Yes, there are some species of crickets which are known to use the regurgitation of foods and the release of bad tasting body fluids to keep from being eaten. Acanthoplus discoidalis, the Armoured Ground Cricket of south and central Africa, is one cricket that will spit up its last meal if grabbed by a predator and it will squirt a foul tasting body fluid "insect blood' out of the joints in its legs as well. It can squirt the greenish blood up to 3 inches if disturbed.
Studies have shown that the foul liquids actually work as both birds and lizards that grab one of the large crickets and get some of the fluid in their mouth, will quickly release the cricket. They also will pass up crickets which already have some of the fluids on them.
No, our native, meaning North American, crickets do not regurgitate or spit up a dark fluid when caught or disturbed. Gryllus sp., which are the most common field crickets and Acheta domesticus, the house cricket, do not use spitting up as a defence mechanism. This is why they are secretive and tend to be nocturnal unlike grasshopper species. It is also why those two types of crickets are the ones raised for feeding insect eating pets like lizards, geckos, some snakes, and spiders. They don't produce any noxious chemicals to make those pets sick or dislike them and they don't produce any spit to stain the hands of those who handle them.
...Hi,
no species spit tobacco like grasshoppers, I was about to mention a few of the other cool mechanisms they have but I saw that you already mentioned them.. :)
Good look with your research!