Riboflavin transporter. Riboflavin transport is Na(+)-independent but pH-sensitive. riboflavin(in) = riboflavin(out) Activity is strongly inhibited by riboflavin analogs, such as lumiflavin and lumichrome. Optimum pH is 5. Expressed in intestine. Highly expressed at L1 larval stage and to a lesser extent in adults. Down-regulated by high levels of riboflavin. RNAi-mediated knockdown causes a severe reduction in the number of laid eggs; the few laid eggs fail to hatch. Belongs to the riboflavin transporter family.