The "Big and Scary" bug shown in the July 18-24 issue of New Scientist is a Dobsonfly, and even though the questioner spotted it in Costa Rica, you don't need to go to the tropics to find them. An even larger one, at least 7 inches long, landed on the side of my house a few years ago in Front Royal, Virginia, USA, which is in the Blue Ridge Mountains. Shocked and awed, I peered at him through my dining room window. Lacking a camera, I grabbed a tablet and drew him to scale, as best I could, shading with the side of a pencil to try to portray his eerie, gossamer, translucent, and weirdly long wings. My drawing stumped the pest control rep who routinely checks our house for unwanted bugs: he thought I had made the thing up to freak him out! After a month of showing the picture around, I finally found someone who recognized the Dobsonfly. I was told that my proximity to the Shenandoah River, numerous creeks, and karstic terrain, made the area hospitable to this "fly." You can find pictures on the internet -- some of them much larger than the ones both I and the Last Word questioner have seen.  best regards, julie savell-mccandless, Front Royal, Virginia, USA