Insects are not spontaneous. Those which suddenly attack your garden plants have probably been hiding during the winter.
Some hibernate as eggs on dry plant stems, some as worms in cells in the soil or under leaves, and others as adult beetles, moths, or flies in piles of plant debris.
With warm weather in the spring, they become active in their various forms. This activity is directly related to the temperature; the warmer the weather, the greater the feeding.
Keep this in mind when applying insecticides. In fact, the closer that you can follow the weather forecasts, the more effective your insect control efforts should be.
During the cutworm season in May and early June, sprays or dust of DDT, chlordane, or a treatment with one of the old-fashioned poisoned bran baits will give better results.
If applied when the temperature at dusk is about 60° degrees Fahrenheit at 45° to 50° degrees Fahrenheit, the worms are sluggish or inactive.
Corn Borer Moths
Corn borer moths will lay many eggs only when the evening temperature is 60° degrees Fahrenheit or higher.
Curculio beetles “sting” and lay eggs in the small plums, apples, and peaches when the mid-day temperature is 75° degrees Fahrenheit or higher.
Fresh Applications Of Insecticide
It is frequently necessary and always helpful to make fresh applications of insecticides just before the insects are most active.
Unfortunately, fungus diseases respond to other stimuli. They are rudimentary plants that are spread from seed-like spores or spawn.
Moisture is necessary for growth, and they are often active at damp, cool temperatures.
Control Of Diseases
Control of diseases is primarily the protection of the plant before the disease infects or enters the plant tissue. Therefore, protective sprays or dust should be applied before an extended rainy or wet period.
Many gardeners hesitate to spray before the rain because the residue will likely be washed off.
Naturally, some residue will be lost, but it is also essential that protection be present when the fungus is active in moisture.
Theoretically, it is actually the most effective spray for fungus protection in the rain.
If your tomato plants suffered more from blight, your roses from black spots, and your phlox from mildew, the frequent and heavy rains were obviously an important cause.
Development Of New Pesticides
The development of new pesticides is so rapid that formulations used for 10 years are now old. For example, DDT, chlordane, and rotenone are now well established.
In general, the new formulations are more effective, but frequently they are more selective, and their use is limited.
When considering the purchase of a new pesticide (or an old one), the uses, precautions, and recommendations on the label should always be read carefully. They are generally reliable.
Know Them By Trade Names
Many new pesticides are now designated by short coined names representing the formulation’s chemical structure and are distinctive from the brand names of manufacturers.
Methoxychlor
For example, methoxychlor is dimethyl-diphenyl-trichloroethane and is sold under such trade names as:
- Marlate
- Methoxcide
- Methoxo
Ferbam
Also ferbam is ferric dimethyl dithio carbamate and is sold as
- Fermate
- Ferberk
- Fermocide
- Carbamate
- Karbam Black and others
Learn these coined names and choose your pesticides accordingly. Some new pesticides that have practical value in the garden include the following.
Japanese Beetle Control
Methoxychlor
Methoxychlor is a chemical relative to DDT used for much the same purpose but safer for the amateur to handle and as a residue.
It is effective against the following:
- Japanese beetle
- Mexican bean beetle
- Elm leaf beetle
- Striped cucumber beetle
- Plum curculio
Generally, it gives protection against many caterpillars, thrips, and leafhoppers. Fruits and vegetables are safer than DDT. However, it is ineffective against aphids and mites and is somewhat more expensive.
TDE
TDE (DDD) is another chemical relative to DDT with limited specific uses.
Especially effective for controlling tomato horn worms and various leaf rollers, it is among the best for specified uses.
Lindane
Lindane, similar to benzene hexachloride (BHC), is excellent for controlling aphids on flowers, shrubs, trees, leaf miners, thrips, lace bugs, and flies. Yet, it may cause off-flavor in fruits and vegetables.
Dieldrin
Dieldrin is similar to chlordane but has greater insecticidal activity. It effectively controls grubs on turf, thrips on gladiolus, curculio on fruits, and black vine weevil on yew. However, it has not yet reached its greatest use.
Heptachlor
Heptachlor is also similar to chlordane and may replace it. However, promising for control of soil-infesting insects, much remains to be learned about its greatest value.
Malathion
Malathion, the safest of the organic phosphates, can be used with ordinary precautions.
Effective for controlling aphids, mites, mealy bugs, scales, and pear psylla, it makes a good combination with DDT or methoxychlor. A fresh supply is needed each year.
Effective Fungicides
The following are some of the most effective fungicides for garden use.
- Ferbam, an iron compound resembling soot in appearance, effectively controls rust and many leaf spots.
It frequently replaces copper for disease control on trees, shrubs, and fruits and is safe on nearly all plants, but the black residue may be objectionable.
- Ziram is a zinc compound similar to ferbam but leaves a white residue. Safe on vegetables, it controls many leaf diseases.
Yet it is ineffective against late blight on tomatoes and potatoes and downy mildew on cucurbits. Therefore, it is not used on fruit.
- Zineb, a zinc compound closely resembling ziram, is most effective for controlling diseases in vegetables, flowers, and shrubs. Gradually replacing copper, it is used in general-purpose mixtures.
- Caplan, a sulfur phthalimide compound, effectively controls many diseases of trees, shrubs, and fruit.
It is outstanding for its safety for fruit and vegetables, often producing a superior finish and appearance. While most promising, it is still being tested experimentally.
- Nabam, a sodium carbamate, is especially effective in controlling potato and tomato blight, but it has limited use.
Choosing Best Pesticides
Everyone recognizes the confusion confronting the amateur or even the professional when he attempts to choose the best pesticides for his particular needs.
Therefore, we are all searching for a single chemical or a combination of compatible formulations available in one package.
It must give adequate control of all the most common pests when applied under practical gardening conditions. We are now closer to that goal than heretofore.
General Purpose Mixture for Fruit Trees
During the past two years, critical tests under both commercial and home garden conditions have demonstrated the practical success of a “General Purpose Mixture for Fruit Trees.”
It is also satisfactory to use on berries and many shrubs. This mixture contains methoxychlor, malathion, and captan as a wettable powder.
It was used at the rate of one pound in 10 gallons of water as a spray.
Thorough and timely applications, varying from three on raspberries and strawberries to nine on apples, produced 90% or more usable fruit free from destructive worms or rots.
All Purpose Mixture
In addition to being safe on plants, it is also one of the safest mixtures for the operator to handle.
A one-package mixture of this formulation should be available in 1955 at the leading garden supply stores.
If not, directions for preparing it from separate ingredients or a similar suitable mixture can be obtained from your area’s county agent or garden information center.
Mixture With Effective Insecticides
Similar mixtures are satisfactory if they contain effective insecticides for combating aphids, spider mites, and the usual insecticides and fungicides.
This mixture has also been used effectively on many shrubs, perennials, and flowers.
Frequent applications throughout the garden should prevent any pest from reaching destructive epidemic numbers. It is less desirable for vegetables.
General Purpose Mixture for Use on Vegetables
A “General Purpose Mixture for Use on Vegetables” has been reported and may be available. It contains methoxychlor and malathion, but zinc is used in place of the captain.
It should be satisfactory but will need to be tested further before general recommendations can be given.
All pesticides should be handled with due respect. However, there is little danger of accidental harm if they are used according to directions.
The greatest danger occurs when handling the concentrated chemicals in preparing the finished spray. Very sensitive persons may need to wear a simple respirator.
Diluted Sprays
Diluted sprays must never be held over from one application to another. As a result, they may break down into ineffective formulations or be harmful to plants.
Always prepare fresh spray for each application. It is also undesirable to hold over packages of pesticides from one season to another.
New Organic Formulations
The new organic formulations will likely lose their potency if stored in open packages.
However, scaled packages kept in a cool, dry place often retain their normal condition and can be used.
Buy according to your needs, and keep them in a closed cupboard or another safe place to which they are returned after use.
Future Holds Promise
Despite the amazing progress in pest control, the future holds greater promise. Studies with systemic insecticides are already in the advanced research stage.
Systemics are insecticidal chemicals that, when absorbed by the plant through the roots, leaves, or stems, kill the insects that catch the plant or suck the sap from it.
Treated plants show no ill effects from moderate dosages but will not tolerate heavy applications.
This treatment eradicates aphids, mites, scales, mealy bugs, and leaf miners from infested plants.
Use of Systemic
Systemics have even been used successfully to kill maggots feeding on the flesh of animals without apparent harm to those animals. The toxic action of these systems disappears after three or four weeks.
Control authorities have already approved their use once in the early growth of the plants on apples and potatoes.
This is the first recommendation for systemic use on a food crop. It is not unreasonable to assume that systemic pesticides will change the whole method of operation in pest control.
Until it does, however, new names, such as endrin, isodrin, maneb, and glyodin, will be added to the list.
In the meantime, get all the information possible before changing your pest control program.
44659 by W. D. Whitcomb