AUGUST
2012

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

08-09-12

Download the audio of On Six Legs: MP3, WMV

To Kill or Not to Kill Insects


To kill or not to kill insects is a question that has bugged humans throughout our existence. The question is rooted in the historical battle between humans and insects for the earth's resources. In addition, some insect species pose health risks to humans through stinging, allergic reactions or transmission of disease-causing organisms. These negative aspects of insects mean, to some people at least, that the only good insect is a dead insect!

The vast majority of insects are not a hazard to humans. However, insects that are dangerous, or that resemble dangerous insects, can cause people to panic. It happened last weekend (Aug. 4) at the Purdue University graduation ceremony.

cicada killer wasp
Cicada killer wasp

While the graduates-to-be were marching to the ceremony, pest control personnel received a panicked call that "wasps were swarming around near Schleman Hall." Those wasps were most likely cicada killer wasps. These large and imposing insects are common on campus this time of year and almost always elicit terror in some of the people who see them. But I have never known a cicada killer wasp to sting any person, including students in graduation gowns. So killing cicada killer wasps is not justified based on potential harm to humans.

While some people are willing to kill any insect they see, other folks are inclined to apply the "live-and-let-live" rule to the insect world. There are even some misconceptions about whether or not certain insects can be killed. For instance, the Associated Press carried a news story, dateline Imperial, PA, about a swarm of bees that delayed a Delta Air Lines flight from Pittsburg to New York (Aug. 4, 2012). The article concludes: "Bees are a protected species that cannot legally be killed."

I am unaware of any federal or state laws that prohibit the killing of honey bees. It is true that honey bees are beneficial insects and have received a lot of press lately about the loss in populations. Consequently, many people and pest control companies are reluctant to destroy colonies. However, there are times when honey bee colonies take up residence in the structures of our homes. Under these conditions, the colonies will need to be removed, and this usually requires destruction of the bees.

Another insect that sometimes raises the question of whether or not an insect can be destroyed is the praying mantid. Praying mantids are widely regarded as beneficial insects and considered desirable residents in our yards and gardens. But there are no laws protecting praying mantids, so - in spite of the common notion that this insect should not be killed - it's OK to include one in an insect collection for school or 4-H.

In 1973 the U.S. Congress passed the Endangered Species Act. This law makes it illegal to destroy plants or animals on the list. The list includes some 600 species of animals and around 800 species of plants. All are endangered or threatened. Species on the list change over time as some are added or removed, as their endangered status changes. There are around 85 mammals, 93 birds, 36 reptiles, 25 amphibians, 151 fish, 65 insects and 12 arachnids on the list.

The insect list: 26 butterflies, 22 beetles, 13 flies, two damselflies, two moths, and one each of a dragonfly, a grasshopper, and a water bug. Of the butterflies on the Endangered Species List, one is the Karner blue. It is a small, blue butterfly. The Karner blue feeds as a caterpillar on only one food source, the leaves of the wild lupine plant. This purple-flowered legume occurs naturally in the Eastern U.S. in dry, sandy soils. Today, it is rare, and so is the insect that depends on the plant as a larval food source.

One of the beetles on the endangered list is the American burying beetle. Once found throughout the Eastern U.S., it is now found only in a few areas, including parts of Nebraska and Oklahoma. It, like the Karner blue, is a victim of habitat destruction.

So what about those 13 flies on the list? Well, there is a flower-loving fly and 12 species of Drosophila, also known as fruit flies. Now I don't know about you, but I'm not much of a fan of fruit flies - even if a few are classified as endangered species. So, because I can't tell an endangered fruit fly from a regular old common fruit fly, I'm still going to swat at the fruit flies hanging around my kitchen counter!

 

Writer: Tom Turpin
Editor: Olivia Maddox