In a mad-scientisty sort of way, I find innovations like this truly fascinating. Just imaging those cute, little guys buzzing around the neighborhood and into our homes…
But, fortunately, we have a highly more elegant model that’s been primed since the early Cretaceous period (about 100 million years ago). The bee—along with other beneficial insects—have been around for a long time. Over the last century, with strides in technology, agriculture and development, there has been an unsettling decline in many species of insects that play vital roles in nature and in the garden.
According to the USDA Natural Resources Conservation Service, there are three primary contributors to the decline of honey bees (along with other pollinators and beneficial insects):
- Loss of nesting and year round foraging habitat.
- Exposure to pesticides and other harmful chemicals.
- Exposure to disease and parasites.
The decrease in bees due to loss of year round habitat (and pesticides) has lead many farmers across the country to import captivite bred bees for crop pollination. Unfortunately, bees bred in captivity are more prone to disease and parasites due to homogeneous gene pools. Species benefit from a wide and diverse population.
Two manageable steps to encouraging the beneficial insects in your garden: a)Reduce/eliminate harmful chemicals found in pesticides, herbicides, and fertilizers [this is where switching to organic options such as worm castings and selecting disease resistant plants can help] and b)Envisioning the garden as a year round foraging ground and habitat for beneficial insects. Just like us, insects with a healthy diet tend to be more resilient to parasites, disease, and winter hibernation.
The Beneficial Bugs
Bees are only one group (albeit integral) of beneficial insects that have declined due to pesticides and lack of habitat. In nature, there is a balance that ensures populations of potentially harmful and disease spreading pests remain under control.
Dragon flies, lady bugs, and hover flies are examples of beneficial predator insects that keep pests like aphids and mosquitoes in check. Parasitoids—probably the inspiration for the alien in Alien—play an important role in controlling populations of beetles, ants, and scale insects.
Below is a brief summary of the beneficial insects you may find in the garden:
| Groups | Bugs | Beneficial Role |
| Pollinators | Bees, hover flies, aphidius, aphidoletes, various wasps | Pollinate wildflowers. Ensure the necessary diversity within plant species. Pollinate crops, vegetable and fruit bearing plants. |
| Insect Predators | Aphidoletes, damsel flies, dragon flies, lacewings, hover flies, lady bugs and other predator insects | Prey on and control aphids, gnats, midges, adult mosquitos, mosquito larvae, and other potentially harmful and disease spreading insects. |
| Insect Parasitoids | Aphidius, parasitic wasps, tachinid flies, and other various parasitoids | Larvae play a parasitic role in controlling ants, aphids, beetles, caterpillars, moth larvae, scale insects, whiteflies and other potentially harmful and disease spreading insects. |
Parasitoids and predator insects indirectly help to reduce disease in the garden. We’ve all woken up to the deflating experience of finding our Beefsteak tomato plants deformed and wilted like a bag of sad potato chips. The curly top virus is spread by the minuscule beet hopper, a favorite prey of many insect predators.
The shade tolerant and evergreen Tufted Hair Grass (Deschampsia cespitosa) is an excellent habitat forming native bunch grass for friendly native insects. Cultivars such as ‘Northern Lights’ make a great addition to the garden
Habitat and Foraging
Honeybees, bumblebees, and other flower visitors require a consistent supply of nectar and pollen from early spring to late fall. It’s best to provide a variety of options for the numerous native species. It’s recommended by the USDA Natural Resources Conservation Service to provide:
- A minimum of 3 forbs for each flowering period of the year (early/spring, mid/summer, late/fall). See the list of perennials below for suggestions.
- At least one bunch grass (preferably native).
Native plants make great additions to the garden. They tend to require less care and many have developed codependent relationships with our native species in the Pacific Northwest. HoneyBeeNet at nasa.gov provides an excellent resource for native plants for honey bees and other foraging insects.
Many native bees and insects require undisturbed habitat to nest throughout the foraging season and hibernate during winter. Holes in bare earth, inside logs and decaying wood, and under grass tussocks are favorite nesting areas for many of our natives. Our native Tufted Hair grass, Deschampsia cespitosa, or a Fountain grass (Pennisetum alopecuroides ‘Hameln’) provide adequate shelter for many insects.
Undisturbed areas in the garden allow bumblebees and other bugs to become established. It’s tempting to remove fallen leaves and debris in early spring, but doing so often destroys the hibernation process of friendly insects. Additionally, a benefit of leaving patches of debris is a reduction in costs of fertilizer and soil additives as decaying matter naturally fortifies the soil.
Hover fly larvae prey on aphids, whiteflies, and leaf hoppers. [click picture for source link]
Foraging Plants
Below are a few suggestions of foraging plants that beneficial insects visit. Ideally, it’s best to have a variety of plants in the garden. Bees and larger insects generally prefer larger flowers, while many predatory and parasitoid adult insects prefer smaller flowers to accommodate their diminuative size. In addition to the perennials listed below, remember that many trees and shrubs make excellent options for beneficial insects if there is available space. Remember to select cultivars that are not invasive or weedy.
Early Blooming |
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| Common Name | Botanical name | Visitors |
| Stonecrop, Sedum | Sedum species | Bees |
| Strawberries | Fragaria species | Bees |
Early-Mid Blooming |
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| Common Name | Botanical name | Visitors |
| Lupine | Lupinus species | Aphididius, aphidoletes, hover flies |
| Seaside Daisy | Erigeron glaucus | Bees |
| Tansy | Phacelia tanaecitifolia | Bees, various predators |
Early-Late Blooming |
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| Common Name | Botanical name | Visitors |
| Candytuft | Iberis species | Bees, hoverflies |
Mid Blooming |
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| Common Name | Botanical name | Visitors |
| Black Eyed Susan | Rudbeckia species | Bees |
| Blue Bells | Phacelia species | Bees |
| Buckwheat | Eriogonum species | Bees |
| Coriander, Cilantro | Coriandrum satirum | Various predators |
| Lavender | Lavandula species | Bees |
| Rosemary | Rosmarinus species | Bees |
| Rue | Ruta graveolens | Bees, parasitic wasps |
| Scented Geraniums | Pelargonium graveolens | Bees |
| Sea Holly | Eryngium species | Bees |
| Spearmint | Mentha spicata | Bees |
| Squash gourd, Pumpkin | Cucurbita species | Bees |
| Thyme | Thymus species | Bees |
| Toadflax | Linaria purpurea | Bees |
Mid-Late Blooming |
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| Common Name | Botanical name | Visitors |
| Alyssum | Aurinia saxitalis | Bees |
| Blanket Flower | Gaillardia grandiflora | Bees, hover flies |
| Cat-mint, Catnip | Nepeta x faassenii | Bees |
| Chicory | Cichorium intybus | Various predators |
| Coneflower | Echinacea species | Bees |
| Dusty Miller | Centaurea cineraria | Various predators |
| Feverfew | Chrysanthemum parthenium | Bees, hover flies, parasitoids, various predators |
| Frikarti Aster | Aster frikartii | Bees |
| Hyssop | Hyssopus species | Bees |
| Lovage | Levisticum officinale | Various predators |
| Mint | Mentha species | Bees |
| Parsley | Petroselinum crispum | Parasitic wasps, hover flies, tachinid flies |
| Penstemon | Penstemon species | Bees |
| Pincushion Flower | Scabiosa colubaria | Bees |
| Rose Campion | Lychnis coronaria | Bees, hoverflies, parasitic wasps |
| Salvia | Salvia species | Bees |
| Statice | Limonium perezii. L. latifolium | Bees, hover flies |
| Sunflower | Helianthus species | Bees, pirate bugs, aphidius |
| Tickseed | Coreopsis grandiflora cultivars | Bees, hoverflies, lacewings, lady bugs, parasitic wasps |
| Trefoil | Lotus corniculatus | Bees |
| Western Yarrow | Achillea millifolia var. occidentalis | Bees, lady bugs, lacewings, aphidius, parasitic wasps |
Late Blooming |
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| Common Name | Botanical name | Visitors | |
| Chrysanthemum (simple flowered) | Chrysanthemum species | Various predators | |
| Globe Thistle | Echinops species | Bees | |
| Goldenrod | Solidago species | Bees | |