Malcom Sanford, an Extension Apiculturist in the Department of Entomology and Nematology at the University of Florida and Roger Hoopingarner, a Professor in the Department of Entomology at Michigan State explain why some beekeepers choose to kill off their colonies in the fall rather than care for them over the winter:
The other option is to kill colonies in the fall, extract and sell most of the honey that would have been consumed during the winter months and start with package bees the following spring. This appears practical since the 60 or so pounds of honey that would have been consumed by an over-wintering colony more than offset the cost of the package of bees. The labor savings seen also support the conclusion that using package bees has advantages. When analyzed more completely, however, the cost savings from selling honey that would have been used in winter may be offset by the reduced success rate of colonies started from packages. Package bee colonies may also have reduced value in pollination and honey production as compared to an overwintered colony (Sanford & Hoopingarrner, 748).