Honeybee brood encompasses all developmental stages of the honeybee except the adult form. Specifically, it includes the egg, larva, and pupa stages. For domestic bees, the brood is mainly found inside the beehive. This brood is critical to the colony’s future since it represents the next generation of bees that will mature into workers, drones, or the mother queen bee.
Brood and adult bees, each with distinct roles, together form a powerful unit working in harmony. The vast number of individual honeybees living cooperatively enables the colony to endure and prosper even in challenging conditions. This makes it essential for beekeepers to thoroughly understand how the brood and colony operate. Without this knowledge, managing or raising flourishing honeybee colonies is nearly impossible. Thus, examining the brood comb is unquestionably a vital part of beehive management. In this article, we will explore how to recognize and study brood comb, also known as brood cells.
Defining Brood Comb and Methods to Recognize It
In simple terms, the brood comb refers to the beeswax cells where the queen bee lays her eggs. These cells are crucial to the honeybee colony as they hold the developments of the upcoming generation.
Brood combs are constructed primarily on the lower section of a beehive, in contrast to honeycombs which are usually found in honey supers. Nurse bees, which are young worker bees, tend to the brood cells. These developing bees require carefully regulated temperature and humidity. Therefore, worker bees are tasked with keeping these conditions steady; failure to do so risks the brood dying. Instinctively, worker bees cluster brood combs into a single area to simplify their care duties.
The brood comb contains brood at different life stages including eggs, larvae, and pupae. Every honeybee develops through these three phases and has a relatively brief lifespan. On average, it takes about 16 days for a queen bee to mature from egg to adult, while workers take approximately 21 days, and drones about 24 days.
The queen bee lays one egg in each cell of the brood comb, which the worker bees have pre-cleaned and sanitized. Fertilized eggs develop into worker or queen bees, whereas unfertilized eggs hatch into drones. These eggs are tiny and can be difficult to spot with the naked eye. Beginners might require a magnifying glass to identify them effectively, as mentioned in beekeeping guides for novices.
The queen generally selects cells for laying eggs at random, placing eggs in any available cell during her free time. Beekeepers typically control this behavior by using a queen excluder to restrict where she can lay eggs.
Worker bees fill each egg-containing cell with food for the developing young. After hatching, the larva feeds on this provision and grows. When the larva is ready to transform into a pupa, worker bees seal the cell with a thin, translucent, papery cap. Inside, the larva spins its cocoon, pupates, and eventually emerges as a young bee by chewing its way out.
Characteristics of Brood Comb
The appearance of brood comb changes with its age. Newly made brood combs are white or pale in color and are used for raising the first generation of brood. Over subsequent years, these combs darken to yellow and then develop a deeper hue. Brood combs reused many times eventually become quite dark, with the oldest combs often turning black.
Several factors contribute to the darkening of brood combs. Initially, leftover cocoon residues from brood development are sticky and cannot be fully cleaned by worker bees. Additionally, debris and dirt adhere to the sticky remnants as bees’ feet transport particles onto the combs. Layers of propolis also add to the darkening effect. Finally, frequent visits by nurse bees as they tend and feed the brood contribute to the combs’ gradual darkening.
Additional Cell Types Within the Brood Nest
The brood comb for workers and drone bees differs visually. Worker brood cells are uniform with each other, while drone cells stand out by protruding from the comb due to their larger size.
Another noteworthy brood cell type is the queen cell or comb. These are constructed when the colony needs a new queen. Various triggers can stimulate queen cell formation, such as an aging or ill queen, or if the current queen dies.
The presence of a capped queen cell should alert the beekeeper. It often signals that the current queen is preparing to swarm, taking about half the worker bees with her. It may also indicate the colony is getting ready to relocate. When you observe a capped queen cell, which resembles a peanut shape and stands out from the comb surface, prompt action might be necessary.
Distinguishing Brood Comb from Honeycomb
As mentioned earlier, brood combs house developing honeybees at various stages. Conversely, honeycomb refers to the cells used for storing honey. Together with wax, honeycombs help provide insulation inside the hive. Honeycombs are typically situated above the brood combs so honey remains easily accessible to young bees.
Honeycombs are hexagonal cells built by worker bees for storing honey. Beekeepers harvest these combs to extract honey, often using a honey extractor. After extraction, these combs can usually be reused, which enhances colony productivity. Before honey extraction, the wax capping on honeycombs is removed with an uncapping tool.
Over time, beekeepers have enhanced their honey extraction methods. Typically, damaged combs are repurposed to create foundations that guide bees in comb construction. These foundations feature smaller hexagonal cells designed to promote the building of worker cells rather than drone cells.
Honeycombs come in two forms: capped and open cells. Open cells generally contain nectar that has yet to be converted into honey or honey that still requires processing. Sealed or capped honeycombs usually hold treated honey. A simple method to check if honey is fully processed is to invert the honeycomb frame—if honey drips out, it indicates the honey is not yet treated by worker bees and isn’t ready for harvest, as it still has a high water content.
Capped Brood vs Capped Honey
Capped honeycombs are found near the top sections of the frames. These serve as the colony’s honey reserves, sustaining it through periods of scarcity. The capped combs cover the upper area and extend toward the hive’s corners.
If a hive lacks capped honey, it signals a critical food shortage threatening the bees. This shortage means the colony requires supplemental feeding. Sometimes, this scarcity can arise unexpectedly—for example, during summer when unfavorable weather prevents foraging bees from flying out.
Beekeepers should feel pleased when they see capped honeycombs, as this reflects the fruits of their effort. However, honeybees don’t store honey for human use—the seasonal cycles drive honey production and storage. Thus, it is crucial that beekeepers avoid over-harvesting to prevent starving their bees.
Honey production begins when worker bees collect nectar from flowers and deposit it into honey cells. They then fan their wings to reduce nectar’s water content to about 20 percent or less, turning it into honey. Once sufficiently processed, the honey cells are capped to guard against contamination. With its low water content, honey remains stable without spoiling or fermenting.
Capped brood refers to cells containing larvae or developing bees beneath them. Regardless of whether the brood is queen, drone, or worker, the cells are capped once the larvae have grown substantially and are about to pupate, after feeding on nutrient-rich provisions from nurse bees.
Worker bees seal brood cells using a translucent, papery substance. Following capping, the developing larva spins a cocoon, completes its pupal development, and emerges as a young bee. Unlike drones and queens, which receive assistance from nurse bees, young worker bees chew their way out of the capped cells on their own.
The presence of capped queen cells indicates the colony is preparing to swarm or has already swarmed. Therefore, hive inspections should include checks for these peanut-shaped protrusions. Prior to winter, worker bees often fill empty brood cells with honey in a process called “backfilling,” helping cushion the colony during harsh weather. These capped cells also support the hive’s insulation.
Differences Between Brood and Honey Cells
Once you learn to recognize their characteristics, brood and honey cells are straightforward to tell apart.
Key distinctions between brood and honey cells include:
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Brood Cell Patterns
Brood cell patterns differ based on the type of bee developing within. For instance, worker bee brood cells are flat and aligned with adjacent cells. They are yellow-capped and usually occupy the middle to lower areas of a comb. Recently laid worker cells have a lighter yellow tint. In contrast, drone and queen cells protrude from the comb surface, are larger, and appear to bulge.
Recognizing Healthy Brood Patterns
Brood combs consist of densely packed, round cells housing eggs, larvae, or capped brood, depending on the queen bee’s recent activity within that area. Any irregular brood pattern could signal problems with the queen or larvae.
Indicators of healthy brood include:
- Dense central brood blocks on frames containing eggs, larvae, and capped brood. Occasional empty cells may be present, serving as space for heater bees. Healthy brood regions tend to be surrounded by honey and pollen cells, aiding brood management.
- Clusters of cells of identical type and age in one area suggest a healthy brood with uniformly developing young.
- Pollen cells typically sit above brood cells, with honey cells above the pollen, collectively forming a rainbow pattern on the frame.
- Healthy brood cells feature smooth, slightly convex wax cappings.
- Well-laid, properly spaced eggs reflect a healthy, active queen. If you cannot spot the queen but see a consistent egg pattern, the colony remains in good health.
- Larvae reside in uncapped cells, making this stage vulnerable to diseases. Healthy larvae appear white and shiny.
- The presence of brood in various developmental stages—eggs, larvae, and capped brood—is a clear sign of colony health, especially during warm seasons. However, during winter, such diversity in brood stages is normally absent.
Recognizing Diseased Brood Patterns
Signs of abnormal or diseased brood patterns include:
- Spotty or patchy brood coverage, often indicating colony illness.
- Misplaced brood cells that disrupt the expected rainbow pattern formed with pollen and honey cells.
- Brood cell cappings that appear sunken rather than raised, a symptom of disease presence.
- Disorganized egg-laying by the queen suggests a weak or unhealthy colony. While eggs may be hard to see for novices, a magnifying glass helps examine them, though experienced beekeepers often do not require one.
- Uncapped brood cells that show a darker to brown hue usually indicate disease. You may also notice dead larvae, signaling a severe disease outbreak within the brood. A large number of dead larvae is especially concerning as it suggests widespread infection. This differs from occasional findings of one or two dead larvae, which can happen and is considered normal.
- If only developing drone brood is present without any worker brood, it suggests that the colony is unhealthy. This condition may result from the queen bee being dead or ill and unable to perform her duties effectively.
- During peak season, the absence of brood at various development stages or brood that looks unusual for the time of year indicates disease. It’s crucial to understand the expected brood pattern corresponding to each season to identify abnormalities.
Note
It is normal to find some empty cells scattered throughout the brood area, but these should not be mistaken for unhealthy brood cells. These empty cells serve a purpose for heater bees that crawl into the space to warm the brood by fanning their wings and vibrating their abdomens, generating heat. Heater bees will leave these cells when temperatures rise. Specifically, the temperature inside the brood area should be maintained between 91 and 96 °F (32 to 35 °C).
Conclusion
Honeybees build brood combs within the frames, and beekeepers must understand the various types and patterns of brood and combs. Experienced or knowledgeable beekeepers can easily identify diseased brood combs. Additionally, assessing your brood combs during regular inspections provides reassurance that your brood is healthy.
A healthy brood comb shows a generally uniform foundation pattern across the frame. Any irregularity in the foundation pattern is a warning sign that might indicate brood disease. Honey and pollen combs also follow consistent healthy patterns, including brood cell capping as noted earlier. Any irregularity in brood combs should be addressed immediately because neglect may result in colony loss, such as the disappearance of future bee generations. Diseases might also spread to adult bees, which can be fatal.