Yard & Garden Line News
Volume 3 Number 1                                                               January 1, 2001
Features this issue:
 Maggots for Lunch? No More!
Pharaoh Ants
Houseplants Brighten Winter Interiors
A Widow at Christmas
Editorial Notes

Maggots For Lunch? No More!
 Larry Zilliox, Extension Educator-Horticulture, Douglas County

Author and the Brevigs, of Herman, MN, looking at some of the bagged apples.
Photo credit: Larry Zilliox
Remember biting into the first ripe apple in the fall? Those warm memories may be marred by "wormy" ones if you've ever bitten into an "inhabited" apple. Some how you can still remember your disgust and the taste of that wormy bite.

This summer, twenty-five Minnesota home apple growers participated in the second year of a research project involving bagging apples to reduce pesticide use. The process eliminates the need to spray the apples to control the apple maggot fly. (See report on first year in "Bag Apples for Spray-Free Apple Maggot Control" http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-Jan0100.html#apple

Home-apple growers from Thief River Falls to Chatfield to Worthington participated in this on going experiment. Each grower selected fifteen apples per tree for the experiment. Five apples were covered with a standard plastic sandwich bag; five with a zipper type closure plastic sandwich bag and five apples were marked as controls and left uncovered. The bags were stapled closed to secure them around the developing fruit.

The project involved 20 different varieties of apples as well as a number of unknowns. We wanted to evaluate as many varieties as possible to see if there were any problems associated with the bagging procedure. We found that short-stemmed varieties such as 'State Fair' and 'Freedom' were a problem as growers found it difficult to attach the bags without knocking some of the apples off the tree. In response we will look at several different types of bags next year that may easier to attach to the fruit.

Pair of apples, one bagged, the other not.
Photo credit: Larry Zilliox
Project participants commented that they felt many of the bagged apples fell off during the experiment. Yet, when comparing summary data, 27% of the control apples fell off while only 19% of the standard bag and 17% of the zipper type fell off during the growing season. This data looks high so we will be evaluating the drop rate again next year to see if similar results occur.

Each apple was visually evaluated for apple maggot damage. A rating scale of (1) = no damage, (2) = slight damage, but parts of the apple are useable, (3) = unusable apple. The experiment again verified that placing the plastic over the apples did prevent the apple maggot from laying eggs under the skin of the apple. Although only 31% of the control apples showed signs of damage, no bagged apples displayed apple maggot symptoms.

Sometimes research raises more questions than it answers. We noticed bagged green skinned varieties; 'Honeygold 'and 'Bonnie Best' had more sooty mold problems than the controls. Maybe the varieties are more susceptible to sooty mold, which is a problem on the skin of the apple. It can be scrubbed off easily but aesthetically the apple doesn't look quite as appealing .

Some of the 1999 participants indicated that they felt the bagged apples were larger than the other apples on the tree. So this year we weighed each apple and found that indeed they do weigh more. In fact, our bagged apples weighed an average of 19% more than the controls. There was some variation between varieties.

A perfect apple.
Photo credit: Larry Zilliox
I've been following work done by the Agricultural Research Service, part of the USDA. Researchers there have sprayed apples, among other plants, with a special clay (kaolin) coating. They've found the coating is highly effective in minimizing insect damage and disease. The apples that were coated weighed an average of 17% more than the uncoated! While this will be great for commercial growers who would have the sprayers needed to coat a tree, home orchardists will benefit from a bagging method. (The article, "Whitewashing Agriculture", was published in the November 2000 issue of Agricultural Research magazine. Read it on-line at: http://www.ars.usda.gov/is/AR/archive/nov00/white1100.htm

If you would like to participate in our project, we will continue for a third year. We are looking for volunteers who have had severe apple maggot problems and would be willing to bag fifteen apples per tree. We would provide all the needed supplies and instructions for bagging. If interested contact the Douglas County Extension office, 720 Fillmore Suite B90, Alexandria MN 56308 or by calling 320-762-3890. You can contact me also by email, larry@mail.co.douglas.mn.us.

Get the low down on this month's insect pests at Insects http://www.extension.umn.edu/projects/yardandgarden/EntWeb/Ent.htm

Pharaoh Ants
Bruce Giebink, Entomology Technician

Pharaoh ant.
Photo credit: U of MN Extension Service
Since winter has arrived, we assume that we don’t have to worry about ants until next spring. However, such is not the case with pavement ants, carpenter ants, yellow ants, Pharaoh ants, and a few other ant species. Most of the ant samples received this winter at the Yard and Garden Clinic have been pavement ants and carpenter ants. Although we have identified only a few Pharaoh ants samples, they are worth discussing for several reasons. First, they can be easily confused with pavement ants and other small ants. Second, Pharaoh ants can be very difficult to control (even by doing everything right). In fact, improper control efforts usually make Pharaoh ant problems worse.

Pharaoh ants, Monomorium pharaonis, are an imported species, probably from the tropical regions of Africa. Although they can nest in any heated building in the Midwest, Pharaoh ants are most commonly found in multi-unit dwellings such as, hospitals, nursing homes, schools and apartments. Pharaoh ants are small (1/16 inch) light yellow to red ants. They resemble pavement ants in size and food preferences (greasy foods) and may be easily confused with pavement ants and other small ants.

To the naked eye, Pharaoh ants can be easily confused with pavement ants and other small ants. Viewed under a microscope Pharaoh ants have the following characteristics:

No other ants will have all these characteristics.

Pharaoh ant.
Image credit: Ohio State
Control – The best method to control Pharaoh ants is bait them. This may seem straightforward, but doing it right is typically a labor-intensive, time-consuming process. Many factors can complicate things. First of all, Pharaoh ants often have multiple, hard-to-reach nests. Second, different nests may prefer different baits. Third, even a preferred bait will be ineffective if it’s not placed where the ants can find it. Finally, depending on the number, size and location of the nests, it may take anywhere from a few weeks to up to a year, for a baiting program to be effective. Because of this, you may decide to use a pest control company that has experience with controlling Pharaoh ants. In addition to experience, they also have access to baits that are more effective than those available to homeowners.

However, if you’d still like to control them yourself, you can improve your chance of success by: You can also make your own bait by mixing two parts boric acid to 98 parts peanut butter, meat grease or similar fat-based food. An example of this would be 1/4 teasoon boric acid to 4 tablespoons food attractant.

Because baits take some time to work, you may be tempted to "speed things up" with an insecticide application or two. Don’t do it! Never spray Pharaoh ants. Insecticide sprays normally cause colonies to bud and form several nests, making nest elimination very difficult.

Houseplants Brighten Winter Interiors
Deborah Brown, Extension Horticulturist

Rubber trees, Ficus species.
Photo credit: U of MN Extension Service
When the holidays are over and the last decorations are packed away for next year, even the most inviting rooms seem a little drab. Why not brighten your favorite room by adding a new houseplant or two? Many Minnesota nurseries and garden centers ship in large fresh supplies of foliage plants this time of year. As added incentive, they often run special sales on them in January or February.

Don't let frigid weather deter you. Plants will be fine if they're wrapped carefully --often double wrapped-- against the cold. They can be delivered in a heated van or you can transport them yourself, provided you warm the car first, and don't dawdle along the way.

Though it may be tempting, never whisk an unprotected plant quickly from a building to a heated car or vice-versa. Even though you expose it to extreme cold for just a very short time, the plant may suffer irreparable damage. Most foliage plants originated in the tropics or sub-tropics and really can't tolerate any cold temperatures.

False aralia, Dizygotheca elegantissima.
Photo credit: Deb Brown
Several Aglaonema species--Chinese evegreens and pewter plant (upper left corner)
Photo credit: U of MN Extension Service
'Dallas' fern, Nephrolepis exaltata 'Dallasii'
Photo credit: Deb Brown
Attractive houseplants can be grown in all but the darkest corners of your home. For bright light locations near south or west-facing windows, consider one of the ficus (fig) trees. They grow best when exposed to several hours of direct sunlight daily, and can tolerate the warmth that usually accompanies conditions near a sunny window.

You'll have many choices of ficus ranging from the old-fashioned rubber tree with its huge glossy, stiff leaves to the newer introduction, Ficus 'Alii'. Its leaves are so narrow and pointed the plant resembles bamboo more than it does ficus. You'll also find several varieties of the popular weeping fig, Ficus benjamina. A particularly showy one is named `Starlite' for the sparkly white margins on its leaves.

Several members of the aralia family also grow well in bright, warm conditions alongside ficus plants. One of the most handsome is called "false aralia", Dizygotheca elegantissima. Its spidery leaves start out bronze, then turn darker green as they expand. The lacy, delicate foliage of Ming aralia, Polyscias fruticosa, makes it difficult to believe the plant is as tough and sturdy as it really is...at least when it has plenty of light.

Fortunately, there are also many choices for use in relatively low light situations where there is no direct sun. These are primarily "understory" plants that evolved in the dappled shade of taller trees in their native environment. Though they tolerate relatively low light, they do need to be very near a north window or some other location where it's bright enough for you to read newsprint easily, most of the day.

Some of the best plants for these conditions belong to the aroid family, a group that includes philodendrons, pothos, peace lilies, anthuriums, dieffenbachias and Chinese evergreens. Of these, only the peace lilies and anthuriums have showy flowers, but Chinese evergreens often develop bright red berries after their inconspicuous flowers fade.

Several dracaenas work well in relatively low light, too, among them the solid green 'Janet Craig' dracaena and the popular cornstalk dracaena that actually resembles a corn plant. You might also grow a small-statured parlor palm (Chamaedorea elegans 'Bella') or group several 'Dallas' ferns together.

If your light conditions are really poor, try growing a cast iron plant, Aspidistra elatior, or a large potted snake plant, Sansevieria trifasciata. Though they're not the most beautiful houseplants you'll see, they are green and living, and they're practically indestructible!


A Widow at Christmas
Jeff Hahn, Assistant Extension Entomologist

Brown widow, hanging upside down in web.
Photo credit: Jeff Hahn
A week before Christmas, we received a most unusual sample. A resident in the Twin Cities found a live spider on her Norfolk Island pine that she had recently purchased from a local garden center. She thought it was a dangerous spider and submitted it to us for identification. We keyed it to Theridiidae (combfooted spiders) and to the genus Latrodectus (the widows). Based on coloration, we identified it as Latrodectus geometricus, the brown widow (we will send the spider to a specialist for verification).

Brown widow spiders are cosmotropical (common throughout the tropics and subtropics). They are found in the United States in southern Florida and the coast of southern California. This appears to be the first time a brown widow has been found in Minnesota. There are five species of widow spiders found in North America, the most common being the black widow, Lactrodectus mactans. Widows are generally about 1 to 1 ½ inches long (including the legs). A female brown widow is brownish with dark bands on the legs, mottled spots on the upper surface of the abdomen, and a red rectangular spot on the underside of the abdomen.

All widow spiders are quite shy and bites are infrequent. However, if a widow (like most spiders) feel threatened because they are mishandled or trapped under clothes, they will bite to protect themselves. Widows inject a neurotoxin into their victims. The initial bite is not very painful (many do not even notice it). Later, the site of the bite can turn into a bluish red spot.

Symptoms of a widow bite can include sweating, increased blood pressure, and nausea. More severe symptoms can include muscle spasms, tremors, severe myalgia (pain in one or more muscles), abdominal rigidity, and chest tightness. In extreme cases, paralysis, stupor, and convulsions can result. Death occurs in only a very small number of cases. Fortunately, no one was bitten at the Twin Cities residence where the brown widow was found.

Editorial Notes

Orchids.
Photo credit: Beth Jarvis
I took the photo of the orchids over a year ago in Seattle at the U of W greenhouse. As I write this, Twin Citians are shoveling about 8 inches of new snow, bringing the winter total to around 40 inches. This is as much as we had for all of last winter. Weather folk are chattering, perhaps too happily, about the prospect of another 30 to 40 inches by the time it all melts. So, indoor gardening is all we'll be able to do for a while. With the holidays over, it's time to stop and smell the roses, or at least admire the orchids, wherever we may find them.

Next month we'll be presenting preliminary findings on a treated lumber study and hearing from a forest products expert on choices for building raised beds or other garden structures.

In March, Colleen Cannon, the U's structural insect pests specialist, will share all sorts of fun facts about carpenter ants.

Then in April we return to publishing two issues per month. For April 1, Dean Hertzfeld, the state pesticide applicator training coordinator, will tell what you should know before hiring a lawn care service.

Other subjects on the back burner are:
*Soluble salts on soil tests--what does it mean?
*Growing grapes in Minnesota.
*Conservation biocontrol--what is it?

I rely on your comments and questions for ideas for future articles. Please, keep the story ideas coming! We really try to be responsive to your needs.

Please feel free to cut and paste any of the articles for use in your own newsletters. All we ask is that you give our authors credit.

Back issues Yard & Garden Line News are on the Yard & Garden Line home page at www.extension.umn.edu/yardandgarden/. Our home page has clickable links to most of the components of the Yard & Garden Line, such as Bell Museum of Natural History, INFO U and the Soil Testing Lab.

Deb Brown answers gardening questions on Minnesota Public Radio's (MPR) "Midmorning" program on the first Thursday of every month at 10 a.m. Katherine Lanpher hosts the program that is broadcast on KNOW 91.1 FM, and available state-wide on the MPR news radio stations.

If you have gardening questions, please call the Yard & Garden Line at (612) 624-4771.

If you would like to receive an e-mail reminder when the next issue of the Yard & Garden Line News is posted to the web, just send an e-mail to: listserv@lists.umn.edu (note: the second E in listserve is omitted), leave the subject line blank, then in the body of the message, type: sub yglnewslist
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Happy gardening!

Beth Jarvis
Yard & Garden Line Project Coordinator

Websites
Sustainable Urban Landscape Information Series. This site contains everything from landscape design planning and lawncare to both herbaceous and woody plant selection databases. The URL is:http://www.sustland.umn.edu
SULIS

For pesticide info, for both home owner and professionals, check out:
pesticides
http://www.crc.agri.umn.edu/~mnhelps/

There's also some very interesting reading at Forest Products website. To get there from here, click on: http://www.cnr.umn.edu/FR/extension/ Forestry
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