When should I requeen?
This is a question we get all the time, and unfortunately, it is easier asked than answered….
But there are a few simple (or least simple to describe) assessments that will help you develop the information you need to answer the question.
1. Are there no (or few) embryos (eggs) present? In this case, move a comb with embryos into this colony from another hive immediately. Introduce a new queen as soon as possible.
2. Is there a chewed-wing virgin, or drone laying queen in the colony? Or has a virgin queen been present with no evidence of oviposition for more than 10 day(s)? Get rid of the queen and start over immediately.
3. Are embryos or eggs widely scattered across one or more combs?
4. Is the brood in adjacent cells of widely varying ages, or does the comb contain many empty cells adjacent to cells with brood? Note, this brood pattern or lack of brood may not be indicative of a failing queen if there is an extreme dearth of pollen or nectar. Moreover, a perfectly good queen can also exhibit a brood pattern like this if the colony has been on a big nectar flow – with the bees filling empty cells with nectar before the queen can deposit new embryos in empty cells after baby bees emerge.
5. Are drone brood cells scattered across the comb, surrounded by worker brood? However, patches of drone brood are no cause for alarm.
6. Are there signs of Varroa destructorparasitism or viruses transmitted by Varroa (e.g., DWV) causing brood or bee mortality or morbidity? – this may present as dead or dying larvae, pupae, or more than a few baby bees with phoretic mites (on the bees) or deformed wings.
7.Are there signs of European Foulbrood? Is there evidence of chalkbrood?
8. Is the colony relatively non-productive (compared to other colonies in your apiary, or to the performance of typical colonies in your location during the same season in previous years)?
9. Are there more cells on the comb in the middle of the brood nest full of pollen and honey than there are cells with brood, and there is no obvious environmental extreme that would explain the paucity of brood?
10. Does the colony exhibit objectionable behavior? Is the colony hyper defensive? Or is the colony building swarm cells when the colony is not jammed full of honey and bees?
11. Has the colony attempted to supersede or raised cells previously, yet has not produced a laying queen?
12. Is there a crippled queen present, and though still laying is impaired in movement?
Numbers 1 & 2, above, are the obvious cases for immediate action and you should introduce a new queen and eliminate the old or damaged queen immediately. Introduce fresh eggs/embryos from another hive, if at all possible, right away.
The more of these issues you see the more urgent the situation is. We routinely requeen if we observe any of them. As queen breeders we have the luxury of having ample queens the majority of the year, and the ability to store queens during the winter months in case a colony cannot wait for a queen.