ACORN NEWSLETTER

September 2002

 

Table of Contents

 

ACORN News

 

Links

 

Featured Natural

Enemy: Spiders

 

Featured Alternative

Control: Insecticidal Soaps

 

ACORN News

 

Ø  Congratulations Farah! Farah gave birth to a beautiful baby boy, Cedric Daniel Berrouet, on July 24th at 6:40pm.

 

Ø  Watch for the 2002 post-season gardener survey in your mail this month.

 

Ø  Remember to submit your data in a timely fashion. Data can be entered on the ACORN web site. If you are having difficulty entering data, feel free to contact me.

 

Ø   The International Master Gardener Conference will be held June 19-22, 2003 in the Greater Cincinnati area. We will be presenting workshops on Saturday, June 21st so tell your friends! More info on the conference can be found at the link below.

 

 

 

Some Useful Links

 


For information on the location and schedule of events for the International Master Gardener Conference visit this link.

 

Visit the Purdue Plant and Pest Diagnostic Laboratory website to read an article written by Cliff Sadof regarding Fall Webworm outbreaks.

 

This link has important information about the West Nile Virus and precautions you can take in reducing the risk of exposure to the virus.

 

Featured Natural Enemy: Spiders

 

Introduction: Many people have a profound dislike for spiders and will not miss an occasion to kill them. Spiders, however, are highly beneficial. Only a few species are dangerous in North America, the black widow and brown recluse. Spiders can be found in many places such as inside the house and garden where they feed on many insects. Some spiders use their webs to capture the prey other spiders, known as hunters don't construct a web. Hunters often sit motionless on flowers and vegetation until their prey comes or they run after the prey to capture it.

 

What to look for?
Spiders differ a lot from one species to another. They have 8 legs (insects have 6), no antennae, and only 2 body regions, (unlike insects, the head and the thorax are fused).

 

Who they kill:

Spiders are generalists, feeding on many different insects, often limited only by the size of the prey. Spiders will tend to avoid wasps, bees, ants and beetles.

 

How to attract them to your garden?
You can help maintain the population of spiders in your garden by avoiding the use of broad-spectrum insecticides that will kill the spiders and their prey. In addition, spiders do better when they can hide or string webs in a course or a mix of tall and short plants. Leave garden stubble or plant grassy perennials to provide shelter for the winter.

 

Release rate and cost:

No spider is commercially available. They have not been successfully used in natural enemy importation programs. However, the Chinese farmers collect them in bundles of straw that are relocated where needed.

 

 

Source: Midwest Biological Control News <<http://www.entomology.wisc.edu/mbcn/mbcn.html>> vol. 3, No 10, Dan Mahr, University of Wisconsin- Madison.
Jeffords, M.R., S.L. Post, R.N. Wiedenmann, C.S. Sadof, and C.P. Nixon. 1997. The Good Guys! Natural Enemies of Insects. <http://www.inhs.uiuc.edu/chf/outreach/good/guysframes.htm>

Featured Alternative Control: Insecticidal Soap

 

What is insecticidal soap?
Insecticidal soap is a contact insecticide that is formulated to kill insects without burning plants.

 

Water quality and insecticidal soaps:
Hard water inactivates the insecticidal soaps. It is better to use soft or rain water f to make the insecticidal soap mixture. Check your water quality by mixing a 2% solution (5 Tbsp/ gal) and letting your mixture stand for about 15 minutes. If the top is coated with a scum, then the water is too hard.

How does it kill the pest?
Soap kills by smothering the pest and causing it to shrivel up and dry. The spray must come in direct contact with the pest to kill it. Typically you will kill about 50% of the pests and susceptible natural enemies on the plant..

 

What pests does it kill?
Insecticidal soap works best on soft-bodied insects such as aphids, mealybugs, spider mites, thrips and whiteflies, and small caterpillars.

 

Can I use it in the home garden?
Insecticidal soaps can be safely used in home garden and on houseplants.

 

Is it compatible with beneficial insects?

Insecticidal soap is compatible with natural enemies. It will not affect ladybird beetle, parasitic wasps and honey bees. However, it will kill soft bodied predators such as the predatory mites and the syrphid fly larva. The pupal stage of parasitoids is not killed. However since only half of the susceptible natural enemies are killed, and the soap is nontoxic after it dries, it has a minimal impact on beneficial populations.

 

Can the insecticidal soaps harm your plants?
Some insecticidal soap may cause damage to your plants. Some plants are known to be sensitive to soaps, for example: horse chestnut, mountain ash, Japanese maple, sweet gum, jade plant, lantana, gardenia, bleeding heart and crown of thorns. Some cultivars of azalea, poinsettia, begonia, impatiens, ferns, palms and succulents may be damaged by insecticidal soaps.

 

Advice: Always read your label before using a product.

Sources:
Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials. Bulletin 504. Retreived on May 1, 2001, from Ohio State University web site <http://www.ag.ohio-state.edu/~ohioline/b504/b504_16.html>

Insecticidal Soap. Retreived on May 1, 2002, from Texas A&M University web site <http://aggie-horticulture.tamu.edu/plantanswers/misc/insectsoap.html>

Guidelines for Insecticidal Soap. Retreived on May 1, 2002, from Gardening in Western Washington- Washington State University web site <http://gardening.wsu.edu/library/lpro002/lpro002.htm>

Insecticidal Soap. Retreived on May 1, 2002, from Montana State University web site <http://scarab.msu.montana.edu/extension/insec016.htm>

Insecticidal Soaps. Retreived on May 1, 2002, from University of Connecticut Integrated Pest Management Program web site <http://www.canr.uconn.edu/ces/ipm/homegrnd/htms/31isoap.htm>


 

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