These female Sminthurides springtail were found crawling in the grass that was partially submerged in a small pond. Frans identified them as Sminthurides weichseli. I can't find any info about this species online, but here's what Frans said "...Sminthurides weichseli, which is characterised by a typical 'washed' blue pigment of head and body. The large blue specimens are adult females. If a Sminthurides male is 'rejected' by a female it often 'practises' its grasping on subadult females and/or other males. So in the 'mating' pics the males are exercising"

The large, dark blue ones are the adult females, the smaller light blue ones are subadult females, and the small brown/brownish-purple ones are the males.