Hello Lynne,
Ask youself this question..."would I live next door to these resident's?"
If not then how can I excpect anyone else to do so.
I have had this situation come up several times over the years. It is never easy to tell grown people "clean your room". However, it is absolutely necessary that you take action, otherwise you will end up losing your good residents.
First I would look at your lease. Our TAA lease states that it is a violation to interfere with the health and comfort of the neighbors. You may also get tips from your pest control provider and attach them or include them in your notice.
I currently inspect each condo every 6 months. I give resident's one week notice so that they are not surprised. I let them know it is a brief walk thru to check the smoke alarms, a/c filters, plumbing for leaks etc. Of course I look at the general condition as well.
I follow up with a letter of commendation for those that take care of their home. Occassionally I have to remind some to keep a fresh battery in the smoke alarm or replace a dirty a/c filter. If a home is dirty or has excessive clutter I remind them that this is a potential pest control problem and schedule another inspection within 1-2 weeks. This can be effective if you follow through. I did have one resident that had a very cluttered place with a dreaded roach infestation (it happens quickly).
Her first lease was about to end. I advised her that if she did not comply we could not renew her lease and she would be asked to move. Rather than clean her place she moved. If you ask someone to move in the middle of a lease documentation is even more vital. (Use your camera!)
Of course if maintenance or the pest control provider notice an issue they let me know so I can notify the resident immediately.
Take Care
Helene