Chelostoma californicum Scissor Bee

Description

Chelostoma californicum is a medium-sized bee of 8-9 mm in length in with a long-shaped, cylindrical black body that has white hairbands across the apex of the tergal segments. It has a hairy head, an elongated scutellum (top of the thorax) and the hair bands on this bee’s abdomen are thickest along the sides. Their wings have 2 submarginal cells. They are called scissor bees because the mandibles of females resemble scissors. This is a difficult bee to identify to species, and most are just narrowed to genus Chelostoma or subgenus Neochelostoma (In fact, under microscope, females are usually identified by the structure of the clypeus and labrum and males by the structure of tergite 7, the sternites and genitalia characteristics).