Vahedi, H.A. 2008a Morphological studies on the second instars of some (not all) cyst forming margarodids (Sternorrhyncha: Coccoidea: Margarodidae) in Kermanshah, Iran.. Proceedings of the XI International Symposium on Scale Insect Studies, Oeiras, Portugal, 24-27 September 2007. ISA Press Lisbon, Portugal 322 pp.

Notes: The cyst form (2nd-instar nymphs) of margarodids feed on the collar of their host plant in the soil, where they remain encysted throughout their development. The morphological studies on Porphyrophora were done using a Scanning Electron Microscope with critical point and those on Neomargarodes by drawing under an Olympus microscope. Both cyst stages had very long stylets, longer than their diameter; this is the stage which causes economic damage. The 2nd-instars vary somewhat in colour but are all red, legless, spherical in shape, with rudimentary antennae, 2 pairs thoracic spiracles, 0-7 pairs abdominal spiracle(s) and a simple anal opening. The cyst becomes enclosed in membranous layer(s) of glassy wax, which may gradually increase in number as the insect continues feeding and growing (for example, up to 12 plates have been counted on Porphyrophora) but only one thick plate on Neomargarodes. The 2nd-ins tar cyst stage is commonly referred to as ground pearl. The morphology of the cyst stages of the two genera, Neomargarodes and Porphyrophora, are compared in detail.