If I pay my adult son, as contract labor in my catering business, he earned less than $3000.00, do I have to issue a Misc- 1099?

Yes, if your business pays a contractor over $600, you must issue a 1099-Misc.

The link below pertains to children who work for their parents.

https://taxmap.irs.gov/taxmap/pubs/p15-002.htm>