Goidanich, A. 1962 Ciclo fenologico abnorme in un genere di Lecaniidae gimnosoma paleartico (Hemiptera Homoptera Coccoidea). [Abnormous [abnormal?] phenological cycle in a palaearctic naked-bodied Lecaniid genus].. Atti della R. Accademia delle Scienze di Torino 96: 269-284.

Notes: In the naked-bodied genera, where the adult females lack waxy coverings or egg-sacks, of the Lecaniidae family (Eulecanium, Coccus, Sphaerolecanium, Saissetia, Eucalymnatus, Physokermes) living in the Palaerctic region, the regular once a year breeding biological cycle results in the overwintering of the young of all the species as second stage nymphs. An exception to this phenological rule is a species living on the Pomoideae, above all on Crataegus, the Eulecanium bituberculatum Signoret. In 1908 K. Sulc proposed the erection of a distinct genus, Palaeolecanioum Sulc, for this species, taken as type. Contrary to its relatives Palaeolecanium bituberculatum regularly spends the entire winter season in embryonic quiescence in the egg stage, sheltered under the hardened body of the mother in the roomy incubatory chamber, which is formed by the retraction of the female's ventral surface. Hatched from the eggs in spring, the females are sometimes already in the adult stage by the end of August and may even be sexually mature at this time. By the end of the October all the eggs are already laid and, dusted with wax, heaped under the mother. Such a seasonal develoment is abnormal in a species of scale of palaerctic origin. It is not consistent with other equally evolved related genera and species in the reaction to the special environmental conditions of the temperate boreal region. Instead of overwintering in the more plastic, euryoecious, resistant form of the second stage nymph, it faces the rigors of the winter season as an egg. This phenomenon accentuates, more than the usual taxonomic characters, the systematic singularity of Palaeolecanium bituberculatum Signoret and justifies the raising of this unusual insect to the rank of a separate genus.