houseplants pests : DEALING WITH COMMON PESTS

houseplants pests : DEALING WITH COMMON PESTS




They may be small but, given the chance, many pests can quickly ruin your precious houseplants.

By checking regularly for pests, you can take action to remove them before they infest your plants, which will make control more difficult.

KEEP UNWELCOME VISITORS AT BAY (houseplants pests)

Plant pests can enter your home on new houseplants that you have bought in, so when buying, always check for them on the leaves, stems, and flowers, and look for insects crawling on the soil.

Open windows and doors also offer pests a route inside, but by giving your plants a health check every week, you should be able to keep most under control by simply picking them off.

A few, such as spider mite, are difficult to see with the naked eye, so look outfor the tell-tale symptoms and take the necessary action to keep your plants free of pests.

DEALING WITH COMMON houseplants pests

APHIDS

THE PROBLEM

These common sapsucking insects can grow up to 1⁄4in (7mm) long.

They cause distorted or curled leaves, stunted flower buds, and poor overall growth.

Aphids also excrete a sticky honeydew, which can lead to the growth of sooty molds.

THE SOLUTION

Look for aphids on flower buds, on stems (below), and under the leaves.

To remove them, wear plastic gloves and gently squeeze them, then wipe them off.

For larger infestations, try a dilute soap based solution or pesticide.

THRIPS

THE PROBLEM

These minute, winged, sap-sucking insects are only 1⁄16in (2mm) long and difficult to see unless they are flying around.

Their nymphs (juveniles) are wingless.

Damage results in dull green leaves with a silvery discoloration and tiny black dots on the upper surfaces.

They also cause distorted shoots and flower buds, while the flowers may have white markings and lose their color, or the buds may fail to open.

THE SOLUTION

Use sticky traps to help to ensnare these tiny insects. Pesticides that control thrips are also available.

EARWIGS

THE PROBLEM These nocturnal brown insects are up to 1⁄2in (15mm) long, and have distinctive pincers on their rear ends.

They eat flowers and leaves, reducing the latter to a skeleton of veins.

While they are not a common houseplant pest, they may attack some of the flowering types.

THE SOLUTION

Inspect your plants at night and remove any insects you find.

Also check inside ornamental containers or pots nearby, where they may be hiding during the day.

STEM AND BULB NEMATODES

THE PROBLEM

Nematodes are not visible to the naked eye, yet they can cause severe damage, feeding on the plant’s fluids and leading to distorted leaves, often with yellow blotches.

The stem tips and buds may also turn black and die.

Nematodes can infect bulbs, too, leading to similar symptoms in the foliage, as well as yellowish swellings or specks on the undersides of leaves.

THE SOLUTION

Remove affected plant parts as soon as you see them, and buy firm, healthy-looking bulbs from reputable suppliers.

There are no chemical controls.

FUNGUS GNATS

THE PROBLEM

 

Also known as sciarid flies, these grayish-brown insects grow up to 1⁄4in (4mm).

They are a nuisance, but do not generally eat live plants, they simply fly around them and run over the potting soil in seed flats.

Their larvae are white maggots with black heads, slightly larger than the adults, and feed on decaying leaves or roots, and occasionally seedlings, but rarely mature plants.

THE SOLUTION

Use sticky traps to ensnare the flies, and a drench of the nematode Steinernema feltiae to control the larvae.

STEM AND BULB NEMATODES (houseplants pests)

THE PROBLEM

Nematodes are not visible to the naked eye, yet they can cause severe damage, feeding on the plant’s fluids and leading to distorted leaves, often with yellow blotches.

The stem tips and buds may also turn black and die.

Nematodes can infect bulbs, too, leading to similar symptoms in the foliage, as well as yellowish swellings or specks on the undersides of leaves.

THE SOLUTION

Remove affected plant parts as soon as you see them, and buy firm, healthy-looking bulbs from reputable suppliers.

There are no chemical controls.




FUNGUS GNATS

THE PROBLEM

Also known as sciarid flies, these grayish-brown insects grow up to 1⁄4in (4mm).

They are a nuisance, but do not generally eat live plants; they simply fly around them and run over the potting soil in seed flats.

Their larvae are white maggots with black heads, slightly larger than the adults, and feed on decaying leaves or roots, and occasionally seedlings.

but rarely mature plants.

THE SOLUTION

Use sticky traps to ensnare the flies, and a drench of the nematode Steinernema feltiae to control the larvae.

Check your plants weekly and, if possible, pick off any insects you find

MEALYBUGS

THE PROBLEM

These sap-sucking pests look like tiny white woodlice and cause distorted or stunted growth.

You will first notice a fluffy white substance in between the leaves and stems or under the foliage—the bugs or their orange-pink eggs are hiding beneath it.

They also secrete honeydew, which can lead to sooty mold, and a few species attack the roots.

THE SOLUTION

Often brought in on new plants, check for bugs before buying. Remove affected parts or apply dilute solutions of soap-based products or denatured alcohol with a brush (test a small area first to check that it will not harm the plant).

Or use pheromone lures to trap the adult males and disrupt breeding. Throw out badly infested plants, pesticides rarely work.

ROOT APHIDS

THE PROBLEM

These aphids feed on plants’ roots, sucking the sap from them, just like those that live above the soil.

However, because they are hidden, you will notice the symptoms before the pests.

Leaves will become stunted, wilt, and turn yellow as the insects destroy the roots.

THE SOLUTION

If watering does not revive a wilting plant, check for root aphids in the soil.

Try washing off the potting soil and aphids outside, then repot in fresh soil, as there is no chemical control.

Some pests are too small to see easily; check the plant for symptoms of infestation instead

SCALE INSECTS

THE PROBLEM

Scales or shell-like bumps up to 1⁄2in (1cm) in length appear on stems or beneath the leaves.

You may also spot the white, waxy eggs.

These sap-sucking insects cause distorted and weak growth, and secrete sugary honeydew, which can lead to the growth of sooty molds.

THE SOLUTION

Remove affected parts, or apply dilute solutions of soap-based products or denatured alcohol with a paint brush (test a small area first to check that it will not harm the plant).

Dispose of heavily infested plants.

 

SPIDER MITE (houseplants pests)

THE PROBLEM

Also known as red spider mite, this tiny sap-sucking insect produces a mottled appearance on plant leaves.

The foliage also loses its color and may then fall off, heavy infestations can eventually kill the plant.

THE SOLUTION

Remove and throw out affected parts promptly; also trash severely infested plants to prevent the pest spreading.

Misting plants regularly can reduce attacks.

but may not eliminate the pest.

You can also use a pesticide.

SLUGS AND SNAILS (houseplants pests)

THE PROBLEM

You will probably be familiar with these slimy mollusks, which eat holes in leaves and munch through stems.

While they mostly affect outdoor plants, they can enter your home on new plants or through open windows.

THE SOLUTION

You can normally see these pests on houseplants, or find them lurking in their ornamental pots.

Pick them off and dispose of them.

Watch out for grubs and nymphs— these can often be just as bad, if not worse, as the adult pest

CATERPILLARS (houseplants pests)

THE PROBLEM

Not many houseplants are affected by these pests, the most common indoors is the Tortrix moth caterpillar, which binds leaves together with fine webbing, causing them to dry up and turn brown, then fall off.

Other caterpillars eat holes in the leaves, and you will see them usually lurking under the foliage.

THE SOLUTION

Pick off caterpillars, or press the affected leaves together to kill the insects and pupae.

For heavier infestations, use a pesticide that controls caterpillars.

ventilate the room when applying it.

VINE WEEVILS

THE PROBLEM

The adult black weevils are about 1⁄2in (9mm) long and easy to spot.

They nibble leaves, making notches along the margins, but do little serious damage.

The white, C-shaped, legless grubs with brown heads (about the same size as the adults) are the real problem because they eat the roots, causing plants to collapse and die.

THE SOLUTION

Shake plants to dislodge the adults or trap them with sticky barriers around the outer pots.

Try to catch the slow-moving weevils before they lay eggs in spring and summer.

If you see the grubs, try hosing the roots outside to remove them, then repot in fresh potting soil, or apply the nematode Steinernema kraussei in fall.

WHITEFLY (houseplants pests)

THE PROBLEM

These white, winged, sap-sucking insects are easy to see, even though they are just under 1⁄16in (2mm) in length.

Clouds of flies rise up when disturbed, and you may also spot the white, scalelike nymphs on the undersides of leaves. Whitefly causes distorted leaves and buds, and stunted growth.

Both adults and nymphs excrete honeydew, which can lead to black sooty mold.

THE SOLUTION (houseplants pests)

Hang sticky sheets near plants to trap the adults or spray the flies with a dilute soap-based solution, which prevents them from flying and disrupts breeding.

Also try standing affected plants outside in summer where beneficial insects will help to control them, or use a pesticide.

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