Wednesday, February 29, 2012

Honey Bee Drifting

End of the line effect

     The concept of drifting is that with a number of hives in a row, on a windy day the bees are more apt to return to the first hive from the direction of the main pollen flow.  Consequently the first hive will be much stronger than the last hive.  Dave Cushman suggests the opposite "end of the line" effect (Dave Cushman on Drifting Behavior in Honey Bees).  Dave goes on to describe the drifting effects of  featureless water.

     In any case the disoriented, drifting bees will have an unfamiliar smell to the guard bees but will usually be allowed entrance if carrying pollen and displaying submissive behavior. Ted Hooper in his book "Guide to Bees and Honey" states:

“a drifting bee entering the colony by mistake, perhaps because it has been blown down to the hive by a cross wind, or misled by a similarity of the approach picture, will be challenged. In this case the guard will press the challenge because the smell of this bee is not the right one. The drifter, because its instinct says it is in the right place, will not try to fight the guard but will submit. If the drifter is facing the guard it will offer food, which the guard will usually ignore. If the guard is attacking from the side [...] the drifter will tuck its tail in and stand quiet, with its head tucked down, or it may rear on to its two back pairs of legs, extending its tongue and strop this with its front legs. These patterns of behavior denote submission and the guard [...] will do no real harm and certainly not attempt to sting. As with all bees, the guard’s concentration period is short, and in a few seconds it gets tired of the whole affair and lets the drifter proceed”

     This study found the percentage of drifting bees to be as high as 60% within unmarked row apiaries (Drifting of Honey Bee Foragers within and between apiaries pollinating blueberry) and up to 4.5% in apiaries 600 mts away.  In the study below (Drifting of Honey Bees) they found that there was no preference in honey bee strain when drifting nor decrease in life span.  They did find an increased drift from center (22%) to edge (39%).

Hive setup that could lead to drifting
      The study below suggests that the optimal distance is 9 meters between hives and 18 meters between rows but this is often not possible.  They list ways to reduce drifting by different apiary layout (circles, squares, U, V, Sigmoid), different entrance orientation and different colors.  The idea is that different colored hives will assist the bees in identifying their own hive.

     The idea is that different colored hives will assist the bees in identifying their own hive.  Bees see colors differently than we do and studies show they prefer purple, violet and blue in that order. Bees can see ultraviolet light patterns invisible to us (Honey Bees ability to identify color).

      Why does drifting matter?  Because unless you live in an isolated area there is a good chance your hives contain bees from neighboring hives along with their pests and diseases (Honey Bee Drifting and the spread of AFB).  Drifting can also occur with Queens returning from mating flights (4% Honey Bee Queen Drifting).
       It's like if you are drunk and walking back to your house and all the homes are of the exact color and architectural style.  This is human drifting.  I have personally experienced this phenomena.  This can be very embarrassing.

My house

Tuesday, February 14, 2012

The Other Pollinators

     Although bees are the major pollinators of the world there are many other species involved in pollination.  Insects such as butterflies, moths, beetles, ants and fruit flies are essential for the pollination of specific plants.  Also, many birds pollinate like the hummingbird, honeyeaters and sunbirds.  Other vertebrates like monkeys, lemurs, possums, rodents, lizards and even humans are responsible for some pollination.  In North America desert plants like the agave and giant cacti depend on bats for pollination.  In the tropics bats pollinate a wide variety of plants like cashew, cloves, durian, carob, balsa wood, bananas, avocados, dates, figs, peaches and mangoes.
     In Canada and the United States bats are especially important in the control of the insect population.  A single brown bat can consume 1000 mosquito sized insects in an hour.  As many of these insects damage commercial food crops the presence of bats reduces the amount of pesticides required.
     Bat populations in Canada and throughout the world are declining for many reasons including loss of habitat.  According to Louie Swartzberg, a pioneer of high-end time-lapse cinematography (The Hidden Beauty of Pollination) "beauty and seduction are nature's tool for survival because we protect what we fall in love with".  Although I think bats are beautiful most people don't and it's for that reason they especially need our protection.
     The United Nations has declared 2011-2012 International Year of the Bat.  Visit Bat Conservation International to find out more about bats.

Thursday, February 9, 2012

Varroa Sensitive Hygiene

Varroa mite on queen bee
     The varroa mite is a small mite (approximately 1 mm in diameter) native to Asia and the Asian honey bee (Apis Cerana) which has developed a resistance to the mite enabling it to cope with it's presence. Russian honey bees from the eastern Primorsky territory have also developed a resistance to the mite (The U.S.D.A and Mite Resistant Honey Bees).  Here is a history of the U.S.D.A's Russian Honey Bee Queen Breeding Project (History).

     Over the last 50 years the varroa has spread from country to country having become a major threat in the last decade to both the native and honeybee populations throughout the world.  This blood sucking parasite transmits a number of honey bee diseases (Some of the viruses transmitted by the Varroa Mite).

Worldwide spread of the Varroa mite

     Australia remains the only beekeeping nation free of the varroa destructor mite.  In Canada the island portion of Newfoundland remains varroa free.  
     There are many methods of treating your hives for mites (Varroa Mite controls) such as pesticides (Apistan and Checkmite), formic or oxalic acid,  sugar dusting, screened bottom boards and brood breaks.  Mites have shown a resistance to the pesticides and it's suggested that a combination of methods must be applied.
     I believe the future of dealing with varroa will be breeding for varroa sensitive hygienic (VSH) behavior.  In hives with VSH behavior bees, bee pupae infected with mites are detected and removed.  Other VSH behavior traits include: more effective self grooming; group grooming; guard bees removing mites from bees entering the hive (either killing the mites or chasing them from the hive) and bees using their mandibles to kill the mites.  For a more detailed description of breeding for mite resistance check out ScientificBeekeeping

     In the picture above the bees are chewing on a mite infested bee larvae.   It is important to remember that Asian honey bees (Apis cerana), African honey bees (Apis mellifera scutellata), Africanized honey bees (hybrid European and African) and a strain of Russian honey bees are effectively resistant (VSH behavior) to the varroa mite.  Most bee breeders are breeding for VSH traits including  Glenn Apiaries  which sells VSH queens.
     The video below shows bees displaying some VSH traits such as aggressive grooming and biting. 

     This year  I will be checking my mite test boards for signs of the varroa being bitten (missing legs).  A screened bottom board is a valuable tool for any beekeeper with mites. The screened bottom board allows removed mites to fall out of the hive and as a bonus increases much needed circulation but the alcohol wash or sugar shake will give you a more accurate mite measurement (Mite Monitoring Methods).
     For further information on hygienic behaviour in honey bees go to the Hygienic Behaviour section of our Beekeepers' Library.

Sunday, February 5, 2012

February Bees

     I took this photo yesterday in Cottonwood Garden of one of our girls enjoying what I believe is an anemone.  It was a sunny 8 degrees C. (46 fahrenheit) and the girls were buzzing about, some returning with yellow pollen which probably came from nearby witch hazels.  I spotted a native blue orchard bee (Mason Bee Vancouver) foraging in the witch hazels as well.

Blue Orchard Mason Bee
    There is a number of plants in bloom including hellebores and plum blossoms.  Reading about the folks at Mudsongs who beekeep in St. John's, Newfoundland and their battle with cold temperatures and snow made me realize how lucky we west coast beekeepers are.
     I will finalize my order this week for a few New Zealand Kintail Carniolan hybrid bee packages due to arrive at the end of the month.  That means I will have to get busy and build my screened bottom boards (Homemade beehive) and other assorted hive body parts.  I fed the ladies a few pollen patties at the end of January and will feed them possibly twice more to stimulate brood production. My goal is to build up the hive population early and split the hive in May.  We may get one more cold snap but with any luck I believe our bees will survive the winter.  Good luck to all the beekeepers in cold locations like St. John's.  Spring is just around the corner.

*Bob at West Coast Bee Supplies (604-272-1921) has lots of bee packages available.  His New Zealand Kintail Carniolan bees will be arriving on February 29th at 4:30 p.m.

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