Plants That Attract Beneficial Insects

Nature wants to make your job as a gardener as easy as possible; but you have to help. We've talked about putting in plants that attract insects whose primary job is to pollinate your garden, helping to insure a bountiful harvest of food and flowers. 

But what about attracting those other "good bugs", the crawling and flying creatures whose diet includes pests that are ravaging your garden plants? These beneficial predatory insects do not live on aphid steaks alone. They need other natural sources of food and shelter for their entire life cycle before they call your backyard a permanent home. 

What are these "Welcome Mat" plants and the beneficial insects they attract?

English Lavender

 Here is a list of those good bugs and the plants that they like to visit for shelter and as another source of food for their diet, the sugar from flowers. For some beneficials, especially syrphid flies, this nectar is necessary in order to mature their eggs. Intersperse these plants among the “problem pest areas” in your yard to attract the garden good guys.

LACEWINGS (Chrysopa spp.)
Beautiful, little (3/4”) green or brown insects with large lacy wings. 

Individual white eggs are found laid on the ends of inch-long stiff threads. 

It is the larvae (which look like little alligators) that destroy most of the pests. They are sometimes called aphid lions for their habit of dining on aphids. They also feed on mites, other small insects and insect eggs. On spring and summer evenings, lacewings can sometimes be seen clinging to porch lights, screens or windows.

Plants that attract lacewings:
•Achillea filipendulina    Fern-leaf yarrow
•Anethum graveolens    Dill
•Angelica gigas    Angelica
•Anthemis tinctoria    Golden marguerite
•Atriplex canescens    Four-wing saltbush
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Coriandrum sativum    Coriander
•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Foeniculum vulgare    Fennel
•Helianthus maximilianii    Prairie sunflower
•Tanacetum vulgare    Tansy
•Taraxacum officinale    Dandelion 

LADYBUGS
Easily recognized when they are adults by most gardeners. However, the young larvae, black with orange markings, eat more pests than the adults, and they can’t fly. Yellowish eggs are laid in clusters usually on the undersides of leaves.

Ladybug larva

 


Plants that attract ladybugs:
•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Ajuga reptans    Carpet bugleweed
•Alyssum saxatilis    Basket of Gold
•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Asclepias tuberosa    Butterfly weed
•Atriplex canescens    Four-wing saltbush
•Coriandrum sativum   Coriander
•Daucus carota    Queen Anne’s lace
•Eriogonum fasciculatum   CA  Buckwheat
•Foeniculum vulgare    Fennel
•Helianthus maximilianii    Prairie sunflower
•Penstemon strictus    Rocky Mt. penstemon
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil
•Tagetes tenuifolia    Marigold “lemon gem”
•Tanacetum vulgare    Tansy
•Taraxacum officinale    Dandelion
•Veronica spicata    Spike speedwell
•Vicia villosa    Hairy vetch

HOVERFLIES

Also known as syrphid fly, predatory aphid fly or flower fly. Adults look like little bees that hover over and dart quickly away. They don’t sting! They lay eggs (white, oval, laid singly or in groups on leaves) which hatch into green, yellow, brown, orange, or white half-inch maggots that look like caterpillars.

They raise up on their hind legs to catch and feed on aphids, mealybugs and others.

Plants that attract hoverflies:

Achillea filipendulina

•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Ajuga reptans    Carpet bugleweed
•Allium tanguticum    Lavender globe lily
•Alyssum saxatilis    Basket of Gold
•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Aster alpinus    Dwarf alpine aster
•Astrantia major    Masterwort
•Atriplex canescens    Four-wing saltbush
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Chrysanthemum parthenium    Feverfew
•Coriandrum sativum    Coriander
•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Eriogonum fasciculatum    CA Buckwheat
•Foeniculum vulgare    Fennel
•Lavandula angustifolia    English lavender
•Limnanthes douglasii    Poached egg plant
•Limonium latifolium    Statice
•Linaria vulgaris    Butter and eggs
•Lobelia erinus    Edging lobelia
•Lobularia maritima    Sweet alyssum white
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Mentha spicata    Spearmint
•Monarda fistulosa    Wild bergamot
•Penstemon strictus    Rocky Mt. penstemon
•Petroselinum crispum    Parsley
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil

Rudbeckia

•Rudbeckia fulgida    Gloriosa daisy
•Sedum kamtschaticum    Orange stonecrop
•Sedum spurium    Stonecrops
 



•Solidago virgaurea    Peter Pan goldenrod
•Stachys officinalis    Wood betony
•Tagetes tenuifolia    Marigold “lemon gem”
•Thymus serpylum coccineus    Crimson thyme
•Veronica spicata    Spike speedwell
•Zinnia elegans    Zinnia "liliput"

PARASITIC MINI-WASPS
Parasites of a variety of insects. They do not sting! The stingers have been adapted to allow the females to lay their eggs in the bodies of insect pests. The eggs then hatch, and the young feed on the pests from the inside, killing them. After they have killed the pests, they leave hollow “mummies.”
 

Braconid wasps (pictured, left) feed on moth, beetle and fly larvae, moth eggs, various insect pupae and adults. If you see lots of white capsules on the backs of a caterpillar, these are the braconid cocoons. Leave the dying  caterpillar alone!

Ichneumonid wasps (pictured, left) control moth, butterfly, beetle and fly larvae and pupae. 

Trichogramma wasps (pictured, right) lay their eggs in the eggs of moths (hungry caterpillars-to-be), killing them and turning them black.

Plants that attract parasitic mini-wasps:
•Achillea filipendulina    Fern-leaf yarrow
•Achillea millefolium    Common yarrow
•Allium tanguticum    Lavender globe lily

Dill

•Anethum graveolens    Dill
•Anthemis tinctoria    Golden marguerite
•Astrantia major    Masterwort
•Callirhoe involucrata    Purple poppy mallow
•Carum carvi    Caraway
•Coriandrum sativum    Coriander
 

•Cosmos bipinnatus    Cosmos white sensation
•Daucus carota    Queen Anne’s lace
•Foeniculum vulgare   Fennel
•Limonium latifolium    Statice
•Linaria vulgaris    Butter and eggs
•Lobelia erinus    Edging lobelia
•Lobularia maritima    Sweet alyssum - white
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Petroselinum crispum    Parsley
•Potentilla recta ‘warrenii’   Sulfur cinquefoil
•Potentilla villosa    Alpine cinquefoil
•Sedum kamtschaticum    Orange stonecrop

Zinnia

•Sweet alyssum - white
•Tagetes tenuifolia  Marigold - lemon gem
•Tanacetum vulgare    Tansy
•Thymus serpylum coccineus   Crimson thyme

•Zinnia elegans    Zinnia - 'liliput'

TACHINID FLIES

Parasites of caterpillars (corn earworm, imported cabbage worm, cabbage loopers, cutworms, armyworms), stink bugs, squash bug nymphs, beetle and fly larvae, some true
bugs, and beetles. Adults are 1/3 to 1/2 inch long. White eggs are deposited on foliage or on the body of the host. Larvae are internal parasites, feeding within the body of the
host, sucking its body fluids to the point that the pest dies.
 
Plants that attract tachinid flies:
•Anthemis tinctoria    Golden marguerite
•Eriogonum fasciculatum    CA Buckwheat
•Melissa officinalis    Lemon balm
•Mentha pulegium    Pennyroyal
•Petroselinum crispum   Parsley
•Phacelia tanacetifolia    Phacelia
•Tanacetum vulgare    Tansy
•Thymus serpyllum coccineus    Crimson thyme

MINUTE PIRATE BUGS (Orius spp.)
Tiny (1/20 inch long) bugs that feed on almost any small insect or mite, including thrips, aphids, mites, scales, whiteflies and soft-bodied arthropods, but are particularly attracted to thrips in spring. 

DAMSEL BUGS (Nabis spp.)
Feed on aphids, leafhoppers, plant bugs, and small caterpillars. They are usually dull brown and resemble other plant bugs that are pests. Their heads are usually longer and narrower then most plant feeding species (the better to eat with!).

 

BIG EYED BUGS (Geocoris spp.)
Small (1/4 inch long), grayish-beige, oval shaped) bugs with large eyes that feed on many small insects (e.g., leaf hoppers, spider mites), insect eggs, and mites, as both nymphs and adults. Eggs are football shaped, whitish-gray with red spots.
 
Plants that attract minute pirate bugs, damsel bugs and big eyed bugs:
•Carum carvi    Caraway
•Cosmos bipinnatus    Cosmos “white sensation”
•Foeniculum vulgare    Fennel
•Medicago sativa    Alfalfa
•Mentha spicata    Spearmint
•Solidago virgaurea    Peter Pan goldenrod
•Tagetes tenuifolia   Marigold “lemon gem”

More Tips to Keep Beneficial Insects 

Working in Your Yard:

• Use a wide variety of attractive plants. Plants that flower at different times of the year can provide beneficials with nectar and pollen when they need it.

• Plantings that are at least 4' by 4' of each variety work best at attracting beneficials. 
 

• A bird bath or backyard water feature not only attracts birds (another predator of insects), but also attracts beneficials.

• Pesticides can kill the good guys, too. Avoid using broad spectrum insecticides (especially those that contain ingredients derived from pyrethroids and organophosphates). Safer alternatives include horticultural oils, insecticidal soaps and products designed solely for specific pests, such as Bt (Bacillus thuringiensis) a bacteriacide for tomato hornworms.
 
• Tolerate minor pest infestations. The beneficial insects will get the memo before you do. This will provide another food source for the beneficials and help keep them in your yard.

• More information about  beneficial predatory insects: "The Natural Enemies Handbook", from the University of California Division of Agriculture and Natural Resources.

Let the garden good guys do the job first!