''Agapostemon texanus'' is a species of

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...

found in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. Commonly known as the metallic green sweat bee or the Texas striped sweat bee, it varies greatly in its appearance, with variations in color and in the amount of black markings on the legs. The flight season of ''A. texanus'' ranges from March to October with their peak activity happening in May to September. They transport pollen on their hind legs.

Range

''A. texanus'' has the greatest range of any species in the genus ''

Agapostemon The genus ''Agapostemon'' (literally "stamen loving") is a common group of Western Hemisphere sweat bees, most of which are known as ''metallic green sweat bees'' for their color. They are members of the family of bees known as Halictidae. Like ...

''. It has been documented as far north as southern Canada and as far south as Costa Rica, but is most common to the west of the

Mississippi River The Mississippi River is the second-longest river and chief river of the second-largest drainage system in North America, second only to the Hudson Bay drainage system. From its traditional source of Lake Itasca in northern Minnesota, it f ...

and on the west coast of the United States. Its range in the southwest United States is interrupted in arid areas. ''A. texanus'' can tolerate a wide range of elevation, documented from sea level all the way up to 8,000 feet in California’s

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

mountain range.

Description

The head and thorax of both male and female ''Agapostemon texanus'' are variations of a bright metallic blue or green. The males can be distinguished by the black and yellow bands on their metasoma, whereas the females are all one color. The females tend to be about 11 mm in length and the males are between 9-10 mm long.

Nesting Habits

''Agapostemon texanus'' is a ground nesting species that builds on both vertical banks and horizontal surfaces. Females fly close to the ground in search of ideal nesting sites and are specifically attracted to dark, hidden spots. They prefer to build in loamy soil, under pebbles and leaves or in pre-existing cracks or holes in the ground to stay hidden. ''A. texanus'' is an exclusively solitary nester, unlike the other members of its genus, which can be found in both solitary and community nests.

Nest Architecture

''Agapostemon texanus'' is considered a ground nesting bee. The ''A. texanus'' nest consists of a nearly vertical tunnel with 6-14 lateral branches, each of which end in a single cell and are dug with no particular sequence. Burrows show a downwards trend in their construction, likely due to periodic deepening of the nest. The vertical tunnel can range in depth from 20-150 cm and the lateral branches can be around 5-20 cm long. The main tunnel is just large enough for the female to be able to turn around in, with a diameter of about 4 cm. The side tunnels are narrower than the main tunnel and as such are too small for the female to turn around in. During excavation, any detritus from the digging is built up in a mound around the entrance of the nest. If undisturbed the size can range from 3-5 cm in diameter with a height of 1-3 cm high. This mound is usually dispersed by wind and other weather conditions. The entrance of the burrow is found at the center of this mound and, unlike the nests of other members of

Halictinae Within the insect order Hymenoptera, the Halictinae are the largest, most diverse, and most recently diverged of the four halictid subfamilies. They comprise over 2400 bee species belonging to the five taxonomic tribes Augochlorini, Thrinchos ...

, the entrance is not usually narrower than the main tunnel. During the night when the bee is no longer foraging, the entrance is sealed with dirt. The lateral tunnels in the main burrow end in a cell that is many times smaller in length than the tunnel itself. This feature is unique to the

genus. Only one side tunnel is open at a time, once finished and filled, the tunnel is packed with dirt. Each cell is about 7 by 11 mm, with an entrance slightly narrower than the width of the attached tunnel. The cell wall is coated with a salivary secretion, forming a fragile film that lines the cell. After the egg has been deposited the female seals the cell with a secretion from her anal region.

Foraging

Similar to honeybees and bumble bees, ''A. texanus'' is observed to make short, direct flights between the flower it forages at and other neighboring flowers. This habit has been shown to decrease the probability of revisiting already foraged flowers. ''A. texanus'' is not observed to have a preference towards any specific flowers and is thus considered a

generalist A generalist is a person with a wide array of knowledge on a variety of subjects, useful or not. It may also refer to: Occupations * a physician who provides general health care, as opposed to a medical specialist; see also: ** General pract ...

. They are recorded foraging at any flower they can during the day.

Parasites and Predators

Based on current research there do not appear to be any specific predators or parasites of ''A. texanus''. The following species are observed to prey on ''A. texanus'': *

Crab spiders The Thomisidae are a family of spiders, including about 170 genera and over 2,100 species. The common name crab spider is often linked to species in this family, but is also applied loosely to many other families of spiders. Many members of th ...

(Thomisidae) * Ambush bugs (Phymatidae) * Philanthe wasps (

Sphecidae The Sphecidae are a cosmopolitan family of wasps of the suborder Apocrita that includes sand wasps, mud daubers, and other thread-waisted wasps. The name Sphecidae was formerly given to a much larger grouping of wasps. This was found to be p ...

) *

Robber flies The Asilidae are the robber fly family, also called assassin flies. They are powerfully built, bristly flies with a short, stout proboscis enclosing the sharp, sucking hypopharynx. The name "robber flies" reflects their notoriously aggressive pre ...

(Asilidae) Blister beetle (

Meloidae Blister beetles are beetles of the family Meloidae, so called for their defensive secretion of a blistering agent, cantharidin. About 7,500 species are known worldwide. Many are conspicuous and some are aposematically colored, announcing their ...

) larvae can be commonly found on adult bees, and are also occasionally found in the cells of ''A. texanus''.

Gallery

File:Agapostemon texanus male.jpg, Agapostemon texanus male from Kirkland, Washington File:Sweat bee, male Texas Agapostemon (Halictidae, Agapostemon texanus (Cresson)) (35635629626).jpg, Sweat bee, male Texas Agapostemon (Halictidae, Agapostemon texanus (Cresson)) USA, TX, Bastrop Co.: Red Rock File:Texas Agapostemon (Halictidae, Agapostemon texanus) (30941172200).jpg, USA, TX, Travis Co.: Austin Brackenridge Field Laboratory File:Sweat bee, female Texas Agapostemon (Halictidae, Agapostemon texanus (Cresson)) (35506388752).jpg, Sweat bee, female Texas Agapostemon (Halictidae, Agapostemon texanus (Cresson)) USA, TX, Travis Co.: Austin Commons Ford Ranch Agapostemon texanus.jpg, Agapostemon texanus, from Maricopa Co., Arizona, USA

References

texanus Hymenoptera of North America Insects described in 1872 Taxa named by Ezra Townsend Cresson {{sweat-bee-stub