In certain cases, yes. An instructor is not required to report the incident or take any action if, in his/her professional judgment, the student's conduct should be dealt with outside the Honor Code as an academic or administrative matter, and the conduct is so dealt with promptly. Many students may not be fully aware that their actions constitute plagiarizing or cheating and may benefit from an instructor discussing the incident with them one-on-one and giving them an opportunity to fix their approach. This can be a teaching moment that can greatly benefit the student. If you believe an official warning is warranted, you’ll need to submit an official report so the warning can be recorded and referred to if there are additional instances of academic dishonesty in the future.
If you need help in discussing the matter with a student, you can contact Student Conduct, Rights & Advocacy for assistance.
If you believe the student’s conduct is particularly egregious and deliberate, and is deserving of sanctions, it is recommended that you formally submit a report.