Saturday, April 29, 2017

La Nina Beekeeping

     The La Nina weather pattern is cooler than average sea surface temperatures in the Pacific Ocean (3-5 degrees C.) resulting in colder temperatures and above average precipitation for us in Vancouver.  We have experienced these conditions through the winter with record snowfall in the local mountains and this weather pattern has continued through the early part of spring.

     As beekeepers we are always acutely aware of the temperature and rainfall and it's effects on our bees foraging particularly in the early spring.  This is a time of great potential brood development with the fruit trees in blossom (pollen) but because of the wet, cool spring both brood development and fruit production will suffer this year.  Although our bees will collect pollen and nectar at colder temperatures we don't get major colony foraging until it's 12 C. (53 F.) and sunny.  In Vancouver we have positive and negative honey bee food accumulation months.  This will vary on your specific location but for our urban apiary the positive months are April 1 through to October 1 with March and October dependent on weather conditions.  This year both March and April were negative.

        How does this effect spring beekeeping management?  For those who supplement their bees' diet feeding of both carbohydrates (sugar) and protein or protein supplement (to stimulate brood development) will be more important.  Keep in mind that below about 12 C. (54 fahrenheit) the bees won't take a liquid syrup as they are unable to process it (Feeding Bees in Winter).
       In order to carry out spring management we must assess the health of our hives.  Many sources (mostly southern) will insist you cannot inspect your frames until 15 C. (60 fahrenheit) for fear of chilling the brood.  Some northern beekeepers would have to wait til well into May for this.  Bees are hardier than most people think.  Peeking briefly into a hive during winter on a non snowy day to assess the food supply is fine as is inspecting the brood at 10 C. (50 fahrenheit).  Use common sense and minimize exposure.  This from the Huron City Bee Company in Michigan,
"How cold is too cold to inspect my hive?"
I hear this question quite often at this time of year. Let me just say, I was late one year and needed inspection papers to transport my hives. So, one January morning, at 28 degrees, the state inspector and I opened the hives and inspected brood frames VERY quickly. The result was no detectable loss of brood. We didn't stand around, and we didn't chat while the hives were open. We worked smoothly, so as to disturb the cluster as little as possible. And we closed them up as quickly as we could.
On the other hand, I've helped with inspections on a 70 degree day, where the beekeeper took out a frame of brood, stood it up and chatted for 20 minutes about what they found. Then later complained about chilled brood.  See where I'm going with this?  Go in, do what you need to do, and then get out quickly.  However, I want to temper this advice with another question. If you DO find something wrong, what's your plan?  Here in Michigan, it's 42 degrees right now. I wouldn't hesitate to pop open the hives. But, to what end? It's too late to replace a queen if I find one failing. The only thing I can do at this point is combine, and even then, they may remain clustered instead of merging.  The take away message is not to be afraid of opening the hives. But, if you have no courses of action if you find something wrong, why bother?"  I think this is a good year-round philosophy.  I go into my hives with a specific purpose and only when required for responsible colony management.
       For us in Vancouver that means we should be able to do a full inspection by March to assess the queen performance (brood pattern), presence of disease (continued excessive bee poop on hive) or mites (small hive beetle has arrived - Honey Bee Diseases and Parasites) and food supply (B.C. Government Spring Management).  Some of the spring beekeeping chores are: The cluster should be in the upper super so reverse the brood boxes; maintain a reduced entrance to prevent robbing or mice visits; optionally equalize the colonies by adding frames of bees of a strong colony to a weaker colony (Equalization of bee colony strength); cull your old foundation if you do so (Replacing brood comb); swarm prevention (checkerboarding, splits ... ) ;  maintain good ventilation and empty your bottom board of dead bees and debris.  In this article Randy Oliver and Dr. Medhat Nasr (Alberta Provincial Apiculturist) discuss the benefits of early season mite control through the formation of nucs with queen cells and the treatment of those nucs (Early Season Mite Management).
       I have been warned of the presence of nosema in some of this year's New Zealand packages.  Whether that is true or an attempt to boost the sales of fumagillin it's always a good idea to watch for signs of nosema (difficulty digesting food).  Nosema is difficult to diagnose without laboratory equipment (Nosema Assessment).  Some suggest a nosema infected midgut will become swollen, whitish and lose it's visible constrictions (a healthy midgut is tan with visible constrictions) but that is also true of other causes of dysentery.  Symptoms that may suggest the presence of nosema are the lack of population buildup as nosema infected bees tend to skip the nurse bee phase and become young foragers, dying at a young age.  Desperate they will forage at cooler temperatures and will not take syrup if fed.  This from Randy Oliver, "Perhaps the most noticeable effect of N. ceranae infection is the lack of population buildup of infected colonies, due to the premature death of infected foragers. Of interest is that nosema-infected bees tend to forage at cooler temperatures. Woyciechowski (1998) suggests that infected bees may engage in more risky foraging behavior, perhaps sensing that they do not have long to live. Additionally, infected bees may simply fly off to die, exhibiting an “altruistic suicide” to help prevent the infection of nestmates (Kralj 2006).  Another symptom, reported by several, and described by Bob Harrison on Bee-L, is that of bees not taking syrup, and then massively drowning in division board feeders. Bob feels that the symptom of going “off feed” is a good indicator for N. ceranae infection, which can be reversed with a drench of fumagillin syrup.  The drowning behavior may have an explanation in a recent paper by Chris Mayak (2009), in which he found that “N. ceranae imposes an energetic stress on infected bees, revealed in their elevated appetite and hunger level…. infected bees attempt to compensate for the imposed energetic stress by feeding more…” Mayak suggests that such hungry, nutritionally stressed bees, exhibiting risky foraging behavior, might play a role in the depopulation of infected colonies."
        Due to the cool, wet La Nina weather plant development (blossoming) and our swarm season will be delayed by a few weeks.  Other aspects of beekeeping like split creation and queen and local nuc availability will also be delayed.  Also, it appears the price of nucs has risen this year to $225-$250.  The delayed blossoming of plants may create a stronger late season September-October food supply for our bees.  The Weather Network predicts a cool, wet spring and a warmer summer than last year.  "Some years there are strong signals in the global pattern that allow for higher confidence in a seasonal forecast, but unfortunately this is not one of those years. During the next few months, one of the keys to our final summer forecast will be the strength of the developing El NiƱo and whether the warmest water remains just west of South America or whether the warmest water shifts west into the central Pacific."  The La Nina weather pattern can last for a few years but hopefully it will be replaced soon by the warmer El Nino phase.  We'll keep our wings crossed.


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