The morphological characters of adult females of Trionymus aberrans Goux 1938 that had been collected in post-industrial wastelands and other habitats in Poland and other countries were studied. A distinctive morphological variability was observed in the specimens that had been collected from post-industrial wastelands in Poland. SEM photos of the morphological characters of T. aberrans are provided. The occurrence of unusual pores with four loculi was demonstrated for the first time in a species of the family Pseudococcidae. The importance of introducing additional morphological characters into the species description is discussed. New data on the frequency and host preference of T. aberrans are also provided. Our research is the first long-time study on scale insect species in post-industrial wastelands. The second-instar nymph of T. aberrans is described. The presence of translucent pores on the hind coxae in second-instar nymph was revealed.