What's happening to our honey bees?

I wrote this article while working for USU Extension. Thought it was appropriate to share here. 

What’s happening to our honey bees? 

By Alicia Moulton                                                                     

Honey bees are on the decline throughout the world.  Here’s why.  

Honey bee Colony Collapse Disorder is a complex matter with many contributing factors that have compounded over time.  These factors put “an enormous burden on the immune and detoxification systems of bees, eventually ‘putting them over the edge’” (Spivak and Reuter, 2007^a).  Scientists have assigned the name “Colony Collapse Disorder” as a placeholder until its nature can be identified. 

Factor 1 As we grow in population, we see a decrease in green, open space and an increase of buildings, roads, and other structures.  This means there are fewer plants for bees to forage for food sources.  Bees do best when there is a variety of pollen and nectar sources with flowers continuously blooming all season long.  Farms often grow one crop type each year.  This means fewer plant species and shorter periods of time when plants are in bloom.  

To help bees, plant a garden with a variety of flowers, fruits, and vegetables which bloom throughout the growing season.  It is also a good idea to leave unmown, herbicide-free strips of land for bees to seek refuge in if you do have to spray.  Choose strips of land that do not contain noxious weeds, as the noxious weed law says weeds on the noxious weed list must be controlled.  Removal of several of these weeds requires herbicides.  

To help bees you can also teach your children the value of bees.  Bees pollinate many of the fruits and vegetables we like to eat, and flowering plants we like to see in the landscape.  They also produce honey, wax, and royal jelly.  Teach them the difference between bees and wasps (See Table 1).  Bees have stout, hairy bodies and are not usually aggressive towards people.  Wasps have smooth bodies with a constricted waist, and are often found scavenging near garbage or picnics.  Sometimes wasps can be aggressive and will sting people.  Remember that while wasps are annoying if they nest around your home, some are considered predatory and beneficial insects.

Factor 2 Crop pesticides used to reduce pest insects can also kill beneficial insects like bees.  Many pesticide applicators are aware of declining bee populations and use chemicals with low toxicity to bees where ever possible.  However, a new class of systematic pesticides moves through plant tissue to reduce crop pests.  These can add to stress on bee immune and detoxification systems because the pesticides may be present in pollen and nectar (Spivak and Reutar, 2007^a), which are bees’ primary food sources.  

To help bees, minimize insecticide use by only spraying when necessary.  Be sure to read all pesticide labels for proper application directions.  There may be several insecticides used for the same pest.  Choose products least harmful to bees.  Also, avoid insecticide use while plants are flowering to minimize bee kill.  

Factor 3 Beekeepers are seeing depressed local honey markets.  To make money, beekeepers ship bees all over the country to fill pollination contracts for almonds, blueberries, cranberries, etc.  The number of acres of these crops is increasing faster than number of bees used to pollinate them, which causes pollination contract prices to increase.  These crops require large numbers of honey bee colonies for pollination.  For example, over 1 million bee colonies are required for California almonds in early spring.  Having large numbers of bees in small areas puts nutritional stress on bees as they compete for pollen and nectar.  Increased movement for pollination leads to disease transfer.  “Shipping bees for pollination is like sending your kids to school,” said one beekeeper, “They come back with all the sicknesses around.”  

To help bees, buy local honey.  If beekeepers make more money locally, they may not need the extra money from pollination and can leave their bees home.  Local honey is fresh, delicious, and it gives a warm feeling to know that you are helping local folks and getting a good product.  Also, you can ask the beekeeper directly how honey is handled and if chemicals were used in production.  Buying locally can create more sustainable agricultural systems.  

Factor 4 Bee diseases and parasites are often present in honey bee hives. Over time, colonies can become weakened or less productive. Diseases contributing to colony collapse disorder are not new, but have been affecting bees for a while.  

Varroa mites (Varroa destructor) were introduced in the U.S. in the 1980s.  These mites attach to bee larvae and parasitize bees, living on the outside of the bee’s body.  They are relatively large compared to the bee, about 1/6^th of the bee’s body weight.  To eliminate varroa mite infestations, beekeepers sometimes put insecticides (pyrethroids and organophosphates) in the beehive with the bees.  Mites are becoming resistant to the insecticides and beekeepers risk residue build-up in beeswax and honey (Spivak and Reuter, 2007^b).

      

The varroa mite is also a possible vector for several honey bee viruses, including Acute Paralysis Virus and Israeli Acute Paralysis Virus.  These viruses can severely weaken bees and makes them more susceptible to other diseases (Bakonyi et al., 2002).  

Acute Paralysis Virus and Israeli Acute Paralysis Virus eventually cause paralysis in honey bees.  Bees are found dead outside the hive.  Both viruses contribute to Colony Collapse Disorder of varroa mite-infested colonies.  

Nosema apis and Nosema ceranae are internal parasites that cause nosemosis, or acute diarrhea, in bees.  Honey bees are generally very clean insects and defecate outside the hive.  Nosemosis causes them to be so sick they cannot make it outside to defecate.  Thus, spores from fecal matter are able to infect other bees in the hive.  Nosema is what causes complete disappearance of bees in the hive.  

Foulbrood and chalk brood are spore-forming bacterial diseases which infect honey bee brood (Hansen and Brosgaard, 2003).  Without proper sanitation, foul brood can weaken or kill a colony in one season.  

Honey comb infected with Foulbrood                                  Healthy Honey comb

                           www.usda.gov                                          http://www.pbase.com/beekeeper/bees

Nosema species, foul brood and chalk brood spores can be stored in old wax combs for years.  Therefore it is important for beekeepers to remove old wax combs from hives. These can contain disease spores and pesticide residue. 

Beekeepers are fighting these diseases using innovative strategies and by developing genetically resistant lines of bees.  For example, some bees exhibit “hygienic behavior,” in which worker bees detect and remove 95% of diseased brood from the comb before hatching (Spivak and Reuter, 2007^b).  Bees which exhibit hygienic behavior detect and remove varroa mite, Nosema and Foulbrood-infected larva.  Queens can pass hygienic behavior to their offspring.  This means beekeepers can select for this trait and make their hives more resistant to disease!  

References:

www.extension.umn.edu/honeybees. University of Minnesota Bee Lab

Bakonyi, T., E. Grabensteiner, J. Kolodziejk, M. Rusvai, G. Topolska, W. Ritter, and N. Nowotny. 2002.  Phylogenetic Analysis of Acute Bee Paralysis Virus Strains. Appl. Environ. Microbiol. 68(12):6446-6450. Available at http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=134446. Accessed May 21, 2008. University of Minnesota.

Cranshaw, W. 2008. What is a Wasp-Hornet-Yellowjacket-Bee?  Available at http://www.coopext.colostate.edu/4dmg/Pests/whatis.htm. Accessed Sept. 25, 2008. Colorado State University Cooperative Extension, Entomology.

Hansen, H. and C.J. Brosgaard. 2003. Control of American foulbrood by the shaking method. APIACTA 38:140-145. Available at http://www.apimondia.org/apiacta/articles/2003/hansen_1.pdf. University of Minnesota Bee Lab.

Vetter, R. 2002. Identification Guide for California Yellowjackets. Available at http://wasps.ucr.edu/waspid.html. Accessed Sept. 25, 2008. University of California Riverside. 

Spivak, M. and Reuter, R. 2007^a. Why are honey bees collapsing? Available: http://www.extension.umn.edu/honeybees/components/03-26-2007_whycollapsing.html. Accessed Sept. 25, 2008. University of Minnesota Bee Lab.

Spivak, M. and G. Reuter.  2007^b. A Sustainable Approach to Controlling Honey Bee Diseases and Varroa Mites. SARE Fact Sheet #03AGI2005. Available  http://www.sare.org/publications/factsheet/0305.htm. Accessed May 21, 2008. University of Minnesota Bee Lab.

Queen Bee

We found this photo of a queen bee in Grandpa’s files and wanted to share. Can you spot her? Queen bees have a longer abdomen and are larger than the other worker bees present. Here you see her laying an egg in a cell of honey comb. 

Bees vs Wasps

We often get calls for swarm removal. Before heading out, we like to make sure the colony we are dealing with is honey bees and not wasps. Here are some of the major similarities and differences between bees and wasps. 

In this photo, you can see bees and wasps drinking from the same sugar syrup, which we spilled outside the hive. 

Bees

Belong to order Hymenoptera

Females raise young on a diet of pollen and nectar.

Hairy-bodied and hairy-legged (helpful for collecting pollen)

Honey bees build nests out of wax and fill the wax comb with honey.

Honey comb

Honey bees do not actively seek to sting people unless they feel threatened.

Females play a major role in plant pollination.

When bees sting, their stinger remains in the skin because of one-way barbs on the stinger.  Stinging kills the bee.

Two Categories of Bees:

1. Social bees

2. Solitary bees

Social bees produce a colony.  Examples include honey bees (Apis Mellifera) 

Honey Bee 

and bumble bees (Bombus spp.).  Bumble bees annually establish new colonies. 

Bumble Bee

Solitary bees individually create colonies underground or in a soft substrate.  Examples include leafcutter bees (usually Megachile spp.) and digger bees.

      

Leafcutter bee (and crab spider)

http://www.ext.colostate.edu/pubs/insect /05576.html

Wasps

Belong to order Hymenoptera

Young develop as a predator or parasite of other insects or are scavengers.

Smooth-bodied and smooth-legged

Social wasps build paper nests.

Baldfaced hornet nest

http://www.ipm.iastate.edu/ipm/iiin/bbaldface.html

Wasps can be aggressive in late summer, when their diet changes to sweets.  At this time, they may sting more frequently. 

Males play a minor role in plant pollination. 

Wasps can withdraw their stinger to sting again.

Three Categories of Wasps:

1. Parasitic wasps

2. Solitary hunting wasps

3. Social Wasps 

Parasitic Wasps lay eggs in or on other insects.  Young usually kill the host.  Females have a long stinger for laying eggs.  They are non-aggressive and if they do sting, it causes little pain. Parasitic wasps are considered beneficial because they kill harmful garden and crop pests.

Parasitic wasp

http://www.ipm.iastate.edu/ipm/icm/node/462

Solitary hunting wasps create rearing cells in some sort of nest.  Females paralyze prey to provision nest cells, then lay eggs in the cells and seal them.   Nests are made by digging into soil, mud nests, and piths of hollow plants. Examples include Sphecidae and Pompilidae families.  Sphecidae hunt insects and have a mild sting, Pompilidae hunt spiders and have “the most painful sting of any insect” (Cranshaw 2008).

      

Solitary hunting wasp (digging wasp)

http://aggie-horticulture.tamu.edu/ galveston/beneficials/

Social wasps (family Vespidae) most often sting humans.  Social wasps establish colonies annually and die off each fall, leaving a few fertilized queens for next season.  They make paper nests from chewed wood pulp.  Examples are western yellow jackets (Vespula pensylvanica) and hornets (Polistes and Mischosvttarus spp.).  Adults feed larvae chewed up prey and larvae secrete a sweet substance, which adults enjoy. 

Yellowjackets conceal nests out of sight, like in children’s playground equipment or fence posts.  They feed on insects and scavenge sweets and proteins.  They can be a nuisance at picnics or around uncovered garbage cans.

Yellowjacket

http://www.cals.uidaho.edu/edcomm/pdf/BUL/BUL0852.pdf by Neil Miller

Hornets sting humans less often than yellow jackets, but are more readily observed because they build large paper nests in trees or under house eaves.  Hornets primarily feed on other insects and don’t frequent outdoor meals.

                

Bald-faced Hornet

http://www.coopext.colostate.edu/4dmg/Pests/whatis.htm by Judy Sedbrook

Paper Wasp

http://www.coopext.colostate.edu/4dmg/Pests/whatis.htm by Judy Sedbrook

Why we use deep boxes exclusively

We only use and sell deep boxes. This is a management preference. All beekeepers do things a bit differently and this is our favorite way. We think our way is more efficient because we don’t have to store several sizes of boxes and frames. (And we’ve had 25 years plus 4 generations of experimentation. Trust us!)

USING THE SAME SIZE BOXES AND FRAMES

Running all deep boxes also makes equipment interchangeable. It is useful to be able to interchange frames from box to box when splitting hives, if the queen lays eggs into the top boxes, and when sorting individual frames to extract honey. It is also nice when splitting a hive, as a super can double as a hive body box by attaching a bottom board.  

When using only deep boxes, you don’t need a queen excluder. If the queen lays eggs in the upper boxes, you can just move the frame(s) down into a lower box, or leave them there. The eggs will hatch out and bees will refill cells with honey. We like to let the queen decide where she wants to go in the hive. 

Not having a queen excluder is advantageous because, as they say, “A queen excluder is a honey excluder.” Queen excluders slow down the hive and can dramatically reduce honey production. (But they can be useful in some methods of splitting hives and queen rearing.) When running a hive with deep box on the bottom with medium or shallow supers on top, you will need a queen excluder. 

USING DEEP BOXES (INSTEAD OF MEDIUMS OR SHALLOWS)

The preferred size of box and frame for beekeepers *and bees* is the deep Langstroth box. Mr. Langstroth worked out the optimal size of brood nest, honey, and pollen for the average sized colony and used this optimization to create his deep, 10-frame box. The Langstroth “deep” box is still most commonly used by commercial beekeepers. 

Three deep boxes are the same volume as 5 medium boxes. The 3 deep boxes will hold 30 deep frames. The 5 medium boxes will require 50 medium frames. 

Using all deep boxes means fewer frames to handle, for the bees and the beekeeper. This means more continuous space for the queen to lay her eggs, and less burr comb to build. It requires more energy for bees to move from frame to frame than within continuous frame space. 

The advantage to medium or shallow boxes is that they weigh less, especially when full of honey. This is the only advantage. If weight is an issue, but you want to try deep boxes, consider not lifting the whole deep super full of honey at once. Instead, inspect individual frames in the bee yard and take the full frames of honey back to extract. 

Some beekeepers bring the entire super home to extract without looking inside much. Then they take the box back and inspect frames in the honey room. We think it is better to inspect individual frames at the hive. I guess we’d rather be outside. And it also means fewer bees in the honey room. 

Thanks for reading! 

Alicia Moulton