Neonicotinoids and Varroa mites force the extending of longevity in a bee colony during overwintering to forget.

A mathematical model that can estimate the apparent longevity of bee-colony proposed previously clarified the following normal seasonal changes in longevity: The longevity remains almost constant from late April to late September in 20-30 days, after which it continues to extend until the end of wintering, reaching 160-200 days. Just after overwintering, the longevity is shortened almost vertically from one sixth to one tenth. Such normal seasonal changes in longevity are shown when a pesticide-free food is administered to the bee-colony and when pesticide-containing sugar syrup is. However, abnormal seasonal changes in longevity, which does not extend even if winter approaches, are shown for the bee-colony ingesting neonicotinoid-containing pollen and for the colony infested with Varroa mites. Judging from the fact that pollen is the main food for the bee-brood, that mites parasitize larvae and pupae, and that the vital functions and organs of honeybees are created during the larval and pupal stages, it can be inferred that a neonicotinoid-containing pollen paste and parasitic mites cause serious damage to the bee ability to detect the arrival of winter. Such dysfunction in the larval and pupal stages probably interferes with extending the longevity of adult bees even as winter approaches.