Bonsai Care
and Beneficial Insects

Beneficial insects are as important to watch for as plant pests. Can you tell the difference?

Beneficials are categorized two ways

• Predators devour the entire host.
• Parasites can feed on the pest, and/or lay eggs that produce larvae that feed on the the host.

Some of the most common beneficial insects include:

Lady Beetles, also known as Ladybirds, Ladybugs and Lady Bugs, are among the most easily recognized and one of the most valuable.

Would you kill the ugly insect to the left?

I hope not. It's not a plant pest. It is the larval stage of a Lady Beetle.

Photo by Mike Kling

There are over 100 species of Lady Bugs . Most are red, some are orange. Some have two spots, seven or more depending upon species.

The adults and larvae devour aphids, immature scale, mealybugs, mites and and some softer insect eggs.

Up to about 500 aphids can be eaten during the larval stage of one Lady Bug and the mature insect is even more voracious!

I once purchased Lady Beetles for our 5 acre nursery and was amazed that they “didn't fly away home”, they stayed. (I guess we had plenty for them to eat.)

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Assassin Bugs are generally black or brown.

However, many also have bright color markings.

They are 1/2 to 1 inch in length.

The nymphs are just as effective in controlling pests as are the adults.

The bad news is they bite and it can be painful.

Try not to handle them.

Young assassin bugs are shown here - to the left.

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Lacewings are common greenish or brownish beneficial insects (about 3/4 inches long) with transparent wings. The adults may be predatory or feed on pollen.

The larvae are often called “aphid lions” and feed on aphids, other small insects and eggs.

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Parasitic Wasps are extremely important. These wasps are very small, most less than 1/8 inch long. They actually do some of your bonsai care for you.

Some larvae feed on and pupate inside the host.  Many harmful insects such as aphids, whiteflies, scales, leafminers and caterpillars are parasitized by these wasps.

Other parasite larvae live on the outside of its host where they construct numerous small, white cocoons attaching to the body of the host.

You may have seen them and wondered if they were eggs.

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Syrphid Flies are often called hover flies.

Over 1,000 species exist and they vary in size and color. Most do "hover" and others buzz.

Most of them are yellow with brown or black bands, so they resemble wasps and bees.

They do not sting. Their larvae love aphids.

Photo by Mike Kling

Snails

The list above represents some of the better known beneficial insects.

In addition to beneficial insects, there are other good critters!

This Florida native tree snail is beneficial because it loves to feed on epiphytic growths such as algae and lichen.

This particular snail found my bonsai Ficus and enjoyed cleaning the tree and pot for months.

A bonsai care helper!

In South Florida, native tree snails are generally cone shaped, 1/2 to 1 1/2 inches in length.

Their shell markings vary from one to another (almost like fingerprints.)

They are commonly found in Florida's native hammocks.

A yard full of native trees (and bonsai) will attract them.

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Not All Snails are Beneficial

There are also many snails that chew everything in site.

Read this warning to find out about the giant African snail.

The Good News

Remember, there are more good bugs than bad.

While you're busy with your everyday bonsai care, don't be too quick to kill insects, snails or even snakes . . .

unless you know whether they're real plant pests or beneficials.

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Where to Go From Here

If you haven't seen the Plant Pests and Bonsai page, it is important.

Healthy bonsai are less susceptible to pests, fertilizer will help!