Q: I see ladybugs and lacewings for sale at my garden center. Is this a good way to control unwanted bugs in my garden?
A: Some beneficial insects can be purchased and turned loose in your garden. The problem with this is that the insects you purchase are not aware that you have given them a special invitation to your particular “garden restaurant” and they may very well fly away.
Here are some tips to consider if purchasing beneficial insects for your garden.
• Identify the pests you want to control, and learn which beneficial bug is appropriate for your situation.
• Learn the best time to release the beneficial bug based on the life cycle of the pest.
• Learn the quantity and life stage (e.g. larva or adult) of the beneficial bug that will be most effective.
• Provide a safe delivery address where the shipment of beneficials will be cared for as soon as it arrives.
• Learn the proper release requirements, such as time of day, food and water needs, etc.
You can also encourage beneficial insects by cultivating plants that they need to survive. For example, many beneficial insects need pollen or nectar to help their eggs mature. Lady beetles, green lacewings and parasitic wasps all use nectar and pollen in this manner.
Some plants that are useful to beneficial insects:
• Achillea (Yarrow)
• Sweet Alyssum
• Edging Lobelia
• European Goldenrod
• Moon Carrot
(List courtesy of CSU Extension Fact Sheet 5.550 – www.ext.colostate.edu/pubs/Insect/05550.html)
To attract and sustain good bugs:
• Develop a tolerance for some damage by insect pests to your plants; many plants can tolerate low levels of pest damage with few ill effects.
• Provide shelter. Leaving some leaf litter and debris under shrubs may provide beneficial bugs a place to hide during adverse conditions such as hot summer days.
• Increase the diversity of your landscape. Grow a wide assortment of plants to create habitat for a wide range of natural enemies. Also, diverse plantings of the right species that are pest and disease resistant make it less likely that pests will cause problems.
• Learn to recognize beneficial insects vs. insect pests. Before making insecticide applications, always check plants to see if the existing beneficial organisms are abundant enough to provide control. Whenever possible, use insecticides that are more selective in their activity and less harmful to beneficial insects.
Contributed by Deb Ross, Certified Colorado Gardener
Photo courtesy of Colorado State University Extension