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OCR
§ The formation of a catenarium, a chain of catenae | 87 hilophagous populations represent the intercalary elements of the catena to which the dead animal belonged. The fauna of a bird nest is not a catenarium, either, although there are obstant and intercalary elements that parasitise birds or live on debris produced by birds; there are also pro tempore and peregrine elements that were unwillingly carried there with the nest material, and have nothing to do with the bird or the oecus. From this, it also follows that we do not consider the animal association in the last two examples as a valid category, because these do not have an impact on the plant cover, without which there is no permanent zoocoenosis. Before their presence, there must be elements that create this link, and only with these can they form a complete zoocoenosis. On the other hand, there can be a catenarium in a rotting log or litter, where there can be active plant-based intercalary elements, attracting obstant and their additional intercalary elements, thus forming starting points of trophic chains or catenae. These catenae will constitute the catenarium of the oecus (rotting logs or trunks). Catenaria can be named adding the -narium end to the genitivus of the genus name. The catenarium can logically be named after a genus of a plantfeeding population or species. Given that, in a catenarium, there can be several catenae, the name cannot be decided haphazardly, and only one way seems to be acceptable: to consider the role that the given population fulfils in the oecus. We shall return to this question during the discussion of the zoocoenological characteristics (see p. 119). Catenaria can be horizontally linked by obstants needing an intermediary host (or prey), or by intercalary elements. Some of the corrumpent elements can occur on several host plants, i.e. in several oceuses. The larvae of Agrotis segetum (segetis) can attack several crop plants in the arvideserta; most of the grasshopper fauna of meadows and pastures cannot be forced into one catenarium, and; the larvae of Aporia crategi can damage nearly all kinds of orchard. All these populations point to the existence of a larger frame of animal associations. Such a frame will also be composed of trophic chains, but these will not be restricted to one oecus, but a group of those or whole biotopes, and the populations are accordingly dispersed. Their corrumpent elements are, consequently, polyphagous. § THE FORMATION OF THE PRESOCIUM, THE HABITAT ASSOCIATION It is only when we view catenae starting from corrumpents that are monoor oligophagous (such as those living on poppies, small grains, oilseed rape, mustard, cabbage, etc.) that the catenaria formed by them seem to be sharply identifiable. The catenarium of the oak trees is different from that of wild rose bushes or beech trees, and sugar beet has a catenarium different from that of lucerne or small grains. The moth Lymantria dispar, however, is present
