design: Total RNA for small RNA library preparation was extracted from  30 embryos and 20 1st-instar nymphs for each biological replicate. Embryos were collected over a two-day period spanning the initial stages of embryogenesis up to the formation of head and thoracic segments 58. Two biological replicates were produced for each developmental stage. Ovaries were dissected in ice-cold 1X PBS and immediately stored on ice. Previtellogenic tissues and mature eggs were teased apart under light microscopy and subjected to total RNA extraction using Trizol Reagent (Invitrogen) as per manufacturer's instructions. For the production of small RNA libraries, 20 g of total RNA was separated on polyacrylamide gel containing 15M Urea (Pane et al., 2011). A gel slice corresponding to 18 to 30 nucleotide RNAs was manually retrieved from the gel and the RNAs were eluted in 3M NaCl overnight. Finally, RNA was precipitated using 0.7 volumes of Isopropanol and 1 ul Glycogen and resuspended in RNAse-free water. Small RNA library preparation and sequencing were carried out at the Max Planck Institute facility in Freiburg (Germany) with Truseq Small RNA library preparation kit as per manufacturer's protocol (Illumina). Total RNA extracted from 1st instar nymphs was also used to produce and sequence RNA-Seq libraries (Macrogen, Korea).