When we talk about bees we often immediately think of the honey bee because it is more familiar to us. However, this is only one species (melliferous), of a genus (apis), of a family among the 12 that make up the superfamily of hymenoptera called Apoidea . This superfamily includes 29,337 species, all of which share a diet of nectar and pollen. Taxonomists classify this multitude of species into two large groups, Spheciformes and Anthophila , which include 5 and 7 families respectively. Only the species of the second group are considered “bees”, as it includes all linear descendants of a single common ancestor. Thus, the number of species that can be defined as “bees” is reduced to 16,000, distributed over all the continents of the world except Antarctica. In Europe we can count about 2000 species, while in Italy, according to the last list drawn up (Pagliano 1995), there are 944 species. The Italian bee fauna is therefore one of the richest in the world in relation to the surface area.
As we have already said, all bees feed on nectar and pollen, but they are divided into oligoleptic species, which draw on only a few varieties of flowers, and polylethic species which, on the contrary, pollinate a wide range of plants. They also differ according to their social life, which is mainly solitary or communal, and to the structure of their nests: bees can build their nests in the ground, in wood or in ravines of all types; the most evolved structure is represented by the honeycomb, a grouping of hexagonal cells modelled with wax secreted by the abdominal glands of the worker bees.
The families present in Italy that are part of the Anthophila taxonomic macrogroup are:
- Halictidae
They are bees of variable size and tend to be dark in colour, sometimes with metallic highlights. They nest in the ground, covering their cells with an insulating layer, and are polyletic insects. They are often referred to as “sweat bees” because they are attracted to human sweat. The main genera are: Halictus, Lasioglossum, Nomiapis, Nomioides, Sphecodes, Systropha.
- Andrenidae / Andrenidae
Very large family, around 2700 species. Bees of variable size and with a sting so small that they cannot sting humans; solitary, rarely observed in aggregations, they nest in the ground and are oligolectic. They include the genera Andrenidae , Panurgus and Mellitturga.
- Apis / Apidae
The largest family of bees, around 6000 species, which therefore has considerable variability in size, colour and hairiness. They all have a very long ligule, the “proboscis” used to suck up nectar, and good stationary flight abilities. They are polyletic species. There are 18 genera: Amegilla, Ammobates, Ammobatoides, Anthophora, Apis, Biastes, Bombus, Ceratina Epeolus, Eucera, Habropoda, Melecta, Nomada, Pasites, Tetralonia, Tetraloniella, Thyrenus, Xylocopa.
- Collectids / Collettidae
Includes about 200 species. They have a short ligule and are solitary bees. They are also known as cellophane bees because the females cover their cells with a substance that, once dry, resembles cellophane. In Italy there are only two genera, Colletes and Hylaeus.
- Megachilidae
Family comprising about 4000 species, mostly polyletic and with long ligula. The females have a characteristic pollen-collecting structure under the abdomen formed by fringes of hairs, called a broom. They often have large, powerful mandibles for chewing plant material, cutting leaves and digging holes in dead wood. The genera are : Anthidiellum, Anthidium, Chelostoma, Coelioxys, Heriades, Hoplitis, Icteranthidium, Lithurgus, Megachile, Osmia, Pseudanthidium, Rhodanthidium, Stelis, Trachusa.
- Melittidae / Melittidae
A small family of 200 species, the Melittidae are small to medium-sized bees that nest in the ground. They are oligoleptic or even monoleptic and are mainly found in the temperate zones of the northern hemisphere and in Africa.
As for the bees bred, they are mainly subspecies of the melliferous species, the most productive and docile. The domestic bees bred in Italy are the Apis mellifera , or European bee, and Apis cerana , also called oriental bee, bred in some areas of Friuli. Within the melliferous species, the Ligustica subspecies, or Italian bee, is the most widespread in the world and on the national territory thanks to its docility, capacity for large production and absence of swarming; in some areas of the central north, the Apis mellifera mellifera, also known as the black bee, which has a marked resistance to cold, is also bred. It is worth noting the presence and uniqueness of the Apis mellifera sicula; this bee is mainly found in the Trapani area, has a dark colour and good immune resistance, a characteristic that makes it an important genetic resource.
The great variety of species that inhabit the area is not only a privilege but also a great responsibility. However, about 25% of all bee species seem to have declined considerably since the 1990s. We know that all bee species collaborate in the pollination process and that their presence is therefore directly related to plant biodiversity; moreover, the genetic variability of bees is their only weapon for adapting to climate change, one of the main threats to their survival. Therefore, we cannot limit ourselves to saving the common honey bee from extinction, but we must maintain and protect the habitats, compromised by human activities, of the many other wild bee species in order to ensure the biodiversity, and therefore the life, of the world.