Weekly Online Lesson Online Lesson Archive Grade Level: 4-9 Subject: Life Science

Grasshopper Plague

Swarming hordes of grasshoppers and their cousins the Mormon crickets are destroying crops and pastures across the West. It may be the worst insect infestation in 60 years. Farmers from Nebraska to Utah are counting 50 to 200 grasshoppers per square yard, compared with 3 or 4 during a normal summer season.

Farmers and ranchers are already suffering because of this year's harsh drought. The insects present an even greater threat to their livelihood. A grasshopper can devour more than half its body weight in vegetation each day, leaving crops looking like Swiss cheese and robbing pastures of feed for cattle.

Why are there so many grasshoppers and crickets? A mild winter and a hot, dry spring season let many more eggs than usual survive and hatch. The drought has also hurt the population of birds and rodents that eat grasshoppers, and it has reduced some of the diseases that normally keep the insect numbers under control..

In this week's online lesson you'll learn about grasshoppers, Mormon crickets, and a serious insect infestation.

Grasshopper Sights and Sounds

Start off this week's lesson by looking at some grasshopper images. You can find a nice picture gallery at Iowa State University's Grasshoppers and Crickets page. Click each of the links on the page to see the photo. Which pictures show the most grasshoppers? How many can you count?

If you want to see pictures of Mormon crickets, here's something even better. Go to the University of Nebraska Etymology page and watch the video of Mormon Crickets Feeding. How are the Mormon crickets different in appearance from the grasshoppers you just saw?

Now that you've seen what these bugs look like, hear what they sound like. Go to Insect Sounds at Naturesongs.com. You can listen to a lot of different sounds here, but for now click any link that says cricket or grasshopper. What does an Acridid Grasshopper sound like to you? What do Pallid-winged Grasshoppers sound like? Which insect sounds the most musical?

How Grasshoppers Jump

Have you ever wondered how a grasshopper can jump so far? Well they don't actually jump. They use their legs as a catapult. Learn more by visiting the University of St Andrews School of Biology and the site How Grasshoppers Jump. Read the short introduction, and then click read on to get the whole story. From here just click Next to see the next part of the story.

1. At Basic Requirements, read and click play on each of the three video windows
2. At How the Legs Work, read about levers and click play on the two video windows
3. At Muscle Force, how much weight could a grasshopper leg lift?
4. At The Problem with Muscle Power, click play on the two video windows to see why speed is so important
5. At Catapults and Power Amplifiers, click play to learn how humans do with a bow and arrow what grasshoppers do with their legs
6. At Grasshopper Springs you will finally see how grasshopper legs work when you click play on the two video windows at the bottom of the page.

You can stop at that page.

Grasshoppers, Crickets, and Crop Damage

This time let's start with the Mormon cricket by reading Mormon Cricket Control. Read as much of this page as you can, but focus on Control Methods. What is the most effective way to reduce the cricket population? Why does it work so well? What makes the crickets such tough insects? Why are they able to cause so much damage?

Turn now to the Weather Notebook and read or listen to this interview about Mormon crickets. How long has it been since the cricket infestation was so bad in Utah?

To learn about grasshoppers and crop damage, go to Colorado State and read Grasshoppers in Field Crops. What are some of the major threats of grasshoppers? Where do infestations begin? What are the two best ways to control them.

Eat Them Right Back

Since the grasshoppers are eating all the crops, we can help by eating some of the grasshoppers. You're probably thinking that sounds gross, but some people in the world actually like to eat grasshoppers. And they're high in protein. Visit Yakscorner to learn about some Mexican kids who like to Catch and Cook Grasshoppers. How do you cook grasshoppers? What do they taste like? Would you like to try eating one?

These kids from Mexico aren't the only ones in the world who enjoy a nice bug snack. Go to the University of Kentucky's page called BugfoodIII: Insect Snacks from Around the World. Find out about the bugs (and recipes) people in other lands like to munch on. As you read, make a list of all the insects people eat.

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