Immature birds are similar to adult females, since young males lack a crown patch.

Immature males also lack the blue pruinescence and have greeny brown eyes.

The male does not bite and lacks hair on eyes.

The female is about 22 mm long; the male is smaller and lacks a stinger.

The males are few in number and lack the power to activate the disks.

In addition, most males lack the back flexibility required by the position (a problem that is known to plague some female skaters as well).

These females seemed to have a common awareness of each other's nature that males lacked.

All females become part of such groups but socially inhibited males may lack mates.

At other seasons the male may entirely lack sexually active female companions.

The male is black and lacks the hypopygium structure which clearly identifies the species in the female.