Why do the bees stop dancing?

Environmental changes affect the special dance patterns of the bees, which they use to locate foodNeta Nissim, Zveta - news agency for science and the environment

For bees and other social insects, the ability to exchange information is essential to the success of the colony. The honeybees do this by dancing, which is a unique pattern of behavior that probably evolved more than 20 million years ago - and continues to surprise and amaze researchers even today.

The dance is based on visual communication, voice communication and touch. A bee that has found a quality food source, returns to the hive and "tells" her friends about her discovery by running along a route that outlines the number 8. The run is performed on one of the vertical honey bees; The direction of the movement represents the location of the food source in relation to the sun, and at the same time, the length of time the dancer completes the dance represents the distance of the food source from the hive. When the hive is dark and the dancing movements cannot be seen, the noise (which is heard at a low frequency) created by the dancing bee, provides the same information that is conveyed in the dance.

The dance of the bees is actually part of the communication system of the bees among themselves, which also includes the secretion of different smells that convey different messages. In recent years, researchers have begun to study in depth the actual benefits of the bee dance. Recently, biologists from the University of Lausanne in Switzerland and the University of Mainz in Germany discovered new findings regarding the effectiveness of the bee dance in changing environments, especially those affected by human activity.

confuse the bees

In a study recently published in the journal Science Advances, the researchers followed the behavior of the bees in the colonies and their dance patterns. In order to better understand the environmental factors that are the key to the colony's success in searching for food sources, when the colony uses the transfer of information socially, by performing the bee's dance, and when it does not.

The experiment was conducted in the spring and summer months near the University of Lausanne in Switzerland. The bee colonies in the experiment were divided into several groups: some were located in urban areas, some in agricultural areas, a minority in wooded areas and a large part of them in infertile areas, where there is little food.

In addition, the researchers performed a number of manipulations whose purpose was to confuse the bees and examine the way of transferring information between them when the conditions do not allow them to dance. To create these conditions, the researchers prevented the light from reaching the honeycombs in some of the colonies, and in addition changed the orientation of the hives to a horizontal position. As a result, the bees did not perform their dance, or it no longer seemed logical and understandable to the other members of the colony.

Bees are endowed with the ability to memorize and remember the location of the food they found even a few days after returning to the hive; Therefore, the research team had to prevent all bee colonies in the experiment from performing their dance for 18 days, to ensure that they could not use their memory to tell other bees in the colony where the quality food sources were.

The dance language is not understood

The study brought up some interesting findings regarding the effectiveness of the bee dance. It was found, for example, that in hives where a dance was performed, the amount of time a single bee spends looking for food actually increased, but the dance led to the discovery and use of higher quality food sources and sites. At the same time, it was found that in the colonies where the dance was not performed, the amount of bees that left the hive in the morning to look for food was 23 percent higher. In addition, the weight loss of the hives (which occurs during the summer when the natural food supply is reduced) was 29 percent higher in the colonies where the dance was performed. According to the researchers' hypothesis, it is possible that in the absence of the dance, the bees changed their foraging strategy, became more proactive and used the time to search for food themselves.

An interesting and important result of the research concerns the effect of human activity on the dance of the bee. In the study, the bees did not perform the dance when environmental conditions were challenging and changing, such as in agricultural and urban areas. In these areas, a periodic change of the surface occurs by man, who plants different crops and non-native flower species. After their flowering, the area remains bare and with low quality food for the honey bees. In these cases, the effectiveness of using dance as a way to convey information decreases. The results of the article show the possibility that the human influence has created environmental changes to which the "dance language" of the bees is not adapted.

worth 200 billion dollars a year

"Humans have the ability to change and influence the bees' honey production patterns," says Ohad Efik, director of the bee field at the Ministry of Agriculture and Rural Development. "The effect can be manifested starting from the location of the hive, its direction and ending with the effect on the type of honey that you want to obtain, citrus or eucalyptus honey for example, through the location of the hives near certain plants that are not local and are not part of the local flora, and did not form part of the original food of the honey bees in the past. However, it is important to remember that the environment is constantly being changed by us, and this has a considerable effect on the bees' actions and the way they choose to look for food."

Indeed, recently the effect of human activity on the bee population in the world is becoming clear. In recent years, entire species of honey bees have disappeared from the face of the earth, and others are suffering from severe depletion, especially in the northern regions of the world. Researchers link this phenomenon to the spread of parasites, deadly viruses and various diseases, to the intensive use of pesticides and also to climate change.

This phenomenon is worrisome because bees are central pollinators of agricultural crops and vital to food production in the world in addition to being honey producers. Experts estimate that this activity of the bees around the world has an economic value of more than 200 billion dollars a year for the agriculture industry. According to Afik, "The bee industry is greatly affected by the changing environmental conditions. The use of pesticides in agriculture, for example, causes a very serious damage to the bee population." He adds that "in order to deal with the issue of pesticides, we work to coordinate between the farmers and the beekeepers, and move beehives according to the location of the spraying so that they are not harmed. In addition, we are trying to influence the spraying plans of the authorities, and today there is also legislation that prohibits spraying an area during the activity of honey bees and wild bees."