Teachers Corner - Helpful Insects

Teacher's Corner

Lesson Plan

LESSON TITLE:

Insects are Helpful!

AUTHOR(S), DATE, SCHOOL/DISTRICT:

Catherine Ryan, Mara Padrick (UC Berkeley)
Spring 2001
Oakland Unified School District

SUBJECTS ADDRESSED:

Silk and silkworms,
Pollination and Honey
Insects as food for humans and pets
Insects are beneficial in a garden
Biological control

GRADE LEVELS:

Upper elementary (3-5)

STATE STANDARDS ADDRESSED:

While discussing silkworm life cycles, pollination, and biological control, the Life Science standards (the characteristics of organisms, life cycles of organisms, and organisms and environment) for grades K-4 are all touched upon.

LESSON PURPOSE OR GOAL:

To teach children that insects do a lot of good and are very valuable to humans and nature. This is part of an ongoing effort to dispel fears of insects

LESSON DESCRIPTION:

Silk and silkworms
Pollination and how insects take part
Bees and honey
Insects are food for humans and domesticated animals
Beneficial insects in gardens
Biological control and observation of a parasitory wasp attacking a navel orange worm
Four stations for children to rotate to: honeycomb tasting, pinned insect pollinators, ladybugs in a cage, pictures of silkworms and their cocoons

APPROX. CLASS TIME NEEDED:

55 minutes

RELATED RESOURCES:

"Introduction to Insect Biology and Diversity," Daly, Howell V., et al.

For silk supplies: http://www.deborahsilk.com

MATERIALS

A small piece of silk for each child
Honeycomb for tasting
Pinned insects that are pollinators (bees, butterflies)
A figure of two vertically cross-sectioned flowers for demonstrating how pollination works with insects
Some navel orange worm and parasitory wasps separately in see-through containers, for biological control demonstration (contact UC Berkeley-Kent Daane¹s lab)

PREPARATION

INTRODUCTION ACTIVITY:

Ask the children if they know of any helpful things that insects do and list ideas on the board or overhead

PROCEDURE:

Start the discussion of helpful insect activities with an explanation about how silk is traditionally made from silkworm cocoons. Pass out pieces of silk for children to feel while explanation continues.
Next, discuss pollination, using the flower diagram to show how pollen can get onto an insect and be brought to another flower.
This topic leads easily into talking about bees and honey, which is a food for humans.
Continuing with the food concept, talk about how people around the world eat insects. Mention the value of insects being food for pet turtles and lizards, in addition to wild animals.
Discuss how some insects, such as ladybugs, in the garden prey on other insects that are harmful to plants, such as aphids. These are beneficial to the garden environment.
Continuing with the example of ladybugs and aphids, explain biological control of pests versus chemical control. Disneyland used a biological control agent (a small parasitory wasp which only attacks the Eugenia psyllid) to help control an insect that was making the leaves of their Eugenia sculpture bushes curl and was distorting the shapes of the sculptures. They couldn't use chemical sprays, due to potential exposure to humans, so they consulted with a UC Berkeley professor to figure out another way. Biological control was the answer and was very successful in this case.
To show the children what biological control can be, show the children the navel orange worm and its parasitoid. Within five minutes after the worm is dropped into a container with the parasitory wasp, the wasp will sting and paralyze the worm. Later the wasp will lay an egg on the worm, and the worm will provide food for the wasp larva. Explain that in this case and in the best and most successful biological control cases, the biological control agent is a specifist for the pest and will not attack us or any other type of organism.
Once the children have all witness the wasp stinging the worm, allow them to rotate around to the four stations to taste honey, investigate the silkworm and silk relationship more, look at pinned pollinating insects, and observe numerous ladybugs.

ASSESSMENT:

While the children are at the different stations, have one to two written questions about a topic related to the station's item. For honey, the question can be aimed toward honey or other food that insects provide. At the pinned insect station, pollination should be the theme. At the silkworm station, a question about where the silk threads come from would be appropriate. Finally, at the ladybug station, questions about beneficial garden insects or biological control could be asked.

EXTENSION ACTIVITIES:

Have the children write a short story about a day in the life of a bee, including pollinating flowers and making honey.

Have the class start a ladybug collection, with a plant covered in aphids for food. It is easily done with a fish bowl with a nylon stocking rubber-banded around the top, so ladybugs can't escape easily. Each child can be assigned a day to take care for the ladybugs, where they will need to make sure the ladybugs have enough food. It teaches responsibility and respect for creatures.

RELATED RESOURCES (internet, community, commercial)

WORKSHEETS & HANDOUTS (attachments or downloads)