Chemical Remedies
Horticultural oil
Examples:
Superior oil, "dormant" oil, SunSpray Ultra-Fine Horticultural Spray Oil, Ortho Horticultural Spray Oil.
Effective Against:
Many types of insects and mites, including aphids, scale, mealybugs, and spider mites.
Crops:
Ornamental plants, fruit trees.
Counteracts these pest(s):
Aphid (See Problem Plants - Page D17)
When To Use:
Most effective when applied as dormant or delayed dormant spray during fall or winter when trees are leafless and insects, insect eggs, and mites cling to the bark. Some summer uses, especially on pear trees.
How To Use:
Consult an expert for advice. Read the label. Dilute as directed (usually about 25:1 or 50:1) and spray to wet surface of plant. Wear gloves and goggles, and avoid breathing spray mist.
Keep away from water; avoid runoff.
Benefits:
Relatively low toxicity to humans (unless accidentally swallowed), biodegradable.
Concerns:
- May cause skin and eye irritation.
- Undiluted material can cause serious illness if accidentally swallowed.
- Toxic to fish. Combustible.
- Will smother all insects it is sprayed on, including non-pest species; use only where pests are present and causing significant damage.
- May be toxic to foliage if used when plant is in leaf.