Hive Activities in March
March comes in like a lion and leaves as a lamb. Or something like that! It’s more the opposite with honeybees. They start off slow and quiet but by the end of the month are roaring strong and mighty like a lion.
This is one of the things I like about honeybees, how they are a combination of opposites. The hive dark, noisy and crowded while they need the sun for flight. For the bees their interior life is about sharing food, trophallaxis, and chemical communication. Once outside they rely more on the other senses we are more familiar with: sight and smell. At the height of summer they take the whole sky to fly in.
But at the beginning of March they are mostly stuck inside.
Significantly the ratio of brood to adult bees is reversed from the beginning of March to the end of the month. At the end of February into the first week of March there are approximately twice as many adults as brood. By the end of March into the first week of April there are two times as many brood as there are adults.
Brood is a beekeeping term meaning immature bees: eggs, larva, and pupa.
The incredible explosion in brood means that the next big hurdle for a honeybee colony to overcome, after having made it past the dangers of Nosema and starvation, is Chalkbrood.
Chalkbrood is a fungal disease that affects the brood. The spores of the disease colonize the digestive system of the developing bee with the hyphae quickly branching out to infect the whole insect. Either just before or during pupation the brood turns hard and slightly crumbly like a piece of chalk with a white, grey or black body and a yellow head.
The fungus has a non-sexual reproductive stage and a sexual reproductive stage. One can tell by the colour of the dead brood; white is the non-sexual reproductive phase, which turns grey or black when the spores are in a sexual reproductive mode. Whatever the colour the dead brood are shedding tremendous amounts of spores into and throughout the colony.
The large brood area is difficult for the nurse bees to keep sufficiently warm. The chilled brood doesn’t get cold enough to die but cool enough for the fungal spores present in the hive to germinate and take hold.
There are several vectors for the establishment of the disease in a colony. The spores are taken to flower blossoms by infected adults, who rarely die from the disease, to be picked up by bees from other colonies that feed it to the developing brood mixed in with pollen.
The other vector is beekeeper error. We open hives and examine frames of brood too early in the season, chilling the brood just enough for the establishment of the spores in bee larva.
Susceptibility to Chalkbrood is said to be a genetically heritable trait so many beekeepers will requeen if a colony seems to have a large or frequent problem with this disease.
In case you like to write letters the farm’s official address is:
P O Box 300021, 12051 No.1 Road, Richmond BC V7E 0A6
Chalkbrood wasn’t a problem for honeybees until the 1970’s when all of a sudden beekeepers started noticing it. Emerging from the research on this new disease was the indication that perhaps it actually started with Osmia lignaria (AKA the Blue Orchard Bee).
It is considered a low-pressure stress induced disease. On occasion it reaches levels that cause an economic impact but most colonies most of the time are able to recover from this infection.
Update on Nosema
In the most recent BeeScene our provincial apiculturist Paul Van Westendorp wrote that feeding pollen to bees at this time of year can actually increase the intensity of Nosema in a colony as well as increase the number of bees that become ill.
Older bees eat the pollen to stimulate their hypopharyngeal glands to feed larvae. This can also weaken those bees and make them more susceptible to Nosema. I personally would have thought that feeding the bees would give them a chance to empty their guts of Nosema. Which I suppose is true except that they do so in the hive with the result of spreading the disease to other bees.
The standard recommended practice of automatically feeding pollen patties to colonies to stimulate brood rearing should be reconsidered in light of the research finding that Mr. Van Westendorp is reporting on. Hives that may be sick with Nosema should be allowed to forage for their own pollen while possibly being fed a medication in sugar syrup.
March is when we can first go into the hive a little at first. In the first week feeding sugar syrup is okay if the hives are short on supplies.
On a warm day when the bees are in flight we can pull out a frame next to the brood area to see their progress. What we are looking for are frames of honey. If there are none readily available to them either consider moving a few closer to the brood frames or begin feeding if there isn’t honey.
The Blessed Bee way isn’t to automatically feed sugar syrup or pollen patties. Bee health comes first. Syrup and pollen patties aren’t the best things but sure beat starvation. As beekeepers we sometimes take missteps and do not calculate what our bees need to overwinter and use during uncertain spring weather. Should we be dogmatic and absolutely refuse them food even though the fault is ours and not theirs? Or should we recognize these food shortages as a learning opportunity for us to do better? I think you can guess my answer.
March is Monitor Month
A few Varroa mites in the colonies now, left unchecked and unknown means the hives will be overrun in a few months. Instead of honey production you will be raising sick bees and a healthy Varroa mite population.
Varroa mites double their population every 22 days. That fact alone is scary enough but their reproductive dynamic is more complicated and much more rapid within the process of doubling. This simple chart below illustrates very well how quickly a few mites can reproduce, increasing by 10 fold from an original 100 mites.
One foundress mite is able to raise on average 1.45 mites in a worker brood cell and an average of 3 mites in a drone cell. The chart below assumes an average of 1.4 new mites per worker cell and that each mite is able to reproduce twice. Each sexually mature female can in fact go through 4 reproductive cycles but this is reduced to 2 for illustrative purposes.
The mite reproductive cycle takes roughly 12 days with 7 days in between.
100 mites March 1st
140 + 100 mother mites = 240 by March 20th
336 + 140 (original foundresses died)
= 476 mites by April 8th
666 + 336 (2nd generation of foundresses dead)
= 1002 by April 27th
A ten-fold increase in approximately 58 days.
Drone production in colonies starts in late April, which accelerates Varroa mite reproduction significantly.
From “The Honey Bee: Around and About” Celia F. Davis, pg 71, Bee Craft Limited, 2007
The economic action threshold in the spring is 1%. When monitoring one needs to take action when the number of mites found equals 1% of adult bees tested. Because of their reproductive rate over 1% maybe too late for effective action: at 2% the Varroa population maybe already too high for any meaningful response. A 2% infestation rate in the spring does not seem too many but is a reflection of how many more are out of reach in cells reproducing; nearly all of them are in cells.
What the Varroa mite does is not only stress bees out, shortening their life spans, making them less than effective and forcing them to quickly move from one life stage to the next, mites have made relatively benign diseases very deadly. Mites have turned the honeybee’s life and the job of keeping bees upside down and inside out. Understanding the bee/mite/beekeeper dynamic is central to being a successful and sustainable apiarist.
One of the easiest tests to use at this time of year is the 24 Hour Natural Drop. Clean your screened bottom board. Use a sticky board with a rubber grid over top for the bees to walk across if the bees have access to it. There are new designs out now which have the bottom board isolated from the rest of the hive that consequently do not require a sticky board. Clean the board; 24 hours later check it for the number of mites that fall off bees.
This is a very rough test, giving only a vague estimate of what might be going on in your hives. When NMD (Natural Mite Drop) levels are increasing every time you check your bottom board from mid-February on, as soon as weather permits do a more thorough and accurate test such as an alcohol wash.
Later in the month when things are really warming up, hopefully, brood frames can be removed briefly to look for diseases and other problems.
Mason bee houses and nests can be placed outdoors at the beginning of the month. At the end of the first week of March is when I release my cocoons: ideally on a warm, sunny and calm day. Days like that seem to be few and far between in March, or have been the last few years; I got tired of waiting for the perfect day and now release my bees ahead of that in expectation they will sort it out. To date I have as much success with that method as I do with any other means.
The occasional sad and stressed out bumblebee queen is found in gardens starting in February.
The major season for bumblebee emergence is early April, timed with dandelion and willow bloom. The bees we see now are out of sync with bloom period. They probably choose an inappropriate location in which to overwinter and heated up too soon.
Frequently we see these queens in greenhouses and other structures that warm up faster than the outside. Because of the chill in the air and a dearth of forage they will not survive.
Soon though the main emergence period will begin for bumblebees.