Grasshoppers have three body segments, they are called: the abdomen, the thorax, and the head.
head,thorax,abdomen
11-12, That's what Wikipedia says anyway on the Insecta page.
A hornet have 18 body segments (excuding appendages segmentations).
The answer to this is probably a little more complicated than you may expect. The egg hatches into a larva which, like the worm-like ancestors of insects, has 19 body segments. Each segment has the...