Identifying Soldier Beetles: Finding Soldier Beetle Larvae In Gardens
The first thing to understand is that there are two types of soldier beetles. There are the “adult” soldiers which hatch from eggs and then live inside your plants until they pupate (turn into adults) or die off.
Then there are the larvae, which look like little maggots but actually feed on plant tissue and grow up to become adult beetles.
Adult beetles have six legs and are brownish-red with black spots. They are the size of a grain of rice and their bodies are covered with spines.
Their heads resemble those of a wasp, except that these beetles’ antennae end in sharp points instead of long stalks. Adult beetles may be found all over the world, although they prefer warm climates where temperatures rarely fall below freezing during winter months.
Larvae, however, are smaller than adults and are greenish-yellow with white spots. They are only a few millimeters long.
When they hatch out of their egg sacs, they look very much like tiny maggots and crawl around on the outside of the leaves until spring arrives when they emerge as fully grown beetles ready to mate and lay eggs. Larvae live in soil all year round and will survive even if you leave your garden completely alone for several years!
Soldier beetles get their name from their habit of feeding on other insects. In fact, they are so predatory that they are regarded as pests in some parts of North America.
They are particularly fond of aphids which infest many gardens, hence their reputation as garden helpers!
If you find a red or orange ‘beetle’ in your garden, don’t automatically assume it is a pest. These bugs are beneficial to your garden as they eat a wide range of insect pests, including aphids, mites and mealy bugs.
If you find any of these insects are taking up residence in your garden, don’t panic but do nothing. These insects generally do no harm to your plants and will only become a pest if their natural food source becomes scarce.
Soldier beetles will not usually lay their eggs on your precious plants. The female beetle will lay her eggs on the ground and the larvae will hatch and feed on a wide range of fungi, mosses, algae and decaying organic matter.
If you are absolutely sure that you have a soldier beetle problem in your garden, then you can take the following steps:
The first thing to do is to remove any weeds or dead vegetation from around your garden as this provides an ideal breeding ground for pests. Then, scout around your plants for eggs, larvae or adult insects and eliminate them.
Make sure you treat your garden with a suitable insecticide which is safe for the plants you want to keep. When spraying your plants, also pay attention to the soil as this is where the larvae will be living.
Now that you know what these little creatures are up to, it’s time to take action. If you have found any adult insects or larvae, it is best to eliminate them before they can lay more eggs.
If your plants are becoming infested with aphids, mealy bugs or other pests that the soldier beetle larvae eat, then you must take steps to eliminate these pests as well, as if left unchecked they will soon over-populate your garden and destroy your plants.
The adult soldier beetles only live for a few weeks during which time they must lay their eggs and look for food. You should scout around your plants looking for eggs, larvae or adult insects and remove them.
If you have many plants or large plants, such as rose bushes, it would be too much work to do it all yourself. For this kind of job, it is better to use an insecticide which will also kill the pests but not harm your plants.
After you have eliminated the problem, there are several steps you can take to prevent it returning:
There are many predators which will keep the numbers of harmful insects in your garden down naturally. These include: birds, frogs, bats, spiders, toads and lizards as well as other insects such as lacewings, ladybirds and hoverflies.
If your garden has a healthy population of these predators, then you probably won’t need to use any pesticides at all.
Plant a variety of garden plants. A mixed environment, which includes flowers, shrubs and trees, provides a more balanced ecosystem and is less likely to fall prey to insect attacks.
Different plants attract different kinds of pests so by growing a wide range of plants you will not be amplifying the problem. Also, if one kind of plant is suffering from an infestation you will have others which are not.
Encourage natural predators into your garden. One of the best ways to do this is to create pond with a rockery and some bamboo.
This will provide a home for frogs as well as habitats for insects which are prey for the birds.
Use natural, organic pesticides rather than chemical ones. There are many of these on the market which are perfectly safe for children and pets but kill insects efficiently.
Sources & references used in this article:
Revealing species‐specific trophic links in soil food webs: molecular identification of scarab predators by A Juen, M Traugott – Molecular Ecology, 2007 – Wiley Online Library
Response to Disturbances in Soldier Beetles by M Boyer, J Marshall – 1st Annual Undergraduate Research …, 2017 – krex.k-state.edu
Pests of the garden and small farm: A grower’s guide to using less pesticide by R Merril – Renee’s Garden. Graham Hill RD. Flton, 2008
The influence of food plant dispersion on caterpillar searching success by ML Flint – 2018 – books.google.com
The organic gardener’s handbook of natural insect and disease control: A complete problem-solving guide to keeping your garden and yard healthy without … by ML Cain, J Eccleston, PM Kareiva – Ecological Entomology, 1985 – Wiley Online Library