your area, the U of I believes you will have adequate time to inoculate your ash tree(s) against the Emerald Ash Borer.
9. Because it is slow to spread, you will most likely to have 2 years to get your tree treated if you choose to, before it might attack your tree.
10. Emerald Ash Borer is not known to attack any other species but ash.
11. When and if you decide on a chemical treatment for your ash trees, you can treat the tree(s) yourself with imidacloprid. It is easy for a homeowner to apply imidacloprid. It is available through several brands such as Fertilome and Bayer. This gives 90% control, which the U of I considers to be excellent control measures.
12. If you are applying the imidacloprid, it requires annual applications. It takes 2 years before older trees are fully inoculated.
13. There is some concern about the affect of imidacloprid on bees. While it is not substantiated, consider whether to use an alternative control when available. Since bees do not pollinate ash, imidacloprid for ash should not be a threat to bees.
14. A tree service can apply Tree-Age. This control can give up to 2 years of control. A homeowner cannot apply this.
15. Ash trees can be subject to many problems. If you have problems on your ash, and the EAB is not in your area, there is likely to be another cause.
16. EAB cannot be detected until it has been in the tree for a few years.
17. Early detection requires destructive measures to the tree. Such methods are reserved for areas where EAB is confirmed.
18. Per the Illinois Department of Agriculture, symptoms of EAB-infestation include decline, crown dye-back, D-shaped exit holes, excess woodpecker damage, basal sprouting, and larval galleries.
19. If, after consultation with a local expert, an EAB infestation is suspected, you should contact the Illinois Department of Agriculture at 1-800-641-3934 or the EAB USDA hotline at 1-800-322-4512.

Eventually, a homeowner may want to consider whether his or her tree is worth the annual cost to treat against EAB. This is a choice the homeowner must make. While we at Hoerr Nursery are no longer selling Ash trees, it is too early to give up on your tree. Perhaps treatment options will improve in the future. Time will tell what action you need to take in your area. For now, keep your eyes and ears open. When conditions or treatment options change significantly, we will keep you updated!

--Dave

 

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Emerald Ash Borer Blog Update

pests , trees , emerald ash borer

This article is in response to the Emerald Ash Borer post on August 28

I attended the Chenoa Emerald Ash Borer Field Day on September 4, 2008. Experts on EAB from various State of Illinois Agencies provided the most up to date information available. Here are a couple of important points I wanted to add:
 

1. Contrary to advertisements by some tree services, Ash infected with EAB can be saved. To say, "Once an Ash tree is infested with EAB it is too late" is false information. EAB can be controlled in an ash that has been attacked by EAB, even up to 30% of the tree.
2. They reiterated that EAB moves only about 1/2 mile per year on its own. Therefore, the University of Illinois strongly believes that once the borer is found within 15 miles of your ash, you have a real good cushion of 7 years or more to get the tree treated.
3. Treatments against EAB must be done forever, like over a million years. So you will want to weigh the costs of treatment. Many municipalities are opting to remove ash in public areas rather than treat them, due to the cost.
4. Only Ash in the genus Fraxinus are susceptible. Mountainash, which is in the genus Sorbus, is resistant.
5. Damage most likely starts in the top of the tree. Early, D-shaped exit holes will not be noticeable from the ground. Other ash problems can also cause the top of the tree to thin out.
6. The Illinois Department of Agriculture recommends you contact a local expert to identify an insect that you suspect may be Emerald Ash Borer before calling them. You are welcome to bring your sample to Hoerr Nursery for ID.
7. The big purple traps are still hanging around, so it will be awhile before we hear the results for our area.
8. Most EAB have a one year life cycle. For larvae that hatched late, they will have a 2-year life cycle.

For more information about the Emerald Ash Borer, visit: www.IllinoisEAB.com

 

-Dave

 

Preparing Young Trees for Winter

spring , gardening tips , pests , trees

Young trees need a little extra protection during the chilly winter months – the trunk is actually the most susceptible to problems. “Sunscald” is when the trunk is actually burned by the sun and can put the tree in danger of developing frost cracks which can harm the tree. No worries! Applying tree wrap is a quick, easy and inexpensive method to protect your tree investment this winter.

Installing Tree Wrap
• First, pick up a tree wrap product at the Garden Center. Begin by wrapping the base of the trunk and working your way upward, overlapping the wrap as you go. This allows the wrap to shed water away from the trunk and prevent water from running down the inside of the tree wrap.

• Continue to wrap tightly until you reach the first horizontal branch. Cut the wrap and secure with twine at the top. Avoid using nylon twine or wire.

• When spring arrives and warm temperatures return, carefully remove the tree wrap. Don't forget! Leaving it on during the warmer months can provide a habitat for harmful insects.

Protection from Animals
Trees are also susceptible to harm from rodents, rabbits, and deer throughout the winter. To prevent problems from small animals, be sure to wrap young trees tightly. Deer love to rub their antlers on the trunks of small trees, so create a barrier of chicken wire around the trunk, and secure it to T-posts in the ground at a height of 3 to 4 feet.

Liquid Fence
For a little extra help, apply a chemical repellant called Liquid Fence to your young trees. This liquid spray can be applied all winter when the temperatures are above freezing, and it will guard the tree against animals.

Take a little extra care to tuck your young trees in for the winter, and they will thank you for it in the spring!

Ella