Be a nature detective.
A. Christmas tree ornament.
B. The fruit of a golf ball tree.
C. An unripe orange.
D. A growth caused by an insect.
A. What happens when a squirrel sneezes.
B. The egg case of a praying mantis.
C. Sap from a ripe suds bush.
D. Decaying cattail.
A. A really scary ski slope.
B. Part of a garden spider's web.
C. Trail left by back-wiggling spitter snake.
D. Bridge built by army ants.
A. Tunnels made in wood by bark beetles.
B. Ancient Native American art.
C. Centipede fossils.
D. Carvings made by bad campers.
A. A sand crab's home.
B. Crater on the moon.
C. Ant trap made by an insect.
D. Doughnut buried in the sand.
1. D. Growth Caused by an Insect
The photo on page 28 isn't a fruit, even though it's called an oak apple. It's a strange plant growth called a gall.
Galls usually start with a female fly, wasp, or other insect. The insect lays her eggs on--or in--a plant. After an egg hatches, the young insect puts special chemicals into the plant. (Sometimes it just scratches the plant.)
The chemicals or scratches make the plant grow around the insect. (You can see the young insect here, in the cut-open willow gall above.) Like a gingerbread house, the gall gives the growing insect a place to live and something to eat at the same time.
Look for galls on tree leaves and twigs and on wildflowers such as goldenrods.
2 B. Egg Case of a Praying Mantis
When a female praying mantis lays her eggs, she squirts white, foamy stuff out of her rear end like icing from a tube. When she's finished, she puts as many as 200 eggs into the walnut-sized gob. The foam is almost white when it's new, but during the next few days it turns brown and gets hard.
If you find a mantid egg case on a branch near you next spring, keep an eye on it. You may be lucky enough to see dozens and dozens of little mantids crawling out (right). That's great news for gardeners -- mantids eat lots of insect pests.
3 B. Part of a Garden Spider's Web
This garden spider (left) has added wide zigzag lines to the center of its web. Scientists think the lines might make the web center look like a flower to some insects. When insects fly toward this fake flower, they don't notice their mistake until it's too late. Oops! Then they're caught in the sticky part of the web.
Do spiders near you weave zigzag lines into their webs? Check it out!
4 A. Tunnels Made by Bark Beetles
These tiny tunnels are really bedrooms for baby bark beetles. The beetle moms (see A, above right) make long tunnels under tree bark. Then they lay their eggs inside them. When the eggs hatch, the larvae begin to chew into the sides of the tunnels (B). After a while, the little tunnels they make look like legs sticking out from the sides of a centipede. (See photo on page 29.) Notice how the side tunnels on page 29 start out narrow and then get wider? That's because the larvae get bigger and bigger as they eat, making bigger and bigger tunnels.
To find tiny beetle tunnels like these, peel off the bark of dead trees.
5 C. Ant Trap Made by an Insect
A few kinds of young antlions--called doodlebugs--make traps in the sand. A doodlebug waits at the bottom of its cone-shaped pit. Its body is covered by sand up to its wide-open, hooked jaws. (In the photo below, the antlion has been uncovered.)
If an ant blunders over the side of the pit, it may tumble to the bottom. If the ant doesn't fall, the doodlebug picks up grains of sand with its jaws and flips them at its prey. The shower of sand makes the ant lose its footing and slide to the bottom. Then--snap!-- the doodlebug grabs the ant with its huge jaws.
Look for antlion pits in dry, sandy soil in protected places, like near houses or under rock ledges.
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|Title Annotation:||nature quiz|
|Article Type:||Cover Story|
|Date:||Aug 1, 1998|
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