“Healthy” vs “Strong” Colonies

Relevance, Definitions & Interpretations

A healthy colony refers to one that is free from disease and minimal pest infestations. The population is of a decent size relative to the season and neighbouring hives. Food stores are plentiful and sufficient; a steady stream of foragers come and go with their resource loads.

A strong colony shares the same traits above, dialled up to 100. The lack of pests and disease is a byproduct of the colony’s strength. Population is booming. The nest contains comb filled with brood of all ages due to the queen’s excellent laying pattern. Her Majesty is likely laying over a thousand eggs a day, expanding the hive for the weeks to come. Hive entrance activity is nonstop – loaded foragers land with pollen and nectar and others depart for their next trip. Guard bees patrol the landing board for potential intruders.

I define healthy colonies as those who are getting by “just fine”, whereas the strong ones dominate the landscape with their foragers. The beekeeper’s goal is to maintain healthy colonies and strengthen them- either through supplemental feeding or proper hive placement in an area full of resources. Article’s over, you can stop reading now.

Strong is Not Invincible: Infection & Infestation Risks

Having a strong colony is a not free pass to let them self-manage. Sure, diseases associated with weak colonies like Nosema and chalkbrood can are of low risk. However, a chance infection by American foulbrood or swarming will reduce population sizes. The former is a death sentence- hive material must be burned or irritated to prevent the spread, whereas the latter is an (expected) reduction to colony size.

In late summer, strength may be the colony’s downfall. If a strong colony engages in robbing behaviour and raids one weakened by such diseases or Varroa, the infection and/or infestation returns to their hives along with their purloined products. The case of Varroa isn’t so much “introducing” an infestation, as much contributing to a preexisting one¹. The increased mite population after robbing will accelerate the deterioration of an otherwise-strong colony, unless treatment is provided (which may come with its own issues).

Pesticide Poisoning: Damage Over Time

The strongest colony will succumb to pesticide poisoning if enough bees forage on affected crops. This rapid dispersal is a consequence of natural social insect behaviours: Bees engage in trophallaxis (feeding one another by regurgitating liquids) and allogrooming (grooming one another). This direct contact leads to an exponential dispersal of the pesticide at the colony level.

Pesticide poisoning manifests through the appearance of dead bees at the hive entrance. Different formulations and application methods influence the duration of colony survival, with the general trend showing that many commercial products are lethal to bees and other nontarget organisms. Further, other types of harm can come indirectly from the indiscriminate application of herbicides and fungicides on bees during flowering periods, termed “sublethal” effects.

Hive Defence & Population Size

Main article: How bees defend themselves

When more adult bees are present, there is an increased delegation to “less essential” roles, like guarding the hive entrance. The colony can focus on tasks beyond survival like reproduction and defence.

Middle-aged workers take on hive guarding duties: Walking around the hive entrance, inspecting incoming bees to determine if they’re a nestmate or foreigner. Returning workers bearing the colony’s pheromones are allowed in, those without the scent are denied entry, or (rarely) allowed in if they beg hard enough. Drones come and go– drifting in between colonies of A. mellifera without repercussion.

Guard bees separate nestmate from non-nestmates by their cuticular hydrocarbons. Nestmates will have the same “smell” or hydrocarbons on exoskeleton as the hive, informing the guards that she is a friendly bee. 

When guards spot a predator, such as a hovering hornet, they raise their abdomen and expose the sting chamber along with alarm pheromones- fanning their wings to disperse these volatile components. The compounds signal actual or perceived dangers to the colony, and are released not just when exposing the stinger, but also during stinging, and when the barb is left in your (unfortunately-exposed) skin.

Assessing Colony Strength

At its core, a strong colony is one with a high adult worker population. A large worker population feeds into everything else – more foraging, more brood rearing, better defence, and better temperature control, amongst others. To assess strength:

• Look at the hive entrance on warm days. Are there plenty of foragers returning with plenty of nectar and pollen? The latter is easier to see on their hind legs’ corbiculae
  • Strong colonies assign more guard bees at the entrance against predators and robbers. Resource delegation is plentiful, and the guards are continually present so long as the weather is appropriate.
• Note whether brood frames contain a “good” brood pattern (centre frames filled with brood), and whether the hive stores adequate for their rearing (outermost frames filed with honey/nectar).
  • Is the ratio of drone to worker brood consistent? I once heard that a good ratio is “two drone brood frames per ten-frame brood box”… seems a bit much, yet I have seen this observation proven (and disproven) in several strong hives.
    • Too many drones places the colony at risk of increased Varroa populations due to the mite’s preference to reproduce in the larger comb. Unless you’re a queen breeder, it doesn’t hurt to replace a  capped drone frame with a fresh one. Be sure to freeze the removed frame for several days to kill the mites.
    • Outside of ensuring food stores are adequate, there’s no such thing as “too many workers”.
• Signs of pests and disease are minimal. Varroa and small hive beetles may be present in small numbers. The former will need control eventually, as it is unlikely your strain of bees is Varroa-resistant. Should a disease like Nosema strike, the infected bees could “self-undertake”- voluntary remove themselves to decrease the spread of infection to their healthy kin (Rueppel et al., 2010).

In short, many worker bees and lots of brood makes for a strong colony.

Having Multiple Colonies Assists with Health Classification

By having multiple colonies, you can assess the health of each hive relative to her neighbour. The level of activity at the hive entrance activity throughout the day will indicate which colony is weak, strong, and which is doing “just fine”. All other factors equal, a high degree of activity in cooler morning means that the colony has enough workers to keep the nest warming against the cooler temperatures. Likewise, a large number of bees bearding outside on a hot day means the population is large and bees must be head outside to lower colony temperatures.

Remember, this is all relative – your strongest colony may in reality be slightly above average. How do you assess absolute strength? With experience.

Strengthening Colonies

Main article: Honey bee nutrition

Supplemental feeding is used in:

• Times of food shortages (e.g. summer dearths),
• To administer medicines (antibiotics like tetracycline are dissolved in sugar syrup and then fed to bees) or,
• When a large bee population is required for pollination.

Bees are smart – they will only ingest supplements when there is no floral forage. For now, the best commercial supplements are not nutritious as natural nectar and pollen. Think breast milk versus infant formula. If you find your supplemental feed untouched, then the bees are likely on a nectar flow, receiving superior food from the environment.

Making the Right Sugar Syrup Feed

Below are examples of sugar syrup formulations according to the season:

• In spring & summer, a 1:1 sugar to water solution is used. Ensure that the final solution is warm to touch (~35°C) before being fed to bees.
  • This mix mimics the sugar concentration of natural nectar and provides bees with the required energy for brood rearing and wax building.
• In autumn and mild winters, a thicker solution of 2 parts sugar to 1 part water is used. Prepare this by dissolving sugar into warm water, ensuring that the serving solution is warm to touch (~35°C).
  • This mix is ideal in the colder months as it allows bees to access carbohydrates without increasing the hive’s moisture content.
• For colder winters, a candied sugar, fondant, is used. This consists of 4 parts sugar to 1 part water with lemon juice added to prevent sugar crystallization. The solidity of the fondant provides bees digestible sugars with a minimal moisture content. Placing the fondant on the top bars/near the cluster reduces the chances of individual bees freezing while extracting it.

In times of natural pollen shortage, supplements are available in the form of pollen patties made from a such as soy flour, brewers’ yeast, sugar and vegetable oil (e.g. Ghramh & Khan 2023). Soy is used as a has a superior amino acid profile when compared to wheat or rye – it is 40-50% protein by weight, compared to the 10-14% of wheat. Brewers’ yeast contains a balanced amino acid profile, as well as vitamins (specifically B- vitamins) and minerals. Sugar is added for additional carbohydrates. Combining the yeast with the flour and vegetable oil, forms the basic pollen substitute that provides brood with an alternative protein source to bee bread.

Maintaining Colony Strength

While you can follow the above to conserve colony strength, natural nectar and pollen are superior. If there’s a drought or period of extended dearth, by all means, continue supplementing- it’ll reduce the risk of colony sickness and prevent them from absconding due to unfavourable conditions. Remember, this is a supplementary not primary source of food.

From Sickness to Health: Curing Disease

The first step in disease treatment is inspection. Know your enemy. Look for signs of disease like irregular brood patterns, discoloured or deformed bees or foul odours (AFB!). If in doubt, send a sample to your agricultural department‘s laboratory for a definitive diagnosis.

Once you know the condition, get treating:

• If it’s a Varroa-mediated disease, consider chemical treatments like flumethrin, or mechanical controls like capped drone brood removal.
• Nosema can be treated with the antibiotic fumagillin, provided in sugar syrup. Alternatively, bees can overcome it in warmer weather when they can defecate outside.
• European foulbrood can be treated with the antibiotic tetracycline, or through the shook swarm method of rehoming bees.
  • If it’s American foulbrood, tough luck – those colonies need to be burned or irradiated as no treatment exists against these hardy bacterial spores.
• Chalkbrood thrives in damp conditions, so increase ventilation and reduce moisture building (e.g. by adding insulative material on the top bars).

General approaches include requeening to boost colony population and supplemental feeding as addressed above. Preventative methods for all diseases revolve around minimising stress and good beekeeping practices. Avoid overcrowding, replace old and contaminated comb (rule of thumb: every three years) and don’t inspect too often, or too aggressively. But you already know that, don’t you?

Does this Mean Healthy Colonies are Bad?

I harked a lot about strong colonies, and not so much on healthy ones. Does this mean that having “healthy” colonies is a bad thing…?

Yes. Yes it does. You want your hives strong to withstand diseases, pollinate crops and make honey. “Healthy” implies average, and an average hive will provide average results.

If you are a natural beekeeper and decline supplements, then make sure hives are located in areas with plenty of seasonal forage and sheltered from weather extremes; ideally in a north-facing position. These guidelines are applicable to all beekeepers. However, I emphasise them for those utilising the natural approach as antibiotics or sugar syrups are not given to help a struggling colony.

“Healthy” is a human term. In nature, the strong triumphs, and the healthy walks in their shadow.

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Footnotes

1. If one colony in your apiary has mites, it’s only a matter of time before the others have it… Unless you live in an area where there no known mite populations (at the time of writing, it was outside the state of New South Wales… now? Who knows, it’s only a matter of time, assume all colonies have Varroa. ↩︎