Abstract
In terms of body size, species of the genus Psyttala Stål, 1859, are the largest known representatives of the subfamily Reduviinae. Among the species belonging to this genus, Psyttala horrida (Stål, 1865) is the most popular, mainly because it is a laboratory breeding species. Individuals of this species were bred in the laboratory of the Zoology Team at the University of Silesia in Katowice, Poland. A description of the morphology of the nymphs and eggs is presented. In addition to descriptions, photos of the successive immature stages are provided and scanning electron microscopy (SEM) images are included to show morphological details and compare the developmental changes in subsequent stages.