This new Methods journal paper from Hudson & Cooley on Drosophila oogenesis includes discussion of in vivo RNAi. Table 1 for example lists relevant Gal4 drivers useful for (among other things) RNAi-based interrogation of germline or somatic tissues in the fly ovary.
Hudson AM, Cooley L. Methods for studying oogenesis. Methods. 2014 Jan 16. pii: S1046-2023(14)00006-1. PMID: 24440745.