For most of us, when we think of native plants in our gardens or landscapes, we often think first of the benefit to native pollinators such as bumble bees, butterflies, and moths. As well we should! Planting native plants has clear, direct, and immediate benefits to local native pollinators by providing nectar, pollen, and habitat resources. But have you ever considered how planting native plants can benefit other, non-pollinator insects?
Dragonflies are a critically important group of insects, often existing as the top, or ‘apex,’ insect predators in the areas where they exist. One of the most important impacts they have on an ecosystem is as a form of biocontrol for other (less pleasant) insects such as mosquitoes and biting flies. Having a stable, healthy dragonfly population can help keep the populations of these ‘pests’ under control, as adult dragonflies will frequently eat these, and other, small insects. Another function of dragonflies is as water quality indicators. All dragonflies begin their lives in water, and spend most of their lives there before emerging from the water as flying adults. This means that as aquatic nymphs they are dependent on water quality, and the presence or absence of certain dragonfly species can indicate how polluted or clean a water body may be.
So what does this have to do with native plants? As exclusively predatory insects, dragonflies don’t directly feed on nectar or pollen…but they depend on the insects that do utilize these native plants. When there’s an increase of the native plants in an area, it’s frequently followed by an increase in the population of small and large pollinator insects, as there are now more resources available. All of those insects feeding on the nectar and pollen are not only beneficial pollinators in their own right, but are also a stable prey source for local dragonflies and other larger, predatory insects. During the summer months dragonflies can be found flying back and forth over prairies, meadows, and other areas with high insect abundance, chasing prey and getting enough energy to continue their reproductive cycle. In fact, when planning large-scale restoration for rare and endangered dragonflies, there needs to be consideration for nearby prairie, meadow, and even landscaped habitats, where these dragonflies source most of their food. Without those abundant and diverse sources of prey, the adult dragonflies won’t be able to survive and reproduce in those areas.
So take a look around, and if you have under-utilized areas of turf to upgrade with native plants and trees, remember that it benefits more than just pollinators!