Cycles - Galls

Focus: Some insect species spend a part of their life cycle inside a gall, a growth on plants that provides food and shelter for the young insect.

Puppets (Woody Woodchuck, Goldie Goldenrod (with ball gall), Oak Apple Gall, Will Willow (with pine cone gall), Raquel Raspberry (with knot gall))

Materials Checklist
Find Your Own (galls of one species, one for each child)
Gall Fantasy (Gall Fantasy story, crackers or carrots, diagram of goldenrod ball gall fly life cycle)
Puppet Show (puppets, script)
View a Variety (gall set, hand lenses, drawing paper, pencils)
Gall Hunt (hand lenses)
What's Inside? (galls, one for each pair of children, hand lenses, knives, cutting boards, Galls video, VCR & TV, optional-plastic bags)
Galls on the School Grounds (5/6 ELF) (Galls on the School Grounds charts, pencils, optional-clipboards, optional-camera)

Supplementary Reference Materials (What You Might Find in a Goldenrod Ball Gall, What Do Those Gall Makers Look Like?, Goldenrod Ball Gall Fly, Some Common Galls and Their Inducers, Some Plant Galls of New York, Galls, Shortened Gall Fantasy, 5/6 ELF Activity: Galls on the School Grounds, 5/6 ELF Supplement: Galls Chart)

Additional Reading/Resources
Novel Aspects of Insect-Plant Interactions, by Pedro Barbosa and Deborah Letourneau, John Wiley and Sons (Intersource), Hoboken, NJ, 1988.
Diseases and Pests of Ornamental Plants, 5th Edition, by Pascal Pirone, John Wiley and Sons, Hoboken, NJ, 1978.
Bucknell University website on Galls (mostly goldenrod galls) General Information on Plant Galls
For information on predation of goldenrod ball galls by birds and insects, click here.

ELF Notes - Template for newsletter on Galls
* Word document * pdf file

Teaching suggestions
Some cultures use galls for black hair dye, herbal cures, etc.
Look for galls before the snow falls so you'll know where to search for them when needed!

Find Your Own
You'll want to keep a collection of 24 goldenrod ball galls with holes in them (already emerged or last-year's) for this exercise rather than having this year's little brown flies emerge in the ELF box.

It takes a long time for every child to introduce his/her goldenrod ball gall, and then later to introduce the gall he/she drew and what made it. Pick one or the other opportunity to share.

One teacher had students measure circumference of their galls (wrapping twine around) and noted variations in galls made by one species.

Gall Fantasy
Remember to review insect life cycles before reading the fantasy script so children recognize the complete metamorphosis stages.

Use carrot sticks (or baby peeled carrots) instead of crackers, which make the kids thirsty.

Puppet Show
Bring some pinecone willow galls, oak apple galls and raspberry knot galls to pass around after the show.

View a Variety
Place a copy of the Gall-Makers illustration at each station so the kids can see what the different critters look like.

Black Knot isn't really a habitat for insects; it is produced by a fungus and will damage the tree.

In three small groups, sort galls by where they appear on the plants. Do you notice any similarities between mite galls, wasp galls, fly galls?

Drawing the galls really improves this activity for older kids. After making the drawing, use the questions out of Hands-On Nature to prompt kids to make close observations so they are able to introduce their galls. After drawings are done, it is fun to have children bring their specimen up to the front of the class, then exchange their drawing with another student and challenge their partner to find the matching gall.

You could divide the kits and the class into three stations. Everyone draws one gall. Then have groups shuffle the pictures at each station so the next group can match them up with the galls. Then shuffle the pictures again and rotate to the next station. This way everyone gets to draw one gall, but views all examples.

You might take digital photos of the galls in your kit. Then have children match each gall to a photo.

For K-2, one group of volunteers drew the pictures of the galls in the gall kit and saved them to use for matching as above. They had the children draw their ball galls instead.

What's Inside
The gall contents key can be helpful in figuring out what's inside in some cases.

Let students hold an opened gall up to the light to see how the light shines through the covering over the exit tunnel (i.e. how thin a membrane is left in place).

You'll want to bring a small jar or cup for carrying any larvae you might find out to the bird feeder.

Some students have tried very carefully taping an opened gall back together and keeping it in the classroom until fly emerges.

Gall Hunt
You might want to set up outside stations ahead of time with questions for students to answer at each station (like: this tree has oak canker galls – can you find any? Hint: look up! or Can you find something called a “spruce pineapple gall” on this tree?, or Can you think of a name for this funny-looking gall?).

Find and mark examples of galls with surveyors tape. Then ask the kids to find other examples of each kind of gall. (e.g. Label one spruce pineapple gall; ask the kids to search the tree for others.)

In the city, preliminary investigation by the leader is advisable to locate accessible specimens nearby. If the school location does not contain many plants, conduct a neighborhood gall hunt. You may need to get viewing permission, especially if the galls are in private yards or gardens. Galls may be visible on all sorts of trees (on trunks, twigs or leaves), shrubs, and weeds.

Extension
You can make a funny snack of rice crispy cookie balls with a tick tack mint inside each ball. Or, make chocolate chip cookies with ONE white chocolate chip. Kids must carefully eat to find the larva.

Jen's Gall Song (to the tune of I'm a Little Teapot)
I'm a little gall fly
Searching as I roam
Where to lay my eggs
So my babes will have a home.

This plant will make a gall
Tho it might look rather small
Inside they'll grow
Till time to go And lay eggs of their own.

Learning Goals

Concepts/Ideas

• A gall is an abnormal growth of plant tissue produced by some irritation or chemical stimulus outside the plant itself.
• The function of an insect or mite gall is to provide a home and food for the developing young. The life cycle of the goldenrod ball gall fly demonstrates why the formation of a gall is vital to the insect's survival.
• Galls come in a wide variety of colors, shapes, and textures.
• Each gall-making insect produces a specific kind of gall that usually grows on one species of plant.

Vocabulary: gall, insect, mite, egg, larva, pupa, pupate, life cycle (definitions)

Skills

• Examining and noticing patterns of similarities and differences among individuals of one type of gall.
• Listening and role-playing to understand the life cycle of one gall insect and why a gall is vital to the insect's survival.
• Identifying characteristics of galls through examination of a variety of galls and gall insects.
• Observing many different kinds of galls outdoors.
• Close examination, using a hand lens, of a gall and its living insect inhabitant.

Grade Expectations:
Grades PK-K (S30, S38) Insects are living animals; they need food, water and shelter to live. Some insects live part of their life inside a gall – a growth on a plant that provides food and shelter the young insect needs to survive.

Grades 1-2 (S30, S31, S38) Some types of insects, like the gallfly, undergo stages of development inside a gall – a growth produced on a living plant. The gall serves as habitat where all needs are met for the developing insect. There are many different kinds of galls and gall insects.

Grades 3-4 (S30, S38, S39) Gall insects depend on plants for food, water, and shelter as they undergo development from egg to adult. Gall insects have physical and behavioral characteristics that help them to locate a 'host' plant and lay an egg where it can grow and develop.

Grades 5-6 (S30, S38) A gall is an abnormal growth of plant tissue cells initiated by some outside irritation or chemical stimulus. Each kind of gall insect lays its egg on a specific kind of plant.

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