Expression of A2bp1dsRNA.Scer\UAS using Scer\GAL4Bx-MS1096 in the presence of one copy of A2bp1EY01049 causes an enhanced L3/L4 vein phenotype: fusion of veins L3 and L4 is accompanied by thickening of the fused vein, and large patches of ectopic veins are observed in regions beyond L5.