Why not the same idea with lasers, if you have an array of low power lasers but they all focus on one 3D location, if you are not at the focus location you will not be exposed to a dangerous laser power. An array of hundred to a thousand low end laser diodes using a an array of mems mirrors to aim the beams will ensure the focus point will fry the bug.
At that point you're deliberately removing the collimation and I'm not sure how much the coherency really adds so you might as well just focus a heat lamp on them.
It's still bad if it somehow does end up targeting something delicate or flammable but at least you've gone from a line to a point. Plus a 500W laser is super pricey but you can pick up a 500W heat lamp at the local hardware store. I wonder if anyone's tried it?
