Sphaeridia pumilisis very common and widespread. It is particularly common in samples of springtails extracted from soil samples. It is pinkish, or greyish yellow in colour and sometimes slightly tinged with blue. Males reach 0.25 mm in length whereas females grow to 0.5 mm.
In Sminthurididae, the male antenna is modified to grasp the female during mating. In Sphaeridia pumilis, the long spine on the second antennal segment (ant2) is straight (Fig. 1). This spine is curved in species of Sminthurides. Females do not possess sub-anal appendages (SAA). In Sphaeridia pumilis, the fourth antennal segment in the female is not divided into subsegments. Only six ocelli are clearly visible in the eye patch (Fig. 2) and the mucro is long and narrow without lamellae (Figs. 3). There is no tibiotarsal organ (tt organ) on the third leg and the empodium of the foot is about the same length as the claw (Fig. 4).