Sunday, May 27, 2007

Sherri's Helpful Hints

Natural Pest Control for the Garden


Natural control: Plant adapted varieties and encourage natural biodiversity, healthy plants, and beneficial insects such as ladybugs, green lacewings, hover flies, praying mantids, and braconid wasps. Avoid feeding plants heavy amounts of nitrogen.

Organic control: Strong blasts of water, garlic-pepper tea, liquid seaweed, and the release of ladybugs and green lacewings. Citrus oil spray can be used for heavy infestations. Biological sprays are also now available. Plant oil products will also work.

To control aphids, plant adapted varieties, encourage biodiversity especially beneficial insects such as ladybugs, lacewings, hover flies, and predatory wasps. Avoid heavy amounts of fertilizers. Spray infested plants with strong blasts of sugar water and release ladybugs. Garlic-pepper tea, Garrett Juice with garlic, neem, and citrus oil based sprays will also help.

Insight: Aphids, one of the most prolific insects, are considered one of our biggest pests. There are over 200 species. They may produce up to fifty generations per year. Some species produce several generations without mating. The females can lay eggs or give live birth, and those already have within them developing embryos for the next generation. The young can be born with or without wings. It all depends on whether they need to migrate away from a natural enemy or to a better food supply. The life cycle varies widely between different species and may even vary within the same species in different geographical locations.

Bag Worms

Identification: Larvae hang in bags from twigs of trees. Bags are camouflaged with pieces of twigs and leaves from the host plant. Adult male is a black moth. The bag has a small opening at the narrow lower end that serves as a waste exhaust port. A wider opening at the top allows the larvae to crawl out and feed.

Biology and life cycle: Newly hatched bagworm larvae make conical bags that they carry upright as they move. Adult females are grublike, have no wings or eyes, and are nearly hairless. The rarely seen male adult is a small flying moth. It has clear wings and feathery antennae and is sooty black. The female lays eggs in the bags in the fall, then goes through the lower opening and drops to the ground and dies. Larvae hatch and lower themselves on silk threads and attach on limbs where they start building their own silk bags.

Habitat: Ornamental trees and shrubs like arborvitae, junipers, fruit trees, and many others.

Feeding habits: Eat foliage starting on the upper part of the plant. They live in and feed on willow, cedar, cypress, some pines, boxelder, locust, sycamore, maple, sumac, persimmon, and other ornamentals and fruit trees.

Economic importance: Defoliation of ornamental plants.

Natural control: Wasps, birds, and several insect parasites and predators.

Organic control: Bt (Bacillus thuringiensis) products sprayed in the spring. Hand picking the rest of the year is by far the best technique. Plant oil products will also work.

Insight: Texas has several recorded species of bagworms. Since the female doesn't have wings or ever leave the bag, it is somewhat of a mystery how bagworms get dispersed. While the larvae are attached to single strands of silk thread after hatching, they may be blown a distance by the wind. The silk thread could get caught on an animal such as a bird and be carried a distance.

Defoliating insects that attack several tree species. Hand remove bags then apply The Sick Tree Treatment. Once the bags has firmly attached to the plant, the only solution is to pull them off and toss into the compost pile. When the female worms are pulling the bag around and feeding in the spring, spray with Bt products with 1 ounce of molasses per gallon of spray and release trichogramma wasps.

Identification: Microscopic animals related to ticks and spiders. Larvae are bright red.

Biology and life cycle: Nymphs hatch in the spring and are parasites on humans and animals. They inject a digestive juice that dissolves skin cells so they can be more easily eaten. Affected skin will redden and swell. Their numbers are the highest in mid-summer. The adults feed on insects.


Habitat: Grasslands and weedy unirrigated areas.

Feeding habits: Nymphs attach to skin of various animals to feed.

Economic importance: Cause severe itching and small reddish welts on skin.

Natural control: Increased soil moisture. Some researchers say chiggers have no natural enemies. That may be true, but the imported fire ants will certainly eliminate them.

Organic control: Sulfur dust is a good repellent. So is lemonmint, also called horsemint (Monarda citriodora). Take a hot, soapy bath to remove larvae. Stop the itching with baking soda, vinegar, aloe vera, or comfrey juice.

Insight: If you have to walk through property that's dry and weedy and it's summertime, take a few precautions. First, don't wear shorts. Second, dust your shoes, pant legs, and socks with powdered sulfur. It's available at any nursery or feed store. Rubbing the crushed flowers of lemonmint on your clothing will also repel chiggers.

Chiggers can be controlled with a broadcast application of diatomaceous earth or an application of granular or dusting sulfur at 5 pounds per 1,000 square feet. If you have alkaline soil, the sulfur is also a good soil amendment. If you have acid soil, just don't overdo it. Excess sulfur will kill or severely imbalance the microorganisms in the soil. If your property is watered occasionally, chiggers won't be a problem.

We know one outdoorsman who swears that if you don't wear underwear or socks, the chiggers won't have a place to hide and won't bother you.

Treat infested sites with elemental sulfur at 5 pounds per 1,000 square feet. People allergic to sulfur can spray the site with the Garden-Ville Fire Ant Control formula. Chiggers like dry infertile soil. Increase the organic matter and the water holding capacity of the soil and the pressure from these mites will be minimal. Lava sand or other volcanic material will help the soil’s moisture retention. Apply baby oil to your body before dressing if you plan to be in infested area.


Gnats can be caused by decaying organic matter but they are more commonly related to keeping the soil too moist. Let the pots dry out more in between waterings and treat the soil with neem.

Gnats can usually be controlled by watering with compost tea with 1 oz of orange oil per gallon of water and waiting a longer period of time between waterings. A light dusting on the soil of horticultural cornmeal often helps and heavy infestations can be controlled with a drenching of neem. There are several products on the market but avoid those that also contain pyrethrum and PBO (piperonyl butoxide).

A listener reported this idea. Put apple juice or apple cider in a mason jar, cover the opening with plastic and secure with a rubber band. Stab a small hole in the plastic. The small gnats are attracted th the apple juice, enter the small hole and can't get out

These hints come from The Dirt Doctor.

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