Morphology of nymphs of common stored-product psocids (Psocoptera, Liposcelididae).

The last developmental instar of female nymphs of the 6 synanthropic Liposcelis species most frequently occurring in stored products worldwide are described. The morphological study deals with overall appearance, chaetotaxy and size measurements of nymphs. Morphological characters include the number and length of setae and their density on the pro- and mesothoracic sternites, vertex of head, lateral lobe of pronotum, abdominal tergites, and the number of ommatidia in the compound eyes. Morphological details are illustrated by SEM micrographs. A key for distinguishing the described instars of the six Liposcelis species is provided.