Insects produce pigment and structural colours mainly for camouflage, signaling, physical protection or temperature regulation, and colour patterns can provide information about individual quality. Although the evolutionary function and nature of the variability in colouration are well known for many invertebrate taxa, there is little information on this topic for ants. We studied individual variation in the melanin-based colour traits of workers of the red wood ant, Formica rufa (Hymenoptera: Formicidae), from 20 colonies in Southern Finland and revealed the type of colouration in this species. First, using the threshold approach we distinguished between continuous and discrete variations. Furthermore, the analyses affirmed nine discrete morphs in terms of the colouration on the head and eight on the pronotum, while only continuous variation were found on the other body parts. Measuring the size of a particular colour pattern, the intensity of colour expression (degree of melanization) and statistical analyses allowed an assessment of the intra-individual variation in both discrete and continuous patterns. The results revealed substantial modularity in the above mentioned colouration traits. In workers of F. rufa there were individuals with a dark head and light coloured thorax and vice a versa. Size of the dark pigment colour patterns exhibited less modularity than the degree of melanization. Finally, the interrelation between colouration traits and individual body size revealed their size-dependent origin. Small individuals had relatively larger areas of colour on the head and thorax than big individuals. These results are likely to facilitate further taxonomical and ecological studies on red wood ants, as they show it is possible to assess colouration traits in ants. However, more studies are needed on the function of polymorphism and modular colouration in this group of ants., Oksana Skaldina, Jouni Sorvari., and Obsahuje bibliografii
Clear-cutting, the main method of harvesting in many forests in the world, causes a series of dramatic environmental changes to the forest habitat and removes habitat resources for arboreal and epigeal species. It results in considerable changes in the composition of both plant and animal communities. Ants have many critical roles in the maintenance and functioning of forest ecosystems. Therefore, the response of ants to clear-cutting and the time it takes for an ant community to recover after clear-cutting are important indicators of the effect of this harvesting technique on the forest ecosystem. We investigated ground-dwelling ant communities during secondary succession of deciduous forests in Transylvania, Romania. Using space-for-time substitution, we explored a chronosequence from clear-cuts to mature forests (> 120 years). The object was to determine if cutting has measurable effects on ant community structure, and if ant species richness differs between successional stages. We recorded a total of 24 species of ants, 11 characteristic of forests and seven of open landscape. Ant species richness was higher in clear-cuts compared to closed-canopy and old stands. Number of ant individuals was highest in young age classes and lowest in closed-canopy age classes. There was no drastic change in species richness during the succession, however differences in community composition at different stages were recorded. Open landscape species are able to rapidly colonize following disturbance but disappear when the forest sites mature and many forest ant species are capable of surviving clear cutting., Ioan Tăuşan, Jens Dauber, Maria R. Trică, Bálint Markó., and Obsahuje bibliografii
Mravenci jsou jednou z nejpočetnějších skupin bezobratlých živočichů žíjících v korunách tropických stromů. Tým vědců z Českých Budějovic objasnil otázky ohledně biodiverzity a ekologických nároků stromových společenstev mravenců za pomoci nejrůznějších metod od vykácení a rozebrání celých kusů pralesa, sestrojení experimentálních pastí až po počítačové simulace. Výzkum pomohl získat klíčové poznatky nejen o tropických lesích pro vědu, ale přispět i k jejich ochraně a vzdělání domorodých obyvatel, kteří v nich žijí., Ants are one of the most abundant groups of invertebrates living in the canopies of tropical trees. In their research a team of scientists from České Budějovice clarified the drivers of high diversity and the ecological preferences of ant arboreal communities using a variety of techniques from felling and dissecting trees in entire forest plots and the construction of special experimental traps to computer simulations. This research helped to advance not only our knowledge about tropical rainforests, but it was also significant for tropical forest conservation and the education of the native people depending on them., and Petr Klimeš, Ondřej Mottl.
Various types of artificial ant nests (formicaries) are described. These include simple laboratory types to more complex formicaries whose esthetic design is suitable for flat interiors. Formicaries facilitate not only the observation of natural ant behaviour inside a nest, but also of the remarkable practices used by young queens to appropriate the nest of a host ant species. In such equipment it is even possible to arrange a predatory raid by slave-making ants and observe their behaviour inside the attacked nest. Such observations would not have been possible in natural conditions. and Pavel Amcha.
Přes obrovský pokrok v molekulárních fylogenetických metodách a množství v nedávné době objevených fosilních taxonů nemáme o fylogenezi a evoluci mravenců (čeleď Formicidae) mnoho ověřených faktů. V současnosti se rozlišuje 16 žijících a tři fosilní podčeledi. Podčeleď Leptanillinae je považována za bazální, zatímco skupina Apoidea (včely a kutilky) se ukazuje jako sesterská k čeledi mravenců., In contrast to the huge progress of molecular phylogenetic methods and many recently discovered fossil taxa, the phylogeny and evolution of ants (Formicidae) remains poorly understood. Today 16 extant and three fossil ant subfamilies are known. The subfamily Leptanillinae is considered as basal, while Apoidea seems to be a sister family to the ants., and Pavel Pech.