A Quantitative Survey of Goldenrods and their Galls in Greencastle, Indiana.

During the spring to summer months, galls—an abnormal growth of plant tissue—are commonly found on goldenrod plants. Some of the most common galls that plague goldenrods are the rosette, ball, and elongated galls caused by different flies and midges. This study set out to quantitatively survey goldenrod galls of those three types in Greencastle, Indiana and their potential fitness effects. The literature currently available focuses heavily on the relationships between ball galls and goldenrods, while the other gall types are understudied. This finding was especially surprising considering that the results of our data analysis suggests that the rosette galls were the most popular— with the difference being significant across sites.