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136 |VIL. Zoocoenological characteristics On apple trees, such a population is that of Diaspidiotus perniciosus, Eriosoma lanigerum, or a tortricid with two-three generations per year. In a wheat field, these include Agriotes spp., Agrotis segetum, or species of wheat flies, etc. The population with the highest degree of corrumpency is not necessarily also the dominant one. In a square metre of wheat field, a few larvae of Agrotis can have a higher degree of corrumpency than a dozen of Oscinella frit. To what degree numerical dominance is unsuitable as a characteristic of the real role of a population can be seen especially well when the corrumpent activity is by the larval semaphoronts, and not the adults. In such cases, the degree of corrumpency of the adult population is zero, and the degree of corrumpency of the given species can only be assessed via the activity of the larval population that follows the adult generation. This clearly indicates what sort of errors we can make during the study of zoocoenoses, if the importance of a species is evaluated based only on the collected adults. In many cases, we cannot yet measure the transformative effect. To assess, for example, the impact of a caterpillar population, we ought to know the per capita foliage consumption. Once we know this, we can calculate the expected transformative effect by a simple multiplication (as in Rudnev 1951), that, from the point of view of the community, expresses the share of the available plant energy source that was used by the studied population. This is also an indirect measure of the degree of corrumpency, because the larger the transformative effect, the lower the chance for new populations to fit into the coenosis, meaning the greater the degree of corrumpency of the population responsible for the transformative effect. Under our current knowledge, however, we cannot calculate, precisely, the degree of corrumpency, because we do not yet know the constancy of the species composition of the various zoocoenoses. The flourishing of producent elements in a zoocoenosis is a potential condition for the full development of a (partially- or nearly-developed) zoocoenosis. Any corrumpent exhausting the producent energy source will impair this possibility, forming a mechanism that acts against the expansion of the biocoenosis. This factor is the degree of corrumpency whose magnitude is inversely proportional to the degree of threat to the vitality of the producents. The manifestation of the degree of corrumpency results in the interaction between populations that utilise the same energy source. This interaction, through degree of corrumpency, is the proof that the catenarium, presocium and supersocion are indeed zoocoenological categories. Currently, we can distinguish three levels of corrumpency. If most of the energy source remains in a condition that it is available to the corrumpent populations that become apparent later, the degree of corrumpency is regressive. This degree is regressive when the transformative effect is <50% of the energy source. The degree of corrumpency becomes progressive when this energy use becomes >50% and, as it exceeds the 50% level, greater food
