ACORN NEWSLETTER

March 2002

 

Table of Contents

 

ACORN News……...........1

 

Links………….…….........1

 

Featured Natural

Enemy: Predatory Mites…………..................2

 

Featured Alternative

Control: Surround Crop Protectant………….........3

 

ACORN News

 

ØWe conducted three successful one-day workshops in the month of January. Many thanks to Denny Shrock, Sandy Mason and Todd Huston for helping us organize workshops in Champaign County, Illinois and Fountain County, Indiana. In two workshops at Champaign County, 62 gardeners and extension educators attended. In Fountain County, 30 gardeners participated actively in the workshops. Thanks to all avid gardeners who attended the workshop and volunteered to participate in our experiment this spring.

 

ØVolunteers are still needed for two experiments: Cabbage Lacewing Experiment and the Floating Row Cover Experiment- Zucchini Squash. If you want to sign up to do an experiment, please see the details on the other two experiments that are being currently offered in the Tactics We Test page of our web site. Due to the overwhelming response by ACORN volunteers we have more than enough gardeners involved in the Weeding Experiment- Snap Bean and the Cabbage Sugar Spray Experiment.

 

ØMore experiments and volunteer opportunities are on the way. We are in the process of developing 2 new experiments. The first project will be to examine how nematodes can be used to kill bagworms, a serious defoliating pest of trees and shrubs. The second project will be to examine if "Surround" a suspension of Kaolin clay, can be sprayed on the stems of zucchini to reduce problems with squash vine borer. See this month's Featured Alternative Control for more information.

 

ØThe results for the Apple Bagging Experiments are online. Please visit the Tactics We Test page on the ACORN website to see the results obtained by home gardener in Minnesota and Indiana.

 

 

 

Some Useful Links

 

Listing of 2600 companies selling over 470 alternative products to agrochemicals.
http://www.agrobiologicals.com/

 

Featured Natural Enemy: Predatory Mites

 

Introduction:

Spider mites feed on plants and are pests in the garden. However, other mites are predators of the pest mites. Outbreaks of the spider mites are usually associated with the use of broad-spectrum insecticides that kill predatory mites. Plant water stress can also contribute to problems with spider mites.

 

How can you distinguish a predatory mite from a spider mite?
You will need a strong 10 X hand magnifying lens to distinguish the predatory mites from spider mites. Either look directly on the injured leaf or shake the mites on to a sheet of white paper for closer examination. Predatory mites are fast moving. They have a pear-shaped body and are more shiny than spider mites. The long legged predaceous mites may be bright white, yellow, red or green. Many appear translucent, although after feeding they often take on the color of their host. Their eggs are more transparent and oblong.

 

How does a predatory mite kill its prey?

A predatory mite will chase and grab the body of its prey so it can pierce it with a needle-sharp mouthpart called a stylet.  They then suck the fluid out of the prey as it bubbles out.

 

Who they kill:

In general, predaceous mites feed on all stages of pant-feeding mites, immature insect eggs and nymph of scale, thrips and whiteflies.


 

Should you release predatory mites in your garden?

Effectiveness of predatory mites in home gardens has yet to be established.  Predatory mites require significant numbers of prey for them to eat in order to fuel reproduction.  For example, an egg-laying female can eat 10 prey per day for several weeks.  Although the release of predatory mites can be appropriate for commercial strawberry fields, container-grown ornamentals and greenhouse-grown vegetables, their use in home gardens has not been evaluated.  Conservation of the predatory mites already feeding on spider mites in your garden is a better first step toward biological control.

 

Release rate and cost:

The release rate and cost vary with type of predatory mite you buy.  Buy a predatory mite that feeds on spider mites and is adapted for use in garden environments.

 

 

Featured Alternative Control: Surround- Crop Protectant

 

What is Surround?
Surround Crop Protectant is an organic product made of Kaolin Clay that acts as a protective barrier on vegetables and fruit trees.
   

Why use Surround in your Garden?
- Surround does not rely on toxicity to kill the insects. It simply deters them from crawling and laying eggs on the plant.
- It is an organic product and is not toxic to bees and earthworms.
- It reduces sunburn damage, resulting in higher yield.

 

Why use Surround on your zucchini squash?
ACORN will be testing Surround in the spring 2002 on zucchini squash to suppress cucumber beetles and squash vine borer. Cucumber beetles and squash vine borers are a major pest of the zucchini. Cucumber beetles feed on the roots, stems and fruits and can cause severe damage by transmitting bacterial wilt. Squash vine borer feed at the base of the stem. There are few or no known alternative control methods that are effective.

 

What does ACORN plan on doing with Surround?
Surround is a wettable powder that we will spray directly on the squash plants after emergence and every week afterwards or when dry foliage has lost its whitish appearance. The Surround should protect the plant from infestation by cucumber beetles.

 

Cost of Surround: GardensAlive manufactures Surround and it costs $24.95 for 5 pounds of dry product. That amount will provide for 20 sprays to protect the 3 zucchini squash.

 

How are We Doing?

ACORN wants to hear form YOU!  Send us an email if you read the newsletter. Tell us what you like and don't like.

 

ACORN is listening! 

If you have any inputs for us or any comments please visit the bulletin board on the website at <http://entm29.entm.purdue.edu/acorn/bb_main.asp>.