Bonomoia opuntiae n. sp., a new species that inhabits rotting Opuntia pieces, is described. In this species, the distal mouthparts (palparmembrane structures) are conspicuously transformed in adaptation to the fluid like habitat where the species is found. A comparative study of the chemotactic orientation of deutonymphs of Bonomoia opuntiae n. sp. and other histiostomatid species was performed. An up and down movement of legs I (waving) to receive scent particles from the air is characteristic of all species of Histiostomatidae. The light sensitive organs of Bonomoia deutonymphs are possibly homologous to the lenticulus of the Oribatida, a type of eye that originated within the paraphyletic Oribatida and probably remained within the Astigmata that phylogenetically come out of the Oribatida. This eye differs completely from the ommatidium type that is usual for other mite groups that exhibit eyes. Experiments demonstrate that Bonomoia opuntiae n. sp. deutonymphs are attracted to light. This is a plesiomorphic character of all Histiostomatidae, but only B. opuntiae n. sp. (or probably Bonomoia in general) is able to recognise slight beam gradients. The special ability to position the body perpendicularly while walking and thereby bring the eyes in a position to receive small spots of light enables the mite easiliy to find the light. The phototactic behavior of B. opuntiae n. sp. is therefore derived and differs from that of other histiostomatids.