The mosquitoes this summer have hit all-time highs and have been a real deterrent to being outside. Mosquito population trends for the summer have reached four times the number from last year. Visit the Iowa State University medical entomology lab mosquito surveillance website at http://mosquito.ent.iastate.edu/browse_county.php for more information.

"It is too late in the season for homeowner mosquito management actions to have much effect," said Laura Jesse, Plant and Insect Diagnostic clinician. "Eliminating all possible water sources - buckets, tires, bird baths, and other objects that hold water that the mosquitoes could use for their development may reduce the number produced on your property, but not those blowing in the wind from outside your property lines."

Floodwater mosquitoes (the most common biters) have no respect for property lines and easily can fly several miles from where they developed, according to Jesse. That's why the most effective mosquito management programs are those that involve an entire community or encompass a large area.

Personal protection remains the most practical way of contending with mosquitoes for the remainder of the year. Avoid the areas and times of day when mosquitoes are most active if you can, and wear long, heavy-knitted clothing. Apply mosquito repellents sparingly but thoroughly prior to going outside and wash thoroughly when you return inside.

The CDC suggests that you use any of several EPA-registered products that have been shown to provide reasonably long-lasting protection. For most people, a low-concentration product will be sufficient for short intervals out-of-doors. Those working outside longer can benefit from a higher concentration of active ingredient, or repeated applications as needed. EPA-registered products contain one of the following active ingredients: DEET, Picaridin, Oil of Lemon Eucalyptus or IR3535.

Consumer Reports magazine, July 2010, reviewed mosquito repellents and found that, "most of the tested products will do the job if you're going to be outside for only a couple of hours."

Also listen to a Consumer Reports podcast about the OFF Clip-On Repellent. Their conclusion was that the clip-on, fan-powered repellent did not work very well at keeping mosquitoes away from test subjects wearing the device in an enclosed cage of mosquitoes. Consumer Reports recommends that you choose a topical repellent for better results.

Giant numbers and giant mosquitoes
In addition to having an incredibly large number of mosquitoes in Iowa this year, extension entomologists also have had more questions and inquiries that start out, "I just saw the biggest mosquito of my life!"

"The very large mosquitoes that bite viciously are one of our 'usual' species found in Iowa," said Donald Lewis, extension entomologist. "However, this year is different in that the population seems to be larger than normal." The extra-large mosquitoes are in a genus called Psorophora. There is no customary common name for these mosquitoes, though some references use the term "gallinipper" or "gallinipper mosquito" for Psorophora mosquitoes.

Psorophora mosquitoes are a floodwater species. The females lay eggs on moist soil and the eggs hatch when covered with water from floods or temporary pools and impoundments. The larvae grow very quickly to the adult stage. Some of the Psorophora mosquito larvae are predacious; that is, they eat the larvae of other mosquitoes sharing the temporary pool. There can be several generations of Psorophora each summer depending on rainfall. In the fall of the year, the last eggs laid for the season remain dormant and wait for floods the following year. Some references claim the eggs can lay dormant for a long time and hatch years later.

Of the 14 species of Psorophora in North America, the one common in Iowa is Psorophora ciliata, a large mosquito with noticeably banded legs, pale stripes on the side of the dark thorax, and stiff, erect hairs along the legs. Females of Psorophora ciliata are vicious biters and prefer to feed on mammals. They will bite during both the day and night and are able to bite through heavy clothing.

"There is nothing special for the control of Psorophora mosquitoes," Lewis said. "The usual homeowner/gardener actions of eliminating breeding sites such as bird baths, plugged rain gutters and old tires may help reduce some kinds of mosquitoes, but not Psrophora that are breeding in flooded fields. Personal repellents remain the best defense against biting."

State Agencies Encourage Preventive Action, Checking on Elderly

CHICAGO - July 17, 2011. Governor Pat Quinn today encouraged Illinoisans to take preventive action during this extremely hot weather to stay safe, cool, and avoid heat-related illnesses. As sweltering summer temperatures grip the Midwest, various Illinois state agencies offer services and information to help ensure the health and safety of the public. 

Governor Quinn urged Illinoisans to take advantage of services available from the Department of Public Health, the Department of Human Services and the Illinois Emergency Management Agency. Everyone is urged to check on those most vulnerable to the high temperatures, including the elderly and children.

"High heat and humidity can lead to serious health problems, particularly for the elderly and young children," Governor Quinn said. "It's extremely important for people to recognize the signs of heat-related illness and take action to prevent becoming sick from the heat. I encourage Illinoisans to take advantage of numerous services statewide to keep them cool and safe."

The Illinois Department of Public Health (IDPH) offered the following tips to help Illinois residents stay cool during hot weather, which can be found in the "Summer? No Sweat Survival Guide" at http://www.idph.state.il.us/public/books/summtoc.htm

• Increase fluid intake and avoid liquids containing caffeine, alcohol or large amounts of sugar;
• Take cool showers, baths or sponge baths;
• Protect your body with lightweight, light-colored, loose-fitting clothing.  When outdoors, wear a hat and use a sunscreen with a sun protection factor (SPF) greater than 15 to protect against sunburn;
• Never leave anyone, including pets, alone in a closed, parked vehicle; 
• Stay indoors, if at all possible, in an air-conditioned location or seek out the nearest air-conditioned facility. 

IDPH also encourages people to learn to recognize signs of heat-related illnesses like heatstroke, which can quickly become serious or even deadly if unattended. Heatstroke is caused by prolonged exposure to the heat. The symptoms of heatstroke include :

• Headache
• Red, dry face
• Skin hot to touch
• Body temperature of 105° F or more
• Strong pulse
• Loss of consciousness in extreme cases
• Seizures, irregular heartbeat

The Illinois Department on Aging also encourages relatives and friends to make daily visits or calls to senior citizens living alone. When temperatures and humidity are extremely high, seniors and people with chronic respiratory health conditions must be watchful for dehydration and other effects of extreme heat. In addition, seniors should eat lighter meals, take longer and more frequent rests, and drink plenty of fluids.

The Illinois Emergency Management Agency coordinates emergency and relief activities statewide. For more information about preparedness, visit the IEMA Ready Illinois website at www.Ready.Illinois.gov. 

###

Vicksburg, Miss. -- (July 7, 2011) The Mississippi Valley Division continues to assess damages and prioritize repairs to the Mississippi River and Tributaries (MR&T) System in the aftermath of historic Mississippi River flooding that broke flow elevation records at many locations.  The repairs will ensure the future integrity of flood risk management projects along the Mississippi and its major tributaries and restore function to critical project components.  All of this recovery work will require significant funding.

Without supplemental funding to address the flood and navigation system repair costs, the Corps is looking at internal funding sources to reset and repair the most critical flood risk management projects damaged by this year's event.

The Flood Control and Coastal Emergencies (FC&CE) appropriation is used for flood fighting, repair and rehabilitation of qualifying non-federal flood and storm protection facilities, and emergency dredging, among other things.  The Secretary of the Army has the authority to transfer funds to the FC&CE appropriation from other flood control appropriations to meet emergency requirements.

Funds that are transferred are revoked from individual studies and projects for which the funds are surplus.  A total of $52 million has been transferred to date.  Thus far, only funds surplus to FY 2011 and FY 2012 requirements have been transferred.  However, additional transfers are very likely.

In some cases the funds transferred ultimately would have been used on the projects from which transferred.  However, the needs of flood fighting and response are more pressing and immediate.  Without additional appropriations, projects losing funds can compete for funds in FY 2013 and beyond through the budget process.

-end-

Trees are one of the most valuable assets in a landscape. All properties enjoy the benefits of having healthy and beautiful trees. In addition to the aesthetic appeal, a healthy tree can add value to a property. Home gardeners with questions about the management of other tree diseases may contact the experts by emailing or calling the ISU Extension horticulture hotline at hortline@iastate.edu or 515-294-3108.

My crabapple has begun to drop some of its leaves. Why?
The leaf drop is probably due to apple scab. Apple scab is a fungal disease caused by the fungus Venturia inaequalis.Cool, wet weather in spring favors apple scab development. Crabapple varieties differ in their susceptibility to apple scab. Some varieties are very susceptible to the disease, while others are resistant to apple scab.

Apple scab appears as velvety, olive-green to black spots on the crabapple leaves. Heavily infected leaves turn yellow and fall from the tree. Highly susceptible crabapple varieties may lose a large percentage of their leaves by mid-summer. Fortunately, apple scab does not kill affected trees. The damage is mainly aesthetic.

Apple scab can be prevented by applying fungicides from bud break through mid-June. For most home gardeners, however, controlling apple scab with fungicides is not practical. Sanitation also plays a role in controlling apple scab. Raking and destroying the leaves as soon as they fall should help reduce the severity of the infection next season. However, the best way to prevent apple scab is to plant scab-resistant crabapple varieties.

Why are the leaves on my pin oak yellow-green?
In Iowa, the foliage of the pin oak (Quercus palustris) often turns a sickly yellow-green. The yellow-green foliage isdue to a deficiency of iron. The problem is referred to as iron chlorosis. (A close examination of chlorotic leaves will show that while most of the leaf is yellow-green, the tissue around the major veins is a darker green.) Most soils in Iowa contain sufficient amounts of iron. However, in alkaline soils (those with a pH above 7.0), the pin oak is unable to absorb adequate amounts of iron because much of it is in an insoluble form. Since many soils in Iowa are alkaline, chlorotic pinoaks are common in Iowa. Wet soil conditions make absorption of iron even more difficult.

Correcting an iron chlorosis problem is difficult. Applying additional iron to the soil usually doesn't help. The soil already contains sufficient amounts of iron. Adding more iron doesn't overcome the problem. Lowering the soil pH to 6.0 to 6.5 would allow the roots of the pin oak to more readily absorb iron in the soil. Unfortunately, lowering the soil pH isextremely difficult, if not impossible. As a result, homeowner efforts to treat iron chlorosis are often unsuccessful.

One strategy that sometimes works is to have an arborist or other tree care professional inject an iron containing compound directly into the trunks of chlorotic pin oak trees. The effects of a trunk injection may last three or four years.

Why is my sycamore tree dropping its leaves?
The leaf drop is likely due to anthracnose. Anthracnose is a common fungal disease of sycamore, ash, maple, oak and other trees. Anthracnose is most severe in years with cool, wet spring weather. While anthracnose may cause extensive defoliation, it does not cause serious harm to healthy, well-established trees.

Symptoms of anthracnose on sycamores include brown blotches on the leaves, death of young buds and shoots, and leaf drop. In cool, wet springs, affected sycamores may lose most of their initial foliage.

Fortunately, the sycamore trees will continue to produce additional leaves and shoots through early summer. Foliage that develops in late spring and early summer shouldn't become infected as warmer, drier weather suppresses anthracnose. Most sycamores should have a good canopy of leaves by late June or early July. 

Since anthracnose does not cause serious harm to sycamores, fungicide treatments are rarely warranted.

The leaves on my peach tree are puckered and reddish in color. What is the problem?
The symptoms are those of peach leaf curl. Peach leaf curl is a fungal disease. The disease is caused by the fungusTaphrina deformans. Infections occur as the peach tree buds begin to swell in spring.

-30-