I really wish I hadn't clicked that link. Ladybugs remind me of bedbugs, and it only gives me a reason to hate them aside from my traumatic experience developing video games for toddlers that taught them how to count using ladybugs. That and their smell....

Anyway, here's how I'd tackle drawing them. I only actually care about the things I can't see insofar as they relate to what I can see. We "draw through" forms like the legs, because they are visible, and therefore we need to fully understand how they exist in space in relation to the other visible forms. The fact that we can't see all of the horrorshow along their underside is entirely fine - we don't need to draw that, because aside from understanding roughly where the legs connect to the body, it has no bearing on the forms we put down. Looking for additional reference (as you did) is helpful for understanding that one point about where the legs connect, but not beyond that.