Hi Rope,
Good looking V. salvadorii - always nice to see a healthy one enjoying its meal. Average humidity in PNG is ~90%, but more in the wet/monsoon season.
A friend of mine had humidity problems with his V. rudicollis, so he hooked up his sink pipes to tubes with spray nozzles and timers on them to spray 3-4 times/day in his caging...he merely hooked the aquarium tubing up along and around door ways and along wall/carpets to hide it...easy to do, not expensive as one would think and easily attainable at Home Depot or other good hardware/supply stores in your area...
thanx for sharing Rope,
mbayless