Lazy hitchhikers? Preliminary evidence for within-habitat phoresy in pygmephoroid mites (Acari, Scutacaridae)

An update on the knowledge about scutacarid mites as phoronts and inquilines

“…Termites could never be seen removing attached mites of I. clementis, even when they were self-or allogrooming. Attachment didn′t happen by claws on leg I, as is typical for Scutacaridae (Baumann 2018), but by large empodia on legs II and III (Baumann et al 2018). This species was thus the first example of a scutacarid without claws on leg I that still can attach to a phoresy host, which indicates that -contrary to previous opinion-all other species without claws I might also be able to perform phoresy using their empodia.…”

“…(Baumann and Ferragut 2019). The latter was found attached to the coxae of Reticulitermes banyulensis (Baumann et al 2018, Baumann andFerragut 2019). Termites could never be seen removing attached mites of I. clementis, even when they were self-or allogrooming.…”

“…Inside the termites' nests, I. clementis was found either on the termites or inside the tunnels that the termites created in dead wood, and they were located preferably near termite carcasses (Baumann et al 2018, Baumann andFerragut 2019). Only few scutacarid specimens could be found in the soil surrounding the nests.…”

“…This species was thus the first example of a scutacarid without claws on leg I that still can attach to a phoresy host, which indicates that -contrary to previous opinion-all other species without claws I might also be able to perform phoresy using their empodia. The attachment of the mites seemed to be weak as the mites detached after the slightest external disturbance, which might indicate that phoresy is restricted to the inside of the termite nest (Baumann et al 2018).…”

“…Regarding behavioural aspects, the studies about Imparipes clementis, which is associated with termites (Baumann et al 2018, Baumann andFerragut 2019), gave some new insights as they demonstrated that phoretic attachment is possible even without claws on leg I, that the hosts never tried to remove attached mites, that mites can be found in areas inside the termite nests where termite corpses are buried and that the number of phoretic mites increases when a colony is in a bad state (presumably so that the mites have a chance to leave the "sinking ship", the moribund nest). There is still a lot of information about behavioral aspects lacking, for example: How exactly is the phoretic behavior initiated, how is it stopped?…”