Apis mellifera

Apis mellifera

The European bee (Apis mellifera Linnaeus, 1758) is an insect hymenopterous belonging to the Apidae family.

Systematics –
From the systematic point of view it belongs to the Domain Eukaryota, Kingdom Animalia, Suburbanum Eumetazoa, Phylum Arthropoda, Subphylum Tracheata, Superclass Hexapoda, Class Insecta, Subclass Pterygota, Coop Endopterygota, Superorder Oligoneoptera, Section Hymenopteroidea, Order Hymenoptera, Suborder Apocrita, Section Aculeata, Superfamily Apoidea, Apidae family, Apinae subfamily, Apini tribe and then Apis genus and A. mellifera species.

Geographic Distribution and Habitat –
The honeybee (Apis Mellifera L.) is a hymenoptera native to Africa that has spread throughout France throughout France. THERE. mellifera is the most bred species in the world. The most bred breed in Italy and mostly widespread throughout the world is the ligustica, although there are others that are divided into three groups: European breeds, Oriental breeds and African breeds.

Morphology –
The body of the bee consists of a chitinous exoskeleton which at the level of the joints remains elastic and thin. Inside are numerous organs with different vital functions not yet fully known. The bee’s body is divided into three segments: head, thorax and abdomen.
The head is characterized by two compound side eyes, covered with microscopic hairs, composed of about 3000 facets (which are ommatidia) for the worker and 6000 – 7000 for the drone. The bee’s eye is sensitive to ultraviolet and insensitive to red that perceives as black. There are three simple eyes (which are the ocelli) located on the upper part of the head for close vision in the dark and inside the hive. There are two adjustable antennas, consisting of a trunk (the scape) on which a whip consists of 12 articles (flagellum). Antennas are sense organs. In the case of the worker, there are 2400 sensitive plates, while there are about 30,000 in the drone.
The mouth has two jaws that serve to shape the wax, collect the propolis and break the antennas of the flowers containing the pollen. In addition there is a ligule or proboscis that serves to suck the nectar and water, this has a variable length from 5.5 to 7 mm. The ligula of the drones is much shorter than that of the workers and not very suitable for bottling the nectar.
Inside the head are the sense organs and the initial part of the digestive tract as well as the hypopharyngeal and mandibular glands necessary for the secretion of the royal jelly. The head is joined to the thorax by a very short neck.
The thorax consists of three rings welded together, on each of which are articulated a pair of legs while on the second and third ring are articulated two pairs of membranous wings. Inside the thorax is the esophagus. There are also air bags in communication on one side with different organs (wings and legs) and on the other through the trachee with the outside. In addition, there are vertical muscles needed to propel the wings.
The legs are made up of some articulated segments that take the name of: hip or coxa, trocantere, femur, tibia, tarsus. The tarsus includes a large prolonged article, from four small articles ending with two claws and a suction cup. The front legs are equipped with a rear window cut to clean the antennas. The intermediate legs have a spur to detach the pollen pellets from the baskets, inside the cells of the honeycombs, upon arrival in the hive. Finally, the hind legs are provided with baskets where the pollen is accumulated and transported in the form of bullets.
The wings of Apis mellifera are membranous, muscular, hollow and transparent and stretched on a rigid rib. The two front wings are articulated on the second ring, or chest half, while the two posterior ones are articulated on the third ring, chest half. Each rear wing is provided on the front edge with about twenty hooks that hook to a special channel located on the rear edge of the front wing. In flight they form a single body. The frequency of the wing beats of a bee varies between 180 and 250 cycles per second.
The abdomen consists of seven rings; of which the first is articulated with the thorax shrinking, while at the opposite end, on the last ring is the sting (only in female workers and queens); the males do not have it. Under the abdomen are located the ceripar glands necessary for the secretion of wax for the construction of the combs.
Other essential organs present in the abdomen are:
– the melaria blister, a sort of ampoule in which bees collect nectar and water to transport them to the hive. Only a small part passes into the stomach as food for them;
– the middle intestine plays the digestive function of food. The posterior bowel instead comprises the rectal ampoule where the dejections accumulate and are retained for several weeks in case of adverse weather conditions before their expulsion;
– the circulatory system for the circulation of the endolymph necessary to supply the various tissues and organs;
– the nervous system constituted as in all the hymenopterans of perisophageal ganglia and a ventral ganglionic chain;
– the Malpighian tubes that perform an excretory function and the conveying task at the entrance of the posterior intestine;
– the venom glands, one alkaline and the other acid that have the function of secreting the poison that is accumulated in the venomous bladder. This bladder communicates with the sting that is a sort of hooked stylet that bees use as a defense against enemies.
At the extremity of the abdomen between the 6th and 7th we find the Nasanoff’s gland, visible to the naked eye when they draw it as an attractive attraction with the emission of a pheromone that performs this function.
As for the reproductive organs, these are atrophied in the workers. In the queen they are made up of two piriform ovaries which in turn are formed by 180 ovarioli each, where the eggs are formed and ripen before their emission. The mature egg passes through the oviduct where the duct of the spermatic bladder opens. When the egg has to give birth to a worker or queen it is fertilized by the spermatozoa, when instead it must give place to a drone it passes without receiving the spermatozoa as the egg of the kelp develops through parthenogenetic way.
In the drone or male the reproductive apparatus consists of two testicles, two seminal vesicles containing the spermatozoa and the copulatory apparatus which tears at the act of fertilization of the queen and the drone dies.
It should be emphasized that there are significant temporal differences in the development of the three castes: that is, a working class queen and a kelp that populate the hive. The exact knowledge of these differences is very important not only for the beekeeper, but especially for specialists who are dedicated to the specialized breeding of queen bees.

Attitude and biological cycle –
The life cycle of Apis mellifera has four main distinct phases: egg, larva, pupa and adult. The total development time for the queen bee is 16 days, 21 days for the worker bee and about 24 days for the male drone or bee.
The first phase of development of the life cycle of the bees consists of the egg which is very small and in the shape reminiscent of poppy seeds. Each egg has an opening on the wider side that allows the sperm to penetrate. The hatching of eggs usually occurs after three days from their deposition.
The larval stage generally lasts for about nine days. During this phase, the larva just emerged from the egg is almost microscopic, without legs or eyes.
For the first two days, the larva is fed with a substance known as royal jelly. During the third day, the larvae that are destined to develop in queen bees continue to feed on royal jelly, while those that will turn into worker bees feed on honey, water and pollen.
The larvae stage of the queen bee has a duration of 5.5 days, that of the working bee of 6 days and that of the drone of 6.5 days.
In the pupa, the reorganization of the tissues occurs massively. The body, which previously had the shape of a worm, is now divided into three distinct parts. This phase usually lasts for 7.5 days for the queen bee, 12 days for the worker bees and 14.5 days for the drones.
At this point all three types of bee are fully grown and are completely ready to perform their tasks. A typical colony of honey bees consists of 50,000 to 60,000 worker bees, 600 to 1000 bees kelp and a single queen bee.
During mild climate periods in spring and summer, males leave the beehive and gather in the “meeting areas of the drones” near the beehive. The virgin queen bees will fly through these areas, attracting males to pheromones.
The males chase and try to mate with the queen in flight. Sometimes, when a group of males gather around the female, a sort of “comet” forms, whose tail is formed by a series of other males trying to catch up. Every male who succeeds in mating successfully falls down, and dies within a few hours or days. Males who do not mate continue to wait in the rally area until they mate or die in the attempt. The queens mate with up to 10 males in one flight.
Queens can mate with both its own beehive and other hives in the area; after this has happened, the queen bee will no longer mate for the rest of her life.
All the activities of the colony are centered around the reproductive behavior of the queen bee and its survival. It lays its eggs almost continuously throughout the year, sometimes stopping in late autumn when the weather becomes cold. A particularly fertile queen can lay up to 1,000 eggs a day and 200,000 eggs during her life.
Because the queen bee reaches adulthood takes about 16 days, and another week or more because it begins to spawn. The males instead take about 24 days to reach the adult stage, and begin to leave the hive a few days later.
The queen bees are able to decide whether the eggs they lay are fertilized or not. Unfertilized eggs develop to become drones and are haploid (they have only one group of chromosomes). Instead, the fertilized eggs are diploid (they have two groups of chromosomes) and they develop as workers or new queens, depending on how they are fed when they are in the larval stage.
The colonies of well-nourished and healthy honey bees reproduce “swarming”. The worker bees of the colony begin with the production of numerous queen larvae, then just before they are born, the current queen bee that lays the eggs leaves the hive, carrying with it up to half of the workers. This swarm forms a temporary colony in a nearby tree, while the workers go in search of a suitable place for a new beehive. Once they find one, the swarm moves to the chosen location and begins the construction of the honeycomb and the start of the process of gathering food and reproduction.
Meanwhile, at the old beehive, the new queens emerge from their cells. After the swarming has been completed, all the remaining new queens try to sting and kill each other, continuing to fight until only one remains alive. Once the competition is over, the surviving queen bee begins to spawn.
Normally the pheromones secreted by a healthy queen bee prevent the worker bees from reproducing, but if a colony stays long without a queen, some of them start to lay their eggs. These eggs are not fertilized, so they will give birth to males.

Ecological role –
The Apis mellifera is an original insect belonging to the old world (Europe, Africa and Asia). There were no bees in the new world. About the spread of bees in the new world there is little news but it seems now certain that a few decades after the discovery of the Americans the Portuguese brought them to Brazil in 1530 and probably in central and southern North America during the same century. Certainly there are evidences in North America that date back to 1638. In Sydney, Australia, the first batches of bees arrived in 1822 and two decades later in New Zealand sent directly from the United Kingdom. Also in the western North America, there were no bees until 1850, when they arrived in California. From here they spread to other regions of the north, it is almost 150 years since the bees belonging to the Apis genus have spread over the five continents.
To the genus Apis belong three other species which are: Apis dorsata F. or “Giant Bee”, for its considerable dimensions (like those of a hornet); it is widespread in India, Indochina and Indomalesia; Apis florea F. or “Ape nana”, smaller in size than mellifera, is widespread in the same areas of the previous species and Apis indica F., very similar to mellifera, but slightly smaller; widespread in India, China and Siberia.
The first ecological importance that the bee plays is that of being an insect pronubo, that is, that favors pollination, transferring the pollen from one flower to another. The maintenance of plant biodiversity, that is an adequate number of species of spontaneous and cultivated plants, is possible only if there is a high quantity of pollinating insects. Among these, the bee plays a role of primary importance. Consider also that bees are used for the pollination of protected crops and specialized orchards – about 80% of pollination is due to the pollinators – ensuring a more effective fertilization and therefore a higher production yield. Another important action that the bee plays at the ecological level is derived from the fact that in a working day, the worker bees that perform boring activities, come out of the hive repeatedly. This means that the bee is in continuous contact with the surrounding environment, bottling on flowers and plants, meadows and woods, as well as coming into contact with other substances, which transport inside the hive. In this way the hive can be a valuable source of information on the presence of pollutants in the air and the bee, with its continuous exploration flights, becomes a real environmental sentinel on which the instrumental analyzes are then carried out to monitor the ‘environment. Some pollutants can be taken from the bee by simple contact with soil, vegetation, air and water.
In addition, bees can be present on the fruits that have suffered injuries, perhaps from hail or other parasitic attacks, such as wasps that are capable of biting and breaking plant tissues. In this case the bees are useful insects because they remove the liquid and sugary substances emitted from the torn fruit, hindering the development on the same mold, which could also spread to the nearby fruits.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– Russo G., 1976. Agricultural Entomology. Special Part. Liguori Editore, Naples.
– Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.