Ptenothrix beta

Ptenothrix beta is a species of springtail in the genus Ptenothrix. It is incredibly variable and ranges across the northwestern US.^[1][2]

This species is identified visually by dark polygons on the anterior abdomen, with a long tapering "carrot" of dark pigment on the posterior. Often the proximal parts of the legs are dark green, and the back "cheeks" of the head are uninterrupted dark brown. ^{[3][2][4][5][6]}

This species is one of the major five species that were mistaken for Ptenothrix maculosa originally (before Ptenothrix delongi was found to exist in the west coast), before early 2025, when antenna microscopy by citizen scientists revealed that it was indeed a separate species.^[7][8]

Soon after this was reviewed there was the realization that there seemed to be a distinct difference in the sides of the Ptenothrix delongi that were being mistaken as Ptenothrix beta.^[3][9]

Many of the Ptenothrix beta Bugguide records are outdated due to the fact that Belgian taxonomist Frans Janssens's website, collembola.org was using the same side images that had been previously caused the original missidentification. Frans was the only real springtail identifier on bugguide before his death in 2024, so there are still unresolved missidenifications circulating.^[10][2]