American beech (Fagus grandifolia) is a native North American tree that has two obligate parasites which are often found on it simultaneously: beech blight aphids (Grylloprociphilus imbricator), a seasonal insect, and beechdrops (Epifagus virginiana), an annual flowering plant. While there is literature on both parasites and their relationships to American beech, we found no studies on the interaction between them. Our study aims to collect data on the presence, abundance, and frequency of occurrence of both parasites on individual beech trees and to investigate the relationship between them. Specifically, we focused on how the presence of beech blight aphids affects the abundance of beechdrops parasitizing a host tree during the year of aphid infestation and the following year. We sampled six random modules and surveyed the same 35 beech trees (paired samples) in a mature mixed-species forest in Shallow Ford Natural Area, Alamance County, North Carolina, during late summer and fall of 2024 and 2025. Within our study site modules, we found that 46.7% of beech trees had beechdrops in 2024 while 60% had beechdrops in 2025. Aphid infestation dropped from 10% of beech trees in 2024 to 0% in 2025. There was no significant difference in beechdrop abundance on infested versus uninfested trees in 2024 (Wilcoxon rank-sum test, p = 0.146). Only two trees were infested with aphids in 2025 and both lacked beechdrops, precluding within-year statistical comparison. However, both previously infested and previously uninfested trees experienced marked increases in beechdrop abundance from 2024 to 2025, with the largest gains occurring on previously infested trees (previously infested, W = 5.00, p =0.001; previously uninfested, W = 0.00, p = 0.005). Our data suggests that aphid infestation may have delayed, indirect effects on beechdrops, with higher abundance appearing the year after infestation.
