Each year I plan my garden and get started as soon as the temperatures warm up. In the spring my plants flourish with little care. As the season progresses, I begin to spend more time in the garden, pulling weeds, deadheading perennials, and watering more often. Then the heat of the summer hits and the battle begins. I find aphids on my roses and hornworms on my tomatoes. Flea beetles attack my sweet potato vine and thrips create streaks all over my annual vinca blooms. Should I panic? Reach for the soapy spray? Will my helpers come to my aid again this year? Without fail, a few days later I notice several lady beetles wandering among the aphids, dining contently.


Each year I plan my garden and get started as soon as the temperatures warm up. In the spring my plants flourish with little care. As the season progresses, I begin to spend more time in the garden, pulling weeds, deadheading perennials, and watering more often. Then the heat of the summer hits and the battle begins. I find aphids on my roses and hornworms on my tomatoes. Flea beetles attack my sweet potato vine and thrips create streaks all over my annual vinca blooms. Should I panic? Reach for the soapy spray? Will my helpers come to my aid again this year? Without fail, a few days later I notice several lady beetles wandering among the aphids, dining contently. 





When most people think about insects they immediately think of pests. What many people do not realize is that not all insects are pests. In fact, many insects help us by pollinating our flowers and reducing the population of insects that are harmful to plants. Encouraging beneficial insects to reside in your yard only takes a few minor changes in the way you garden and a little patience.   



Beneficial insects need a stable habitat to stay happy and healthy. This includes a steady food supply and places to take refuge during storms. If shelter is provided where insects can find protection during bad weather they are more likely to stick around. Plots of cover crops, perennial flower beds, and hedges near flower and vegetable gardens all provide excellent shelter for beneficial insects. 



Just like everything else, insects need water to survive. Providing a small, shallow container will work, but be sure to change the water every 2-3 days to discourage mosquitoes from breeding. Place small sticks or rocks in the water to give the insects a place to perch.



When pest populations are low, beneficial insects will feed on pollen, nectar or plant juices to supplement or replace their insect diet. Make sure they have access to this alternate food source in your yard by planting a wide variety of flowering plants to bloom throughout the year. If pest levels temporarily run low in your yard, do not worry. Beneficial insects can hold off laying eggs when no pests are present or if pest populations are not high enough to feed their hatching young.



In order to sustain their food source, beneficial insects must allow some of their prey to feed and reproduce. They may not be able to solve all your pest problems, especially if you cannot tolerate a small amount of damage. Choosing the right plant for the right place, selecting plants that are resistant to pests, and enriching the soil are all sustainable ways of managing pest insects.



Pesticides are another option but should always be the last resort. Often when we spray we kill the pests as well as the beneficials, but it takes longer for beneficial insects to rebuild their populations. That is why when pesticides are used you often see an increase in pests a few weeks after you spray; the eggs of the pests have hatched but the beneficial insects have all been killed. 



Many beneficial insects are small and unfamiliar. When you find an unknown insect in the garden, begin with the proper identification of the pest and plant host. Observe if the insect is munching on leaves or buds or if they are feeding on other insects. Are they flying or crawling?  What is their physical appearance? All these questions can help you determine which insects you are encountering and how to manage them effectively.



Once you know the insect, you can place them into one of three categories: bad, benign, or beneficial.  Ninety percent of the insects we encounter in the garden are either benign or beneficial. Even seemingly bad insects serve a purpose, whether it is pollination, decomposition, or food for other creatures higher up the food chain. When plant damaging insects are present, wait a few days before taking action to see if beneficials will do the job for you. 



Learn more



To see images of beneficial insects and learn more about supporting them in your yard, visit the NCSU Department of Entomology’s ‘Biological Control Information Center’ at http://www4.ncsu.edu/~dorr/index.html. For assistance identifying and managing insect problems, visit ces.ncsu.edu, where you can post your questions via the ‘Ask an Expert’ link, or contact your local Extension office. If you live in Pender County, call 910-259-1235. In New Hanover County, call 910-798-7660. In Brunswick County, call 910-253-2610.



Susan Brown is the horticulture agent with the New Hanover County Center of the N.C. Cooperative Extension.