A Study of Golden Rod Galls Mrs. Paparella SWCSD Living Environment 2015

Tall Goldenrod Solidago Altissima This is the species of goldenrod that we find the golden rod galls growing in. This site will take you to an online key to identifying the different types of gall contents. Solidago Eurosta Galls Main Page

What are goldenrod galls? A ball-shaped growth in the stem of the goldenrod plant Formed in the Spring when the female goldenrod gall fly lays her fertilized eggs in the stem of the plant.

Gall Fly Facts Adult gall flies live about 2 weeks They do not eat 5 mm long Males< Females Lives on the goldenrod plant Males attract females with a dance Female uses her ovipositor to imbed her eggs into the stem of the goldenrod plant

Organisms in this Food Web

Gall Fly-Golden Rod Parasitism The egg hatches in 10days and forms fly larvae. The saliva of the larvae has a chemical in it which causes the plant to grow into the ball-shape. The larvae digs an escape tunnel for next Spring and then returns to the center of the gall to live for an entire year. The plant growth actually provides food and shelter for the larvae to grow and develop into the pupae. Chemicals in the larvae act like an antifreeze for them to be able to survive the cold winter.

Gall Fly Parasitic Predators 2 parasitic wasps seek out the goldenrod galls Wasp #1Eurytoma obtusiventris Wasp #2 Eurytoma gigantea These wasps lay their eggs in the gall and then their larvae eat the gall fly larvae and use the already built escape tunnel in the Spring! We will be looking for these wasp larvae in the galls too.

Winged Predators of the Gall Fly Carolina Chickadee Downy Woodpecker Red Winged Blackbird Wild Turkey American Goldfinch Ruby Throated Hummingbird Common Yellowthroat

Insect Predators of the Gall Fly Mordellistena Unicolor Beetle Rabid Wolf Spider Goldenrod Spider

Insect Predators of the Gall Fly Daring Jumping Spiders Chinese Mantid Harvestmen

Check for Galls in your Ecosystem Find galls in your fields throughout the winter. Collect some and cut them open and see what you find. Let them warm up and watch the larvae “wake up” from their deep freeze. Look for Galls with holes in them…. What does that mean?? See if you can find gall flies emerging in the Spring.

Resources http://www.facstaff.bucknell.edu/abrahmsn/solidago/main.html http://www.fcps.edu/islandcreekes/ecology/goldenrod_gall_fly.htm