The beginning of a new growing season is upon us. With the sun warming up the earth, memories of nasty pest infestations from last year, large hairy caterpillars, tiny aphids everywhere, or beetles eating the peppers may present itself. We grow all of our vegetables pesticide-free and know that the struggle is real. But what can be done? Aren’t the pests just part of the natural cycle of the garden? That they are. But today I will share with you the top 5 predatory insects to have you in your vegetable garden to naturally balance the garden.
What are predatory insects?
Predatory insects are insects that prey on other insects, beetles, or other pests in the garden. They come in a vast array of varieties, shapes, and purposes. Some can be found naturally in the garden, but it is also possible to purchase predatory insects as well. As in many areas of life and things we observe, nature is constantly trying to find an equilibrium. A state in which opposing parties are balanced. And beneficial insects offer the potential to bring that equilibrium directly to your home garden.
The challenging thing when comparing our gardens with nature is nature has so many overlapping segments that make the equilibrium both harder and easier to find. Harder from the stance that one small impact causes a drastic impact elsewhere. But easier in that there are multiple layers to the complexity to the equilibrium, lessening the chance of one change to impact the whole ecosystem at once.
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Our gardens, however, are much more fragile. We weed the gardens, concentrating the tasty plants for the pests and removing potential harbors for predatory insects to live in. This is where companion planting can help as another layer of pest solutions in your garden, and you can learn more about it in our other blog post: “Top companion plants for tomatoes.” We also lack layers in the garden as nature shows us in woodlands and other habitats. The more we can do to encourage the predatory insects, however, the better footing you will find yourself at encouraging the top 5 predatory insects in your garden.
Ladybugs
You have likely encountered the ladybug at some point in time. I remember as a kid watching hundreds of them congregate in the corners of our rooms. In piles in the garage. Or all over the shed in the backyard. These beautiful little beetles work their magic in the garden by feasting on smaller insects such as aphids and thrips. One ladybug can feast on up to 50 aphids a day! Which is wonderful, especially if you have an aphid infestation.
It is possible to naturally attract ladybugs to your garden by planting a host plant. They like cilantro, dill, fennel, caraway, and yarrow. While they may live on these plants, they travel to other crops around the area as they need food. But even if you do not have room for host plants, ladybugs are fantastic at finding their own meals. If you have aphids or thrips really bad, you may find it takes a few weeks for the ladybugs to catch up. As they feast on the pests, these little predators will reproduce, and continue to increase in population until there is an equilibrium in the natural insect balance.
For more immediate results, it is possible to purchase ladybugs as well! I have found this especially helpful when growing in a greenhouse where aphids can multiply quickly and it can be hard to control them otherwise. The beautiful thing about working with a bug for pest control is as soon as the pests are taken care of, they will move on elsewhere to find food contributing to the overall balance of the insect ecosystem.
Nematodes
Day by day, we live in a macro view of life. With nematodes, we dive into the micro world that is easy to overlook but nonetheless is significant. Not all nematodes, however, are beneficial. Some will actually puncture and feed on the cell wall of plant root systems. This can lead to the death of the plant by the incorporation of diseases or bacteria. So, what are nematodes? They are roundworms, not closely related to the true worms that range in size from microscopic to over several inches long. They are multicellular insects with smooth bodies that are unsegmented.
There are over 15,000 known species of nematodes throughout the world! And more is yet to be discovered. Not only that, but they are the most numerous animal in the world. E.O Wilson captures the significance of nematodes in our ecosystems quite well when he said: “Consider the nematode roundworm, the most abundant of all animals. Four out of five animals on Earth are nematode worms — if all solid materials except nematode worms were to be eliminated, you could still see the ghostly outline of most of it in nematode worms.” E. O. Wilson (paraphrasing N. A. Cobb)
Where to buy nematodes
There are specific varieties of nematodes that are especially helpful in the garden with pest control and have made it to our top 5 predatory insects for your garden because of their effectiveness. My favorite place to purchase beneficial nematodes is Arbico Organics. In addition to having fantastic products, they also have easy to follow instructions on how to apply nematodes. What I love about them is how easy they are to distribute. Simply place the prescribed amount of nematodes into a backpack sprayer or garden hose sprayer and water the ground. Those nematodes will quickly disperse into the ground and look for prey.
Beneficial nematodes, depending on the variety, will target specific pests that may be impacting your garden. Such as flea beetles, fungus gnats, grubs, and many others. If you have a particular pest that is affecting your garden, look to see if nematodes could be a solution to your problems. They do not act immediately as many beneficial nematodes are microscopic and they can take 7-10 days to kill their host. For this reason, I like to use them as a preventative rather than a solution if possible. My favorite time to apply them is spring and fall when the soil temperature is the ideal temperature, not too hot or cold.
Praying Mantis
One of my favorite insects to watch happens to be a beneficial predator for the garden – the praying mantis. These fascinating creatures seem slow, almost sluggish upon the first inspection. But after stalking their prey, it is truly amazing how fast they can jump into action to catch their meal. They also have a voracious appetite eating anything from caterpillars to beetles. Aphids to crickets. And sometimes even moths at night as well! The tricky balance is they can also eat other beneficial insects as well such as lacewings if they run out of other food sources. But I haven’t personally run into this issue as of yet as there is usually plenty of food to go around.
Praying mantis can be introduced into your garden via egg sacks if you desire to boost their population or introduce them into your environment. I have not had to do this yet as our environment has naturally helped them flourish. But if you have not noticed this fantastic insect in your garden yet, you can purchase some here! They are inexpensive, fun to watch, and quite effective at helping keep pests managed around your garden.
Spiders
These eight-legged creatures are spectacular at bringing balance to the garden and have earned their spot well on the top 5 predatory insects. If you are anything like me, you may find spiders a little disconcerting. But they truly work wonders in the garden. Part of their effectiveness is the diversity of ways they trap other insects. The most common type of spider we interact with is the web spinners, such as the yellow orb weaver. But there are others such as the burrowing spiders, jumping spiders, and stalkers.
Between these different types of spiders, they can help keep a large range of pests under control ranging from moths and beetles to aphids and flies. Most of the time, we do not even see them at work. But they are a pivotal insect in the ecology of an ecosystem. I love them as they do not eat any plants as other beneficial insects can and are voracious eaters. One thing to be mindful of is that they are generalists when it comes to food. They do not discriminate between one insect or another (even other spiders!) as all they see is food.
This particular aspect does not make them well-tuned for introducing into an environment to manage one particular pest. If, however, the goal is to reduce the general number of pests, they are perfect! I have found they work delightfully well with other beneficial insects such as ladybugs or lacewings that have a more specified appetite.
Spiders are not frequently bought to introduce into the garden. There are several ways we can attract them though! My favorite tool is creating a comfortable habitat for them. One great way to do this is mix some woody perennials amongst the annual vegetable plants. This could be a rosemary bush, creeping thyme, sage, lavender, mint, lemon balm, or even some flowers. Mulching your paths also helps to attract them by giving countless nooks and crannys for them to hide in while maintaining moisture levels.
Lacewings
Last but not least are the lacewings. They may be unfamiliar to you as they are not as large as the praying mantis or flashy as the ladybugs. But they, nonetheless, are effective insects to have in the garden. Lacewings are a bit different than other beneficial insects in that their effective stage for pest control is when they are larvae. As adults, they feed on nectar and pollen. But no need to worry, their voraciousness as larvae makes the especially effective against soft bodied insects such as aphids. These little larvae will feast on up to 100 aphids every week! They also feast upon most other soft bodied pests such as spider mites, leafhopper nymphs, mealybugs, and others. Imagine an army of these little insects patrolling your garden. Before long, any major soft bodied insect problems you may have should be cleared up!
As the food supply diminishes, lacewings will tend to fly away as adults in search of more food. But once they are in a particular environment, they can colonize for a more permanent residence as well. They can be purchased at the larvae, egg, or adult stage enabling you to manage pests as soon as you need. I like to get the eggs if the pests are starting to become a problem. Larvae if they are already taking over. Or adults if there is not a large enough population of pests to be of dire concern but desired to be maintained in 3-4 weeks.
Ultimately, I have found that the pursuit of a balanced ecosystem in the garden will have the longest benefit for managing pests. Beneficial insects are an important tool to find this balance and can help make your garden a better success. And I hope these top 5 predatory insects help you in your gardening success!