Part 1 - Cultural Pest Management

Part 2 - 2009 - 2010 Pesticide Guidelines

New York State Pesticide Labels

Other Resources

NYSIPM

Houseplant Pest Management

6. Houseplant Pest Management

Contents

Pesticides

IPM Considerations

Fungus gnats

Pesticides

Many of the pesticides available for use on houseplants are formulated in ready-to-use pressurized cans or as pump sprays. Make sure the product you choose is labeled for use indoors and on houseplants. Other formulations may cause plant injury (phytotoxicity) or plant death. All pesticides labeled for use on houseplants should be applied outdoors.

Plant spikes containing insecticides may also be available. Be sure to follow label directions carefully checking for the amount to use, how to water, storing unused spikes, precautionary statements, and hazards to humans. Wash hands thoroughly with soap and water after handling, or better yet, wear disposable gloves and discard after use.

IPM Considerations

For a general description of some common insects and diseases on houseplants and for information on nonpesticidal management of houseplant pests and diseases, see Chapter 5 in Part I: Cultural Methods, of Pest Management Around the Home.

Consider removing infected leaves or discarding infested plants rather than treating with a toxic substance. Most chemical pesticides are effective at protecting plants against disease but cannot “cure” existing infections. If houseplants need to be sprayed, remove them from the living space for treatment. If weather allows, take the plants out of doors or into a garage to make the application. Bring plants back indoors when dry.

Fungus gnats

FungusGnatCycleLabelled

Life cycle of a typical fungus gnat species, Bradysia corophila:

Adult gnats live approximately 7 days.

The female lays up to 150 eggs, which hatch in approximately 5 days.

Larvae grow for 10 to 14 days, and then pupate.

The pupal stage lasts approximately 3 to 4 days, before developing into an adult fungus gnat.

Fungus gnats are small flies that can sometimes be a problem indoors, especially if houseplants are kept constantly moist. Adult fungus gnats are attracted to damp locations where fungi are likely to flourish, such as houseplant potting mix. Larvae feed primarily on fungi, but occasionally attack roots of growing plants. Adult gnats may become nuisance pests. Avoid keeping potting mixes too wet and prevent accumulations of stagnant water in pot saucers or other containers. To check for the presence of fungus gnat larvae in potting mix, cut a small potato in half, place cut side down, and lightly press into mix. Leave for 3 to 4 days, then lift up and look for shiny white larvae with black heads. For adult monitoring and capture, yellow sticky cards can be used: place on rim of pot. Larvae may be controlled using B.t.i. (Bacillus thuringiensis var. israelensis), or beneficial nematodes (Steinernema feltiae).

Table 6. Houseplant pesticide guidelines Also see Chapter 5 in Part I: Cultural Methods,* of Pest Management Around the Home.*
Plant	Pest	Some Pest Management Options
African violet	Botrytis blight (gray mold)	Apply hydrophobic neem oil or copper soap (copper octanoate), one time, following cultural plant sanitation practices.
	Powdery mildew	Apply hydrophobic neem oil or copper soap (copper octanoate), per label directions.
	Cyclamen mites	No pesticides available. Discard infested plant. Isolate new plants for three to four months before placing in your collection.
	Mealybug	Use insecticidal soap (potassium salts of fatty acids) or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Root mealybug	Apply insecticidal soap, using drench treatment as specified on label.
Asparagus fern	Aphids	Spray with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or horticultural oil. Some products should not be used on delicate ferns; test a small leaf first. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Begonia	Bacterial leaf spot (Xanthomonas sp.)	Apply Bacillus subtilis per label directions.
	Botrytis blight (gray mold)	Apply Bacillus subtilis, hydrophobic neem oil, or potassium bicarbonate.
	Powdery mildew	Apply Bacillus subtilis, hydrophobic neem oil, or potassium bicarbonate.
	Aphids	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, Mite-X (plant extracts), or permethrin. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Mealybug	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or permethrin. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Whitefly	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or permethrin. Good coverage of leaf undersides is important for control. Repeat sprays may be needed. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Citrus	Scale	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Treat the crawler stage (the young insect that emerges from the egg and “crawls” to a feeding site).
	Spider mites	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
	Whitefly	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat applications may be needed.
Coleus	Mealybug	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Whitefly	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Croton	Mealybug	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or pyrethrins with insecticidal soap. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Dieffenbachia	Spider mites	Treat with horticultural oil, insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
Dracaena	Mealybug	Treat with horticultural oil, insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Spider mites	Treat with horticultural oil, insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
False aralia	Scale	Treat with horticultural oil, insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or pyrethrins with insecticidal soap. Apply when crawlers are active. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Spider mites	Treat with horticultural oil, insecticidal soap (potassium salts of fatty acids), or hydrophobic neem oil. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
Ferns	Anthracnose	Apply potassium bicarbonate if needed, or hydrophobic neem oil as a preventative.
	Scale	Treat with horticultural oil, hydrophobic neem oil, or insecticidal soap (potassium salts of fatty acids). Check all pesticide labels carefully. Products may not be registered on all varieties or may not be tested on all rare or unusual varieties. If host and pest are not listed on the label, do not use the pesticide. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Fuchsia	Botrytis blight (gray mold)	Apply Bacillus subtilis if needed. If a product with hydrophobic neem oil is used, test a small area of foliage first.
	Mealybug	Use insecticidal soap (potassium salts of fatty acids) or permethrin. Some product labels recommend testing on a small area first. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Whitefly	Use insecticidal soap (potassium salts of fatty acids) or permethrin. Some product labels recommend testing on a small area first. Good coverage of leaf undersides is important for control. Repeat sprays may be needed. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Gardenia	Fungal leaf spot	Apply Bacillus subtilis or hydrophobic neem oil if needed.
* Note: Some formulations containing insecticidal soap should not be used on gardenias. Some varieties have shown sensitivity to it. Read label directions carefully before using.	Mealybug	Treat with insecticidal soap, pyrethrins with insecticidal soap, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Scale	Treat with horticultural oil, insecticidal soap, pyrethrins with insecticidal soap, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
	Spider mites	Treat with horticultural oil, insecticidal soap, pyrethrins with insecticidal soap, or hydrophobic neem oil. Good coverage of leaf undersides is important. Repeat sprays may be needed.
	Whitefly	Treat with horticultural oil, insecticidal soap, pyrethrins with insecticidal soap, or hydrophobic neem oil. Good coverage of leaf undersides is important for control. Repeat applications may be needed. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk.
Geranium	Black leg (Pythium spp.)	No products for homeowner use are available. Discard diseased plants and potting mix.
	Botrytis blight (gray mold)	Apply Bacillus subtilis, hydrophobic neem oil, or potassium bicarbonate.
	Caterpillars	To control caterpillars, remove by hand, or use hydrophobic neem oil.
	Spider mites	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, Mite-X (plant extracts), or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
	Whitefly	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Gloxinia	Aphids	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or pyrethrins with insecticidal soap. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
	Cyclamen mite	No pesticides available. Discard infested plant. Isolate new plants for three to four months before placing in your collection.
	Mealybug	Treat with insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, or pyrethrins with insecticidal soap. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Grape ivy (Cissus)	Powdery mildew	Treat with Bacillus subtilis, hydrophobic neem oil, or copper soap (copper octanoate).
Ivy (English)	Fungal leaf spot	Treat with Bacillus subtilis, hydrophobic neem oil, copper soap (copper octanoate), or potassium bicarbonate.
	Spider mites	Use insecticidal soap (potassium salts of fatty acids), hydrophobic neem oil, Mite-X (plant extracts), permethrin, or pyrethrins with insecticidal soap. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
Jade plant (Crassula)	Powdery mildew	Apply Bacillus subtilis, or hydrophobic neem oil, according to label directions.
	Mealybug	Use horticultural oil, hydrophobic neem oil, or insecticidal soap (potassium salts of fatty acids). Some product labels recommend testing on a small area first. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Palms	Mealybug	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, horticultural oil, hydrophobic neem oil, or permethrin. Check all pesticide labels carefully. Products may not be registered on all varieties or may not be tested on all rare or unusual varieties. If host and pest are not listed on the label, do not use the pesticide. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
	Spider mites	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, horticultural oil, hydrophobic neem oil, or permethrin. Check all labels carefully. Products may not be registered or tested on all varieties. If host and pest are not listed on the label, do not use the pesticide. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
Philodendron	Scale	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, horticultural oil, hydrophobic neem oil, or permethrin. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Pittosporum	Spider mites	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, or hydrophobic neem oil.
Podocarpus	Spider mites	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, or hydrophobic neem oil.
Poinsettia	Whitefly	Discard infested plant to avoid spread of whiteflies to other plants, or isolate and treat with insecticidal soap (potassium salts of fatty acids) or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Roses (miniature)	Botrytis blight (gray mold)	Treat with Bacillus subtilis or hydrophobic neem oil.
	Powdery mildew	Treat with Bacillus subtilis or hydrophobic neem oil.
	Spider mites	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, hydrophobic neem oil, Mite-X (plant extracts), or permethrin. Good coverage of leaf undersides is important for control. Repeat sprays may be needed.
Rubber plant (Ficus)	Anthracnose	Treat with hydrophobic neem oil.
Rubber plant (Ficus)	Mealybug	Use insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
	Scale	Treat crawler stage with insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
Schefflera	Anthracnose	Treat with hydrophobic neem oil.
	Scale	Treat crawler stage with insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, permethrin, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk
	Spider mites	Treat with insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, permethrin, or hydrophobic neem oil.
Weeping fig	Phomopsis canker and dieback	No homeowner products are currently available. Prune out dead or dying branches.
	Scale	Treat crawler stage with insecticidal soap (potassium salts of fatty acids), pyrethrins with insecticidal soap, or hydrophobic neem oil. Systemic imidacloprid for use in potted houseplants is available, but is not registered for home use in the New York counties of Kings, Queens, Nassau, or Suffolk

Table 6 Notes:

Pesticides

IPM Considerations

Fungus gnats

Further Reading

African violet

Asparagus fern

Begonia

Citrus

Coleus

Croton

Dieffenbachia

Dracaena

False aralia

Ferns

Fuchsia

Gardenia

Geranium

Gloxinia

Grape ivy (Cissus)

Ivy (English)

Jade plant

Palms

Philodendron

Pittosporum

Podocarpus

Poinsettia

Roses (miniature)

Rubber plant

Schefflera

Weeping fig

Pest Management Guidelines A Cornell Cooperative Extension Publication	New York Pest Management Guidelines
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