Benefits of Honeybee Propolis

A Science Daily article titled Antioxidant In Substance From Honeybees May Protect Athletes From Overheating contains this information:

ScienceDaily (2009-07-29) -- A compound from honeybees known as propolis, the substance bees use to seal their hives, may protect against heat stress in athletes, according to a new article.

Honeybee propolis has also been described as bee glue. It has a history of usage for medicinal purposes. There is an ingredient in propolis called caffeic acid phenethyl ester, or CAPE for short. Some of its beneficial properties include it being an antioxidant and having anti-inflammatory and antiviral effects.

Honey Bee Landing Technique

The University of Queensland in Australia features an online article titled Bees show off the perfect landing. As it indicates bee landing on a flower is marked by a transition from speedy flight, comparable to an aircraft's movement, to the hovering more typical of helicopters. The bee landing is contrasted with that of a fly whose landing is described as a ‘controlled crash'. Also interesting is the analogy between the bee landing and the landing of a human pilot. Professor Mandyam Srinivasan noted the degree of difficulty for a human pilot. Yet bees routinely accomplish the feat.

Use of a high speed camera made possible a sequential breakdown in bee activity leading to a landing. Scientists observed bee antennae touch a surface prior to landing and this seems to trigger surface grasping by bee legs. The antennae role came as a surprise and pointed out the coordinated actions of visual identification, antennae surface touching and leg grasping in the act of landing.

The Interplay between Temperature Sensing and Learning among Honeybees

Tobin J. Hammer, Curtis Hata and James C. Nieh authored the research article Thermal learning in the honeybee, Apis mellifera, which was published in The Journal of Experimental Biology [212, 3928-3934 (2009)]. The study showed that honeybees can learn to associate temperature differences above and below ambient environmental temperatures with nectar rewards. Learning was enhanced when temperatures were warmer than the ambient norm as opposed to cooler. The rate was about twice as great when the temperature was 10C degrees above the norm as compared with 10C degrees below.

Researchers hypothesized that temperature sensory capabilities in honeybees could influence foraging decisions and could be a component involved in the exchange of information between nest mate honeybees.

Is CCD the Consequence of Viral Infection of Ribosomes?

DNA clue to honey bee deaths is a BBC News article dated August 24, 2009. Colony Collapse Disorder (CCD) is a mysterious malady afflicting honeybees. For some beekeepers losses in hives have been horrific. The article refers to a study, published in the scientific journal PNAS, based on research of cells obtained from bee guts. Whole genome microarrays were utilized for comparison purposes. The idea was to compare healthy bees to bees having the CCD disorder. 10,000 bee genes were involved in the comparisons.

Researchers tested for elevated expression of pesticide response genes but did not find this. Expression of genes involved in immune response also was analyzed without yielding information of significance. However, researchers did find that ribosome function of infected bees was likely compromised by viruses. The viruses were described as picorna-like. Apparently ribosomes of infected honeybees make viral proteins rather than honeybee proteins.

The lead scientist for the related study was identified as May Berenbaum from the University of Illinois.

Beeswax

Keeping Bees and Making Honey₁ is an easy to read book for those fascinated by bees or thinking about getting into the business of beekeeping. It is well illustrated and makes the following facts about beeswax available:

• Beeswax is generated by bees as a result of the honey they consume.


• Worker bees between 12 and 18 days of age secrete beeswax. They have wax-secretion glands in their abdomen.


• Beeswax is yellow has a melting point between 146 and 149 degrees Fahrenheit.


• Uses of beeswax include wood finishing and wood conditioning, waterproofing, coating of fishing lines to facilitate floating and lubrication (wooden drawers, tools...).₂

Reference

1. Keeping Bees and Making Honey by Alison Benjamin and Brian McCallum; Publisher, F+W Publications Inc., Copyright by David and Charles Ltd. 2008.
2. Keeping Bees and Making Honey by Alison Benjamin and Brian McCallum; Publisher, F+W Publications Inc., Copyright by David and Charles Ltd. 2008; Pages 106-107.


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Beetle Infestation of Honeybee Hives

Beetles' Attack On Bee Hives May Contribute To Colony Collapse Disorder is a Science Daily article describing honey bee problems with a beetle pest. An "alarm chemical" naturally produced within honey bee hives attracts small hive beetles whose infestations may be a contributory factor to the phenomenon that has become known as colony collapse disorder or CCD. European honeybees were bred for docility and behavior that made it easier to work with them. Not surprisingly they have been less able to cope with beetle infestation than their more aggressive African bee cousins.

The combination of small hive beetle and yeast infestations can lead to very messy honeycombs. This in turn can induce honeybees to abandon their hives to beetles which then consume food provided at the cost of honeybee energy. This is beneficial to beetles but not to honeybees. It is hoped that knowledge gained about the process of beetle infestation and hive abandonment will lead to counter measures that protect honeybees. Honeybees greatly enhance agricultural output.

Using Honey Bees to Study the Ageing Process

Biology News Net has an entry titled A young brain for an old bee. The brief article notes that cognitive function delines with age but it also mentions that our specific activites can impact the decline according to recent studies. That's where the study of bees comes in.

There are two specific bee activities which have differing cognitive decline correlates. Foraging is performed by the oldest bees in a colony. A diminished learning capacity has been linked to time spent foraging. The longer the bee forages the greater the cognitive decline.

On the other hand bees devoted to nursing functions are resistent to cognitive decline. It was demonstrated that foraging bees, when forced to become nursing bees, acquire improved learning ability. The implications for humans are exciting. If human activities can be linked to enhanced and diminished learning capacities then those activities will acquire an important new dimension particularly relevant to ageing effects.

Glucose Oxidase, Honey, Mites and a Possible Linkage

Biology News Net features an archived article titled Bee mites suppress bee immunity, open door for viruses and bacteria, which provides some clues about the problem known as colony collapse disorder afflicting honey bees in the United States. Penn State researchers published their related report in PNAS.

The mite parasite Varroa destructor was implicated in the phenomenon. It is suspected that the mite adversely affects bee immune systems. A combination of mites, bacteria and viruses may lead to the collapse of hives. Of particular interest was the finding that bees with mites produce less of an enzyme known as glucose oxidase, (GOX), which worker bees place in honey to prevent bacterial infection. Bees eat honey they make and if the level of bacteria is elevated this might facilitate the collapse of a hive.

Research on Bee Vision

New insight into how bees see is a Biology News Net piece revealing results of research from Monash University in Australia. Dr. Adrian Dyer is a reknown bee expert in Australia. His research, alluded to in this article, indicates that honeybees have the ability to learn to recognize human faces from different vantage points.

A reward and punishment system was used to test bee capabilities. A sugar reward was given for correct choices and a bitter tasting solution for incorrect ones. Faces were shown on a vertical screen and bees learned which face was the correct one to choose from. Dr. Dyer explains: "Bee brains clearly use image interpolation to solve the problem. In other words, bees that had learnt what a particular face looked like from two different viewpoints could then recognise a novel view of this target face. However, bees that had only learnt a single view could not recognise novel views."

The research results, published in PLoS ONE, may enable advances in artificial intelligence which has had a record of poor performances in face recognition. Imaging technology also was mentioned as possibly benefiting from the research. I can see possible benefits in the security field as well.

Can Bumble Bees Estimate Time?

Bumble bees can estimate time intervals is a Biology News Net article. The article notes that humans and other vertebrates are known to have the ability to estimate time short time intervals with greater sophistication than their invertebrate counterparts. But a paper published in Current Biology and authored by Michael Boisvert and David Sherry shows that the bumble bee has time interval estimation abilities. Estimating time durations is linked to the need that bees and other insects have to make decisions. Floral nectar, which is cyclical with respect to renewal and depletion, is the object of attention of insect pollinators like bees. Estimating time intervals may be required to communicate and navigate accurately.

Helping Bees Look for Food

Bumblebees learn the sweet smell of foraging success is a Biology News Net article which points out differences in the ways bumblebees and honeybees search for food. Honeybees communicate sources of food through a waggle dance. The waggle dance gives bees in the nest information about the distance and direction of food sources.

Bumblebees rely on the release of a recruitment pheromone to facilitate the food gathering process. They can also bring back flower scents which clue in other bumblebees to look for the relevant flowers.

Dancing Honeybees

East Learns from West: Asiatic Honeybees Can Understand Dance Language of European Honeybees is the title of this PLOS One paper authored by Songkun Su, Fang Cai, Aung Si, Shaowu Zhang, Jürgen Tautz and Shenglu Chen. Quoting from the abstract of the paper:

The honeybee waggle dance, through which foragers advertise the existence and location of a food source to their hive mates, is acknowledged as the only known form of symbolic communication in an invertebrate. However, the suggestion, that different species of honeybee might possess distinct ‘dialects’ of the waggle dance, remains controversial. Furthermore, it remains unclear whether different species of honeybee can learn from and communicate with each other. This study reports experiments using a mixed-species colony that is composed of the Asiatic bee Apis cerana cerana (Acc), and the European bee Apis mellifera ligustica (Aml). Using video recordings made at an observation hive, we first confirm that Acc and Aml have significantly different dance dialects, even when made to forage in identical environments. When reared in the same colony, these two species are able to communicate with each other: Acc foragers could decode the dances of Aml to successfully locate an indicated food source. We believe that this is the first report of successful symbolic communication between two honeybee species; our study hints at the possibility of social learning between the two honeybee species, and at the existence of a learning component in the honeybee dance language.

So the honeybee waggle dance is the only known symbolic communication form existing among invertebrates. I did not know that. This paper also notes that two different species of honeybee- the Asiatic bee Apis cerana cerana (Acc) and Apis mellifera ligustica (Aml), the European bee- have distinct waggle dance dialects. The authors suggest a question that can be resolved experimentally namely, can different species of honeybee learn from and communicate with each other? And the answer? First a preliminary step- a quote from the paper:

Successful establishment of a mixed-species colony

We organized two types of mixed colonies consisting of an Apis cerana cerana (Acc) queen, Acc workers and Apis mellifera ligustica (Aml) workers, and two other mixed colonies consisting of an Aml queen, Aml workers and Acc workers. In the former colonies, the workers cohabited well for more than 20 days, while in the latter colonies, the Acc workers were killed and cleaned up by Aml workers after 2–3 days. Thus, we were only able to use the former mixed-species colony to carry out our experiments (see figure 1). We put the mixed colonies into observation hives when we transported them to the experimental location.

The stage is set by mixing bee colonies. The two mixed groups are Apis cerana cerana bees and Apis mellifera ligustica bees. More from the paper:

Acc and Aml possess distinct ‘dialects’ of the waggle dance

Figure 2 shows the waggle dance duration of Aml and Acc foragers, from mixed or pure colonies, that had been trained to an artificial feeder placed at different distances (100, 200, 300 and 400 m away). Under normal conditions, i.e. in single-species colonies, Acc foragers consistently had a much greater waggle duration for a given distance than did Aml foragers, as has been previously reported [13]. Further, the waggle durations of dancers from both species increased in a linear manner with increasing distance. The slope of the distance-waggle duration curve for Acc in the single-species colony was significantly steeper than that of Aml bees in the single-species colony (pairwise comparison, t-test, t = 8.8, d.f. = 6, P<0.001, Figure 3). The slope for Acc in the mixed-species colony was also significantly steeper than that of the Aml bees in the same colony (pairwise comparison, t-test, t = 4.4, d.f. = 6, P<0.01, Figure 3). Moreover, at the 100, 200, 300 and 400 meter positions, foragers of a particular species generally displayed similar waggle durations, regardless of whether they were from a single-species or mixed-species colony (P>0.05, ANOVA for Two-stage Nested Design and Tukey's test, see Table S1). The slope of the distance-waggle duration curve for Acc in the single-species colony was not significantly different to that of Acc in the mixed-species colony (pairwise comparison, t-test, t = 2.3, d.f. = 6, P>0.05, Figure 3). Similarly, the curve for Aml in the single-species colony was not significantly different to that of Aml in the mixed-species colony (pairwise comparison, t-test, t = 1.44, d.f. = 6, P>0.05, Figure 3). The waggle duration results show that there really are dialect differences between Acc and Aml. The mean dance angle, the direction of the waggle run relative to the vertical direction, was not significantly different (P>0.05, pairwise t-test) between Acc and Aml in the mixed-species colony (Table 1; see Methods for details of analysis).

Studies document the symbolic communication differences in the dances of two honeybee species, Acc and Aml. Waggle duration is a distinguishing feature.

The Pathway to a Queen

A report in Science titled Nutritional Control of Reproductive Status in Honeybees via DNA Methylation by R. Kucharski, J. Maleszka, S. Foret and R. Maleszka, points out that the two forms of adult female honeybees (workers and queens) were once genetically identical larvae. The feeding of royal jelly induces the development of a queen. Researchers were able to show that silencing the expression of DNA methyltransferase Dnmt3 can lead to the development of queens. Results suggest, according to the authors, that developmental fates are linked to alterations of epigenetic information stored through DNA methylation by means of nutritional input.

Weapons Against Varroa Destructor

Ross Conrad has done a great job of explaining the different methods of controlling the mite Varroa destructor and keeping it from overwhelming bee hives in his book Natural Beekeeping. Included in the arsenal are grease patties, esential oils, food grade mineral oil, sugar solutions, formic acid, oxalic acid, lactic acid and acetic acid.

Grease patties can be formed from white sugar and vegetable oil with honey or essential oil added to the mix in a ratio of two parts oil to one part sugar.1 The grease appears to form a fine film on bees which makes it difficult for mites to retain their footing. Essential oils, when added to the mix, can be toxic to varroa.

A component of thyme oil known as thymol is very deadly to varroa mites although it is safe for humans. Thymol and other essential oils, when evaporated within a hive, can kill off varroa.2

A mixture that includes food grade mineral oil, beeswax, honey and a solution of thymol in alcohol is another mixture that can be used against varroa mites. The mixture, when soaked into cotton cordage, can be placed on top of a brood nest.3

Sugar esters can kill varroa through suffocation and dehydration resulting from the breakdown of a waxy coating of the body of these mites. A commercial product called Sucrocide takes advantage of this and can be used to treat varroa.4

The organic acids- formic acid, oxalic acid, lactic acid and acetic acid- when mixed and applied properly, also can serve as effective treatments for varroa. An advantage of using these natural acids is that honey can be kept safe for human consumption.5



References:

1. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Page 128.

2. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Page 130-131.

3. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Page 133.

4. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Page 134.

5. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Page 136-139.

Varied Learning Rates Among Bees

Fast learning bumblebees reap greater nectar rewards tells of the importance of learning rates among bees. Bees which are faster learners have greater ability to collect more nectar from flowers. In tests involving a dozen bee colonies blue and yellow artificial flowers were packed with different levels of nectar. The yellow flowers were provided more nectar to test the ability of bees to overcome their natural predisposition toward blue flowers. Surprisingly there was as much as a five fold difference in learning speeds among the colonies.

Bees are able to sense other cues besides color. They include patterns and scents. Results of the study are published in the journal Proceedings of the Royal Society

Strategies for Treating Varroa Destructor Infestation

Ross Conrad authored an excellent book titled Natural Beekeeping. Conrad is a beekeeper with hands on experience dealing with issues discussed in his book. One of the most prominent problems facing beekeepers is colony collapse disorder- a phenomenon that has led to the demise of many beehives. A high profile suspect in this whodunnit mystery is a species of mites known as Varroa destructor, more commonly known as varroa mites or simply varroa. These parasitic mites have been the bane of many a beehive. Keeping varroa from overwhelming their hives has been a challenge to apiculturists.

Not surprisingly treating the varroa problem has included the use of chemicals intended to kill off or weaken varroa. But this has some major drawbacks which include cost of chemicals, acquisition of resistence to chemicals by the mites, undesireable deleterious side affects on the bees themselves and contamination of honey subsequently purchased and eaten. In pointing to treatment alternatives Conrad has emphasized the importance of an alternative organic approach.

One approach to the varroa problem has been to make splits of existing hives to enhance winter survival rates. The idea is to reduce the mite count which a split would clearly do based on the mechanical nature of it alone. However, there is a more subtle fact that splits may be exploiting. The splits may disrupt the reproduction cycle of the mites when bee colonies must raise up a new queen. Slowing the growth rate of varroa can make the difference between a future colony collapse and a colony that survives and becomes a productive source of honey.1



References:

1. Natural Beekeeping; authored by Ross Conrad; Chelsea Green Publishing; Copyrite 2007; Chapter 4; Page 70.

Carpenter Bees

In continuing with a series of posts based on the article in Natural History titled Unsung heroines of pollination (May 1997 Vol. 106 Issue 4, p42), carpenter bees are the subject of this blog entry. Carpenter bees are large and look like bumblebees. Unlike bumblebees however, which are social in nature, carpenter bees are solitary. Although they tend to be found in tropical climates there are eight species found in North America. Wildflowers and crops are pollinated by carpenter bees in North America. Carpenter bees are ideally suited to pollinate certain flowers because of their size which can be advantagous with certain structures. Passion fruit flowers, which includes the North American maypop, are examples of flowers benefiting from pollination by carpenter bees.

While male carpenter bees near nests and flowers, pregnant females prefer tunnels in soft dry wood. This can include wood found in homes. Neat round entrance holes mark the nests.

Bumblebees and Leaf-Cutter Bees

The previously discussed article in Natural History titled Unsung heroines of pollination, provides information about a variety of bees which include bumblebees and leaf-cutter bees. Information in this blog entry is derived from that aricle.

Bumblebees are those familiar large and fuzzy bees. Their genus is Bombus and in North America there are 46 species of bumblebees. Bumblebees sometimes form their nests in abandoned mouse nests. The queen is the only one to live through winters and in the spring will lay the eggs that give birth to workers and new colonies.

Since bumblebees adapt well to greenhouses they can be active during the entire year when housed this way. Growers are able to take advantage of this property of bumblebees and can pollinate hothouse tomatoes and other plants with them.

There are about 120 species of leaf-cutter bees in North America although these bees are found throughout the world. Unlike the social bumblebees, leaf-cutter bees are solitary and usually nest in preexisting holes. Pollen is carried under their abdomen. A species known as the Eurasian alfalfa leaf-cutter bee, (M. rotundata), is prized and raised by the millions in the United States because it pollinates alfalfa. Alfalfa is very important to livestock.

There are Many Varieties of Bees in North America

Many people would be surprised to learn that there are about 3,500 different species of bees in North America; so accustomed have we become to associating the honeybee with bees. An article in Natural History titled Unsung heroines of pollination discusses this and more (May 1997 Vol. 106 Issue 4, p42). The article makes the following points:

* Some species of bees may look more like other insects we know such as wasps, flying ants and fuzzy flies.

* Although differing in appearance from the familiar honeybee such bees resemble the honeybee in their behavior. That is they engage in packing pollen from flowers onto their hind legs. or under the abdomen.

* There are bees that are native to North America which, along with some other insects that visit flowers, are capable of fulfilling the pollination needs of backyard gardens in the USA and even small farms. It is the larger farms that have become honeybee dependent.

* There is an interest in other species of bees, often referred to as pollen bees, because they are better adapted to pollinating certain crops and there has recently been a decline in the population of honeybees.

* The majority of bees, that are native to North America (about 85%), in contrast to honeybees, lead solitary lives. Their nesting locations include hollow plant stems, wooden buildings and the ground.

Inhibiting Aversions to Queen Bees

A compound produced by honeybee queens known as homovanillyl alcohol (HVA) may prevent aversions on the part of worker bees as spelled out in a Nature article titled Queen bees avert the sting in the tail Honeybee queens may use scent to stay popular in negative situations (published online: 19 July 2007; | doi:10.1038/news070716-14). Article author Heidi Ledford jokes that politicians would love to get their hands on chemicals like the ones at the disposal of the queens and for good reasons. Workers feed and groom queens and also apparently overlook negative experiences resulting from encounters with queens. Test results from a referenced study indicate that, although workers respond to a nasty encounter, they don't learn to associate it with adversity toward the queen.

The experiment, on which conclusions are based, entailed administering mild electrical shocks that were associated with a specified odor. A stinger extension was an observed effect. After some repetitions stinger responses were induced merely through the sense of smell- except when the odor was associated with the queen. Specifically, exposure to pheromones of the queen, particularly homovanillyl alcohol (HVA), were not linked to the electric shocks.

Experimental findings are consistent with observed beehive behavior. There are worker bees who groom the queen with their proboscises. They also use their antennae to rub the queen. In performing these functions they come in contact with compounds that are found on the surface of the queen's body. In this way queen pheromones can be distributed to other bees in the hive when the queen attendant workers mix with them. This has a calming effect on worker bees. Further reinforcing the point is the observation that young worker bees become less aggressive when a queen is put in the colony.