Page 49 [49]
§ The structural elements of a zoocoenosis | 47
structural elements. From the foundation of a coenosis, only the existence
of a corrumpent element is decisive. The nature of the actual elementary life
forms within which the semaphoronts are active is not fixed; they can feed
by sap sucking, leaf chewing, can form galls, etc. The obstant coetus should
be considered the same way, whereby it does not matter if the semaphoronts
are predators or parasites. Therefore, one cannot conceive an essential
structural element that is smaller than the coetus. The role of the syntrophium
is to diversify the coetus; this role only modifies the qualitative composition
of the zoocoenosis, but does not change its structure.
By using these seven groups, we can fully characterise the animal association
of an area (for example, an association of a crop plant). The collected animal
sample has to be analysed using these seven groups, to exclude the elements
that do not belong to the coenosis. The zoocoenosis itself is composed of a
maximum of four structural elements, the coeti of corrumpents, sustinents,
obstants and intercalary elements. The protempore or hospitant elements do
not form a coetus; they contain semaphoronts that can originate from any
of the four coeti, and can be distinguished by their spatial relationships. Both
are, however, members of the fauna of that area, can, themselves, also be
energy sources, and can cause the appearance, and insertion into the coenosis,
of otherwise foreign elements. An example of a protempore element is Cydia
pomonella that pupates in the stem of an Artemisia plant, and which can
attract one of its parasitoids, which has no link whatsoever with the Artemisia,
yet they share the same space.”
Populations can only be part of the same animal association if they belong
to at least one of its trophic chains, and this link is permanent; thus, they find
their living conditions at that trophic level. Therefore, peregrinant elements,
that cross the association at a horizontal level, do not belong to it. They cannot
become members even if, en route, they occasionally prey on a member of
the association, or take a bite from one of its plants, or themselves become
accidental prey to one of the association’s predators. Their impact on the
quantitative composition of that association is insignificant, precisely because
they are peregrinants, and have their permanent home elsewhere; an animal
can only be a peregrinant if its role is unimportant, and their feeding is no
more than accidental.
From the argument above, the following emerges; if the zoocoenosis is
composed of the above structural elements, and if all animals belong to a
zoocoenosis, they must also belong to a coetus. However, if a zoocoenosis is
composed of coeti, then eo ipso, it cannot contain peregrinants, hospitants
or protempore elements, because these represent semaphoronts that are
foreign elements in the zoocoenosis. All of them are members of some coetus,
and they can be classified into one of the three groups only because of their
> Such a case was observed repeatedly at Dolinapuszta, near Pomaz, in the overwintering caterpillar
populations of the codling moth, in 1952. The stems of Artemisia examined were about 20 m from
the next sample tree.