Scheduled meetings should begin on time. Do not wait for late comers unless it is a client or boss. Waiting for late comers is rude to the individuals who arrived on time and sends a message that it is all right to be late to your meetings.
If you maintian a reputation of starting your meetings on time, participants will get into a habit of arriving on time.
I once worked for a boss who locked the door once the meeting began. It was rare anyone arrived late to one of his meetings.