These are your butterflies for NJ -- Click on your county to narrow the butterfly species that have been seen in your area.
Swallowtails winter over as chrysalis in your area. When fall comes they produce a type of antifreeze. Some butterflies winter over has caterpillars. Some as adults. They are hiding. Don't clean up your yard too much in the fall and wait until late May to do major cleaning. Many are hanging on perennials and shrubs or in the leaves on the ground.
There are some butterflies that do a partial migration south. Some of them are: Painted Ladies, Red Admirals, American Ladies, Buckeyes, Cloudless Sulphurs, Variegated Fritillaries.http://www.butterfliesandmoths.org/spec ... w%20Jersey
Eastern Tiger Swallowtail. I have chrysalis now of the black form tiger swallowtails. I am hoping they do not emerge until spring because it is getting cold here, too. If you raise butterflies, you must leave the chrysalis in a cold area to winter over or they will emerge. The "Life History" section tells you what they do in the winter.
Hope this helps.