Megachile pruina

Smith, 1853

Hoary Leafcutter Bee

Megachile pruina, commonly known as the Hoary Leafcutter , is a solitary leafcutter bee in the . It is -sized (11–13 mm) and exhibits sexual dichromatism, with females often appearing very dark. The occurs along coastal from Virginia to Florida and westward to Texas, with an isolated in Bermuda that represents a genetically distinct evolutionary lineage. Bermuda's population is classified as Vulnerable and is the only protected under the Bermuda Protected Species Act.

Megachile pruina, f, charlotte county, fl, face 2016-08-24-13.28 (29252005705) by USGS Bee Inventory and Monitoring Lab from Beltsville, Maryland, USA. Used under a Public domain license.

Probably Hoary Leaf-cutter Bee Megachile pruinas (38403781282) by gailhampshire from Cradley, Malvern, U.K. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Megachile pruina: //ˌmɛɡəˈkaɪli ˈpruɪnə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other Megachile by its size (11–13 mm), coastal distribution, and the very dark coloration of females. The Bermuda is genetically distinct from mainland US populations. Former (M. pruina bermudensis, M. pruina nigropinguis) based on color variants are likely invalid based on 2024 genetic evidence showing no significant genetic differentiation among US populations.

Images

Appearance

-sized measuring 11–13 mm in length. Sexual dichromatism is present: females can be very dark in coloration, while males differ in appearance. The exhibits the general Megachile body plan with a build typical of leafcutter bees.

Habitat

Coastal . In Bermuda, restricted to the Castle Harbour Islands Nature Reserve, primarily on Nonsuch Island (11.5 ha), with additional observations on Cooper's Island, Southampton Island, Horn Rock, and Castle Island.

Distribution

United States: Virginia to Florida, westward to Texas, mostly along coastal . Bermuda: , currently restricted to Castle Harbour Islands Nature Reserve.

Human Relevance

Bermuda's is the only protected under the Bermuda Protected Act (Vulnerable status, 2016). Subject of concern due to restriction and low genetic diversity in the isolated Bermuda population.

Similar Taxa

Other Megachile speciesM. pruina can be distinguished by its specific size range, coastal distribution, and female coloration; genetic analysis confirms its distinct lineage, particularly for the Bermuda

More Details

Taxonomic History

Originally described by Smith in 1853. Bermuda specimens were initially classified as M. pruina bermudensis (1929), later reclassified as M. pruina pruina. A second subspecies M. pruina nigropinguis was described in 1937 for a dark female variant from Texas. 2024 genomic analysis found Bermuda genetically distinct from all US populations, and no genetic differentiation among US populations, suggesting subspecies are invalid.

Conservation Genetics

2024 study found Bermuda's M. pruina has lower genetic diversity than US , indicating higher vulnerability than previously recognized. The population shows no close genetic association with any sampled US population, supporting its status as a unique evolutionary lineage.