Written by Richard Mills, Extension Master Gardener

Insects account for about 80% of the known animal life on Earth, but as Oliver Milman states in his recent book “The Insect Crisis”, the worldwide number and diversity of insects is rapidly declining due to pesticides, habitat loss, pollution, invasive species, and climate change. Based on numerous studies, Biological Conservation’s 2019 summary concluded that 40% of our Earth’s insect species are decreasing in number and a third are endangered. We may consider some, such as mosquitos and roaches, to be pests, but the majority of insects provide a wide range of services essential to our environment and critical to the survival of most life on Earth, including ourselves! Along with plants, insects constitute the foundation of our food web.

In recent years gardeners have been encouraged to replace introduced plants with insect-friendly natives, like milkweeds, beebalm, sunflowers, goldenrod, etc. with the objective of benefiting butterflies, bees, wasps, flies, and other pollinators. Dr. Douglas Tallamy in Nature’s Best Hope, asks homeowners to take environmental action by planting native trees, such as oaks, cherries, willows, etc. with the objective of providing forage for insects. We can certainly benefit insects by selectively planting and protecting their important food plants and, in recent years, much has been written regarding the best species to propagate. Numerous publications are readily available telling us how to construct butterfly and bee-friendly gardens, most of them focusing on diurnal and conspicuous insects, such as Monarch butterflies and bumblebees, which we can easily observe and appreciate.

Much less information is available regarding crepuscular and nocturnal insects, many of which are inconspicuous and more difficult to observe. Although aware of the moths and other insects that, at night, gather around our outside lights and flutter at our windows we, mostly, pay little attention to and know very little about them. However, the U.S. Department of Agriculture has determined that these nocturnal insects are important pollinators, comparable to the better-known diurnal butterflies, wasps, flies, and bees.

During the past 30 years advances in lighting technology have exponentially increased night sky brightness. We now know that artificial lights have a significant adverse effect on nocturnally active insects, decreasing their ability to feed, migrate, disperse, avoid predators, and reproduce, resulting in a reduction of their numbers, diversity and detrimental to the ecosystem services they provide. Artificial lights have radically altered the nocturnal environment for many plants and animals by disrupting their natural daily and seasonal light cycles.

Although our ability, as individuals, to reduce the commercial use of pesticides, curtail habitat loss, eliminate invasive species, and reduce the rate of climate change may be minimal, we are able to make a difference regarding the reduction of nocturnal light pollution. A few of the simple things we can do include using fewer lights and turning them off when not in use, keeping blinds and drapes closed at night, installing motion detectors and timers on outdoor security lights, and exchanging our incandescent, neon, and fluorescent lights for LED bulbs that have been filtered to be yellow or amber in color. The best options are yellow, compact, fluorescent lights which can be ordered online or purchased from local stores. So, what has this got to do with “being kind to our fine feathered friends”? Perhaps you have noticed a reduction in the number of birds over the last few years? If so, you are not alone. The Cornell Laboratory of Ornithology documents that, since 1970, North America’s bird population is down by nearly 3 billion breeding adults, and if you care about birds, you need to garden for caterpillars. Yes, caterpillars! Raise your awareness regarding caterpillars and take a bird’s-eye view of the situation. The majority of the food songbirds in our area require for their nestlings are caterpillars, and although some are the larvae of butterflies, most are from moths. As one example, a pair of Carolina chickadees must provide their nestlings with between 7,000 and 9,000 caterpillars between the time they hatch and fledge. So, by simply turning off the lights, we can be kind to our fine feathered friends.