Willows are extremely susceptible to gall induction and growth manipulation and Salix is one of the plant genera with the highest known numbers of associated galler species.

[1] The oviposition of this species results in a chemical interaction that halts the lengthwise growth of infected willow shoots, the leaves however continue to develop and thus the characteristic "rose" forms at the tip of the affected shoot.

The development in the United Kingdom begins in May / June with leaf expansion and reaches maturity in August / September while the leaves are still green.

The gall becomes brown and remains on the tree over winter until it is forced off by new growth in spring.

[5] A 2020 study which analysed the COI gene of mitochondrial DNA extracted from Rabdophaga larvae that induce rosette galls on Salix in the Holarctic Region showed that R. rosaria could be divided into 2 clades, 1 and 2, and the latter further divided into subclades 2A and 2B.