Beneficial Insects: How to Control Houseplant Pests Using Good Bugs

When houseplant collections get to a certain size, houseplant pests become inevitable. One of the ways that pests can be proactively managed is by introducing beneficial insects.

Beneficial insects can make pest management easier because instead of only having one human looking for pests, you now have one human and hundreds of bugs on the lookout for pests.

Table of Contents

What are beneficial insects?

Beneficial insects are bugs that naturally eat the bad bugs we find on our houseplants.

Many beneficial bugs eat multiple different houseplant pests, which means that you can help to control many populations by introducing various bugs into your home.

Some of the beneficial bugs, like ladybugs, are easily visible among the plants and in your home. This may not be appealing to some houseplant owners, whereas I enjoy seeing them working and traveling around my home.

Many beneficial insects are so small that it requires a very close examination to know that they are even there, which is wonderful for those who don’t want to have visible workers around their homes.

One example of tiny plant helpers is the Minute Pirate Bug which feasts on a range of pests while being so tiny they barely visible, even when really looking for them.

What pests do each beneficial insect control?

Ladybugs

Ladybug, Photo by: Daniel Rautenbach, iNaturlist, Source

Ladybugs are wonderful beneficial insects because they will consume spider mites, thrips, mealybugs, whiteflies, scale, and aphids. That makes them a winner.

Typically ladybugs are sold as adults. These tiny workers are also easy to see, which means you can easily check on where they are and what they are working on.

This can be a downside for some people too, who may not want to see bugs crawling and flying around their homes from time to time.

The other downside is that ladybugs will sometimes get distracted by windows and need help finding their way back to the plants.

Ladybugs are usually sold in little containers that can be opened and the bugs can be allowed to disperse on their own or you can walk around your plants and place a few in each area.

Green Lacewings

Adult Green Lacewing, Photo by: Klaus Dühr, iNaturalist, Source
Larval Green Lacewing, Photo by: faltlabbet, iNaturalist, Source

Green lacewings are also wonderful predators for houseplant pests, consuming everything except adult, hard scale.

You can find green lacewings for sale as eggs, juveniles, and adults. Each stage looks amazingly different from the other.

The eggs are tiny specs, hardly visible. You can buy them on cards that you can hang in a plant or loose to be dispersed in plants.

The juveniles are tiny, long-bodied bugs that crawl around the plants. They do not have the ability to fly and have voracious appetites, which makes them great predators. Because they cannot fly, they are less likely to be found roaming other areas of your home.

The adults are visible, bright green-bodied bugs with intricately veined wings that are see-through between the veins. Adults do not have the same huge appetite as the juveniles do, but they do still consume bad bugs.

Green lacewing larvae, my personal favorite to buy, are typically sold in containers that allow you to walk around your plants and shake a few into each plant or among affected areas.

Minute Pirate Bugs

Minute Pirate Bug, Photo by: Sam R, iNaturalist, Source

Minute pirate bugs are tiny black bugs that will crawl around the plants, consuming pests. They are so small that they are hardly visible to the naked eye, which is great for those of us who would prefer not to see the bugs in our home.

Minute pirate bugs will eat all of the major houseplant pests except scale.

They are typically sold in containers that allow you to shake a few into each plant or among affected areas.

Mealybug Destroyer, Cryptolaemus montrouzieri

Mealybug Destroyer, Photo by: Julien Waller, iNaturalist, Source

Mealybug destroyers earned their name because they LOVE to eat all kinds of mealybugs. While they will eat aphids and immature forms of other pests, they much prefer mealies.

So, if you are having trouble controlling a mealybug outbreak, these guys might be the ones for you!

Just like ladybugs, they are more easily visible. They also sometimes fly into areas that you don’t want them, like on windows or near other light sources. So, you may need to give these bugs a ride back to their food source.

Mealybug destroyers are usually sold in little containers that can be opened and the bugs can be allowed to disperse on their own or you can walk around your plants and place a few in each area.

Amblyseius cucumeris

Amyblyseius cucumeris is a teeny tiny predatory mite. These guys specialize in eating thrips and are great for ensuring thrips are controlled. They will also eat spider mites.

These bugs are so small that you won’t see them unless you are really looking for them (you may need a magnifying glass!).

Amblyseius cucumeris are typically sold in containers that allow you to walk around your plants and shake some into each plant or among affected areas.

Neoseiulus / Amblyseius californicus

Amblyseius californicus is another predatory mite, specializing in spider mite elimination. Just as the other predatory mite on this list, they are teeny tiny and hardly visible to the naked eye.

Amblyseius californicus are typically sold in containers that allow you to walk around your plants and shake some into each plant or among affected areas.

What beneficial insects control certain pests?

Spider Mites

Spider Mites, Photo by: Naufal Urfi Dhiya’ulhaq, iNaturalist, Source

Spider mites are very tiny pests that multiple incredibly quickly and feed off of the foliage of the plant, causing tiny discolored dots and eventually sections of the plant to look damaged and fall off. They are often identified by the webbing between branches and leaves.

Beneficial insects that will help control spider mites: Amblyseius californicus, Amblyseius cucumeris, ladybugs, green lacewings, minute pirate bugs

Thrips

Thrips, multiple life stages, Photo by: MaJye, iNaturalist, Source

Thrips are tiny pests with long, skinny bodies. They use their mouthparts to scrape the leaves and stems for food. These pests multiply rapidly and cause major damage to plants. Leaves will appear yellow, discolored, faded, and even silvery from thrips damage..

Beneficial insects that will help control thrips: Amblyseius cucumeris, ladybugs, green lacewings, minute pirate bugs

Mealybugs

Mealybug, Photo by: lantinantoine, iNaturalist, Source

Mealybugs are cottony, white bugs that suck the sap from leaves and stems. As they suck sap from plants, mealybugs sometimes produce a sticky, clear substance called honeydew that can be seen on the leaves or stems. They are easier to identify than some of the other pests due to their bright white, powdery appearance. These pests particularly love succulent plants.

Beneficial insects that will help control mealybugs: Mealybug destroyers, ladybugs, green lacewings, minute pirate bugs

Aphids

Aphids, Photo by: Thomas R. Philbin, iNaturalist, Source

Aphids are tear-drop-shaped bugs that are found in a huge range of colors. They are most often found indoors in yellow, green, and white. Similar to mealybugs, aphids love succulent plants and like to suck the sap from leaves and stems. Aphids can also produce honeydew, the sticky substance found on leaves and stems.

Beneficial insects that will help control aphids: Ladybugs, green lacewings, minute pirate bugs, mealybug destroyers

Whiteflies

Whiteflies, Photo by: jimmers94, iNaturalist, Source

Whiteflies are tiny, white flies, as the name suggests. They love to hang out on the undersides of leaves and may only be noticed when the foliage is disturbed, causing the bugs to fly up from their hiding places. Whiteflies also suck the sap from leaves and may leave behind a sticky clear substance called honeydew.

Beneficial insects that will help control whiteflies: Ladybugs, green lacewings, minute pirate bugs

Scale

Scale, Photo by: Ivan Clemente Torres, iNaturalist, Source

Scale are small, bumplike bugs that look like scales on the surface of the plant. Most often scale is found indoors in shades of brown, from light tan to a deep dark brown. These bugs are frustrating to control because their scaley armor protects them from sprays and fewer predators are willing to deal with them.

Beneficial insects that will help control scale: Ladybugs for all life stages, green lacewings for juvenile scale.

Are there beneficial bugs to help control Fungus Gnats?

Fungus Gnat, Photo by: Sienna Zamlich, iNaturalist, Source

Yes!

There are beneficial bugs that can control fungus gnat populations. These are called Beneficial Nematodes or Steinernema feltiae.

What are beneficial nematodes? They are microscopic organisms that feed on the immature stages of fungus gnats living in the soil. Beneficial nematodes will also feed on fruit flies and some other larval pests in the soil.

These organisms usually come as a refrigerated package of dust-looking particles that can be added to water and then dispersed among plants by watering the plants with specially mixed water. Pretty easy, right?

The only downside is that it does take some patience to see the results because these guys are only controlling the larval population, not the adults. However, adults have a relatively short lifespan and once they have reached the end of their lifespans, no new adults should emerge.

I didn’t include fungus gnats in the chart above because fungus gnats, in 99% of cases, aren’t going to do any major harm to our houseplants. The reason why we all dislike fungus gnats so much is because of how annoying and irritating it is to have them flying around our plants.

Since they aren’t a major threat to our plants, I am giving them their own little section.

How effective is the use of beneficial insects?

Beneficial bugs are very effective at pest prevention and control. Releasing beneficial bugs regularly can be very effective at preventing huge infestations.

However, beneficial insects aren’t going to necessarily wipe out every pest in your home. This is especially true for plants that are already infested, which will likely need your help to fight off the pests.

In other words, it is still prudent to check your plants regularly and treat any large infestations manually because the beneficial bugs may not be fast enough or aware enough before pests are out of hand.

Where can you buy beneficial insects for purchase?

Beneficial bugs can be purchased online for delivery directly to your home and purchased at some local nurseries and greenhouses.

One of the greenhouses near my house regularly has ladybugs for sale throughout the growing season. It is much cheaper to buy them locally (if possible) because the cost of overnight shipping is expensive (but necessary with live creatures).

However, many of the specialized predatory insects may not be available locally and must be purchased online.

When / How often should you use beneficial insects?

I prefer to release beneficial insects at least once each season, especially in the transitional times between spring and summer, summer and fall, and so on.

I’ve also heard of others releasing them once a month year-round or once every couple of months year-round. Whatever works for you, your plants, and your bank account should be just fine.

What are the downsides to using beneficial insects

The big downside of beneficial insects is mistakenly assuming that all plant pest problems will be taken care of by the beneficial insects.

Unfortunately, that just isn’t true. I’ve had a few times where I realize (because the infestation becomes large) that a certain plant or two isn’t being managed quickly enough by beneficial insects. Since I assumed the beneficial bugs were on top of it, I wasn’t checking.

The result is that a few infestations crept up under my radar that did a lot more damage than I would have allowed if I was checking regularly.

It isn’t safe to assume that the little workers will be on top of everything so continue to do some occasional checking as well!

Beneficial insects aren’t cheap, especially the more specialized predators

Using beneficial bugs to help control pests among your plants does cost a decent amount. While some of the bugs may only cost a small amount, overnight shipping for them is still expensive. Some of the beneficial insects are much more expensive before shipping as well, making them a larger investment.

However, if you do have a large collection of plants, especially expensive plants, the cost of beneficial insects is totally worth it.

Beneficial bugs might give some people the heeby-jeebies.

While some people (like myself) really enjoy and appreciate all of the bugs out there, others might find them downright disturbing and gross.

For people who don’t want to see bugs outdoors, let alone in their homes, beneficial bugs are probably not a great solution.

What are the major benefits to using beneficial insects?

Beneficial bugs will be looking for and eliminating pests even when you aren’t

Since beneficial bugs need pests to eat and live, they will always be on the lookout for pest issues. This means you have full-time workers helping to protect your plants!

Beneficial bugs are safe for you and your family members

Some insecticide and control solutions contain scary chemicals that can be harmful to you and your family. Beneficial bugs are a wonderful way to avoid needing harsh, harmful chemicals to control pests.

Beneficial bugs are awesome to watch at work

It’s pretty cool to be able to walk by your plants and see some of your tiny workers out looking for a meal or perhaps even consuming a pest. It can be a wonderful way to experience how the natural world works to keep everything in balance in your own home.

Beneficial bugs are pretty cute, if you are a fan of bugs

For those of us who are a fan of bugs anyway, introducing these lovely creatures can be really rewarding. Many of them are easy to grow fond of between their unique appearance and the help they offer.

I personally find ladybugs and adult green lacewings really cute and it makes me happy to see them around.

Have you tried using beneficial insects? What was your experience like? What beneficial insects do you prefer to manage your pests?

Happy Growing!

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