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§ Ouantitative characteristics | 131 be attributed to this space. As we have seen, from the point of view of a zoocoenosis, the biotope means both a space suitable for its activity, and the plants growing in that space; therefore, for the animals, the plants also constitute space. Space interpreted in this way allows that we measure the abundance by area or volume of space, but only for elements that are directly linked to plant-based energy sources. This view places the evaluation of abundance into a totally different light, liberating it from all artificiality. Studying the abundance of sustinent elements using, for example, a quadrat, strip or other artificially separated spatial method, will say nothing if we forget that, for the zoocoenosis, plants are not only “space” but also a source of energy. The abundance of Adrena hattorfiana, that visits only Knautia, Cichorium or Scabiosa, or that of Melitta nigricans, visiting exclusively Lythrum salicaria (Olberg, 1951), can reach a certain (positive) value only where these plants are present. Likewise, the abundance of Aporia crataegi cannot be measured in regularly placed quadrats, only on trees where it can survive. Certain oeci can attract disproportionate numbers of flower-visiting Apoidea: Möczär (1954) found that in a Festucion sulcatae stand, 31.3% of apoid species, and 45.9% of their adult semaphoronts, visited one plant species, Eryngium campestre. The quality of litter will probably exert a significant influence on the abundance of litter-consuming intercalary elements. It may be that our knowledge in this area is not vast but, again, this indicates that zoocoenological studies are not possible without deep idiobiological knowledge. The abundance of corrumpent, sustinent and intercalary syrmatophagous elements is studied through projection onto the plant cover, and the abundance of other elements will be related to this factor. Naturally, this will happen in space, not because the zoocoenosis is identical to some spatial extent but, since parts of the coenosis are linked to the plants occupying this space, and others are related to these first elements of a census. Space, in this situation, fills a secondary role, but this is still an important role because - in addition to providing energy sources - it also contains macro- and microclimatic conditions that, although secondary, still have a profound influence on the formation of the zoocoenosis. The measurement of abundance currently uses heterogeneous, and consequently - incomparable, methods: units of surface or volume, both in the canopy, counting on leaves, etc. These methods lead to a confusing mass of data, leading, inevitably, to false conclusions. The abundance of the larval population of Operophthera brumata can, justifiably, be related to the number (either surface area or mass) of leaves, but the ants hunting for them cannot be censused in the same way because they do not search the canopy for the leaves but for the larvae that are there, and ant abundance will be greatest where the presence of larvae is high. The abundance of ants can, therefore, only be related to the number of Operophthera larvae. For example, out of 14600 cherry leaves, 8760 had a single Operophthera larva; on these larvae,
