What is a Nuc?
Simply, a Nucleus (Nuc), is an established, fully functional colony in a smaller box. Typically 5, deep frames.
A Nuc has:
- drawn comb
- full spectrum of population (nurses, guards, foragers, etc)
They're an established colony - just in a smaller, easier to handle box. As such, chances for success for new beekeepers are much higher when setting up for the first time. But, they do cost more and are usually available only later in the season (June). Because they include drawn comb, they can also carry 'hidden' problems. Such as mites in brood cells, disease or other unseen issues.
Yes, nucs sold for the establishment of new hives are often in cardboard boxes. The cardboard will have a plastic coating for strenght and moisture. They're adequate (Not as heavy as wood) for shipping and limited exposure to weather conditions. They are not expected to be used to house a colony for anything longer than shipping.
Wooden Nuc boxes are often used for queen rearing. Cell builder, Finishing and mating nucs are quite common in queen production. Wooden boxes, just like normal hives, need a good exterior finish to survive conditions for many years. One of the caveat's of wooden nucs are their lids. It's typical to have a 'migratory' style lid. Meaning it overlaps on the front and back, but is a simple butt edge on the sides. Often made of plywood, it's not at all unusual for these lids to warp, leaving large gaps at the tops of the box. Earlier in the season, this can lead to a dead nuc if things turn cold or wet, unexpectedly. I've been known to add a 1/8" thick, 2" wide strip of wood to the sides of these lids to prevent problems. (inclimate weather, robbing, etc.)
Introducing a nuc to a full size hive is a trivial matter of simply moving the frames - in the same order - from the nuc box to a full size box. Often this can be done as a 'cluster' of frames, instead of individually. Doing so with the brood nest helps to prevent disturbing or injuring your queen. And then dumping any straggler in the nuc box into the new hive. Add frames to either side of the nuc's frames to fill the box. Done!
One of the very real disadvantages of a Nuc is it's incompatibility with non-Langstroth hives. If you start a Top Bar (traditional), you'll have to cut the brood out of the Nuc frames and figure out how to attach them to your bars. Similar problem with Warre hives. It's much easier and likely as effective to start non-Langstroth hives with a package, instead of a Nuc.