There is at least one species of exotic Isotomurus with strong lateral purple bands that has been found in heated glasshouses in England. Goto (1953) reported that J.C. Felton had found a single specimen of Isotomurus palustris forma balteata on soil in a hothouse (30 degrees Celsius) at Chelsea Physic Gardens, London in February 1953. There is a single specimen of Isotomurus 'balteata' in the NHML slide collection collected by C.H. Jackson from an orchid house in Cambridge Botanic Gardens in February 1925. Strong bands are present on the abdomen but the specimen is otherwise in very poor condition and no other morphological features can be discerned.
It is impossible to say with certainly what these specimens represent. They are clearly different from all other Isotomurus that have been reported from the UK but their identity remains a mystery. In view of the diverse global sources of the plants in heated glasshouses, it is possible that they are species new to science. Further collecting is required in the heated glasshouses in major botanical gardens, to see whether the species can be rediscovered.
If you think you have an Isotomurus balteatus in the UK, be very careful to rule out Isotomurus antennalis which looks most identical (contrary to the drawing of I. antennalis in Hopkin (2007). The best test is presence / absence of trichobothria (present in I. balteatus); also balteatus has a lateral seta on its mucro as well as 4 teeth, unlike antennalis.