Your outdoor space, whether an urban balcony or a large-acreage tract, is a balanced ecosystem that at times can shift, resulting in an invasion of insect pests. As we have seen, natural planting practices can help reduce the likelihood of an infestation, and organic pesticide products can help control one. An even better option is to modulate your ecosystem to attract beneficial organisms that will kill and feed on insect pests for you.
There are several key concepts for creating a favorable environment for beneficial species. First, minimize the use of broad-spectrum pesticides, both synthetic and organic. These kill both the problem-causing culprits as well as helpful species, and may adversely affect other animals including people. In fact, you may not want to kill every last pest since they do provide food for other organisms; wiping out one species can have unintended consequences in the ecosystem.
Second, cultivate a diverse array of plants including trees, shrubs, perennials and annuals. This will prevent a monoculture of plant life that could be vulnerable to a single pest or climate change. And a large selection of plants will provide habitats for a variety of beneficial animals.
Third, make available food, water and shelter for the useful organisms. Diverse plant life may provide both food and shelter, while bird and bat houses, together with a water source, will help create a favorable environment attractive to these helpful species.
Types of Beneficial Organisms
Many organisms eat or parasitize insects we consider pests. Below are some examples.
Beneficial insects can be categorized as either predators or parasitoids of pests. Predators feed on problem insects during at least one stage of their life cycle. Examples include aphid-eating lady beetles, lacewings, praying mantises and spiders. Some predators, like lady beetles, only target specific insects; others like spiders and praying mantises feed on a variety of organisms.
Parasitoids are comprised mainly of small, non-stinging wasps that lay their eggs or larva in the pest insect. The juvenile wasps feed off their host as they develop, eventually killing it. Each parasitoid is specific for a particular pest, and can be very effective at targeting and reducing their numbers.
One way to recruit helpful insects is to include plants that attract them in your landscape. Refer to Appendix A of the National Sustainable Agriculture Information Service’s Pest Management Systems Guide for a detailed list of beneficial insects and the plants that attract them. In addition, see the sources below for companies that sell useful insects.
Nematodes are small (usually less than 1 mm in length) non-segmented worms that should not be confused with earthworms. There are many types of nematodes; some are parasitic to plants or animals, others are free living, while a few target problem insects. These beneficial nematodes are very effective at controlling specific pests, and have no adverse effect on other organisms, including humans. A publication from Cornell University on the use of nematodes contains information on insect pests, the species of nematodes that target them, and a list of suppliers.
Most common birds will eat a variety of insects. You can easily fill your yard with these eager insect controllers with a few simple measures.
- Provide food with a feeder or plants. Carefully select an appropriate feeder since some birds prefer certain foods and feeder styles, and place it in a good location. According to the Cornell Lab of Ornithology, feeders will not prevent birds from catching insects.
- Provide water, especially moving water such as a fountain, for drinking and bathing.
- Provide nesting areas with a diversity of plant life or birdhouses to recruit entire families of birds. AllAboutBirds.org has a handy guide to help you in correctly designing birdhouses for specific birds.
While they may not have the best reputation thanks to horror mythology, bats are voracious eaters of night-flying insects. The brown bat can eat 1,000 mosquitoes in an hour, and pregnant or nursing mother bats can consume their body weight in insects every night, according to Bat Conservation International. The best way to attract bats is to purchase or build bat houses. As a bonus, if you place a shallow tray underneath the house, you can collect the guano to use as fertilizer for your garden.
Employing nature’s pest-control agents requires products such as plants, bird seed, lady beetles and bird houses instead of harmful pesticides. Ideally, these beneficial organisms will incorporate into your ecosystem and help tip the balance toward fewer infestations. The strategies in this series are intended to help control pests in an environmentally friendly way, and while they may require enduring small amounts of insect damage, the exchange is a chemical-free environment.
See Part 1: Planting Practices That Reduce Pest Invasion
See Part 2: Mineral, Plant and Microbial-Based Organic Pesticides
Buglogical Control Systems
A-1 Unique Insect Control
The Beneficial Insect Company
Plants That Attract Beneficial Insects
How to Plant a Vegetable Garden
Become an Urban Farmer: Here's How
Breaking Down the Bones: How to Compost Meat and Other Animal Products
How to Compost and Build a Compost Heap
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