2007 will bring some major insect problems. This is the year for the emergence of the 17 year periodical cicada in northern Illinois. Included with the newsletter is a fact sheet of the emergence of this pest. You can also find great information at our cicada website http://web.extension.uiuc.edu/cicadas/.
We will continue to be on the watch for the emerald ash borer. It was found last year in Kane and Cook counties. Included in the newsletter is an article that gives information that may help you determine if you ash tree is suffering from the emerald ash borer or something else. (It is important to remember that there are other problems that affect ash. Every sick ash is not a victim of the borer). This article is a repeat from last year, but worth a second look.
Critters to Watch
This is a list of common insects that crop up early in the season and often catch us unaware. Be looking for these pests. If you see them in your yard, call your local Extension office for information on how to control them.
April
Iris borer: tiny larvae will feed on iris leaves in April and are usually found about the time the leaves are six inches tall. Look for small amounts of damage on the lower part of the leaves. In July, when the larvae are larger, they will move into the rhizome underground and tunnel into it causing more damage.
May
Eastern Tent Caterpillar: this caterpillar may be seen on trees, usually in late May. They form neat, tidy 'tents' of webbing in the branch angles. The caterpillars come out to feed duing the day hours and return to the tent at night. Removing the tent at night gets rid of the problem.
Gypsy moth: the caterpillars are found on trees (often in upper branches) in May. The caterpillar is hairy and has pairs of blue bumps and pairs of red bumps lined up on its back.
Pine Sawfly: The larvae of this pest look like caterpillars and can be found out on the ends of branches on various pine trees. When they are approached, they will pull up their front and back ends in a defensive position. They can easily be knocked off the tree by spraying them with a strong stream of water from the garden hose.
Facts on the Cicada Emergence for 2007
In 2007, northern Illinois will see the emergence of a brood of periodical cicadas (17 year cicadas). The periodical cicadas will come out in large numbers.
This year, as in every year, there will also be an emergence later in the season of the annual or "dogday" cicadas. This emergence tends to be relatively small.
They are flying, plant sucking insects related to leafhoppers and treehoppers.
Cicadas are large (usually about 1 ¼ to 1 ½ inches long).
Periodical cicadas have black bodies and red-orange eyes, legs and wing veins.
When will they arrive?
Periodical cicadas will emerge from late May through June. They should be most numerous during the last two weeks of May and very early June.
What damage do they cause?
Cicadas do not harm humans or pets. They cannot bite or sting.
They are NOT poisonous, so if a pet eats them they will not be harmed (if a pet eats large numbers of cicadas, it may regurgitate or become constipated).
Small trees and shrubs can be damaged by the insects feeding on sap and by the egg laying activities of the female. Excessive egg-laying may lead to small branches breaking. The egg-laying damages small branches because the female splits the bark to lay her eggs. Mature trees usually suffer relatively little damage.
Periodical cicadas can be annoying because they emerge in large numbers. When numerous males "sing" to attract females, the sound can be very loud.
What control measures can I use?
Avoid planting young trees and shrubs until fall this year. Trees and shrubs planted in spring this year will probably suffer the most damage.
Small trees and shrubs can be covered with cheesecloth to prevent the females from coming in contact with the plant and laying eggs. Cover the tree or shrub, then tie the cheesecloth to the trunk below the lowest branches. It should be in place when males are first heard "singing".
Insecticides will be of little use due to the large populations expected to emerge.
Annual or dogday cicadas
are slightly larger in size than the periodical cicadas.
have green to brown bodies with black markings. Their wings have green veins.
will emerge later in the season in the heat of summer (late June-August).
A Few "To-do" items for April-May
April
if the soil is dry enough, begin to prepare annual and vegetable beds by rototilling in some organic matter
cool season vegetables (like cabbage, lettuce and peas) can be planted outside now.
target crabgrass preventers for late April (soil temperatures need to be 55-60 degrees for 5-7 days before crabgrass will germinate.)
May
watch for late frosts that may damage tender plants
lawns can be core aerated if needed, as long as lawn is actively growing
be sure frost is past before planting annuals and warm season vegetables (best to wait for late May)
Emerald Ash Borer in Illinois
The Emerald Ash Borer (EAB) which has been devastating to ash trees in Michigan was found in three sites in the Chicago area (one site in Kane County and 2 sites in Cook County). The Illinois Department of Agriculture is calling upon citizens to check their ash trees and report trees that appear to have the beetle.
This is certainly a time for all of us to be alert, but we must not panic. Let's go into this fully informed of the facts so that we can determine whether or not a tree has been infested by the EAB.
Here are some useful facts to help with that determination:
EAB attacks ash trees. If your trees are not ash, they are not infested with this pest. Mountain ash trees are not true ashes and they will not be attacked.
There are many other green beetles in nature. Just because you see a green beetle, does not mean it is the EAB. If you see a green beetle, try to capture it, so it can be properly identified.
Ash trees suffer from many other problems including diseases, other insects, root damage and environmental stress. An ash that looks unhealthy may be suffering from one of these problems.
There is a native ash borer in the Midwest already (a totally different insect that does far less damage). If you see holes in the trunk of your ash tree, it may be this pest, rather than the EAB.
The EAB makes a hole shaped like a capital 'D' (flat on one side, rounded on the other) and is 1/8 inch in diameter. The native ash borer makes a ROUND TO OVAL hole that is ¼ inch in diameter.
EAB does a great deal of damage to a tree in a relatively short time (about 2 years). This damage includes dieback in the top of the tree, sprouting of new branches on the lower portion of the tree, and splitting of the bark. Ash trees infested with the native ash borer may have the insect for years and show relatively little damage. This damage often looks like a gradual decline of the tree.
If you feel you have a tree infested with EAB, call your local University of Illinois Extension office for help. Extension offices are working with the public to determine if a tree is infested or not. This will entail an Extension staff person or a Master Gardener talking to a homeowner about what they are seeing on the tree. Homeowners need to inspect trees carefully and give accurate information about what they observe.
From the information given, the Extension office will determine if the damage reflects infestation by the EAB or another problem. If it seems that EAB is a real possibility, the Extension office will try to confirm this (either through inspection of samples brought to the office by the homeowner or a visual inspection of the tree itself).
With the vast number of ash trees in the state, it is impossible for Extension or Department of Agriculture staff to inspect every one. The system outlined above will help sort out possible EAB infestations from other problems found on ash trees. This way we can focus on the trees that have the greatest potential to truly be infested with the EAB. We need and appreciate your help.
Garden Tidbit
Boxelder bugs are very active now. They spent the winter in your house and now they are trying to leave your house and go outside again. Open the door and help them out. Do not smash them as they will stain.
