The rubber thrips deserves to be more widely known, not only on account of its economic importance, but because it forms the type of a small group of the genus Physothrips, separated at once by the structure of the sternites 3 to 7 in the ♂. In some species the sternites are simple, but in most they are characterised by one well-formed and defined thinly chitinised area in the centre of each, either round, transverse or oviform, generally largish but sometimes reduced to a small puncture-like depression. These male features are found also in other genera. In P. funtumiae and its allies however the sternites 3 to 7 have numerous, usually irregular, depressions, smaller or greater, arranged in 2 to 4 more or less regular or defined, transverse rows. In one species (P. funtumiae) the anterior row of areas is characterised by the possession of a long, transverse, median area; but this is occasionally broken up to a greater or less degree.