Cenizo Journal Winter 2012 | Page 26

Bees, cont’d from page 4 S PRIGGS B OOT & S ADDLE Repair • Tack • Jewelry • Rodeo Motorcycle Gear • Gifts and more! We ship anywhere 608 1/2 E Holland Ave. • Alpine (432) 837-5000 C ONTEMPORARY W EST T EXAS A RT 401 N. 5th Street • Alpine TX 79830 (432)837-5999 Representing work by Charles Bell • Karl Glocke Ling Dong • Carlos Campana Hours vary or by appointment Art and Guitar classes • Weekend workshops offered Hand-painted signs and graphics Music To Your Ears CDs • DVDs • Vinyl Games • Special Orders Quilts Etc. by Mon-Fri 10-6 203 E Holland Ave, Alpine Marguerite Made in the Big Bend 432.837.1055 HWY 118 • Terlingua ringtailrecords@sbcglobal.net 432.371.2292 26 3/4 mile N of HWY 170 tive, as are shrubby members of the sunflower family such as skeleton-leaf goldeneye (Viguiera stenoloba). Observe on a warm sunny day, and in short order you will see bees working in the flow- ers. Native bees vary in size, from miniscule and ant-like to robust, like our big, black carpenter bee. Many have strikingly colored integument (insect skin), like the vibrant copper squash bee (Xenoglossa, family Apidae) and the brilliantly iri- descent-green sweat bees (family Halictidae); or colored pubescence (insect fur), like bumblebees, with their characteristic black and yellow pattern. Bee abdomens (rear ends) are sometimes notice- ably banded, as with honeybees, where the band- ing is dark brown and golden. The rear end of native bees may be distinctly black and white or have fuzzy cream-colored bands or bright yellow markings. Honeybees are highly social insects, and the hive itself functions almost as an organism. Individual bees forfeit their lives for the hive, aggressively protecting it by stinging intruders. A few species of native bees live a somewhat social life, with up to a few hundred bees living in one colony, compared to the tens of thousands of honeybees in a hive. Bumblebees are an example of a native social bee. They build wax nest cells and live in annual colonies of a few hundred indi- viduals. However, most native bees are solitary, meaning one female builds and provisions a nest and lays just a few eggs during her short adult life. Many species build nests in cavities in stems, twigs, rotting wood, abandoned snail shells or other suitably sized tunnels. Most native bees nest in the ground, however, excavating burrows sever- al inches below the surface. Soil preferences – amounts of moisture, slope, alkalinity and other factors – vary by species, and reproductive success depends upon the availability of both vegetation and appropriate nesting soils. Pollen is the ecological tie between bees and flowering plants and key to the critical role bees play in terrestrial ecosystems. The male gamete is housed in the pollen grain, but for the plant to benefit from sexual reproduction, the pollen grain needs to be moved from one plant to another. Along comes a bee, lured by nectar and looking for pollen to provision her nest. As she is busy with her important task of collecting nectar and pollen for her progeny, she is also incidentally pollinating native vegetation. A bee’s pubescence contributes to its effectiveness as a pollinator. Fuzzy pubes- cence has a static charge, and pollen clings to it. It is this pollen that fortuitously attaches itself to the bee that is most available for pollinating the next plant visited. Pollen collected purposefully for her progeny is carried to the nest in specialized struc- tures called pollen baskets. Most bees have pollen baskets on their hind legs. In some, like honey and bumblebees, the basket is a corbicula, a smoothed concavity surrounded by curved hairs. In other species, a dense patch of long plumose (feathery) hairs forms the pollen basket. In one family, that Cenizo First Quarter 2012 Photo by Cathryn Hoyt A common iridescent-green sweat bee working on the anthers of silverleaf nightshade. On the upper half of her hind leg, her pollen basket is loaded with pale pollen. of the leafcutter bee (Megachilidae), the pollen basket is a patch of hairs under the abdomen. Loaded baskets are quite visible and can confuse identification, as bright yellow pollen is easily mis- taken for yellow markings on legs, abdomens, backs and heads. One of our most conspicuous native bees is the robust, shiny-black carpenter bee, Xylocopa cali- fornica (family Apidae). In West Texas, the carpen- ter bee takes advantage of dry sotol, yucca and agave stalks for nesting material. Using her strong mandibles (jaws), the female carpenter bee chews a perfectly round entrance hole into the pithy stem and excavates the inside of the stalk, chew- ing up the fibrous material and leaving a telltale pile of sawdust outside the nest. Once a nest cell is constructed, she provisions it with a mass of col- lected pollen moistened with regurgitated nectar called bee bread. After a single egg is laid upon the bee bread, she seals the cell with a plug of wood pulp and begins working on the next nest cell. The bee egg hatches in a few days, and the larva consumes the bee bread, growing for a few weeks until it pupates and emerges as an adult bee. If the new adult is female, she flies out to mate, then starts her own nest building. Males do not participate in nest building, but play a differ- ent role. At flowers, they land for a quick sip of nectar, but spend most of their time courting females. Hovering around nest holes, waiting for females to emerge, their goal is to live long enough to mate. News about the plight of the bees invariably refers to honeybees. Although scientists are still dissecting the causes of colony collapse disorder, there is no doubt that bees are suffering from a