Beneficial Insects

Conserving beneficial insects is everyone's business, from landscapers, to consumers, to state and federal land managers. Biodiversity and conservation practices are key to a healthy environment and reducing beneficial insect and pollinator decline.

assassin bug
Assassin bug (family Reduviidae) preys on Spotted
cucumber beetle (Diabrotica undecimpunctata).
photo: Bettyongardening

Natural predators are a long-lasting, natural, non-toxic solution that will further the ecological diversity of your green space. Natural predators can be divided into two groups – predators and parasitoids.  Many are attracted to flowering plants for pollen and nectar and contribute to pollination services. Conserve them with habitat containing native and heirloom plants that provide pollen and nectar.  

What is biocontrol or biological control?  Using natural enemies to depress pest insect populations which usually includes a human role . These natural enemies or natural predators are "biological control agents" or "biocontrol agents."  Keep in mind that all insect species are also suppressed by naturally occurring organisms and environmental factors, with no human input.

Managing for beneficials includes non-chemical methods such as pruning, hand-picking, covering plants with netting, or other means. The conservation of beneficial insects, that includes bees, insect predators, parasitic wasps, and other good bugs, is an essential part of Integrated Pest management (IPM) programs.  IPM recognizes that the few remaining pest insects will support beneficial predators and parasitic wasps.

When scouting plants for pest insects, check for populations of both pest and beneficial insects, such as lady beetles and bees. If beneficial insects are present, wait to spray insecticides to see if the beneficial insects control the pest insects or use specific insecticides that only target the pest insect. Avoid pesticide use but if necessary, do not apply insecticides while plants are in bloom, and spot treat leaves in the evening when bees and lady beetles are not foraging.

Beneficial insects or good bugs include predators, parasitoids and pollinators

Less than 1% of insect species are considered harmful to health, homes, animals, food and landscapes (such as aphids and grasshoppers) (Hill, Dennis 1997 The Economic Importance of Insects).  Beneficial insects are found in many insect orders including social and solitary wasps, parasitic wasps, beetles, bees, true bugs, flies, butterflies, moths, dragonflies and many others.

Beneficial insects help by:  

  • Preying on pest insects.
  • Parasitizing pest insects.
  • Pollinating plants.

Best types of flowers for beneficial insects:

  • Umbels.  umnbrella-like clusters such as dill, angelica, fennel and yarrow.
  • Composites. These have a center of tiny true flowers surrounded by rays including sunflowers, coneflowers, daisies, cosmos and asters.
  • Spikes.  Plants with flowers similar to lavendar, goldenrod, liatrus and hyssop.
  • Cups. Small insects won't get trapped in the almost flat cups of evening primose, viola or buttercups.

Attract this top list of beneficial insects and spiders (arthropods) for natural pest control to your yard, garden and landscape:

Predatory wasps 

cicada k
Sphecius speciosus (Cicada killer). The female wasps sting cicadas and haul them back to the nest for larvae to feed on. photo: Bugguide.org

 Lady beetles

lady beetle beneficial
Coccinellidae (lady beetle): voracious predator of aphids, mites, insects eggs and larvae. Some species of lady beetle have favorite prey. photo: Pavlos Skenteridis, Bio-insecta.

Green and brown lacewings 

lacewing
Neuroptera (lacewing): larvae are called "aphid lions", they attack and consume many aphids, mites, lace bugs and small insects. photo: Dvoribird, Bugguide.

Predatory wasps 

black wasp
Sphex pensylvanicus (Giant black wasp): Pollinator, and predator of caterpillars and spiders. photo: Laurie Schneider.

Predatory bugs

pirate bug
Pirate bugs (Orius spp.) adults and nymphs are predators of small bugs such as thrips, mites and insect eggs. photo: bugwood.org.

Parasitic and predatory flies 

syrphid fly
Syrphidae (syrphid fly): Pollinator, and larvae are predators of aphids, thrips, scale, caterpillars. photo: Whitney Cranshaw, Colorado State University.

Mud dauber

mud dauber
Mud dauber (family sphecidae) mostly prey on small spiders around homes. photo: bugwood.org.

Spiders

orb spider
Yellow garden spider (Argipe aurantia). Most abundant predators in the home landscape. Spiders hunt or ambush their prey.  photo: PFA.

Parasitic wasps 

aphidius spp.
Aphidius spp. (braconid wasp):  Parasitoid lay eggs on host which hatches and feeds on host caterpillars such as gypsy moth, japanese beetles, sawfly and grasshoppers. photo: David Cappaert, Bugwood.

 

Pictorial ode to insect flight by Karl Foord