Beneficial Insects

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HalictidBee_KWixted.jpgDid you know that over 95% of the insects aren’t pests? Some insects help pollinate fruits and vegetables while others take care of common garden pests. By limiting pesticide use in your yard and by providing the right type of plants, you can encourage beneficial bugs to inhabit your backyard habitat which will reduce your need for pesticides.

Steps for Encouraging Beneficial Insects

  1. Design your garden or backyard to have blooming plants throughout the spring, summer and fall to provide nectar and pollen.
  2. Provide a water source.
  3. Provide shelter such as leaf litter on the ground or groundcovers.
  4. Have patience and tolerate a few pests until beneficial insects establish.
  5. Identify pest problems before treating and choose treatments according to the pest.
  6. Resist the urge to spray when you first see damage, and if spraying is necessary, consider using safer pesticides.

Least Toxic Pest Products

Problem

Active Ingredient

Aphids Ladybugs
Caterpillars Bacillus thuringiensis var. kurstaki
Fungal Problems Copper octonate
Extract of Neem oil
Potassium bicarbonate (85%)
Sulfur
General Insect Pests Capsaicin and related capsaicinoids
Extract of Neem oil
Fatty Acid Soap
Potassium salts of fatty acids
Lawn Pests
(Grubs and Fleas)
Cedar oil (2%)
Steinernema carpocapsae (Nematodes)
Mosquito Larvae Bacillus thuringiensis var. iseaeliensis (10%)
Snails and Slugs Iron phosphate (1%)
Note: While products like pyrethrum and rotenone are naturally-derived, they are broad spectrum insecticides which can kill both pests and beneficial insects. Therefore, it is best to use narrow spectrum insecticides when possible.

Lady Beetle photo by Kerry Wixted Predatory Fly (Robber fly) photo by Kerry Wixted


Common Beneficial Insects

Insect

Food

Attractants

 

Assassin Bug 
 
Beetles, caterpillars, other bugs Sunflowers

Juvenile Assassin Bug photo by Kerry Wixted
Damsel Bugs
 
Caterpillar eggs, fleahoppers, leafhoppers and spider mites Clover
Damselflies & Dragonflies Mosquitoes, gnats and flying insects Open water, small ponds, open fields
 
Ground Beetles
 
Snails, slugs and root-feeding insects Stone pathways, clover & compost piles
Honey Bees Pollen and flower nectar Flowers such as asters & goldenrods
 
Lacewings Aphids, small caterpillars, whiteflies and thrips Nectar plants including geraniums Predatory Wasp (Pelecinid Wasp) photo by Kerry Wixted
Lady Bugs Aphids, scales, mites and soft-bodied pests Nectar plants including geraniums
Praying Mantis Other insects Flower & vegetable gardens
Predatory Flies Caterpillars, beetle larvae and sawflies Nectar plants
Predatory Wasps Other insects Pollen producing plants like fennel
Spiders Other insects Flower & vegetable gardens
Syrphid Flies Aphids, beetles, caterpillars and thrips Composites like dill, fennel and coreopsis
Wheel Bugs Caterpillars, moths, squash bugs, cucumber beetles Shrubs and trees
Note: While many stores sell beneficial insects, it is best to attempt to attract your own. Sometimes, these insects are not sustainably collected from the wild, or those that are mass reared may have diseases that could be accidentally introduced into wild populations.

 

Many wasps and other natural enemies of insects rely on plant nectar or pollen as adults and invertebrates as juveniles. Therefore, planting flowers that attract adult predators and parasitoids can increase natural pest control in your backyard. Predators are animals that attack and consume other animals whereas parasitoids live in or on their host and kill the host in the process. Most parasitoids are specialists and only attack certain species. For example, a common parasitoid is the braconid wasp (Cotesia congregatus) which lays its eggs inside of tobacco and tomato hornworms.

Common Name Scientific Name Bloom Time Notes
Golden Alexanders Zizia aurea April-June Host plant for black swallowtail
Canada Anemone Anemone canadensis May-July Likes moist soil
Dill Anethum graveolens May-June Attracts green lacewings, syrphid flies, and ladybugs; host plant for black swallowtail
Lanceleaf Tickseed Coreopsis lanceolata June-October Great bee and butterfly nectar plant
Indian Hemp Apocynum cannabinum June-August Nectar source for monarchs
Meadowsweet Spiraea alba June-September Grows best in western Maryland
Spotted Beebalm Monarda punctata June-October Attracts wasps
Wild Bergamot Monarda fistulosa June-September Attracts wasps
Canada goldenrod Solidago canadensis July-October Great nectar source for migrating monarchs; attracts beetles and wasps
Boneset Eupatorium perfoliatum July-October Great for bees and butterflies
Blue Lobelia Lobelia siphilitica August-October Likes moist soil
New England Aster  Symphyotrichum novae-angliae August-October Great nectar source for migrating monarchs

When planting, it is best to either interplant the species listed above within your garden design or to create small borders around your garden. These flowers can be used in all types of gardens from edible gardens to pollinator gardens.

Resources:

Fiedler, A., Tuell, J., Isaacs, R., and D. Landis. 2007. Attracting beneficial insects with native flowering plants. Extension Bulletin E-2973.

Xerces Society. 2014. Farming with Native Beneficial Insects: Ecological Pest Control Solutions. ISBN-13: 978-1612122830

For Additional Information, Contact:

Kerry Wixted
Wildlife and Heritage Service
580 Taylor Ave, E-1
Annapolis, MD 21401
kerry.wixted@maryland.gov
Phone: 410-260-8566
Fax: 410-260-8596​
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Acknowledgements:

All photos by Kerry Wixted