Alien bug...?

Question:I was in my garden picking some of my swiss chard. (chard is a leafy vegetable, sort of like spinich but larger leaves) on one of the leaves was some bubbly foam. I went to wipe it off and realized swimming around in the bubbles was this tiny alien looking bug. It was the strangest bug I had ever seen. It was sort of yellow colored and had big green eyes. Anyone have any idea what it was???

Answers:
well, what sort of bug did it look like? a fly? a beetle?