The Seasoned Gardener

Buyer Beware - Ash Tree Treatments

I was surprised to see an online ad for a local tree expert on my blog site today.  The expert was advertising treatment to protect trees against the Emerald Ash Borer, a very destructive pest which has recently been found in northern Illinois.  The ad was brief and not intentionally deceptive, but it did advertise treatment of ash trees to protect against this insect. 

While there are both commercial and homeowner applied products which will protect against the EAB, if your tree is diagnosed with the insect, it will, in all likelihood have to be cut down and removed as part of a quarantine program being initiated by a number of localities in Illinois.  Having the insecticide applied will not eliminate the pest if it's already in the tree.  In addition, if you are in an area where the insect has been found, and you have ash trees, they will likely be quarantined and removed to prevent the insect's spread. 

If you have ash trees be sure to check them for "D" shaped emergence holes in the bark.  If a tree is infested, the damage will be noted as the leaves wilt and die in the summer.  I posted some information on this pest and the symptoms of it's infestation on July 15, 2006.  Hopefully you are not in one of the quarantine areas, but if you are, chances are you will lose your ash! (humor intended).

SG

Wish You Were Here - Overwintering Insect Pests

As we approach fall, most of us think of cool nights, turning leaves and football.  Fall is also a time for insects to begin to look for places to spend their winter vacation.  A couple of these insects can become a real nuisance if they choose your house as their winter destination.  There are some easy steps you  can take now to minimize the invasion of these pests. 

One of the most common home invaders is the Asian Multicolored Lady Beetle or MALB.  These insects were imported into the southeastern US as a natural predator on aphids which were affecting the pecan crops in that area.  The story is the same for many imported insects.  No predators and basically a good life until winter comes.  Then, these ladybug looking insects seek shelter in the cracks and crevices of your house, especially the west facing walls where it is warm.  They can infiltrate into your home where they gather on window ledges and on inside walls, sometimes in large numbers.  The MALB is considered by many people to be a beneficial insect.  Personally, I feel that they become a pest when they show up in the house uninvited. 

Another seasonal pest, is the Boxelder Bug.  Again, this fall hatching insect would like to share your hearth and home for the winter.  Hatching in the late summer and fall in large numbers, these red and black insects emerge in large numbers.  They also seek their way into your house.  Once inside they move about, leaving red marks on white walls and curtains.  If you squash them you will leave a lingering red mark where you did the deed.  Boxelder Bugs are not considered beneficial, and can be a real problem in many areas. 

Controlling these insects and eliminating them from your home requires some work, but it's not impossible.  Exclusion is the best and most effective means to keep these pests outside. Caulking around doors and windows and replacing weatherstripping around doors can eliminate the entry points for these home invaders.  Replace damaged screens to improve your chances of keeping them out as well.  A prudent application of an approved indoor/outdoor insecticide such as Bayer's Home Insect Control ready to use can be effective in creating a barrier to the insects outdoors and also killing them indoors.  Be sure to use a product which is specifically labeled for indoor use.  The Bayer product is available with a handy electric pump sprayer which makes application easier. 

Another way to remove these pests from your home is to use a vacuum cleaner...with the following caveats...these pests can smell very bad if they are vacuumed up and vacuuming them does not automatically kill them.  Here's a recommendation.

If you are going to vacuum these pests, cut a leg off a pair of discarded panty hose and insert it into the suction tube end of the vacuum. Use an elastic band to tightly secure the open end of the panty hose leg around the tube opening.  This creates a net-like catching container in the tube and will eliminate the insects from being inhaled into the vacuum itself.  When you're done vacuuming them up, simply remove the panty hose leg from the tube and either discard it or release the now bewildered insects back outdoors so that they can try it again. 

As always, the best protection against these pesky visitors is to keep them outside.  If that fails and you want to eliminate them indoors you can use the insecticide option above or the "Tube of Mercy" way to gather up the insects. 

SG

Organic and Synthetic Pesticides Have Similar Risks

   There is a perception in gardening that the word “organic” when used to describe pesticides, implies safety.  In fact, organic does not mean safe nor does synthetic equal dangerous.  The toxicity of a garden pesticide is indicated by its “Signal Word” which is always present on the front of the label.  Signal words relate directly to a products toxicity using a standardized test called “LD50.”  This number is determined the same way for all pesticides whether organic or synthetic, and it represents the number of milligrams of pesticide per kilogram of body weight to cause 50% of a population of test animals to die as a result of exposure.  LD50 means “Lethal Dose 50%.”  The higher the LD50 of a pest control product the LESS toxic it is. 

   This can be a very confusing idea to explain even to garden experts, so the EPA has developed a series of “Signal Words” that are incorporated in the labels of numerous household products, not just pesticides.  Signal words are shown on pesticide products, whether organic or synthetic to place them in the correct toxicity category.  Signal words are an easier way to evaluate the toxicity of a product if you know what they mean. 

   Pesticide signal words relate directly to the LD50 of a product.  This chart shows the oral, inhalation, dermal and eye and skin effects for each signal word category. The designation of mg/kg or mg/l is the same as "parts per million."

                                          

Signal Word>	Caution   (Level 1)	Caution	Warning	Danger &  Danger Poison
Oral LD50	Over 5000 mg/kg	500-5000 mg/kg	50-500 mg/kg	Less than 50 mg/kg
Inhalation LD50*	Over 20 mg/l	2-20 mg/l	0.2-2 mg/l	Less than 0.2 mg/l
Dermal LD50	Over 5000 mg/kg	2000-5000 mg/kg	200-2000 mg/kg	Less than 200 mg/kg
Eye Effects	No Irritation	Reverses in 7 days	More than 7 days	Corrosive
Skin Effects**	Mild irritation	Moderate irritation	Severe irritation	Corrosive

                                     * Inhalation LD50 is shown in mg/liter of air.

     ** Skin effects are after 72 hours of exposure                            

                                  In this sample label, the signal word is “Caution” which means that the product is among the least toxic products in the consumer pesticide category. To reduce the confusion on the part of consumers when making a purchase, there is no differentiation in the Caution Level 1 and the regular Caution categories.  The categories are also used by the EPA and the industry when evaluating the risk represented by a product.  Risk is a mathematical product of toxicity and anticipated exposure.  The formula for determining a pesticide’s risk is this:

           Risk = Toxicity X Exposure                   

   By using the risk calculation, the EPA can decide to limit uses for specific products or to eliminate them entirely from the market. Exposure is the variable component of the calculation while toxicity is the constant.  Risk can be reduced by reducing exposure.

 

   Some products including organic and synthetic pest control products don’t require an EPA signal word on the label.  This list of about 40 products includes many plant based oils and mineral products.  The EPA is very clear that it does not endorse these products and that the manufacturers must meet specific requirements to maintain this “Non-Reviewed” status.

   Another classification of pesticides which may also lead to inaccurate conclusions about safety is the “Botanical” insecticide.  Since many plants produce their own defensive compounds to protect themselves from insects, botanical insecticides may imply that they are organic and thus safe.  In reality, botanical insecticides including rotenone, cube, pyrethrum, and nicotine all require registration and a signal word.  The fact that they are naturally derived does not minimize their toxicity or the risk associated with exposure.  In fact, nicotine sulfate, a common insecticide for homeowner use carried the signal word “Danger/Poison” due to its very high toxicity when ingested.  It has since been withdrawn from the marketplace.

 

   Pesticides are not the only products which must carry an EPA signal word.  Other products including household cleaners, automotive fluids, and aerosol paints are also required to carry the same warnings.  The process to determine the signal word for these products is exactly the same as it is for pesticides.

Ultimately the choice to use a pesticide is up to the consumer.  The assumption of safety of organic products or toxicity of synthetics is far less important than understanding and following the product directions carefully, and using common sense when applying products to your house or garden.  The opportunity for misapplication and increased risk does not come from the toxicity of a product as much as exposure from a misapplication. 

   Regardless whether a pesticide is organic or synthetic, there are no safe pesticides.  Safety is in the choice of the right product, and application according to label directions.

 

SG