I disagree with some of the people above who wrote it's not needed.Should I mist an Avicularia Avicularia and if so how often and much ?
Smart point, as the OP didn't specify."Misting" is fine if you're doing it to provide some water droplets on the webbing or side/top of the enclosure for drinking occasionally. But if you're doing it for humidity reasons it's a waste of time as it evaporates too quickly to be of any use...for that just stick with a nice big water dish for avics.
I hate quoting people and just saying +1 or same here but +1and same here..I disagree with some of the people above who wrote it's not needed.
I've owned and raised Avics for many years. While I generally tell people "misting is for plants not tarantulas" IME with Avics this is not always true for some reason. I provide them all a water dish for them to drink out of. However for reasons unknown to me sometimes they "forget" for lack of a better word that fresh water is available. Yet if I mist them or add water, they readily drink from web canopy or container sides. I suggest if you are going to manually add water to apply w/a syringe and not to mist them. Primarily because misting freaks them out, and the droplets are small. Most of it will evaporate before the T can use it. But if you are able to put nice large droplets in the Avic canopy, that will last longer. Sometimes if the canopy is thick enough you can form a small pool of water which they will readily drink from.
Sometimes they simply won't drink from the dish, or are sporadic about its use. I have 2 juvi Avics (2-4") that always use their dish typically, however there have been times where they don't and I must apply water to web canopy with a blunt needle and syringe.
If you are getting a SLING, the best way to keep your Avic hydrated is feeding it a lot and often! Keep their abdomen's plump and provide sufficient ventilation for them.
They key to knowing when is by constantly evaluating their abdominal size and activity level IME.
I've seen some Avics not eat, didn't drink from their bowl but after drinking readily take a cricket after a day or two.
I STRONGLY suggest you read up on Avics before you own one. They are not as easy as they typical terrestrial.
Read this reply, questions, ask back here http://arachnoboards.com/threads/avicularia-husbandry.282549/#post-2461399