While working on the project, we found a plethora of information about honeybees. Just like doctors ought to know their patients, we needed to know who we were helping. Our mathematical model needed to understand their development; our lab work needed to be based on their pathologies; human practices couldn’t have been faced without enough knowledge of their handling.

Through this research, we fell in love with these quirky eusocial laborers. We didn’t want to see all this information to go to waste, so we decided to put the best of it here; that way you too can be fascinated by the marvelous life of bees.

Honeybees are very important for us, so we would like to mention some interesting facts about them. First of all is important to remark that they are social insects and divide into three different type of individuals: the queen, the worker and the drone. Each of them has a special function in the hive. There is only one queen per colony and she is the only female completely developed sexually, that's the reason why it’s the mother of all bees. We could think that since she is the "queen" she should govern the workers or tell any other bee what to do, but it's not the case, she simply lays eggs. A very important function of the queen is to ensure the nest stability and continuity. She controls the sex of her offspring: if its a fertilized egg it will be female, if the egg is unfertilized it would be a male.

On the other hand, the worker honey bees do all of the main tasks in the colony maintain it in good condition. They are females that are not fully developed sexually. The tasks change with their age because they're correlated with the physiological development of different glands, but can also change depending on the needs of the colony.

The last type of honey bee are the drones, the males of the colony. They just have one function: fertilize the queen. After mating, the drone dies. They don't have a sting, do not carry pollen, are unable to produce wax and only last six months.¹

Queens lay an egg for each cell. Their yolk serves as food source until, three days later, a larva emerges. On the fourth and fifth day, larvae feed on royal jelly. On the sixth day, larvae transition from jelly to pollen and honey (bee bread), which they will feed on until the ninth day. Brood prepared to be queens are fed royal jelly (and not bee bread) until the ninth day. Larval cells are then capped with wax, where bees will develop as pupae until they emerge depending on their caste. Worker bees emerge on the 16th day, queen bees emerge the 21st and drones emerge last, on the 24th.

Workers assume different roles throughout their lives. During the first three weeks, they are called house bees and assume roles within the hive. Their first role is as cleaners, where they take care of debris and waste inside the hive. After three to five days, they assume a role as nurses, where they feed the larvae with royal jelly and bee bread. Afterwards, they assume a number of roles, from feeding the queen and ventilating the hive to making honey and becoming executioners and guards. Beginning between the 18th and 21st day, a worker will spend the remainder of its life as a field bee, where its jobs will be just as varied; they become scouts, nectar gatherers, water collectors and robbers. ³

The honeybee's immune system is the principal barrier against diseases and pathogens. It is classified into social and individual immunity ⁴.

The social immunity is a collective behavior seen in Apis mellifera (Honeybee) and other social insects, and it has the objective to reduce the risk of disease outbreaks. Every bee in the colony does small tasks and altogether have a high impact against parasites and pathogens.4 Social immunity is divided into defensive behavior and environment modification. The defensive behavior includes the hygienic behavior as grooming themselves or to each other, exhaustive beehive cleaning of potential infectious elements such as residues or carcasses within the hive. Also, they clean up after the death (2). The environment modification consists of the collection of propolis (plant resins)5 and use them to create an antiviral and antimicrobial envelope for the beehive.⁴.

On the other hand, the individual immunity of honeybees has several lines of innate immune defense against pathogens. The chemical and physical barriers like the exoskeleton cuticle and the peritrophic membranes at the digestive tract are the first line of defense against pathogens. In the case of a breach of the physical and chemical barriers, there is a cellular and humoral response that constitute the second line of defense. The innate immunity of the bee is activated due to the recognition of the structural motifs on the pathogens' surface known as Pathogen-Associated Molecular Patterns by Pattern Recognition Receptors. The signal cascades could active the phagocytosis, coagulation or melanization of the hemolymph or the synthesis of antimicrobial peptides (AMPs) such as abaecin, apidaecin, defensin and hymenoptaecin.⁴.

The antimicrobial peptides are synthesized in the fat body of the honeybee as pro-peptides (inactive-form) and are cleaved (active-form) upon infection. These peptides have properties against bacteria, viruses, and fungi.⁵.

The mouth is the first part of the digestive system. It is in the anteroinferior part of the head and belongs to the licking-sucking classification. The queen, the drone and the worker bee present different structures.⁶

When Bees take liquid foods using the proboscis, which is formed by different pieces of the oral apparatus.⁶ The proboscis is not an organ as such, but it is a group of structures that unite and have a particular function. By this retractable structure is how it ingest and regurgitates, nectar, water or honey.⁷ Bellow is an image where the structure is retracted and when it is not.

When the proboscis is retracted, the tube is under the head; when the bee prepares to absorb liquids, it projects it forward, extending its distal parts around the tongue, in such a way that a tube is formed that closes in front of the distal end of the maxilla; in the back, the labial palps close.⁶

Unfolding the tube is introduced into the liquid, in quick movements back and forth the liquid rises. When the mandible and proboscis are contaminated, are the vehicle for an infestation of larvae by American foulbrood (Paenibacillus larvae) or European foulbrood (Melissococcus plutonius).⁶

The Esophagus is a tube that extends along the thorax, whereby food does it road thanks to its contraction movements, by muscle waves that move in an anteroposterior way.⁶

In the proximal end of the abdomen, the esophagus widens into a sack with thin and highly elastic walls, named the social stomach. When it is filled, their walls expand rhythmically causing their content mix. It is also used as food stock. The proventriculus is a narrow, muscular channel that controls the entry of food into the stomach (ventricle) of the bees, acting as a filter, eliminating the solids from the content of the social stomach. Its previous part is X-shaped. Through this valve, the bee can selectively remove the pollen from the nectar or honey and pass it to the ventricle. Below is an illustration of this valve.^6,7

The ventricle is where the digestion and absorption of food from the food material takes place. The folds of the inner membrane increase the digestive surface. It is a long and wide tube of endodermal origin. In it, there is no cuticular layer, but the peritrophic membrane is present throughout the length of the tube, which is selective and through it pass the digested nouns and mix with the hemolymph. ^6,7,9

In this membrane are collected the liquids coming from the proventriculus, the soluble products of the digestion of the solid foods, the digestive enzymes secreted by the epithelial cells and the fluids reabsorbed by the tubules of Malpighi. The functions of this membrane are:

• Mechanical protection to ventricle cells.
• Physical barrier for digestive enzymes and products of digestion.
• Device to help the process of non-excretion of digestive enzymes.
• Prevention of non-specific ligations of undigested materials with the carrier proteins in the membranes of epithelial cells.

The permeability of this multilaminar membrane is very little known. Today it is known that nutrients must cross this membrane to be absorbed by the epithelial cells to reach different tissues. ⁹

In the larva, it is the place (the ventricle) of attack of Paenibacillus larvae (American foulbrood) the spores of bacteria germinate in the ventricle just after the operculation that is the moment in which the concentration of sugars goes down, later the bacterium invades all the larva. ⁶

The proctodeum is divided into two main parts: the small intestine and the large intestine or rectum, the first is attached to the ventricle by the pylorus, which is the regulating valve of the passage of food between the ventricle and intestines. ⁸

The large intestine contains the rectal organs that serve to absorb water. It is a structure similar to a bag with several longitudinal folds that give it the ability to contract or expand with the presence of intestinal content. The rectum accumulates both digestion residues and the excretions of Malpighi tubes, especially in the winter or rainy seasons. ⁸

The Malpighi tubes are about 100 long sinuous tubes that roll together in the viscera and end at the junction between the ventricle and the small intestine. ⁸

Is an ectoparasitosis caused in honeybees, Apis mellifera, by the mite Varroa destructor. This parasitosis often causes the loss of infested colonies within two to four years from the time of initial infestation. Is one of the most serious diseases of bees and if it isn´t correctly treated may become to a mortal disease into the colony. Infested bees live half the time compared to healthy ones, therefore colony loss is predictable when many bees are infested. ¹¹

Varroa destructor is an arthropod that is currently classified in the type Artopoda, class Arachhnida, order Parasitiformes, suborder Gamasida, superfamily Dermanyssoidea and family Varroidae. Is a bee’s specific parasite that affects in all the grow phases. Breeds mainly in the drone cells in Apis cerana, and that limits their danger. In the European bee exist is this preference for dealing with cells of drone but not as marked as in the case of A. cerana, that brings its high ganger as a result. ¹⁰

After a period of life outside the cell, female varroa, arranged for the oogenesis, seek a cell about to be consumed. The mite that has entered in a cell, in contact with the food which are the larvae enters a State of hipobiosis, due to the low concentration of oxygen and high carbon dioxide concentration. Consumed by bee breeding larval and consumed food bound box, the parasite resumes its activity and takes lot of hemolymph before egg-laying. ¹⁰

Nosemosis is a disease of adult bees caused by a protozoan unicellular microsporidium called Nosema apis. This microorganism lives as a parasite in the epithelial cells that line the interior of the midgut of bees where it reaches its life cycle. During its development, the causal agent produces spores that can remain dormant for 3 months in honey, 2 months in soil and shade, 10 to 20 days in rotten bees and in feces for more than 2 years. ¹²

The spores are spread by the fecal matter of the infected adult bees. When the excrement accumulates inside the hive, the danger of contagion is very high because the younger bees that are dedicated to cleaning the cells are contaminated and transmit it to the other bees in the hive. When the infection reaches its maximum level, the host can hold 30 to 50 million spores. ¹²

If the multiplication of the spores is not blocked, the digestive function is canceled from 14 to 21 days later. In an intermediate state, bees do not digest pollen or honey well, so that food consumption increases by 30%.¹²

It’s a sweetened substance that bees produce from the nectar they collect from flowers. It’s the basic food of the bees, they get the energy the energy needed in order to accomplish all the colony tasks. Because of its high sugar content, honey is considered a source of calories.

Wax is a substance produced by bees through their wax glands. Bees use wax to build honeycombs, in this combs the queen lays the egg and and where larvaes will grow until they reach adult stage. They also use it for the storage of honey and pollen. In order for bees to produce 1 kg of wax they need to consume about 7 to 8 kg of honey. We use this wax to produce candles, oils and other craftsmades.

This is a substance given from nurses to larvaes to feed for their first 3 days of life while the queen is fed all her life with it. It is made of pollen, honey and water and produced in the hypopharyngeal glands. It is commonly used as a source of vitamin B

It is a resin that bees collect form the trunks of some trees. Propolis are a very important product for the beehive since it’s use to maintain the temperature of the hive and for maintaining the hygiene inside. They are commonly used in the field of medicine for injures healing, bactericide and fungicide.

It’s the masculine element of a flower, Although it’s not produced by bees, pollen is vital for the development of the hive because it’s consumption is their source of protein, lipids, vitamins and minerals.

The venom is produced only by worker bees and is used as a mechanism of defence against animals and other insects that put in risk the hive.

On May 20th we celebrated the World Bee Day. The United Nations declared May 20th as World Bee Day thanks to a Slovenia’s proposal. After three years of international efforts, member states of the UN approved this proposal, proclaiming this important day. This date is celebrated in several countries to light up important facts about bees and to raise awareness on people about bees. There exist several projects which contribute to this initiative, thus iGEM Tec-Chihuahua decided to play a part in this plan.

We wanted to let people know that we care for bee’s health and due to that, we are trying to use science to enhance beekeeping. Therefore, we made some flyers and took some pictures of us dressed as bees to make diffusion of these wonderful organisms. We also put a brief description of our first project proposal, which later was improved and integrated for beekeepers necessities.

The flyers were uploaded to our social media, as well as our favorite bee-pictures. Below you can find some of our work for the World Bee Day and a few pictures we took dressed as bees!

References

1. Ellis, J. (2015). The members of a honey bee colony. October 6, 2018, in American Bee Journal. Web site: https://americanbeejournal.com/the-members-of-a-honey-bee-colony/


2. NAFI. (n.d.). Honeybee Castes. National Farmers Information Service. Retrieved from http://www.nafis.go.ke/livestock/bee-keeping/honey-bee-castes/


3. Adjare, S. (1990). Chapter 2: Colony life and social organization. In Beekeeping in Africa (Agricultural Services Bulletin). Rome: Food and Agriculture Organisation of the United Nations.


4. DeGrandi-Hoffman, G., & Chen, Y. (2015). Nutrition, immunity and viral infections in honey bees. Current Opinion in Insect Science, 10, 170–176. doi:10.1016/j.cois.2015.05.007


5. Khilnani, J. (2015). "The Effects of Honeybee (Apis mellifera) Antimicrobial Peptides on Paenibacillus larvae". UNLV Theses, Dissertations, Professional Papers, and Capstones. 2486. https://digitalscholarship.unlv.edu/thesesdissertations/2486


6. Llorente, J. (n.d). Internal anatomy of bees. July 26, 2018, de Fundation of Friends of the Bees (FAA) Web site: https://abejas.org/anatomia-interna-de-las-abejas/


7. Anatomy of bee. (2011). JCYL. Retrieved from http://revistas.educa.jcyl.es/divergaceta/images/stories/oct11/03-anatomia_abeja.pdf


8. Corona, M. (2017). Digestive Anatomy of Bees. July 26, 2018, de Corona de Apicultores Web site: http://revistas.educa.jcyl.es/divergaceta/images/stories/oct11/03-anatomia_abeja.pdf


9. Bazurro. (2012). Digestive system. July 26, 2018, de Corona de apicultores Web site: http://coronaapicultores.blogspot.com/2012/12/buche-o-estomago-de-miel.html
10. Yadav, S., Kumar, Y., & Jat, B. L. (2017). Honeybee: Diversity, Castes and Life Cycle. In Industrial Entomology (pp. 5-34). Springer, Singapore.


11. Somerville, D. and Goulburn, T. (2011). European Foulbrood and its control. NSW government. Retrieved from https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0010/333388/European-foulbrood-and-its-control.pdf


12. European Foulbrood EFB. (n.d.). National Bee Unit. Retrieved from http://www.nationalbeeunit.com/gallery/displayImage.cfm?image=15


13. Yellow/White colour of larva (n.d.). National Bee Unit. Retrieved from http://www.nationalbeeunit.com/gallery/displayImage.cfm?image=14


14. Infected comb. (n.d.). National Bee Unit. Retrieved from http://www.nationalbeeunit.com/gallery/displayImage.cfm?image=106


15. Medina-Flores, C., Guzmán-Novoa, E., Aréchiga-Flores, C., Aguilera-Soto, J. and Gutiérrez-Piña, F. (2011). Efecto del nivel de infestación de Varroa destructor sobre la producción de miel de colonias de Apis mellifera en el altiplano semiárido de México / Effect of Varroa destructor infestations on honey yields of Apis mellifera colonies in Mexico’s semiarid high plateau. Retrieved from http://www.scielo.org.mx/pdf/rmcp/v2n3/v2n3a6.pdf


16. Fundación amigos de las abejas. (2015). Varroosis. Retrieved from https://abejas.org/las-abejas/patologias-de-las-abejas/varroosis-parte-1/


17. Valega, O. (nd). Nosemosis. Retrieved from https://www.apiservices.biz/es/articulos/ordenar-por-popularidad/1188-nosemosis


18. SAGARPA. (n.d.). Manual básico de apícola. Retrieved from http://www.mieldemalaga.com/data/manual_basico_apicultura.mex.pdf


19. Simone-Finstrom, M. (2017). Social Immunity and the Superorganism: Behavioral Defenses Protecting Honey Bee Colonies from Pathogens and Parasites. Bee World, 94(1), 21–29. doi:10.1080/0005772x.2017.1307800