it is a good idea to wean your dovii off the live feeders as soon as possible, start feeding it pellets rather than feeders, sooning or later it will take them.
how large is your dovii?
I have the same problem. I bought a little guy for $4.00 and he wont eat anything buy live. I keep him with a giraffe cat and sometimes he'll go after pellets, but wont eat em. Eventually i'll get tired of guppies and he'll have no choice to switch......or die.....
It shouldn't take to long for him to switch when you dont' give in and give feeders. Just make sure that if you are going to keep offering pellets you are taking the uneaten ones (which may be all of them ) out so that they don't pollute the water. When weening the big boys off of live foods I like to let them go two days without food being offered at all (if they've refused it) instead of wasting food on them and adding waste to the tank. Hikari and Omega One are expensive enough as it is