“The little things that run the world”

The Role of Insects in the Ecosystem

Guest Blog by Angela Dombrowski

E.O. Wilson, eminent biologist and the father of biodiversity, called insects “the little things that run the world” because of the many essential ecological roles they play every day. Insects are the most diverse group of animals on Earth and include ants, lady bugs, bees, fireflies, butterflies, dragonflies, grasshoppers, and true flies. Insects can be grouped into three broad categories: pollinators, prey, and ecological balance.

Insects Are Pollinators

Pollination is the transfer by insects of pollen from the male part of a flower to the female part, which fertilizes the plant. Insects visit flowers and collect food (nectar and pollen). The pollen sticks to their bodies and as they travel about, it gets deposited on the female parts of a similar flower, resulting in fertilization. The fertilized flowers produce both fruit and seeds.

Insects pollinate 87% of flowering plants. The remaining 13% rely primarily on wind or water to carry pollen. Did you realize that 1 out of every 3 bites of food you eat depends on pollinators? Our nutrient-dense foods rely on insects––without insect pollinators we would lose:

• fruits & berries: apples, blueberries, strawberries, and melon
• vegetables: tomatoes, squash, cucumbers, and broccoli
• nuts & oil: almonds and canola
• treats: coffee, chocolate, and vanilla

Even the dairy and meat industries are indirectly dependent on insects, as cattle often rely on insect-pollinated crops like alfalfa.

Insects Are Prey

A lot of animals eat plants directly – squirrels eat nuts, cows eat grass. But many animals do not eat plants but instead eat the insects that eat the plants. As prey, insects serve as food for other animals by delivering the plant nutrients they need.

Insects Provide Ecological Balance

Insects rapidly decompose dead plants, releasing the nutrients they contain into the soil for use by new plant life. These dead plants and insects hold enormous amounts of carbon within their bodies and deposit it in the soil around the roots. Sequestering this carbon or storing it will help in mitigating climate change.

As Douglas Tallamy observed, it is remarkable that our cultural relationship with insects is one of disgust and animosity rather than awe and appreciation. We have declared war on insects and without thinking, we have driven many species into extinction. By killing insects, we are biting the hand that feeds us.

Can we learn to share the Earth with these little creatures? Below are just a few simple ways a homeowner can help sustain these “little things that run the world”.

Lighting – use lights at night only when needed

Lights reduce the insect population in several ways. Insects gather at artificial light because their natural reaction to keep their back toward the brightest light gets confused by the artificial source. Their sense of “up” is disrupted. Insects fly into the light and repeatedly collide with the bulb, killing themselves. Others that do not beat themselves to death frantically fly around the light, deplete their energy, and die of exhaustion. In the short lives of insects, lights waste precious time for them to carry out their function.

The firefly is a good example of how artificial light disrupts their life cycle. Actually, fireflies are not a bug or a fly, but closer to a beetle. In their larvae life cycle stage, they live in the soil and eat pests like slugs, snails, and earthworms. They remain in this larvae growth stage for about 2 years. Then, they develop to the adult stage as fireflies and live for only a few weeks.

In those few weeks as adult fireflies, they use their bioluminescent light source to find a mate and reproduce 50-500 eggs just below the soil surface. The eggs will hatch to larvae in 3-4 weeks in moist soil (and leaf litter) and the cycle begins again. We have 28 different species of fireflies in Ohio.

Adult fireflies use their bioluminescent for communication––with distinct flashing patterns that enable them to find mates. Artificial light confuses the signal and disrupts mating. Fireflies are a bioindicator of a healthy ecosystem, because their presence or absence directly reflects the quality of the local environment.

Consider using motion sensors on your property’s night lights. Whether the lights are for safe passage or for security, this simple change will make an enormous difference for insects, particularly for night-flying moths and fireflies. Other choices to consider are to shield lights that do not shine upward; use warm LED bulbs or amber colored lights; or position lights away from areas where you want to minimize insect presence (like patios).

Plants – which plants we need most

Insects are picky eaters, and providing diverse plants will prove to sustain the insect population. We need plants for pollinators to get nectar for their food. We need plants for insects to eat and to create a habitat for other insects to reproduce.

The caterpillars are a good example of insects that provide food. Caterpillars are the mainstay of most bird diets, especially when rearing their young. Caterpillars are thin and flexible, like soft bags of food, making them easy to digest. Caterpillars usually hang out on vegetation, making them easy for birds to find. They are more nutritious than other insects and provide healthy carotenoids for the birds. Carotenoids provide nutrition and are a major factor in colorful feather pigment.

Birds grow from egg to adult in about two weeks. During that time, the nest is the most vulnerable to its predators. The best defense is to minimize the time in the nest. To achieve the fast growth, the birds need lots of caterpillars. A nesting bird eats about 30-40 times per day. Therefore, most bird parents will forage in a defined area near the nest – or better stated, birds will nest where the food conditions are plentiful.

In his 1961 study, ornithologist Richard Brewer observed California chickadees and counted the number of caterpillars they brought to their nest. Over the course of a typical nesting period (16 days on average), chickadee parents delivered 6000 to 9000 caterpillars to bring one nest of tiny (three ounce) birds to fledging. That is about 350 to 570 caterpillars per day.

Carolina chickadee parents continue to feed their young for up to 21 days after fledging. Imagine the number of trips that the parents need to make to find 350-570 caterpillars! It would be less work if the plants that support the life cycle of caterpillars were located closer to the bird’s nest. Like running to the neighborhood grocery for your food supply. To have birds in our yard, we need native plant species to host caterpillars.

Plant Selection

Annual or perennial beds and shrub plantings anywhere in the landscape will provide a perfect soil layer for caterpillars to complete their life cycle and provide food for birds.

To sustain the insect population, we need the right plants. Most Insects are very picky eaters. About 90% of the plant-eating insects (herbivores) eat only two types of plants. This is because plants really do not want to be eaten. Plants have defenses like tasting bad or have poisonous chemicals somewhere inside their leaves that some insects cannot digest. So, like all of us, they have favorites and become picky eaters.

Native plants feed our picky eaters. A native plant is a plant species that occurs naturally in a specific region and has been around for thousands of years. When choosing native plants for a bed, consider both the height and how different bloom times will make for a beautiful presentation through all seasons.

It is best to plant a variety to achieve the diversity while making sure to plant 3-5 of the same plant. The insect will need a little bit of a patch of blooms to stop by. Websites (with many pictures!) that can assist with simple designs and the selection of native plants are listed in the resource section below.

Groundcovers planted under trees, such as native pachysandra or ginger, make a perfect site for moths to complete their development safely.  Moths are a food source for other animals. Fireflies also need groundcover to complete their life cycle.

Conclusion

Are we using up the Earth’s resources wisely? Insects––the little things that run the world––need our support. What to do starts in our own backyard––literally! With only some simple modifications, the earth can provide for everything – insects, birds, animals, and humans.  As E.O. Wilson reminds us, “The biosphere doesn’t belong to us, we belong to it”. We cannot afford to ignore the health of the earth.

Resources

The Native Plant Finder Home – Native Plants Finder. Enter your zip code and you can find out which native plants are best in that area.

Native Garden Design Plans for Small Spaces. (Woodland, Prairie, Butterfly & Rain Gardens), Sag Moraine Native Plant Community www.youtube.com/live/7yPuwVsDKKs

Matrix Planting presented by Scott Vogt, Arboretum Director www.youtube.com/watch?v=8FsLvRlk-i0

“Matrix Landscape Design” with Benjamin Vogt www.youtube.com/watch?v=8FsLvRlk-i0

Native Garden Design., Larry Weaner for Wild Ones www.youtube.com/watch?v=UsZ7X3Vf26c

“Turn That Patch Into a Plan” Workshop led by Zoe and Heather Evans www.youtube.com/watch?v=sHv2Yea57SY

Pollinator Pathway, Franklin County www.franklinpollinatorpathway.org/home