I've no idea who built this, but the orange stripe strikes me as a warning to potential predators. I believe this is an egg mass rather than a single egg or larva. I also suspect some sort of Lepidopteran...
I'd always wondered how lacewings create those pretty little clumps of eggs where individual eggs sit at the end of a delicate thread. Here you can see the process in two photos. In this photo, there is already a cluster of eight eggs near the bottom of her wings. The lacewing is beginning the process of laying her next egg. She has bent her body so her ovipositor touches the substrate (in this case, tree bark). And you can see, she is releasing a silk-like thread that is stuck to the bark. My guess is that the thread starts as a liquid and hardens on contact with the air. As she straightens her body, the thread lengthens... The little cluster of eggs she has already laid seems to be a bit tangled. But I've never seen this when I've found lacewing eggs, so I assume they separate once she has finished. (See the second photo)
In this photo, the lacewing has lifted her rear and is releasing an egg that will stay suspended at the end of the thread. It looked to me as if she had a belly full of eggs. But typically, I see lacewings eggs in clusters of under ten or twelve. So she likely lays clutches at several different locations.
