Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  mrówki
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
PL
Plag egipskich, którymi Mojżesz wspierał swe żądania o wyjście Żydów z Egiptu, było dziesięć. Do krwi w Nilu, żab, komarów, much, pomoru bydła, wrzodów, szarańczy, gradu, ciemności i śmierci pierworodnych trzeba by chyba dopisać jedenastą plagę. To mrówki.
PL
W ekosystemie miast liczba stawonogów może wynosić blisko 4000 osobników na metr kwadratowy. Według amerykańskiej Agencji Ochrony Środowiska (EPA), mrówki jako owady towarzyszące człowiekowi plasują się w swej dokuczliwości, potencjalnym zagrożeniu epidemiologicznym i trudności w zwalczaniu na pierwszym miejscu, pokonując tym samym nawet wszędobylskie karaczany.
EN
Ants are highly widespread organisms, which dominate a lot of ecosystems. Their plasticity allows them to adapt to new habitats, sometimes far away from their original localities. Some species are able to live near humans — in cities or even in houses. They can become not only pests which can pollute food, but also can be vectors to pathogens dangerous to humans. This is the reason, why we have to do our best to understand those small insects better. Gaining proper knowledge about their biology, ecology and even physiology will make reducing their negative impact easier.
EN
The mound building narrowheaded ant Formica exsecta builds guarding outstations, usually at the root of the aphid-housing plants. Colonies of this species can develop into huge polydomous systems, so-called supercolonies, made up of several hundred of related nests and outstations. Although the existence of these guarding structures is well-known, still there is little information available concerning their characteristics. In the frame of this study we analyze the characteristics and the integrative role of outstations within a large polydomous system of F. exsecta as a function of ant nest density. The study was carried out in Transylvania, Romania. Two areas with different ant nest densities were selected for the purpose of this study: high (HD) and low density (LD) sites. Parallel to the density of ant nests, the density of outstations was also higher at the HD site, while the size of outstations and the number of ants residing in them did not differ significantly between the two sites. Outstations were usually maintained by a single ant nest at the LD site, thus the common exploitation of food resources was less frequent, whereas at the HD site outstations were used by more ant nests. This article provides the first evidence to shared use of outstations in F. exsecta. In the view of our results outstations, in addition to guarding aphid colonies, also function as permanent meeting points for workers from different nests, which contribute essentially to the integration of nests within a polydomous system.
EN
Wood ants, i.e. species of the subgenus Formica s. str., are known to be temporary social parasites of ants of the subgenus Serviformica For. However, not only Serviformica colonies are used by young wood ant queens to start their own colonies. They are also able to take over colonies, at least queenless ones, of related species of the subgenus Formica s. str. This study followed five experimental colonies of wood ants - three of hybrid Formica aquilonia x F. polyctena, one of F. aquilonia-like form, and one of F. polyctena - artificially planted on islands of the Tvńrminne archipelago, S Finland. After some years, the species identity of all colonies was F. polyctena, i.e. four of them had been taken over by heterospecific queens, whose offspring gradually replaced the old workers. These findings, together with already documented existence of hybrids in wood ants, partly explain the interspecific and intracolonial, until recently unaccountable, variability in wood ants of the Formica rufa group, frequently observed in southern Finland.
EN
Some literature reports show that ants use bodies of their dead nestmates and other insect remains in conflict situations. The paper describes such phenomenon in a Formica rufa L. colony brought into conflict with a F. cinerea Mayr colony when the former tried to extend its own territory at the expense of the latter. A territorially stable F. rufa colony, neighbouring the same F. cinerea colony, served as control. Workers of the expansive F. rufa colony were repeatedly observed to carry numerous ant corpses, empty pupal cocoons and insect leftovers from their nest to the place of confrontation with F. cinerea, on a much bigger scale than workers of the stable F. rufa colony. Corpse-carrying intensity was not correlated with the general activity level of foragers which suggests that corpse carriers could be a separate task group. Workers of a small colony of F. cinerea were also observed to surround their nest entrance with corpses of their nestmates and prey remains, taken out from inside the nest, in response to intensified traffic of workers of F. rufa in the vicinity of their nest. These results are discussed in the context of a possible interrelation between ant aggressive behaviour and transport behaviour. Two hypotheses are proposed to explain the observed phenomenon: (1) explaining it as a by-product of the aggressive arousal of workers, and (2) ascribing to it a possible signalling function in conflict situations.
EN
Myrmica schencki Em. and M. rubra (L.), common Palaearctic ant species, collect fallen male Scots pine (Pinus sylvestris L.) inflorescence during the pine blossom time, take it to their nests and then gather it on rubbish piles close to nest-entrances. Dissection of M. schencki workers revealed the presence of numerous pollen grains in their crops and midguts proving at least periodical pollenivory of these ants. So far, only some Neotropical ants of the genus Cephalotes Latr. have been known to eat pollen.
EN
Czechowski and Pisarski (1990) described the species composition and structure of ant communities of wooded patches (originally Tilio-Carpinetum) in Warsaw, situated along the Vistula river escarpment within the city. The paper was immediately succeeded by Seifert's (1991, 1992) taxonomic revision, where one of the most abundant species there, Lasius niger, was split into two sibling species: L. niger (L.) and L. platythorax Seifert, which clearly differ in their ecological requirements. Re-examination of the old material in the light of the present taxonomic knowledge showed that only L. niger, a polytope of moderately dry open habitats, was present in the study habitat. L. platythorax, a polytope of moderately wet forests, was lacking from urban wooded areas.
EN
Unusual rubbish piles of Myrmica schencki Em. colonies nesting within territories of Formica polyctena Forst. are described. The piles tightly surrounded M. schencki nest entrances and consisted mainly of remains of F. polyctena corpses (with a small addition of corpses of other local ant species) previously collected as food by M. schencki foragers in F. polyctena waste disposal zones. This observation shows that, under certain conditions, M. schencki can actually be a specialised myrmecophagous scavenger. The peculiar finding of M. schencki rubbish piles, in connection with other observations of using dead bodies and other remains by ants, suggests that such piles can play some role in interspecific relations in ants. This possibility is considered in the context of the competitive hierarchy of ant species.
EN
The paper discusses the directionality of slave raids of a colony of Polyergus rufescens (Latr.), an obligate European slave-making ant species, in the presence of colonies of Formica sanguinea Latr., a facultative slave-maker, in the neighbourhood. Both these social parasites use the same host species. The results strongly suggest that P. rufescens avoided raiding the area occupied by its competitor. An explanation is offered based on a demonstrated at the same time tendency of this species to avoid dangerous places.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.