I have an endless battle with vervet monkeys in Zimbabwe. Not only fruit, but vegetables, too - especially carrots. Last year they destroyed entire guava, pawpaw, mullberry, granadilla, banana and orange crops, alongside entire crops of brocolli, caulieflower, carrots, pumpkin, gem squash, butternut and some very hard to find (here) "heritage" tomatoes. There is only one solution and it is very expensive. You have to cage everything you grow in chicken wire. Shade cloth is hopeless. They just bounce on it until it breaks. If you resort to a shotgun, you'll get no criticism from me. They will also take poultry, given half a chance. Most of the food taken isn't eaten - they take one bite and throw it away. I now have a troop of baboons vnturing closer by the month and no doubt the chicken wire will prove too flimsy. Forget rubber snakes, forget flashing lights or loudnoise. They soon become habituated to anything that doesn't kill them. By the way, they don't take lemons or lettuce!