The Centridini are a tribe of large apid bees, many of which possess adaptations for carrying floral oils rather than (or in addition to)

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...

or nectar. The floral oils are often gathered from plants of the family

Malpighiaceae Malpighiaceae is a family of flowering plants in the order Malpighiales. It comprises about 73 genera and 1315 species, all of which are native to the tropics and subtropics. About 80% of the genera and 90% of the species occur in the New Worl ...

, though other plants may be visited. The oil-collecting species typically have "combs" composed of closely spaced, flattened, blunt bristles on the margins of the first tarsal segments of the front and middle legs; others may have velvety "pads" to absorb the oils. They also commonly gather plant

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on n ...

s for use in nest cell construction. They have a tiny

pterostigma The pterostigma (plural: pterostigmata) is a group of specialized cells in the outer wings of insects, which are often thickened or coloured, and thus stand out from other cells. It is particularly noticeable in dragonflies, but present also in ...

in the forewing, the female

scopa ''Scopa'' (; literally "broom") is an Italian card game, and one of the three major national card games in Italy, the others being '' Briscola'' and '' Tresette''. It is also popular in Argentina and Brazil, brought in by Italian immigrants, mos ...

is very bushy, and the first

flagellomere Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one o ...

of the antenna is often longer than the scape. ''

Centris The genus ''Centris'' contains circa 250 species of large apid bees occurring in the Neotropical and Nearctic realms, from Kansas to Argentina. Most females of these bees possess adaptations for carrying floral oils rather than (or in addition ...

'' are commonly encountered bees in American deserts, and are active at very high ambient temperatures when many other species are in hiding. They can often be seen in large numbers on palo verde blossoms. A common example in Arizona is ''

Centris pallida ''Centris pallida'' is a species of solitary bee native to North America. It lacks an accepted common name; however, it has been called the digger bee, the desert bee, and the pallid bee due to its actions, habitat, and color respectively. The s ...

''.

References

C. D. Michener Charles Duncan Michener (September 22, 1918 – November 1, 2015) was an American entomologist born in Pasadena, California. He was a leading expert on bees, his ''magnum opus'' being ''The Bees of the World'' published in 2000. __TOC__ Biogra ...

(2000) ''The Bees of the World'', Johns Hopkins University Press. Apinae Bee tribes {{Apinae-stub