Organic Guide

The Guide to Organic Gardening

Chapter 6

Basic Solutions

Extremely Simple Products for Insect Control

Diatomaceous Earth

What is Diatomaceous Earth?

Diatomaceous Earth is a non-toxic, safe substance made up from crushed fossils of freshwater organisms and marine life. Crushed to a fine powder and observed through a microscope, the particles resemble bits of broken glass. They are deadly to any insect and completely harmless to animals, fish, fowl or food. Most insects have a waxy outer shell covering their bodies. INSECT STOP scratches through this shell causing the insect to dehydrate leading to eventual death.

How Does Diatomaceous Earth Work?

Diatomaceous Earth's mode of action for insect and parasite control is strictly mechanical. The microscopically sharp edges contact the insect or parasite, and pierce their protective coating, so they soon dehydrate and die. The larvae are affected in the same way. This makes Diatomaceous Earth an excellent and totally natural pest control, with no indication of mechanical or chemical damage to animal tissue. It can be used as a dust for fleas, lice and other external pests by rubbing into the coat of the animal.

Both internal and external parasite and insect pest control will result in improvement in animal health, appearance and behavior, as well as improved assimilation of feed, which means improved weight gain and lowered feed cost.

How Safe is Diatomaceous Earth?

Diatomaceous Earth is a natural-grade diatomite. It requires no warning label on the bag or container. However, the continual breathing of any dust should he absolutely avoided.

How do I use Diatomaceous Earth?

Diatomaceous Earth can be used as a dust or spray for control of flies and other insects in buildings, on pastures, crops and trees.

DUSTING: For crops and pastures use 6 to 18 kgs per hectare (6 to 10 kgs. in calm air). Dust after rain, overhead irrigation, or after a heavy dew to increase sticking of the powder. Dust plant upward from the ground, covering all stems, top and underside of leaves. For enclosed areas use 1/2 to 3/4 lbs. per 1000 sq. ft. Hang dust bags in doorways of barns, milking parlors, etc. Sprinkle in areas where ants and roaches are present or areas in which they run, such as baseboards, under sinks, etc.

SPRAYING: Mix two lbs. per gal. of water with a wetting agent. Rates as low as 1/4 lb. per 5 gal. water with a wetting agent have been effective. Be sure to keep the mixture agitated.

TREES: Sprinkle liberally on the ground and around tree trunks. Tree trunks can also be painted with a mixture of Diatomaceous Earth, water, flax soap or a wetting agent. This will inhibit migration of various fruit flies (maggot stage), worms, and the Japanese Beetle (grub stage). When a spray is desired, refer to spray rates.

Animal Use - Suggested Feeding and Application Rates

ANIMAL	SUGGESTED RATE
Beef Cattle	1% of total weight of dry ration or 5% in grain
Dairy Cattle	1% of total weight of dry ration
Calves	4 grams in morning milk per calf
Chickens	5% in feed, use at full strength in dusting boxes
Hogs	0.2% of total feed ration, dust or spray on bedding and animals
Horses	5 oz. (1 cup) in daily feed ration
Sheep	1% in ground grains, 1 part Diatomaceous Earth to 2 parts T-M salt
Goats	1% in grain, 5% per bushel of feed; up to 50% in T-M salt
Dogs	1 T. per day in daily ration for dogs over 55 lbs., 1 tsp. per day in ration for small dogs and puppies, rub powder at full strength into the coat for fleas and sprinkle on bedding
Cats	1 tsp. per daily ration, rub at full strength into coat for fleas and sprinkle on bedding

What Pests are Controlled by Diatomaceous Earth?

When used at proper rates, Diatomaceous Earth has been effective against ants, aphids, bollworms, salt marsh caterpillars, cockroachs, cornworms, earwigs, house flies, fruit flies, lead perforators, leaf hoppers, lygus bugs, mites, pink boll weevils, red spider mites, slugs, snails, termites, Japanese beetles (grub stage) and many other insects.

Neem Oil

What is Neem Oil?

Neem oil is a broad-spectrum botanical insecticide, miticide, and fungicide treatment derived from the seeds of the neem tree (Azadirachta Indica). Neem trees are native to India and Burma and are a botanical relative of mahogany. The main active ingredient of neem oil is Azadirachtin. Neem has been used for centuries in India for pest control. Neem oil is biodegradable.

How does Neem Oil Work?

Neem has many main modes of action with the primary role being disruption of an insect's metamorphosis. It is most effective on earlier stages of an insect's development than when it has reached its adult form. Best control is achieved when insect populations are light to moderate. Neem makes an excellent antifeedant and repellant when sprayed on plant foliage. It has an extremely bitter flavor to it, which can make many insects stop feeding on the host plant. We have noticed this behavior particularly with adult grasshoppers. Neem can also suffocate mites, whiteflies, aphids and other types of soft bodied insects on contact. Neem has also been used for boxelder bugs, armyworms, cabbage loopers, Colorado potato beetles, corn ear worms, cutworms, corn borers, flea beetles, fungus gnats, flies, leaf-hoppers, leaf-miners, spruce budworms, tent caterpillars, thrips and many others.

One very encouraging aspect of neem as an organic type pesticide is that insects have shown no resistance or immunity to it as long as it has been in use.

As a fungicide, neem is mainly used as a preventative and when disease is just starting to show—it coats the leaf surface which in turn prevents the germination of the fungal spores. Neem is effective against rots, mildews, rusts, scab, leafspot and blights.

How do I use Neem Oil?

The product is mixed with water at a ratio of 0.05% to 2.0% depending upon the targeted use. You then apply it as a foliar spray, keeping it agitated during application to keep it well mixed. It must be used within 8 hours after mixing with water. It comes with complete instructions.

How Safe is Neem Oil?

It is non toxic to humans, birds, earthworms or animals. Being an oil, it can affect bees if it is actually sprayed on them so it is recommended to use it when bees are not visiting. Once the spray has settled it will not hurt the bees.

What Pests are Controlled by Neem Oil?

Aphids, Army Worms, Beet Army Worms, Blow Flies, Brown Plant Hoppers, Caterpillars, Chinch Bugs, Colorado Potato Beetles, Cotton Boll Worms, Cowpea Weevils, Desert Locusts, Diamondback Moths, Fungus Gnats, Grain Borers, Green Rice Leaf Hopper,s Greenhouse White Flies, Gypsy Moths, Horn Flies, Horn Worms, Japanese Beetles, Kharpa Beetles, Leaf Beetles, Leaf Hoppers, Leaf Miners, Loopers, Mealy Bugs, Mexican Bean Beetles, Migratory Locusts, Pink Boll Worms, Plant Bugs, Potato Tuber Moths, Red Cotton Bugs, Red Flour Beetles, Rice Gal Midges, Rice Hispas, Rice Leaf Folders, Rice Weevils, Sorghum Shoot Flies, Spiny Boll Worms, Spotted Cucumber Beetles, Sweet Potato White Flies, Thrips, Tobacco Caterpillars, Tobacco Horn Worms, Vegetable Leaf Miners, Web Worms, and Weevils.

Kaolin Clay

Insects Don't Like Biting the Dust, using Kaolin Clay

After several years of testing, the product is proving its prowess against all shapes and sizes of insects. The white leaves keep insects from recognizing their favorite hosts, and the tiny particles ensure a lack of hospitality. Just as people don't like climbing into a bed full of sand, insects don't like crawling on a plant or tree covered with kaolin. It sticks to their wings, legs, and mouth parts, so they quickly leave to find a more comfortable place to feed and lay eggs.

In studies around the country, codling moths, apple maggots, plum curculio, leafhoppers, Japanese beetles, rose chafer, thrips, and rust mites—not to mention pear psylla—have fled whitewashed crops in search of greener pastures. Even glassy-winged sharpshooters—the transmitter of Pierce's disease, which threatens to devastate southern California's grape vineyards—avoid kaolin-treated lemon trees. And early results suggest they'll stay away from treated grapevines too.

ARS' Puterka says the specially formulated kaolin particles "have the potential to work against almost any insect. The key is getting good coverage of the crop. If you can get it to stick and stay, it will control most insects." One crop that has failed the stick test is cabbage, so Surround doesn't control cabbage loopers and other worms. And because it's eventually washed off all crops by rain, areas of low rainfall are most adaptable to this technology, Puterka adds.

Don Gallagher of Gallagher Vineyards in Manteca, California, was pleased with the early results of Surround on 12 of his 57 rows of grapes. "When I put it on, there were a lot of mealybugs on the vines. But I can't find one of them now. I don't know where they've gone." Gallagher did, however, find a couple of mealybugs on insecticide-treated vines, he says, noting that he's finding a similar pattern for leafhoppers on the crop.

Jay Brunner, professor of entomology at Washington State University in Wenatchee, is looking at Surround's clout against insect pests of the state's apple orchards. His results have been mixed. "It's as good as many selective insecticides for controlling Lacanobia fruit worms and leafrollers," he says. But it proved only fair for codling moths and variable for stinkbugs. Plus, it seems to interfere with helpful parasitic insects that hang around the orchard and keep leafminers under control, Brunner adds. A water-repelling kaolin formula may have other applications. Tests show that this hydrophobic film protects tender plants and trees from frost damage. Normally, when the temperature drops below freezing, ice crystals forming on a wet leaf penetrate the surface and freeze the leaf tissue. Frost damage can cost U.S. growers hundreds of millions of dollars annually.

But the waterproof kaolin keeps water from direct contact with the leaf surface. And it makes water bead up, which further reduces the surface area of the droplet resting on the leaf, says ARS' Michael E. Wisniewski, a plant physiologist at Kearneysville. In his tests in environmental chambers, kaolin-treated tomato and bean plants have withstood temperatures as low as 21 [degrees] F (-6 [degrees] C). They normally die when the thermometer drops to 28 [degrees] F (-2 [degrees] C).