Wednesday, December 10, 2008

Save the Insects

Join Audubon South Carolina and, "Save the Insects!" Sure, whales, pandas, and mountain gorillas have an easier time grabbing the headlines, but insects are vital components in most non-marine food webs. Remember those ubiquitous grasshoppers in the science textbook diagrams? Maybe that was the last time, besides the life-ending stomp you put on a Palmetto Bug, that you thought about insects. Too bad, because our existence as a species depends on a healthy insect population and insects are under attack by aliens!

Sycamore Tussock Moth (Halysidota harrisii)

That's right, we typed, "Aliens!" These are not aliens from another planet, so there is no need to don the aluminum foil hat. However, these aliens have the same mission as nefarious domination and the elimination of the human race! You may ask, "Who are these aliens and why hasn't the Department of Homeland Security issued a colorful threat condition?" The aliens are non-native plants (and often non-native animal hitchhikers) that are often welcomed to (not repelled from) our shores by our federal government! "Plants? You got my blood pressure up for plants? Alien insects had a chance, but plants? Really?"

Jack-in-the-Pulpit (Arisaema triphyllum)

We understand that most people do not feel threatened by non-native plants and that most Americans don't keep a finger on the pulse of the insect world. However, according to Professor Douglas W. Tallamy, your quality of life may be adversely affected unless you pay closer attention to these topics. In his book Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens, Tallamy connects the dots between non-native (alien) plants and native insects (cannot or will not eat non-native plants) and other native wildlife, especially birds, which do not benefit directly from non-native plants and/or suffer from the food-shortage-induced decline in native insect populations. Non-native plants capture the sun's energy and use nutrients in the soil, but because few of these plants are eaten by native fauna (mainly insects), that energy is not passed up to higher trophic levels in the food chain (Spoiler alert: We're at the high end). "Pound for pound, most insect species contain more protein than beef" (Lyon, W. F. 1996. Insects as human food. Ohio State University Extension Fact Sheet. HYG 2160-96) and 96% of terrestrial bird species in North America rely on insects and other arthropods (typically, the spiders that eat insects) to feed their young (Dickinson, M. B. 1999. Field Guide to Birds of North America. 3rd ed. Washington, D. C.: National Geographic Society). Fewer insects mean fewer birds.

Angular-winged Katydid (Microcentrum retinerve)

"Okay, but what does that have to do with me?" Tallamy writes that gardeners' arguments for native plants over alien ornamentals "might describe the 'sense of place' that is created by using plants that 'belong' or the dangers of releasing yet another species of invasive alien to outcompete and smother native vegetation. They might recognize the costly wastefulness of lawns populated with alien grasses that demand high-nitrogen fertilizers, broad-leaf herbicides, and pollution-belching mowers. Or they might mention the imperative of resucing endangered native plants from extinction. These are all well-documented reasons for the increasing popularity of growing native plants." Tallmay encourages the "use of native species to create simplified vestiges of the ecosystems that once made this land such a rich source of life for its indigenous peoples and, later, for European colonists and their descendants."

Jewelweed (Impatiens capensis)

"Whew! I don't have a yard, so I'm good." E. O. Wilson points out that "because so many animals depend partially or entirely on insect protein for food, a land without insects is a land without most forms of higher life. (The little things that run the world: The importance and conservation of invertebrates" Conservation Biology 1:344-346). Tallamy notes, "Even the most incorrigible antienvironmentalist would be hard pressed to make an attractive case for such sterility. Pure anthropocentrists should be alarmed as well, since the terrestrial ecosystems on which we humans all depend for our continued existence would cease to function without our six-legged friends."

Plant native flora and save the insects (and us too)!

Images by Mark Musselman

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