Oldal 102 [102]
100 ÍV. The dynamics of the animal communities
from year to year. So far, there is little difference from the aspect used in
phytocoenology.
The aspects are not associations linked by trophic connections, but the
totality of populations, freguently belonging to different food chains, that
are active at the same time and, thus, are animal communities that can be
subject to the full force of competition. Ihe aspect is a moving segment of
an animal association, including the populations that display the most intense
activity of the zoocoenosis. The aspect is a snapshot of the zoocoenosis
because, in a part of the activity season, it represents less than the totality of
the association, being restricted to the apparent populations that give the
characteristic appearance of the aspect.
If two populations of an aspect specialise on the same food source, they
can have a mutual relationship that seems competitive. Instead of this
anthropocentric term, we would rather use “a clash of interests” that happens
with all its - frequently grave —- consequences, and without any elements of
real “competition”. Such a clash can occur between the flower-chewing
Tortricidae and Hoplocampa testudinea on apple trees and, also, between
Tortricidae + Hoplocampa and Rynchites spp. Both the Rynchites bacchus and
Tatianaerhynchites (Rhynchites) aequatus lay their eggs in fertilised, developing
fruit. It is not known if they tolerate each other in the same fruit, but it is
very likely the two populations are not indifferent to each other.
The scale insects Diaspidiotus (Aspidiotus) ostreaeformis and Epidiaspis
leperii (betulae) frequently form mixed gynopedia, especially on stone fruit.
The same cannot be said of Diaspidiotus (Aspidiotus) pyri (piri) and
Diaspidiotus (Aspidiotus) perniciosus, that exclude all other scale insects, plus
the D. perniciosus even the D. pyri. Consequently, these always occur in pure
stands, with the excluded species hardly present. It is also known that ant
activity in aphid colonies disturbs the egg-laying parasitoids. The same
phenomenon was observed on pines infested by wood borers, where Formica
ants disturbed the activity of obstant elements (Wichmann, 1954).
If the aspects of animal communities are represented by characteristic
species combinations, the reason for this is hidden in the ontogenesis of the
species — developing through metamorphosis that, on the first level
(herbivores), adapts to plant phenology, bringing different populations to
the surface and making them noticeable. The aspects will, therefore, be
represented by semaphoronts that are active within the zoocoenosis, whilst
the inactive developmental stages, that are temporarily in a resting phase,
will not be seen. Only the larval (+nymphal) and adult stages are active in
the coenosis; the eggs and pupae, and the diapausing stages cannot take an
active part in the life of the zoocoenosis.
The zoocoenosis, at any given time, has active and inactive populations;
thus we distinguish apparent and latent components.
The apparent part of a zoocoenosis is composed of the populations that,
through their activity, have a direct influence on the plant cover or the other