■ ossils show us that insects were living on Earth even I before the dinosaurs. In the millions of years insects have been around, our world has changed a lot. There have been floods, ice ages, volcanic eruptions, and meteor crashes. Although these events killed most of the insects and other animals that existed at these times, enough insects survived to continue reproducing. As the world changed, so did the insects. Their bodies and habits adapted to the different environments, so that now, insects can be found almost everywhere.Tiny non-biting, mosquito-looking midges can be found in Antarctica. On ocean coasts, the seashore spring-tail hides in air-filled pockets under rocks at high tide, then looks like a speck of dirt as it springs along the shore looking for plant litter to eat when the water has receded. Fleas find your pets irresistible, moths like your clothes, and cockroaches hide in your basement.
In order to reduce competition for food and other necessi ties, insects have become active at various times: day, night, winter, spring, summer, or fall. Although it is easiest to find the greatest variety of insects outside at dusk on a summer evening, you can look for fuzzy white mealybugs attached to the underside of the leaves of your houseplants anytime. Snow fleas can be found at the base of trees on a winter day, while cicadas sing on hot summer evenings.
With so many out there, insects should be easy to find—
right? Maybe. Maybe not! Treehoppers can look like thorns.Walking sticks— as their name suggests— look like sticks.The South American hawk caterpillar looks like a snake, and Salvodora species of caterpillars look like bird poop!
If insects are so well camou flaged, then how can you watch, catch, or collect them? The activities in this chapter give you tips and tricks to finding a large variety and number of insects.
Explorers and scientists have long used field notes to help them understand the world. Field notes help you focus on what is in front of you, instead of just looking at it quickly then putting it back. Charles Darwin used his notes and collections from an around-the-world trip to write a famous book called The Origin of Species.
Whether you find an insect using one of the ways listed here, or an insect finds you, record your actions and observations in your journal. Do this for each insect you find.
These are the weather conditions:
This is where I found the insect:
This is how I captured the insect:
I think this insect is a:
This is a drawing of the insect:
% / ou can look for insects one I at a time, but they are masters at hiding and escaping. An easier way to catch a wide variety and high number of insects is to use a sweep net.
Wire coat hanger
Wire cutter Scissors
Old pillowcase (with no holes) Old broomstick (or thick dowel rod)
Hold the sweep net a few inches off the ground as you walk through a grassy area.
Metal hose clamp, optional (sold in hardware or automotive stores) Screwdriver Looking jar
Ask an adult to help you use the pliers to untwist the coat hanger and form an open loop. Use the wire cutters to snip off the hook, saving it for the activity Fly-Tying a Big Bug (on page 98). Cut a small slit in the hem at the mouth of the pillowcase. Thread the coat hanger through the hem. Place one end of the coat hanger now threaded through the pillowcase on each side of the broomstick.Wrap the wire and broomstick with duct tape. For extra holding power, slip a circular, metal hose clamp over the duct tape and coat
Hold the sweep net a few inches off the ground as you walk through a grassy area.
hanger, then tighten its screw using a screwdriver.
To use a sweep net, go to an area with grass. One of the best places to find insects is at the top of the tallest hill in an area. Many male butterflies, moths, and other insects head up high to make it easier for females to find them, but any weedy field or even your backyard is fine. Hold the net end a few inches above the ground.Walk forward and swivel the net opening from side to side as you sweep through the grass, knocking insects off the plants and into your net. After about 20 steps, lift the net up and let any stinging insects fly free. Grab the net around the middle so that no other insects can escape, then gently shake your catch as you move your hand down the bag. When your hand is only about 3 inches (7 to 8 cm) from the bottom, move the net close to the mouth of your looking jar. Carefully open your net-filled hand while you use your free hand to gently turn the pillow-
Stop Right There!
What do a monarch butterfly, box elder bug, ladybird beetle, hunting safety vest, construction cone, and stop sign have in common? They all use bright red or orange colors to send a warning message. What are they saying? Usually it is "Hey! Be careful around me!" Most insects that have noticeable red or orange markings also taste pretty bad and can make predators gag. So an animal might try to eat a red one once, then leave all other red ones alone!
case inside out as you transfer the insects into the looking jar. Shake any clinging insects off the net and then remove the net with one hand while you put the lid on the jar with the other hand.
If you follow the same instructions using sheer curtains instead of a pillowcase, you will make an aerial net. Aerial nets are more delicate, so you shouldn't sweep the grass with them. You can use an aerial net to catch an insect such as a butterfly, moth, or dragonfly as it is flying, or wait until an insect has landed, then gently drop the net over it and surround it.
Sweep nets work well for insects that are crawling on plant leaves and stems. But ants, roaches, and many beetles spend much of their time on the ground. A pit trap is a better way to catch these insects.
Leaf Jitter Shaker
1 2-liter bottle
Bait (raw meat the size of a meatball)
Small garden trowel Four small, flat rocks Board that is about 5 inches
(13 cm) square
Cut off the top third of the bottle, making a funnel shape. Place the bait in the bottom piece of the bottle. Nest the funnel piece top upside down inside the bottle bottom. Use the trowel to dig a hole deep enough so that the top of the bottle will be even with the ground. (Check with an adult before digging.) The slick sides and funnel will keep many of the creatures that fall into the trap stuck inside. Place the rocks around the edge of the bottle, and place the board on top of the rocks. This will leave enough room for insects to investigate the smell, but keep rain and heavy dew out of the trap. Check on the trap every morning and again every evening.
Berlese's Itty-Bitty Bugs
Do you trap more insects during the day or night?
Antonio Berlese was an Italian entomologist who studied very small insects and mites that spend most of their time in the soil. Although thousands of these tiny animals can live in just a shovelful of soil, it is hard to spy and catch them. Instead of looking in the soil for them, Berlese figured out how to get them to leave the soil. He placed a small screen near the bottom of a funnel. He put some soil in the funnel, and put the funnel in a tall jar that had alcohol in the bottom. He finished by putting some hot water around the funnel. As the soil warmed up and dried out, the small animals moved farther and farther down, until they fell out of the bottom of the funnel and into the jar. He shared his invention with other entomologists. Many years later, instead of using hot water, a scientist named Tullgren hung a lightbulb over the funnel. Today students and scien-
tists all over the world use the Berlese-Tullgren funnel to see what animals are living in the soil.
1 pringtails, scavenger beetles, \ jumping ground bugs, and vJother arthropods eat dead leaves and plants. Unless you put a trap right under them, you might not find these decomposers. To find them, you need to shake them out.
Plastic ice cream tub with lid Thick rag Pencil Dead leaves Light-colored sheet
Place the lid of the ice cream tub on the thick rag. Use the pencil to punch large holes in the lid. Fill the tub with clumps of dead leaves that are brown and crumbly, then put the lid on tightly. Hold the tub upside down over a light-colored sheet and shake it. In your journal, record which insects fall onto the
sheet, sketch the different types, and include a total count.
Providing water is a great way to attract many insects. A cockroach can live for about a month without food, but for only about one week without water. Place a damp rag on the floor in your garage. (Check with an adult first.) Check under the rag early in the morning to see if a roach or any other insect is hiding underneath it.
I I ere's another way to collect I I insects. In this collection J- X activity you may find it raining insects.
Katydids and cicadas spend a great deal of time in trees.To catch them, open the umbrella and place it upside down under a tree or bush. Take a stron and hit a large branch of or bush several times to k insects off the branch and i the umbrella. Gently tap the of the umbrella to shake the insects down to the center, then scoop them into your looking jar.
Gross Entomology: Pantry Pests insects down to the center, then scoop them into your looking jar.
Another place to look for insects is in the food you eat. Food would be too expensive to grow, harvest, and process if everyone had to get out all insect pieces and parts. Considering the fact that in many countries, people eat insects on purpose, it seems a bit silly to worry about a few ant antennae or beetle wings that might find their way into your mouth. But to make sure what you eat is safe, there are standards of how many insects or pieces of insects are allowed in different types of food. The U.S. Food and Drug Administration considers food safe even with the following amounts of insect parts:
Flour: Up to 75 insect fragments in about 2 cups (50 g)
Canned citrus juice: Five or more fruit fly eggs or other fly eggs in about 1 cup (250 ml)
Peanut butter: An average of 30 insect fragments in a little less than 1/ cup (100 g)
Ground cinnamon: An average of 400 or more insect fragments per 1/3 cup (50 g)
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