How to Identify & Control Houseplant Pests

Almost all plants are subjected to pests like aphids, spider mites, and scale at some point in their lives.

They usually enter your home on newly purchased plants and once in your house, they can quickly spread to your other plants.  You must get rid of them as soon as you notice them before they damage your plants by sucking the juices from the plants and feeding on the leaves.

Types of Houseplant Pests

• Whiteflies:  These are small white flies that live on the underside of leaves.  They are a common problem in the greenhouse.
• Spider mites:  These are small spider-like insects and are related to the spider.  They can be a variety of colors such as brown, grey, spotted, red, or black.  They like to spin webs all over the plant and eat the liquid in the leaves.  They are quite hard to get rid of.
• Mealy bugs:  Sometimes they are confused as a plant disease because they sit on the plants and rarely move.  They look like tiny little spots of white cotton.
• Aphids:  These insects are about one-fourth inch long and usually wingless, and are green, brown, or red.  They can be found on the underside of the leaves.  They will generally suck the sap from new soft plant growth, flowers, tips, etc.
• Scales:  They form colonies on the plants and are cream, brown, or white.  When they are in a mass together, they may not look like insects at all.  They can look like an infection on the plant.
• Thrips:  These are so tiny that you will most likely notice the damage they cause to the plant before you see them.

Damage These Pests can Cause 

Almost all of these pests will suck the juices of the plants.  They do this using their piercing mouths.  When they feed on your plant you may notice that the leaves and stems are wilting, yellowed, or limp.  You may also notice a sticky substance that is secreted by the whiteflies and aphids on the leaves.  This is called honeydew.  The sticky substance attracts an unattractive black growth called sooty mold that feeds on the honey dew.  The spider mites and thrips will tunnel through the leaves and leave small, white stipled areas on them.  On the underside of the leaves, you may also notice webbing or transparent spots.

Preventing Houseplant Pests

• When you purchase your houseplants, make sure that you are buying them from a reputable nursery.  
• Examine the plants closely for any signs that it could have an insect infestation.  
• Avoid any plants that have drooping, ragged, or yellow leaves.  Make sure that you look under the leaves to see if you see any insects.  
• When you first bring your plant home make sure that you wash the leaves with a gentle stream of water to dislodge any that you might have missed.  Also, quarantine the plant for two to three weeks in a room away from other plants to make sure that the new plant does not have pest problems.  Check the stems and under the leaves daily to make sure there are no pests and if there are, you can take care of them
• If you move your indoor plants outside during the summer, follow the same procedures as it were a new plant
• Provide them with the proper growing conditions to keep them healthy, such as bright light and moderately moist soil.  These are the plants that can fend off pest infestations better.
• From time to time wash the plant to remove the dust and clean up any plant debris and dead leaves from time to time.  
• Avoid over-fertilizing them, which will encourage new growth and make them vulnerable to damage from insects.

How to get rid of Them

Water:  The least invasive control is a stream of water.  Cover the base of your plant with your hand on the soil in the pot to keep it in the pot.  Turn it upside down to get at the underside of the leaves and gently run water over the leaves to dislodge any insects.  

Insecticidal oil or soap:  Spray plant with either of these to control most of the houseplant insects.  These work by coating the soft bodies of the pests.  This will smother them and dry them out.  Make sure that you coat both the bottoms and tops every week.  

Alcohol:  Dip a cotton ball in alcohol and dab any mealy bugs or aphids with it.

Pesticides:   This includes neem oil and other pesticides to control houseplant insects.  Make sure that you follow package directions carefully.  Apply the pesticide outside.  Try other measures first because they can be dangerous to your health.

Dish soap:  Put some warm water in a spray bottle with a small amount of liquid soap and shake it until it foams.  Spray your plant generously with the soapy water.  Wait five minutes and then rinse the soapy water off.  You may have to repeat this a few weeks later. This works well on aphids.

Tepid shower:  This is used to get rid of spider mites.  Put the plant in the shower once a week and give it a quick, light shower to wash off the webbing and reduce the insects.  You can also mist the plant between showers.

Conclusion

Many times, if the houseplant is really infected with insects, you may just need to discard it.  The reason is that it will be difficult to treat and there is a big chance your other plants will be invested before you can treat it completely.  It is more common for you to find these houseplant pests on your outdoor plants but they still can get on the ones inside.  Learn how to recognize them, the damage they do, and how to get rid of them before they infest all of your indoor plants.  If you think your household plant has pests, you need to get rid of them quickly to avoid an infestation.

Also read: Common Houseplant Diseases – Identification & Treatment