Andrena
Encyclopedia
Andrena is the largest genus
in the family Andrenidae
, and is nearly worldwide in distribution, with the notable exceptions of Oceania
and South America
. With over 1,300 species, it is one of the largest of all bee genera. Species are often brown to black with whitish abdominal hair bands, though other colors are possible, most commonly reddish, but also including metallic blue or green.
Body length commonly ranges between 8 - 17 mm with males smaller and more slender than females, which often show a black triangle (the "pygidial plate") at the abdominal apex. In temperate areas, Andrena bees (both males and females) emerge from the underground cells where their prepupae spend the winter, when the temperature ranges from about 20°C to 30°C. They mate, and the females then seek sites for their nest burrows, where they construct small cells containing a ball of pollen mixed with nectar, upon which an egg is laid, before each cell is sealed. Andrena usually prefer sandy soils for a nesting substrate, near or under shrubs to be protected from heat and frost.
Andrena females can be readily distinguished from most other small bees by the possession of broad velvety areas in between the compound eyes and the antennal
bases, called "facial foveae". They also tend to have very long scopal hairs
on the trochanters
of the hind leg. Most species also have a well-developed "corbicula", or pollen basket, on the sides of the thorax; it is formed by an outer fringe of hairs and may or may not contain internal hairs.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in the family Andrenidae
Andrenidae
The family Andrenidae is a large cosmopolitan non-parasitic bee family, with most of the diversity in temperate and/or arid areas , including some truly enormous genera...
, and is nearly worldwide in distribution, with the notable exceptions of Oceania
Oceania
Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. With over 1,300 species, it is one of the largest of all bee genera. Species are often brown to black with whitish abdominal hair bands, though other colors are possible, most commonly reddish, but also including metallic blue or green.
Body length commonly ranges between 8 - 17 mm with males smaller and more slender than females, which often show a black triangle (the "pygidial plate") at the abdominal apex. In temperate areas, Andrena bees (both males and females) emerge from the underground cells where their prepupae spend the winter, when the temperature ranges from about 20°C to 30°C. They mate, and the females then seek sites for their nest burrows, where they construct small cells containing a ball of pollen mixed with nectar, upon which an egg is laid, before each cell is sealed. Andrena usually prefer sandy soils for a nesting substrate, near or under shrubs to be protected from heat and frost.
Andrena females can be readily distinguished from most other small bees by the possession of broad velvety areas in between the compound eyes and the antennal
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
bases, called "facial foveae". They also tend to have very long scopal hairs
Scopa (biology)
The term scopa is used to refer to any of a number of different modifications on the body of a non-parasitic bee that form a pollen-carrying apparatus. In most bees, the scopa is simply a particularly dense mass of elongated, often branched, hairs on the hind leg...
on the trochanters
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
of the hind leg. Most species also have a well-developed "corbicula", or pollen basket, on the sides of the thorax; it is formed by an outer fringe of hairs and may or may not contain internal hairs.
Species
Partial list of species:- Andrena angustitarsata
- Andrena auricoma
- Andrena cineraria, Europe
- Andrena fulva, Europe
- Andrena lauraceaAndrena lauraceaAndrena lauracea is a rare bee species from the United States. It has been collected twice in Carlinville, Illinois, once around 1897 and once in 1970–1972. There are also two putative specimens from Texas....
, known only from 4 specimens in TexasTexasTexas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and IllinoisIllinoisIllinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, in the central United States - Andrena saliciflorisWillow Mining BeeAndrena salicifloris, commonly known as the willow mining bee, is a bee in the genus Andrena. The bee ranges from Colorado to California and north to British Columbia, and often inhabits arid and alpine lands. The bee is often black or dark brown, and is sparsely coated with grayish hair on the...
, western North America - Andrena milwaukeensis, United States and Southern Canada
External links
- http://www.bugguide.net (Search for Andrena or Andrenidae, North American species only).
- Andrena miserabilis diagnostic photographs and information
- Andrena Identification Guide (female)
- Andrena Identification Guide (male)
- List of Species
- Worldwide Species Map