OK, I’ll try to remember that.
You might find it more successful to carefully observe your terrarium (who eats what etc.), and try different things to see what works and what doesn’t.
Except that I take big risks (at least in the case of a species for which we have little information on the diet) because it can attack many other individuals in the terrarium.
it may be that this ground beetle is a generalist targeting germinating seeds underground.
And what about seeds from plant waste?
I also wonder about their consumption capacity in relation to the size of the seeds.