Goldenrod Galls

These images show white growths (called galls) on the stems of plants and the internal structure of a gall. The relationship of egg-laying causing a plant response that in essence allows the plant to continue living and creates a habitat for sustaining the fly life cycle. The fly life cycle is dependent on the plant as the adaptation allows overwintering in the plant stem. This is a unique symbiotic relationship that is easily seen in prairies, remnant prairies or road ditches in the fall through winter and even into the spring. 

• Why do some of these plant stems look different?

• What makes a bulge in a plant?
• How does the fly grow while inside the plant? 
• How does the plant continue to grow while the fly grows inside?

Students could:

• Discuss symbiotic relationships and insect life cycles
• Investigate a wasp or fly life cycle to expand on existing knowledge about butterfly lifecycles. 
• Share if they have a parent or grandparent that goes ice fishing, and if so, they know that the “grub” or larva is often used for bait.
• Symbiosis is incredibly fascinating for young children to explore.

• Cornell Institute for Biology Teachers | Goldenrod Galls: More information on goldenrod galls.
• iNaturalist | Goldenrod Galls: Another article on goldenrod galls for teachers.
• ThoughtCo | Mutualism: Symbiotic Relationships: Article about symbiotic relationships.