Rainato, A., & Pellizzari, G. 2008a First observations on the biology and phenology of Parthenolecanium rufulum (Cockerell, 1903) (Hemiptera: Coccoidea: Coccidae) in Northeastern Italy.. Proceedings of the XI International Symposium on Scale Insect Studies, Oeiras, Portugal, 24-27 September 2007. ISA Press Lisbon, Portugal

Notes: Parthenolecanium rufulum is a Palaearctic species common on Quercus sp., but also recorded on other host plants, such as Fagus, Castanea, Vaccinum, Sarothamnus, Carpinus, Rosa and Rubus. Its biology in central Europe was outlined by Schmutterer (1954; 1972) Germany) and Dziedzicka (1968) (Poland). Until a few years ago, P. rufulum was of no economic importance, but recently it has been reported as a pest of hazelnut in Turkey and infesting deciduous oaks in urban environments in Turkey and Georgia (Ankara and Tbilisi) (Japoshvili, 2001; ?lgent?rk, 2004). Deciduous oaks are increasingly important as ornamental trees in Italian urban parks and gardens, where they are frequently planted. Among the insects living on deciduous s in urban environments, P. rufulum is a very common and widespread species. Due to the fact that this soft scale could became a potential pest of ornamental oaks, a study on its biology and phenology was carried out on 18 year-old Quercus robur in northeastern Italy, starting in July 2006. Random samples were collected every 15 days from 50 trees, each about 5 m height. The results show that the scale has one generation/ year and overwinters as a 2nd_ins tar nymph on lignified twigs. Its phenology appears to be slightly earlier than the data reported for central Europe. The moult to adult females occurs from mid April onward. No males have been observed. Egg-laying starts at the end of April and lasts one month. Each female lays an average of 1511 eggs with a range of 425-2410 eggs/female. Egg hatching commences from the end of May. The crawlers settle on the under surface of the leaves. The first moults, that give raise to he 2nd_ instar nymphs, start at the beginning of August. One month later, at the beginning of September, the whole scale population is composed of 2nd instars. From mid September, the 2nd_ins tar nymphs gradually migrate from the leaves to the twigs to overwinter. This migration is completed by mid November, before leaf fall. These data suggest that the phenology of the northern Italian population is earlier than that in Central Europe by about one month and the fecundity · higher (average 1500 eggs/female) than the populations in Germany (800 eggs/female) and Poland (700 eggs/female).