[1] This species has been solely recorded at the Craters of the Moon National Monument found in Idaho, and is endemic to this location.

This specimen is preserved in the Los Angeles County Museum entomology collection.

[3] Hylaeus lunicraterius has a flight season from July to August.

[2] It is known to be a pollinator of mouse buckwheat (Eriogonum nudum var.

The Hylaeus genus is characterised by nesting in uninhabited beetle holes and dead wood, but is suspected to utilize crevices in lava flows as well.