Cloning and injections were performed using established protocols [14 (link)]. A pair of gRNAs designed to delete the region 2R:18,380,931 to 18,391,053 were cloned into pU6-BbsI-chiRNA (Addgene plasmid # 45946). Homology arms (766bp and 840bp left and right, respectively) were cloned into pDsRed-attP (Addgene plasmid # 51019). pBS-Hsp70-Cas9 (Addgene plasmid # 46294) was used as the Cas9 source. Constructs were injected into w1118 flies.