If you can, repeat the dosage 3 to 4 weeks later, then any eggs that have hatched will be dealt with. If it is too late in the growing season, then 1 now and then 2 next season should keep them to a minimum if not eradicating them.
For anyone with only a few plants or when buying plants, I would recommend washing all soil off the roots to make sure there are no mealy or eggs there.
Good luck with them.
Lithops,Cacti,Conophytums,Tylecodons,Sempervivums and Sedums