Q. What are some good beneficial insects for my garden? Where can I buy them?
Although it is possible to buy beneficial insects like lady bugs for your home garden, they may not stick around long without the proper garden environment of preferred plants, pests, and safe habitat they prefer. The predatory and parasitic insects that attack and destroy pests are the helpers we seek, so It is possible to attract beneficial insects by planting particular plants. Dill, parsley, carrot, coriander, angelica, and parsnip feature flat-topped clusters of small flowers that have strong fragrances. They seem to attract large numbers of beneficial insects--particularly predatory wasps and flies--making them good candidates for companion planting, although there are many other attractant plants for a garden. But, yes you can buy the beneficial insects. It's the timing that is critical for optimal controls. You want to introduce predatory and parasitic insects before pest get out of hand. So for the long term, there needs to be a sufficient numbers of them to keep the beneficials busy and well fed. Unless they find insects to eat and the right plants to shelter them they will go elsewhere. If you plan to buy them, consider the type of environment they need. If you have aphid problems consider recruiting the assistance of aphid midges. Midges are N. American natives. the small orange larvae have a voracious appetite for many species of aphids. Midges are sold in the pupal stages. When the adults emerge, each female will go looking for aphids on which to lay her eggs. She will lay about 250 eggs. The larvae that hatch will then eat the aphids. The life cycle of aphid midges lasts only about three weeks in the summer and they increase quickly. Another helper is the ladybug an endearing insect, and also help to control aphids. They can eat up to 40 aphids an hour and will also make meals of thrips, mealybugs, various small larvae, beetle grubs, scale insects spider mites, whiteflies and other soft-bodied pests, as well as insect eggs. Other beneficial insects include the Green Lacewing larvae, Tiger Beetles, Tachinid flies, and Syrphid flies. Syrphids can be lured by planting their favorite flowers. It's the syrphid fly's larvae that are the predators, eating aphids, leafhoppers,thrips, and a number of other soft-bodied pests. Plant Coreopsis, baby blue eyes, candytuft, morning glory, or oleander to host these beneficials. Parasitic wasps are especially found of Queen Anne's lace and other members of the carrot family. Daisies, related flowers, and some evergreens provide a haven for all sorts of helpful insects. Plants are not the only helpful lure. Water is as important to maintaining a beneficial insect population as is food and shelter. Consider placing birdbaths in the garden. Stack several piles of small stones in them to allow the insects to drink water without the danger of drowning.
Courtesy of the NYBG Plant Information Service.