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There’s a hidden world in every garden and orchard, a tiny jungle filled with insects living among your plants. Some are pests who wreak havoc on your plants and trees; but others are beneficial bugs that are helpful in the garden.
In episode 3 of the Urban Forestry Radio Show, author and horticulturalist Jessica Walliser of Pittsburgh, PA, talked with Susan Poizner of OrchardPeople.com about how we can encourage good bugs to come and help fight off fruit tree pests.
Walliser is the author of Attracting Beneficial Bugs to Your Garden (affiliate link), which takes an in-depth look at the world of garden insects and how a grower may use them to their advantage. You can listen to the entire show below, or read on!
There are over a million species of discovered insects in the world, with scientists estimating twice that number in existence, waiting to be discovered. Less than 1 percent of these are agricultural pests - and in her book, Walliser says that if we can turn our time and energy away from fighting bad bugs and into supporting good bugs, the bad bugs would naturally be pushed back.
Walliser described three different beneficial insect populations: the pollinators, the predators, and the parasitoids. Each population plays its own role in helping a garden thrive.
Pollinators are self-explanatory - they pollinate! This group includes any critter that helps pollinate a garden: bees, wasps, butterflies, beetle species, and even hummingbirds. This is the group that most people think of when they hear the term ‘beneficial insects’.
Predators are insects that capture and consume other ones directly, such as spiders, ladybugs, mantises, and anything else that eats other bugs. They are essential members of the garden’s ecosystem, and we especially love the ones that prey on pests.
Parasitoids are a little more gruesome - these are the bugs that capture and use other bugs as food for their young. For example, certain wasps are known to lay their eggs in live caterpillars, eventually leading to the death of the host as the parasitoid larvae hatch and feed.
Much like lions preying on the gazelle of the African savanna, a healthy garden becomes a micro-ecosystem of predator and prey. So instead of growing your fruit trees in a monoculture, with little more than trees and grass, you might consider "farmscaping". Farmscaping helps bring diversity into your orchard by introducing a wide variety of plants to your growing space. Planting hedgerows or windbreaks helps alter airflow, and flowering plants (other than your fruit trees) attract a wide variety of insects. These beneficial bugs bring complexity and competition to your growing space, and they reduce the ability for pests to have free reign.
So what can the average grower plant to bring beneficial insects into the their orchard? Walliser suggests six things to consider that will fit into any orchard, small or large.
Sunflowers are an asset in any garden, as they attract beneficial insects like ladybugs and lacewings that feast on insect pests, thereby protecting your plants and trees.
A hedgerow creates a microclimate, breaking the strength of wind while also building a small habitat for insects to live within year-round. Any kind of native flowering shrub in a steady row through an orchard will help out. They work best as a blend of shrubs, perennials, and native grasses, creating a shelter for local insects to live.
Beetle banks or beetle bumps are small habitats for beetles. You can create a raised berm about 12-18 inches from the ground, with native grasses that are welcome to grow all season long. This becomes a shelter for native ground beetles that prey upon grubs, slugs, maggots, and other pests.
In this context, an insectary is a bed or border around the orchard or garden that houses a diversity of flowering perennials and annuals, which shelter beneficial insects. The second half of Walliser's book discusses attracting specific plants - if you’re having trouble with certain insects, consider adding more of a plant that attracts appropriate predators. You can also create a permaculture garden that will attract a wide range of beneficial bugs.
Bat boxes are simple wooden structures built to shelter wild bats in an area. Bats consume large numbers of nocturnal insects, many of which are pests that aren’t handled by daytime helpers.
Birdhouses that attract and house beneficial bug-eating birds are great additions to any garden or orchard as they become part of the natural predator-prey cycle. Sure, they might eat good bugs too - but that’s alright, it’s the natural order of things.
And that’s what it comes down to: helping encourage the natural order of things by inviting in the good bugs that are your pests’ natural predators.
Kameron Chausse is a communications intern at OrchardPeople.com.