To pluck or not to pluck...

Hello all hope your doing well,

I want n the gh today and noticed how dense the leaves were. And I was hoping I could get some in site on defoliating. I know nothing so all options and opinions are needed. I know there is a lot of controversy over plucking vs not, so let me say I'm not trying to start a virtual fist fight lol. Jus need to know the basics like what should go what should stay and y.
Also what's this bug? Thanks guys lookin forward to your replies...this is a outdoor grow so it's still veg.

The plant is using an enormous amount of energy to produce leaves for a reason.