For a start, if it's an insect then it's not a spider by definition Nice shots though.I think it's some kind of thrip or leaf-sucking thing, I'll see if I can find it in my insect book somewhere (and i'm an engineer too), or you can search for some online ID guides somewhere...
Well, engineer here also ... so, I don't know how credible I can be re bugs. Being macro-addict however makes you curious to know about wth you are shooting at (wonder why people have to dive abysses when there are so many weirdos crawling the earth to be observed ... . Your insect could be a woolly aphid but you might want to get confirmation by an expert ... For your ref: http://en.wikipedia.org/wiki/Eriosomatinae - Hope this helps.
Think alot of engineers get into photography? I am one as well but I also believe I know the type of bug this is....whooly aphid!
I could only see six legs, so that would make it an insect, but just to complicate things, some spiders/mites have modified front legs, which are used for other purposes (such as touch, like the antennae of insects), so appear to only have six.