Infection of midgut epithelia of T. ni larvae at 48 hpi. The midguts of 4th-instar larvae ingesting 50,000 OBs of vAc96null, vAc96null-AC96HA, or vAcBac were isolated and observed under a bright-field (left) or a UV fluorescence (right) microscope. As indicated by GFP expression, infection with vAc96null-AC96HA or vAcBac, but not with vAc96null, was observed.