| Megachile | |
|---|---|
 | |
| Megachile lagopoda | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Megachilidae |
| Genus: | Megachile Latreille, 1802 |
| Subgenera | |
Over 50 subgenera and1520 spp., see list | |
| Synonyms | |
| |
_-_Keila.jpg)
The genusMegachile is acosmopolitan group of solitarybees, often calledleafcutter bees orleafcutting bees; it also includes the resin bees and mortar bees. While othergenera within the familyMegachilidae may chew leaves or petals into fragments to build their nests, certain species withinMegachile neatly cut pieces of leaves or petals, hence their common name. This is one of the largest genera of bees, with more than 1500 species[1] in over 50 subgenera.[2] The alfalfa leafcutter bee (Megachile rotundata) is managed on a commercial scale forcrop pollination, and has been introduced by humans to various regions around the world.
Nests are sometimes constructed within hollow twigs or other similarly constricted natural cavities, but often are in burrows in the ground. Nests are typically composed of single long columns of cells, the cells being sequentially constructed from the deepest portion of the tunnel outwards. The female places an egg in each cell with a supply of food, generally pollen, sometimes mixed with nectar. She builds a cap and walls off the cell. The larva hatches from the egg and consumes the food supply. After moulting a few times, it spins a cocoon and pupates, often after several months ofhibernation as aprepupa. It emerges from the nest as an adult. Males, which are typically smaller and emerge in advance of females, die shortly after mating, but females survive for another few weeks, during which time they build new nests. Numerous families of wasps and bees parasitizeMegachile nests, includingGasteruptiidae,Leucospidae,Sapygidae, and variouskleptoparasitic megachilids, such as the closely related genusCoelioxys.M. rotundata andM. campanulae are among of the first insects documented in scientific literature to usesynthetic materials for making nests.[3]
ManyMegachile species use cut leaves to line the cells of their nests. It is thought that the leaf discs help prevent thedesiccation of the larva's food supply.[1] Various species in the genus, especially those in the subgenusChalicodoma and related groups, do not use cut leaves to line the cells, but instead use fairly dry plant resin, which they carry in their mandibles. The subgenusChalicodoma includes the world's largest bee,Megachile pluto, as well as one of the largest megachilids in the United States, the recently introduced Asian species,Megachile sculpturalis.
SomeMegachile species have no lobe (arolia) between their claws, thus are unable to climb smooth walls or glass.[4]
The genusMegachile contains 56 subgenera with 1520 recognized species.[1] See also thelist ofMegachile species.
Notable subgenera:
Notable species:
_from_Badlands_National_Park%2c_South_Dakota_-_USGS_Bee_Inventory_and_Monitoring_Laboratory.jpg)
