We have a property in Jamaica where there are land crabs which dig into our lawn which creates a walking hazard. We have not found an effective pesticide yet that will work. Since we are by the sea, we need to be careful of any runoff which could affect the coral and fishes.
Hi, I would be hesitant to think any sort of chemical application would be effective (or even legal?) for the land crabs and yet leave other crustaceans in the nearby unharmed. You might consider some sort of physical barrier to keep the crabs off the property. This approach has been somewhat effective in the state of ME to keep green crabs out of certain areas of the intertidal. A short fence or landscape/ground wall would likely work. A smoother material like wood, and a slight angle away from the property would likely preclude them from climbing.