Lighten up your guide drawing and then draw the details of the face. We'll give the eyes a simple, standard insect eye pattern. Just use criss-crossed lines to indicate the detail of the eye. If you're up for it, you can instead draw lots of tiny dots to show the individual lenses, but leave a bare spot where the light reflects off the eye. The mouth is made up of four beak-like shapes. They meet up in the center to form something of a + or plus sign shape, if that makes sense. Don't forget to draw the antennae. I made them a bit thick and gnarled, but you can draw them thinner if you wish, with just a couple of nice curves.