Kozár, F. 1987 The probability of interspecific competitive situations in scale-insects (Homoptera, Coccoidea): interspecific competition of scale-insects.. Oecologia 73: 99-104.

Notes: A large scale survey, covering some 25 million km of eastern Europe, provided distributional data, and a more detailed picture on factors determining species composition and abundance of scale-insects colonizing deciduous orchard trees; no interspecific competition or competitive situations were detected among the 21 scale insect species, when taking into consideration the whole geographic area surveyed; only 3.2% showed significant spatial separation in smaller geographic regions; no evidence for competition was found between species with overlapping distributions; discussions of introduced species and "transitional zones".