Sunday 25 May 2014

A new species of Leafcutter Bee from Mexico.

Leafcutter Bees (Megachilidae) get their name from their habit of cutting segments from leaves with which to line their nests. They are solitary Bees, each female Bee building her own nest in a wood cavity, plant stem or the ground, in which several young are raised in separate cells. The cells are each provided with their own food source of nectar before being sealed. Typically the female young are placed in larger cells with more food, further inside the nest, as adult females are larger and take longer to mature. The sex of the adult Bee appears to be determined by the size of its cell and the amount of food it was provided with as a larva.

In a paper published in the journal ZooKeys on 13 September 2012, Emily Bzdyk of the Bohart Museum of Entomology at the University of California, Davis, describes a new species of Leafcutter Bee from Mexico, as part of a wider study of North American Leafcutter Bees.

The new species is placed in the genus Megachile, and given the specific name pankus, which Bzdyk describes as a ‘nonsense combination’. Megachile pankus is described from five female specimens from Hidalgo and Sonora States in Mexico between 1935 and 1991 and stored in the entomological collections of the Bee Biology and Systematics Lab in Logan, Utah, the American Museum of Natural History in New York and the Bohart Museum of Entomology. The males of the species are unknown. Megachile pankus is differentiated from all closely related species by the arrangement of teeth on its mouthparts. It is a 10 mm black Leafcutter Bee with white hairs and brown tinted wings.

Illustration of Megachile pankus in dorsal view. Bzdyk (2012).

Photographs of Megachile pankus: (A) Lateral view. (B) Dorsal view. (C). Mandible showing angulation. Bzdyk (2012).

Megachile pankus belongs to a group of Bees mostly distributed in more northerly climates (southern US to southern Canada); while it has several relatives that are also found in Mexico it appears to be unique in its exclusively Mexican distribution. There are records of it being seen visiting only one flower, a species of Petalostemon, a type of Legume.

The known distribution of Megachile pankus. Bzdyk (2012).

See also…

Bees (Anthophila) are generally accepted to have arisen during the Mesozoic, but estimates of exactly when vary considerably. The group are not well known in the fossil record (at least in part because many early palaeontologists tended to ignore Insect fossils in Mesozoic beds, happily destroying them in the quest for Dinosaurs and other large, glamorous Vertebrates), with the earliest putative Bee being Melittosphex burmensis, from 100-110 million-year-old Burmese Amber, which some...

The film Jurassic Park is based upon the idea that it might be possible to recover the DNA of Dinosaurs from inside Mosquitoes preserved in amber (fossilized tree resin). However attempts to recover biological material from amber have generally ended in failure, leaving most palaeobiologists to conclude that this is in fact impossible, and that organisms are effectively preserved in amber only as images. 

Oil Bees (Centridini) are largish Bees with special combs of bristles or velvety pads on their legs and abdomens, which they use to gather floral oils instead of or as well as nectar and pollen. They are mostly found in the Neotropics.

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