[219R]

That is the plate that covers the hole that the oil screen resides. The screen is a round tube shaped part about 3" tall, maybe 1-1/4" in diam. kinda gets the big stuff floating in the oil. The Big Bolt next to it is, of course, the oil drain plug. If it is just a very small film of oil I wouldn't worry about it.
If it is a bother, you can remove the plate, clean the screen, and reinstall using a really good sealant, like Yamabond or equal. Or take it to a Dealer for the next oil change if so inclined.

 

[219R]

Pat has been a long time contributor to this Forum, since 2008/2009, when it was Ducati-Spot...And really a backbone to the membership. His insights to all things Ducati has been an inspiration, and over the years we have shared many posts. He is a valued member.

On another note,.. Glad to see you back Velocemoto, Aussie_Bob....... Life is good.

 

[219R]

^^ Not with a ten foot pole,.... not even mine!!!