Why Bees Weaken

This week I want to return to the discussion of weak honey beehives and the underlying causes which I started in my previous blog post linked here: https://www.hamakuabees.com/blog/2020/1/17/nbew5z5ebeaa2hk3fl7d7j5vrvydvf

When I find a weak or failing hive I am sort of disappointed. I usually expect to see busy, bustling hives with thousands of bees. But it is inevitable as a beekeeper to discover that, sometimes, a hive is dying. These are the two main causes of failing honey bee hives.

Queenlessness:

I have previously discussed finding a Queenless hive here: https://www.hamakuabees.com/blog/2020/1/3/checking-nucs

The Queenless hives I have found have less bees than a healthy hive would have. With no Queen to lay eggs there are no new bees to replace the population. In a Queenless hive there is little or no brood. Any brood that I have found in these hives is drone brood laid by a worker which will develop into sterile drone bees.

Varroa Mite on Queen Bee

Queenless hives can occur for a number of reasons. A Queen may die and the hive may fail to develop a replacement successfully. A hive may attempt to replace or kill a Queen that is failing or injured and still fail to develop a new Queen. Bees will usually prepare for this by creating supersedure cells, these are cells designed to raise a new Queen when the current one is failing. These cells look like swarm cells, sort of like peanut shells, but are usually found on the face of the comb. This process is generally effective in replacing a Queen but when it fails the hive may find itself without a Queen. A hive may also be Queenless after a swarm discussed here: https://www.hamakuabees.com/blog/2020/1/10/when-bees-swarm

When the original Queen leaves she lays eggs to become her possible successors and continue the hive. Sometimes these eggs do not become strong Queens. It is also conceivable that the new Queen will swarm again leaving behind no Queen for the hive.

Queenlessness can be solved by a beekeeper by adding a new Queen to the hive.

Varroa Mite:

Varroa Mites are the number one killer of honey bees globally. The Varroa Mite can be found is almost every country around the world. It was first found in the USA in 1987. If Varroa is left unchecked in a hive it will almost certainly kill the colony.

The Varroa Mite is an external parasite of the honey bee. While a Varroa Mite is no more than two millimeters in length is it one of the largest parasites by ratio to its host. To put their size in perspective it would be like a human hosting a basketball-sized tick.

I have found one of the first indicators of Varroa Mite is concave and sporadic brood. The capped brood will have an almost sunken in appearance rather than having the smooth texture of healthy brood.

The Mites feed on adult bee and bee pupae blood. The Varroa Mite is only able to reproduce in a beehive. To reproduce the female Varroa Mite will target larvae which is just about to be capped, that is the cell being covered in wax by a worker bee so the larvae can begin its last stages of pupation. The pheromone which alerts the worker bees to cap the larvae also alerts the Varroa Mite. She will climb into the cell underneath the larvae. Once the cell is capped she feeds on the larvae inside. Then she lays eggs. The first of which is male and it mates with the subsequent female eggs she lays.

When the bee she has infected hatches from the cell it will carry all the female Mites with it. The Mites, then attach themselves to other bees and can rapidly spread throughout a colony. It is possible for the Varroa Mite to kill the larvae before it ever hatches.

Bees affected by Varroa Mites can develop viruses and diseases. One of the most easily identifiable is the Deformed Wing Virus. This causes a honey bee’s wings to be deformed, often forming a K-shape. These wings are useless; The bee will never fly. The presence of Varroa Mites can weaken a hive quickly. They cause death in infected bees and compound the effects by causing no new young unaffected bees to hatch.

The Varroa Mite is more attracted to drone brood for reproduction because the larvae remains capped for three more days on average than that of a worker. Knowing this, I am often instructed, by my beekeeping mentor, to destroy drone brood by scraping the capped brood off of frames.

The Varroa Mite can be controlled by using genetics. It has been found that some bees are more hygienic than others. This means the workers are able to detect mites within the capped cells and remove the infected pupae. A female Varroa Mite only has three chances to reproduce before she becomes sterile. If the hygienic bees can detect and remove her eggs three times she will no longer be able to produce more Mites. When a Queen is producing hygienic workers she may be selected for breeding stock so she can pass on this genetic trait. Using bees which have this genetic trait can reduce the Varroa Mite population by 40-50%. Next week I will discuss my first venture in breeding genetically strong Queens.

Varroa Mites can be treated chemically when their population becomes too much of a threat to the hive. Some of the chemical products of the past such as Apistan and Coumaphos have been over, and therefore, mis-used. The Mites have developed resistance to these chemicals. I have been cautioned to only use chemical treatments when necessary.

As a beekeeper apprentice it is important I understand the many ways the health of bees can be affected. I am learning to combat them to ensure there are strong honey bees in the future.

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