The alfalfa leafcutting bee, Megachile rotundata: the world's most intensively managed solitary bee.

@article{PittsSinger2011TheAL,
  title={The alfalfa leafcutting bee, Megachile rotundata: the world's most intensively managed solitary bee.},
  author={Theresa L. Pitts‐Singer and James H. Cane},
  journal={Annual review of entomology},
  year={2011},
  volume={56},
  pages={
          221-37
        }
}
The alfalfa leafcutting bee (ALCB), Megachile rotundata F. (Megachildae), was accidentally introduced into the United States by the 1940s. Nest management of this Eurasian nonsocial pollinator transformed the alfalfa seed industry in North America, tripling seed production. The most common ALCB management practice is the loose cell system, in which cocooned bees are removed from nesting cavities for cleaning and storage. Traits of ALCBs that favored their commercialization include gregarious… 
Variation in Alfalfa Leafcutting Bee (Hymenoptera: Megachilidae) Reproductive Success According to Location of Nests in United States Commercial Domiciles
TLDR
Bee cells produced in a small alfalfa field and collected from domiciles showed that the production of live overwintering prepupae, diseased larvae, other dead eggs and larvae, and cells attacked by natural enemies varied according to board orientations and positions, and portions of the boards.
Health Status of Alfalfa Leafcutting Bee Larvae (Hymenoptera: Megachilidae) in United States Alfalfa Seed Fields
TLDR
Vapona is used to control parasitoids when the parent bees are incubated before release, and use of this fumigant was associated with an increase in both chalkbrood and diapausing offspring, although any reason for these correlations are unknown.
Nesting Biology of the Leafcutting Bee Megachile minutissima (Hymenoptera: Megachilidae) in Central Saudi Arabia
TLDR
The leafcutting bee Megachile (Eutricharaea) minutissima Radoszkowski is a widely distributed species in the Middle East and a promising pollinator of alfalfa and some degree of polylecty as well as either bivoltinism or multivolt inism is indicated.
Examining historical rates of leafcutting bee cell pathogens to establish baseline infectivity rates for alfalfa seed growers
TLDR
Historical data from the Parma Cocoon Diagnostic Laboratory is used to determine baseline rates of pathogen and parasite infection of Megachile rotundata cells and used this analysis to determine historical infection rates and cutoffs for management practices.
Intended Release and Actual Retention of Alfalfa Leafcutting Bees (Hymenoptera: Megachilidae) for Pollination in Commercial Alfalfa Seed Fields
TLDR
Significant positive relationships were found between the intended stocking densities and the number of females that actually survived incubation and field emergence and 2) the numberof females that established nests, which indicates that it may be more frugal to use modest numbers of M. rotundata for pollination, because many of the bees at medium and high stocking density do not nest in grower-provided bee boards.
Novel microsatellite loci reveal high genetic diversity yet low population structure for alfalfa leafcutting bees in North America
TLDR
The trade and movement of these bees by humans has created a nearly panmictic M. rotundata population across the continent, which has implications relevant to the preservation and conservation of other bee pollinators.
Mortality Dynamics and Life Tables of Megachile rotundata (Hymenoptera: Megachilidae), a Pollinator Managed for Alfalfa Seed Production
TLDR
Mortality from each class was highly irreplaceable, and strategies to mitigate those causes may help producers decrease total population loss of M. rotundata before the adult stage.
Pruned petioles of papaya as nesting sites of the leafcutting bee, Megachile laticeps Smith and its pollen fidelity
TLDR
Nest pollen analysis indicated that Fabaceae pollen was the most prevalent in the brood provision, and shows the importance of pollinator species’ characteristics for developing conservation strategies to enhance pollination services in agro-ecosystems.
Leafcutter Bees (Hymenoptera: Megachilidae) as Pollinators of Pigeon Pea (Cajanus cajan (L.) Millsp., Fabaceae): Artificial Trap Nests as a strategy for their conservation
TLDR
It is concluded that female bees possess more wing wear during the vegetative stage of the crop when compared to the flowering stage, proving the importance of leafcutter bees for the pollination of Cajanus cajan crop.
Supersedure of Isodontia mexicana (Saussure) (Hymenoptera: Sphecidae) Nests by Megachile rotundata (F.) (Hymenoptera: Megachilidae): Do Bees Destroy Wasp Cocoons?
TLDR
By simply observing the spatial patterning of cells in mixed-species nests, one cannot determine if two species are in direct competition or whether one occupied a nest only after it was abandoned by the other, recent evidence suggests a more direct effect of one species on the other.
...
...

References

SHOWING 1-10 OF 177 REFERENCES
Potential of the alfalfa leafcutter bee, Megachile rotundata (F.) (Hym., Megachilidae) to pollinate hairy and winter vetches (Vicia spp.)
TLDR
Evaluating the effectiveness of the alfalfa leafcutter bee as a potential pollinator of winter (woollypod) vetch, Vicia dasycarpa Ten.
Nest Establishment, Pollination Efficiency, and Reproductive Success of Megachile rotundata (Hymenoptera: Megachilidae) in Relation to Resource Availability in Field Enclosures
TLDR
It is concluded that bee nest establishment, pollination efficiency, and reproductive success are compromised when bee densities are high relative to floral resource availability.
Artificial Nesting Sites for the Propagation of the Leaf-Cutter Bee, Megachile (Eutricharaea) rotundata, for Alfalfa Pollination
The leaf-cutter bee, Megachile rotundata (Fabr.), although endemic to Eurasia, is found throughout most of continental United States where it has been reported polylectic on a variety of floral
Emergence Success and Sex Ratio of Commercial Alfalfa Leafcutting Bees from the United States and Canada
TLDR
This study supports the commonly held belief that alfalfa leafcutting bees raised in Canada and then sold to the United States represent a more viable source of bees than most bees produced in the United United States.
Examination of ‘pollen balls’ in nests of the alfalfa leafcutting bee, Megachile rotundata
TLDR
X-radiography was used to analyse nests of Megachile rotundata and revealed that 20–50% of the bee cells contained so-called ‘pollen balls’, a term commonly used in the USA to indicate cells that are provisioned but lack healthy eggs or developing larvae.
The alfalfa leafcutter bee, Megachile rotundata: a potential pollinator for some annual forage clovers
TLDR
The arrowleaf, berseem and crimson clovers were essentially self-sterile and produced very little seed when bees were excluded, whereas about one-third of the Persian clover flowers were self-pollinated.
Alfalfa leafcutting bee (Hymenoptera: Megachilidae) pollination of oilseed rape (Brassica napus L.) under isolation tents for hybrid seed production
TLDR
Production of hybrid seed within tents varied with leafcutting bee stocking rate, with the highest seed yield achieved at stocking rates equivalent to half of that achieved in a 1 yr test of bumble bees.
Prewinter Management Affects Megachile rotundata (Hymenoptera: Megachilidae) Prepupal Physiology and Adult Emergence and Survival
TLDR
The results show that the timing of the onset of winter storage and incubation does affect prepupal weights, prep upal lipid and water contents, adult emergence, and adult female longevity, and some prewinter management regimes for M. rotundata commercial stocks may be more effective than others for achieving optimal adult emergence synchrony, as well as adult survival and longevity for pollination of a summer crop.
Cell production by the alfalfa leafcutting bee (Megachile rotundata F.) in new and used wood and polystyrene nesting materials
Wood and polystyrene are two predominantly used nesting materials for the alfalfa leafcutting bee, Megachile rotundata. Bee cell production in both new and used nesting boards of these two materials
An Open-Field Test of Megachile Rotundata as a Potential Pollinator in Hybrid Carrot Seed Fields
TLDR
Flies, rather than M. rotundata, may be a useful alternative to the honeybee for carrot pollination, and were abundant on both male-fertile and sterile varieties.
...
...