The paper
A. Korgaonkar et al., “A novel family of secreted insect proteins linked to plant gall development,” Curr Biol, doi:10.1016/j.cub.2021.01.104, 2021.
In spring, an Hormaphis cornu aphid foundress injects saliva into a witch hazel leaf, coercing the plant to grow an elongated cone-shaped growth that encloses her. Inside this structure, known as a gall, she feeds and asexually reproduces. After a few weeks, the gall opens and the mature offspring fly to river birch trees, which host several generations of aphids that don’t produce galls before the cycle begins again with a new foundress generation.
Galls come in all manner of strange shapes and colors, each unique to the insect species that creates them. Exactly how gall-producing insects reprogram plant physiology to develop these abnormal structures has mystified scientists for centuries, says David Stern, a biologist at the Howard Hughes Medical Institute’s Janelia Research Campus. Wandering the woods one days, ...
