I have slept under a tarp off and on while backpacking for over 30 years. I came back to tarps permanently about 10 years ago or so. I can't see much use in tents except for car camping or long term camping. Tarps are much lighter than tents and can be easily set up to be roomier. I've never had a problem with bugs, even sleeping next to a subalpine swamp. I use a headnet with hoops in it to deal with the bugs when I have to. I've also bought a little mosquito net thingy that consists of one coiled hoop and will cover you down to the waist. I haven't tried it out yet because so far this year, I haven't had any bug problems in the backcountry. It weights 8 ounces.
I've tried a bivy and they are ok if you don't mind being confined and can't move around. After a two-week trek with one, I said no mas.
This is a pic of a 10x10 Campmor tarp that I used for many years. Still looks like new and still waterproof. It's standard weight nylon and still weighs less than half of what my Northface Tadpole weighs or the Sierra Design Flashlight pitched in the background.
Here's a pic of a sil tarp from Campmor I've been using for a couple years. Amazing how well they shed wind and rain. And unlike urethane coated nylon, which is coated on one side only, they don't absorb water, so they don't stretch like ordinary coated nylon.
And here's a couple pics of a tarp I used on my last outing, the Integral Designs Sil Shelter. A lot of protection and it weighs about the same as an 8x10 sil tarp, around 15 ounces. It's held up by one pole, which I cut from a sapling. Alternatively, you can use an adjustable hiking stick.
The sil shelter is probably the ultimate tarp although a regular 8x10 sil tarp is easier to set up and much cheaper. I'm happy with either setup and don't miss the extra multiple pounds of a tent one bit. Bugs I can live with for the lower weight and improved ventilation of the tarp. Only in the worst of bug infected areas would I consider going back to a tent for backpacking. And I haven't found that place yet.
