Not all the insects, worms, spiders and flies that frequent our gardens should be considered pests. Many of them actually benefit the plants we’re trying to grow by pollinating flowers, aerating the soil and preying on other, not so beneficial insects. Arbitrary pesticide usage will kill off these helpful critters; fortunately, the services they provide for us could eliminate the need for pesticides altogether.
Predatory insects are nature’s way of controlling other insect populations. For this reason, indiscriminately killing off bugs can unbalance a garden’s ecosystem and cause other types of unwanted pests to proliferate. It’s therefore important to recognize and welcome those insects that are most beneficial to the garden. What follows is a list of eight of the most common:
Closely related to dragonflies, damselflies are usually more slender and bright blue. Their range is much more limited than that of dragonflies, preferring to stay near ponds and streams. They will eat nearly any other insect – particularly aphids (notorious garden pests).
These insects are most commonly found near a source of water, but they are quite capable of flying long distances to other areas. Dragonflies are very proficient hunters of both mosquitoes and flies. They come in an array of colors and can be identified by their two sets of finely netted and permanently extended wings.
3. Assassin Bugs
So named because of the paralyzing venom that they inject into their victims, assassin bugs prey on flies, Japanese beetles, tomato hornworms and other caterpillars. Their bodies are oval (usually a dull brown color, though some may be brighter) and they have long legs, long narrow heads, and curved beaks.
4. Ant Lions
There are roughly 2,000 species of ant lions and adults can be easily mistaken for damselflies, except that their antennae are generally longer and blunter at the ends. Adult ant lions prey on various small insects, often coming out at dusk or dark to hunt. The larvae of most species have more commonly recognizable eating habits, often digging pits to trap unwary prey.
5. Ground Beetles
Ground beetles are small (1/8 inch to 1 inch maximum). They are either bluish-black or dark brown, though they can have a metallic sheen of green or bronze. Ground beetles have large, strong jaws and yet can move quite quickly, feeding on the larvae of other insects.
Because of their bright color, it’s easy to spot these beneficial bugs (widely referred to by entomologists as ladybird beetles) in your garden. They can feed on a variety of tiny insects, but aphids are their favorite.
7. Braconid Wasps
These valued predators, which grow no bigger than ½ inch, look similar to flying ants. Various species have different diets, but their prey often include tomato hornworms, cabbage worms, gypsy moths, and various insect pupae. Wasps lay their eggs under the skin of a host, such as the tomato hornworm caterpillar. The eggs hatch and the tiny larvae come to the surface and spin cocoons, where they stay until they emerge as adults. Needless to say, the host caterpillar dies in this process.
8. Aphid Wasps
These wasps have a distinctive method of killing their prey: by paralyzing the host and laying their eggs on its body, which the larvae will then consume after hatching. As the name implies, aphid wasps prefer aphids as their hosts, and each female can find hundreds to prey on in a single day. They resemble flying ants with long antennae, although the aphid wasps are generally smaller.
If encouraged, insects can play a crucial role in the health and well-being of any garden. Rather than resorting to the extensive use of pesticides, relying instead on natural solutions such as these eight common insect species can have a profoundly beneficial impact on one’s gardening efforts.
Perennial flowers are a great way to entice beneficial insects into your landscape and best of all they grow back year after year. Learn more about gardening with perennials here.