C6/36 cells (Aedes albopictus mosquito larvae) were maintained in Earle's MEM supplemented with 10% fetal bovine serum (HyClone), 2 mM L-glutamine (Invitrogen), and 1 mM non-essential amino acids. Vero cells (African green monkey kidney) were maintained in Opti-PRO™SFM medium (Invitrogen) supplemented with 4 mM L-glutamine (Invitrogen).