There are a huge number of garden bugs and insects that inhabit our outside environments. Some harm our plants, others are beneficial in our environment primarily because they are predators of the bugs we regard as pests.
When we look at a scenario of good bugs vs bad bugs, we are looking at the impact of different bugs in your garden. Good bugs are beneficial to your garden while bad bugs are going to damage your plants. But how can you tell the difference?
What are garden bugs?
Garden bugs are all kinds of insects that you will find in your garden, but not all of them are true bugs. They change form through their lives and metamorphose from eggs to some sort of adult creatures.
According to the Washington-based Smithsonian, there are about 40,000 species of true bugs, more than 3,800 of which are found in the U.S.
Smithsonian describes true bugs as insects with two pairs of wings and hypodermic needle-like mouthparts. They use this proboscis to suck out fluids from plants and animals.
Many bugs and insects go through metamorphosis, changing form from eggs, to larva, pupa, and then adult form. True bugs, including stink bugs, have incomplete metamorphosis with only three stages: egg, nymph, and adult. There is no pupa stage.
Other insects that have incomplete metamorphosis include cockroaches, praying mantises, and grasshoppers. Bugs that undergo incomplete metamorphosis produce young that look similar to adults but without wings.
Types of garden bugs
Molly Keck from the University of Texas A&M’s AgriLife Extension has produced a student booklet that explains exactly what garden bugs are. Called Good Bugs & Bad Bugs, it dips into entomology, insect lifestyles, and the metamorphosis of bugs.
It also explores the world of predators, pollinators, and harmful insects. Amazingly, she points out that only about 5% of insects on earth are in fact harmful.
But why and how are they harmful? They transmit diseases, cause allergic reactions, and do other types of damage, including to crops and gardens.
Garden and landscape pests, including various bad garden bugs, can destroy our garden plants. But some of them pollinate plants and so are considered beneficial.
Are there good bugs and bad bugs?
As explained by Keck, there are good bugs and bad bugs. But Betty Gray from the University of Texas A&M’s AgriLife Extension has a slightly different approach.
Even though she agrees there are good and bad bugs, she maintains that we label some bugs good because they assist us in meeting certain goals. If they don’t, we label them bad.
Rather, she says, there is no such thing as a good bug or a bad bug. In the world of nature, regardless of the human perspective, every bug or insect has an essential role in maintaining a healthy, balanced ecosystem.
And she points out that not all humans think alike. For instance, someone with a butterfly garden will be thrilled to see the larvae of the beautiful swallowtail butterfly on a lemon tree. But citrus growers will be more likely to resort to pest control.
Similarly, assassin bugs, considered beneficial insects because they devour caterpillars and other so-called bad bugs, are generally hated by those encouraging butterflies to their gardens.
The praying mantis is another bug most people regard as good. But, while it preys on many garden pests, it also eats other beneficial insects and even its own.
Green lacewings feed on young caterpillars and caterpillar eggs and are also considered to be good bugs. But, like the praying mantis, they too are cannibalistic, the lacewing larvae sometimes eating its sibling larvae.
So too are milkweed assassin bugs which will happily eat each other.
Gray also points out that honey bees are considered good insects because they pollinate plants and produce honey. But how good will you think a honey bee is if it stings you?
Ultimately, she urges us to value insects and beneficial bugs for the vital roles they play in keeping our gardens healthy. We should also learn to recognize the good, beneficial insects because they are our allies, keeping bad bugs in check.
How to Identify Good and Bad Bugs
In very general terms, a good bug is a beneficial insect that usually eats bad garden bugs or their eggs or larvae. Bad bugs, on the other hand, are damaging insects in your garden.
The best way to identify the good from the bad is to know what they look like.
A good starting point is The Bug Book: a garden field guide published by the Southside Community Land Trust. It has been shared online by the United States Environmental Protection Agency (EPA) making it accessible to everyone.
In addition to pictures and information about 15 bad bugs and 7 good bugs, the authors share tips on how to control the baddies and attract beneficial insects. There are also photographs of the damage caused by bad garden bugs.
A student booklet produced by Molly Keck of the University of Texas A&M’s AgriLife Extension also provides useful information that will help you to identify and tell difference between the good and bad. Good Bugs & Bad Bugs is a very basic introduction to entomology.
Different good garden bugs
Good garden bugs are, quite simply, beneficial insects. Keck explains that there are three types of beneficial insects: pollinators, predators, and recyclers.
- Predators prey on and eat bad bugs.
- Pollinators help to spread pollen needed to produce fruits, vegetables, and other plants.
- Recyclers break down waste and aid its decomposition.
Examples of predators include distinctive red-spotted ladybeetles, also called ladybugs. Praying mantises and lacewings are also predators.
Bumble bees, honey bees, wasps, and butterflies are all important pollinators. When they visit flowers to feed on the nectar, they transfer pollen from one flower to another.
Recyclers include insects we usually consider bad, like flies and termites. But they have an important function.
For example, termites, which live in the soil, help to decompose the wood of dead trees and plants. Flies feed on trash and animal dung, helping to get rid of it.
Grubs or larvae of the giant rhinoceros beetle are also recyclers. If you make your own compost, you might find these grubs eating scraps in the compost. Let them be, they are helping to break down the compost more quickly.
Dung beetles feed on manure (dung) and help to recycle it. You might spot these beetles rolling up small balls of dung. This is where the female lays her eggs.
The beneficial insects listed in The Bug Book are:
- Assassin bugs
- Braconid wasps
- Damsel bugs
- Lady beetles/ladybugs
- Praying mantis
- Soldier beetles
Different bad garden bugs
The bad bugs listed in The Bug Book are:
- Cabbage loopers
- Colorado potato beetles
- Cucumber beetles
- Flea beetles
- Garden webworms
- Lace bugs
- Mexican bean beetles
- Squash bugs
- Tomato hornworms
Bad bugs are harmful for one reason or another. Some transmit diseases, cause allergic reactions, or sting.
Some bad bugs damage crops or garden plants. Others damage buildings.
Medically relevant bugs
These are bugs that affect our health in some way. They include mosquitoes, which are considered the deadliest insects in the world because of the diseases they transmit.
Red imported fire ants sting, leaving blisters or pustules on your skin. Many people are also allergic to these bad bugs and some have life-threatening reactions.
Even though bees and wasps also sting, they are still regarded as beneficial insects. But generally, they will only sting if they feel threatened, or if you tamper with the nest or queen bee.
There are also true bugs that are medically relevant. For example, bed bugs cause itching and kissing bugs that pierce the skin and suck blood, sometimes causing disease.
Garden and landscape pests
There are many bad bugs that we categorize as garden pests. One of the most common is tiny aphids that suck the sap out of plants.
Caterpillars are another very common garden pest, including the tomato hornworm. And cabbage loopers.
Structural damaging pests
Three of the worst bugs that affect structures are termites that eat wood, carpenter ants that live in rotting wood, and cockroaches. But you’re more likely to find these insides than in the garden.
How to get rid of bad garden bugs
The Bug Book has detailed information about how to get rid of the 15 bad bugs they mention. There is no one fix. However, they also give some general tips.
Crop rotation is a good way to control bad bugs. Growing plants, particularly vegetables, in different parts of your garden each year also minimizes the depletion of nutrients in the soil.
It is also important to keep your garden clean. Bugs love to hide under piles of wood, logs, or weeds.
There are some excellent homemade bug-killing recipes you can try. But use these early in the morning or late in the afternoon. Don’t spray if it’s windy or raining.
If possible don’t resort to pesticides, even organic types will kill good and bad bugs.
How to prevent bad garden bugs in your garden
The Bug Book suggests that you walk through your garden daily, looking for bugs or damage caused by bugs.
When you spot them, spray with one of these simple recipes for bug control.
You can make a chili and garlic spray by crushing 6 large cloves and mixing it with a tablespoon of cayenne pepper and a quart of warm water. Mix, cover, and leave in a warm location for 2-3 days.
Strain into a spray bottle and spray all over, especially under plant leaves.
A similar mixture involves chopping up a head of garlic and a small onion and blending it until smooth. Add a teaspoon of cayenne pepper and a quart of water.
Let the mixture sit for an hour, strain, and then add a tablespoon of liquid soap. It will last for about a week in the refrigerator.
An even simpler mixture may be made by combining 2 tablespoons of liquid soap with a quart of water.
If you enjoy gardening, you will come across many bugs that enjoy your garden as much as you do. The trick is to identify which ones are harmful and which are beneficial.
Protect the good ones and get rid of the bad ones.