Lithurgopsis

Taxonomy

Family: Megachilidae
Subfamily: Lithurginae
Tribe: Lithurgini
Genus: Lithurgopsis Fox, 1902
Subgenera: none
Common name: none

Overview

Lithurgopsis have a robust, rounded body form (Michener 2007). They range in body length from 7.5–20 mm. They are dull black, often with pale bands of hair on the terga and sterna (Michener 2007). Females often have lobes or horns on their supraclypeal area underneath the antennae and dense ventral scopae. Lithurgopsis was previously a subgenus of Lithurgus (Gonzalez et al. 2013).

Diversity

Lithurgopsis contains 9 species worldwide; 7 species occur in North America north of Mexico, and 3 species occur in Argentina (Snelling 1983, 1986; Michener 2007; Gonzalez et al. 2013).

Diagnostic characteristics

(modified from Michener 2007 unless otherwise stated)

May be confused with

Lithurgopsis looks similar to some Megachile, Austrothurgus, and Lithurgus, but can be distinguished by the characters listed above.

Known invasives

There are no known invasives.

Host associations

In the U.S., Lithurgopsis spp. are primarily specialists on Cactaceae, including Opuntia spp. and Echinocactus spp., and may serve a very important role in their pollination (Wilson and Carril 2016). This host limitation may limit Lithurgopsis to xeric regions.

Nesting behavior

Lithurgopsis spp. are solitary, although sometimes gregarious, wood-boring bees that excavate their own cavities within the wood (Rozen and Hall 2014). Dead rotting wood as well as firm nondegraded wood, woody stems such as Agave stalks, and occasionally man-made wood structures or wood-based materials are used (Rozen and Hall 2014). Their habit of burrowing into standing wooden structures can be particularly damaging over time. Their nesting habits can be peculiar compared to other megachilid bees. They typically do not line nests, but L. apicalis will occasionally lacquer the nest entrance with nectar (Rust et al. 2004). One elongated chamber, or branch, may contain multiple provisions with brood contained one after another in a linear series (Rozen and Hall 2014). Wood particles are sometimes used to partition the nest chamber into multiple separate cells (Rozen and Hall 2014).

Distribution

Lithurgopsis occurs only in the Western Hemisphere, usually in warm temperate or tropic areas. In the U.S., it occupies the dry areas of the southern and western U.S., and is rare or absent in the northeastern U.S. (Michener 2007).

​Distribution map generated by Discover Life -- click on map for details, credits, and terms of use.

<p><em>Lithurgopsis litoralis</em> male face, photo: C. Ritner</p>
Lithurgopsis litoralis male face, photo: C. Ritner
<p><em>Lithurgopsis littoralis </em>male lateral habitus, photo: C. Ritner</p>
Lithurgopsis littoralis male lateral habitus, photo: C. Ritner
<p><em>Lithurgopsis littoralis</em> male abdomen, photo: T. Brady</p>
Lithurgopsis littoralis male abdomen, photo: T. Brady
<p><em>Lithurgopsis littoralis</em> male antenna, photo: C. Ritner</p>
Lithurgopsis littoralis male antenna, photo: C. Ritner
<p><em>Lithurgopsis apicalis</em> male hind basitarsus, photo: C. Ritner</p>
Lithurgopsis apicalis male hind basitarsus, photo: C. Ritner
<p><em>Lithurgopsis apicalis</em> female tibial spur, photo: C. Ritner</p>
Lithurgopsis apicalis female tibial spur, photo: C. Ritner
<p><em>Lithurgopsis littoralis</em> male tarsal claw with arolia present, photo: C. Ritner</p>
Lithurgopsis littoralis male tarsal claw with arolia present, photo: C. Ritner