Honey bee colonies rely on stored nectar and pollen during periods of scarcity known as dearth. Dearth occurs when there is a shortage of nectar-producing flowers, and while the most well-known dearth happens during winter, many regions also experience a summer nectar dearth. This is a hot and dry period between the flowering seasons of spring and autumn.
The summer nectar dearth often goes unnoticed by new beekeepers as the world appears green and flowers seem abundant. However, not all flowers produce nectar accessible to honey bees, and even among those that do, factors like low rainfall and extreme heat can reduce the nectar yield.
The summer dearth can be more devastating to honey bee colonies than winter. It can lead to the destruction of a colony at a faster rate. Unlike winter, when colonies have time to prepare by increasing their food stores and reducing population, a summer dearth strikes when bee populations are at their highest. Large colonies with a significant number of active bees require a substantial amount of food. They can quickly deplete their stores, particularly if the beekeeper has already harvested honey.
In times of dearth, bees may engage in unwanted behavior due to desperation. One common problem is nectar robbing, where strong colonies attempt to steal the food reserves of weaker colonies. Once robbing begins, a colony can be stripped of its food, leading to fighting, death, and even the killing of the queen. Additionally, the smell of open honey attracts predators such as yellowjackets and bald-faced hornets, which further decimate the weakened colony. Even a strong colony can be destroyed if workers from another strong colony gain entry. Multiple hives may join forces and overpower even the strongest colony, so careful observation is essential.
Nectar robbing can also result in the transfer of Varroa mites from the robbed colony to the robbing colony. Colonies previously unaffected by mite problems can suddenly become overwhelmed by mites brought back with the stolen honey. This phenomenon contributes to the rapid collapse of strong hives in late fall. The number of mites in a colony is heavily influenced by external sources, and robbing is a significant source of mites.
So, what can beekeepers do to address a summer dearth? The first step is to recognize when a dearth is occurring. Observing the local flora and considering the signs mentioned in the post “How to recognize a nectar dearth” can help with identification.
Once a dearth is recognized, several actions can minimize the damage it causes:
- Feeding syrup during a dearth is a double-edged sword. While it can prevent starvation if the colony is low on stores, it can also attract robbers. If feeding is necessary, avoid using entrance feeders that signal easy access for robbers. Instead, opt for internal or enclosed hive-top feeders that minimize spills and drips.
- If there is a strong nectar flow in autumn, feeding bees during the summer dearth can have advantages. It helps maintain higher colony populations, as the queen restricts egg laying when nectar stops coming in. A larger colony entering autumn will be better equipped to capitalize on late nectar flows.
- Essential oils and additives like Honey-B-Healthy should be avoided during a dearth as they can attract bees from far away. Bees should have no trouble finding syrup within their hive.
- Reduce entrances to the hive to minimize the risk of robbing. Consider using robbing screens for small or weak colonies.
- Close upper entrances during a dearth to make it easier for bees to defend their hive. Use screened inner covers or an eke with screened ventilation ports if upper ventilation is necessary.
Photo by Dmitry Grigoriev on Unsplash