V práci je nastíněn jiný pohled na potravní specializaci půdních roztočů (která se projevuje jako značná) - pohled mikroanatomický, prováděný histologickou metodou, a to včetně fluorescenční a konfokální mikroskopie. Jako parametry se využívají: obsah trávicí soustavy, její aktivita dle sekrece enzymů, přítomnost hemocytů i extraintestinálních vnitřních bakteriálních těles, kultivace mikroorganismů z homogenátu a působení získaných bakteriálních enzymů na potravu, jmenovitě na vláknité půdní houby., This study examines the feeding habits of soil saprophagous mites from the point of view of microanatomy, using not only the histological method but also fluorescence staining and confocal microscopy. The research looks at a combination of the following factors: the alimentary tract, including its contents and secretion enzyme activity; the presence of hemocytes as well as internal extraintestinal bacterial bodies, all supplemented by purification of bacteria from the mite homogenate; and the impact of extracted bacterial enzymes on soil fungi., and Jaroslav Smrž.
Současná biologie se bouřlivě rozvíjí v oblasti genomiky. Tyto přístupy pronikají stále více do ekologie i evoluční biologie. Vznikl nový obor populační genomika, který propojuje terénní a laboratorní biologii. Využívá nové metodiky sekvenování a bioinformatických analýz, které v tomto článku stručně popisujeme a vysvětlujeme., Genomics is a rapidly developing field of modern biology. Novel genomic approaches are increasingly utilized in ecology and evolutionary biology. Population genomics has been recently established as a new discipline, connecting field and laboratory biology. It uses new sequencing methods as well as bioinformatic analyses, briefly described and explained in this article., and Helena Štorchová.
Genomická a transkriptomická studia u dvou druhů bublinatky (Utricularia gibba a bublinatky obecné - Utricularia vulgaris) přinesla průlomové poznatky. Ukázala, že miniaturní genom Utricularia gibba obsahuje zhruba stejný počet genů jako jiné kvetoucí rostliny a u některých genových rodin došlo k výrazné expanzi. To se týká např. genů zodpovědných za tvorbu kutikuly nebo za reakci na chitin, což souvisí s životním stylem této vodní masožravé rostliny. Současná nepřítomnost genů souvisejících s vývojem a funkcí kořene u obou druhů bublinatky naznačuje ztrátu „kořenových” genů u společného předka těchto druhů., Genomic and transcriptomic studies in Utricularia gibba and U. vulgaris have led to important discoveries. It was found that the miniature genome of U. gibba contained about the same number of genes as other angiosperms and that some gene families even expanded. For example, the genes responsible for cuticle development or the response to chitin are more numerous than in other plants, which may be related to the aquatic carnivorous lifestyle. Coincident absence of the genes associated with root development and function in U. gibba and U. vulgaris indicates the loss of the root genes already in their common ancestor., and Helena Štorchová.
Travinné ekosystémy jsou významnou součástí středoevropské krajiny. Polopřirozená travinná společenstva dnes tvoří v Evropě místa s vysokou biodiverzitou, jsou velmi náchylná k degradaci a k jejich efektivní ochraně je nutné znát vlivy různých typů managementu. Neodmyslitelnými obyvateli těchto ekosystémů jsou také zástupci rovnokřídlého hmyzu (Orthoptera), kteří zde hrají důležitou roli v potravní síti. Zároveň jsou vhodným indikátorem změn stanovištních podmínek, a to zejména struktury vegetace, čehož lze využít při zjišťování dopadů různých managementových opatření. Jedním z nejběžnějších a zároveň pro hmyz nejméně vhodných typů péče je dnes mechanizovaná seč. Nevhodná péče o travinné ekosystémy může ovlivňovat druhovou bohatost jak v měřítku lokálním tak i v měřítku krajiny. Snížení negativního dopadu seče ve prospěch biodiverzity lze docílit několika způsoby - např. zmírněnou intenzitou zásahu, a to posunutím nebo vynecháním první seče, nebo ponecháním neposečených ploch., Grasslands are an important part of the Central European landscape. Seminatural grasslands are considered to be biodiversity hotspots in Europe, with high conservation value. However, they are very unstable, and for their effective conservation it is necessary to know how different management systems affect the progression of the ecosystem. Orthopterans play an important role in the food web and they are also a good indicator of changes in habitat conditions, particularly in the vegetation structure, which can be used in determining the impact of different types of conservation management. Nowadays, one of the most common and least insect-friendly type of care is mechanized hay harvesting. Improper care can affect the species richness (both, on the local and landscape scale). The negative impact of mowing can be reduced in favour of biodiversity in several ways, as described (e.g., mitigating the intensity of the process by delaying or omitting the first mowing, or leaving uncut refuges)., and Oto Kaláb.
Článek shrnuje současné znalosti o taxonomickém postavení, rozšíření a ekologii žížaly Allolobophora hrabei a o jejím vlivu na stepní ekosystémy. A. hrabei dnes chybí na většině lokalit, kde se historicky vyskytovala a je nutno ji považovat za ohrožený druh. Na místech s dostatečně velkou populací může významně ovlivňovat půdní vlastnosti i společenstva ostatních půdních organismů., This contribution summarizes current knowledge about the taxonomic position, distribution and ecology of the earthworm Allolobophora hrabei and its role in fragile fragments of central European steppe ecosystems. Nowadays, A. hrabei should be classified endangered as it is absent at most of its historical sites. Nevertheless, it may significantly affect both soil parameters and other soil organisms at the sites inhabited by larger populations., and Václav Pižl.
Příspěvek shrnuje dosavadní poznatky o skupině mořských bezobratlých - nohatkách (Pantopoda). Přibližuje jejich ekologii, morfologii, rozmnožování a fylogenezi. Zároveň ukazuje preparáty nohatek uložené ve sbírkách Národního muzea v Praze., This contribution summarizes the current knowledge about the sea spiders (Pantopoda). It is focused mainly on their ecology, morphology, reproduction and phylogeny. The review is also accompanied by figures of the specimens deposited in the National Museum in Prague., and Petr Dolejš.
In herbivorous insects, differences in the degree of specialization to host plants emerge when the distribution of an herbivore differs from that of its host plants, which results in a mosaic of populations differing in performance on the different host plants. Using a specialized butterfly, Battus polydamas archidamas Boisduval, 1936, which feeds exclusively on the genus Aristolochia, we test whether host plant co-occurrence and associated differences in host quality modify local adaptation in terms of larval preference and performance. We compared individuals from a monospecific host stand of Aristolochia chilensis with those from a mixed host stand of A. chilensis and A. bridgesii. Individuals were reared in a reciprocal transfer experiment in which source population and the host species fed to larvae were fully crossed in a two-by-two factorial experiment in order to quantify their preference, performance (development time, size and growth rate) and survival. Individuals from both populations preferred the species they ate during their larval development over the other host, which indicates host plant-induced preference with non-adaptive implications. Larvae from mixed and monospecific stands grew faster and survived better when reared on A. bridgesii than A. chilensis. Larvae from a monospecific host stand grew slower and fewer individuals survived under the same local conditions, which is contrary to expectations. Therefore, rearing the butterfly on A. bridgesii consistently resulted in better performance, which indicates that the monospecific population is less well adapted to its host than the mixed population. Variation in the occurrence of the two host plants in the two populations can result in divergent selection due to the variation in plant quality, which in this case could result in opposing adaptive processes., Rodrigo S. Rios, Cristian Salgado-Luarte, Gisela C. Stotz, Ernesto Gianoli., and Obsahuje bibliografii
Two blacklight traps were operated in a non-agricultural setting in Cary, North Carolina, USA, from spring through fall in 2004 and 2005 and all Coccinellidae collected and identified. More than 1300 lady beetles were collected in each of the two years, with Harmonia axyridis dominant (> 98%) and collected consistently over the course of the trapping period. Although other coccinellid species were observed in the vicinity of the traps during photophase, their appearance in blacklight traps was negligible. Harmonia axyridis exhibited a distinct diel periodicity in appearance at the traps, beginning approximately an hour after sunset and ending about midnight. Sunrise and sunset collections from flight interference and sticky traps in a local alfalfa field suggest that H. axyridis may be more flight active during the scotophase than Coleomegilla maculata, Hippodamia convergens, and Coccinella septempunctata. This study supports the suggestion that blacklight traps give a biased depiction of coccinellid species composition in a given area, and indicates that seasonal and circadian thresholds for flight activity, phototaxis, or both in H. axyridis may diverge from those in most other Coccinellidae., Christine A. Nalepa., and Obsahuje seznam literatury
Under seasonal conditions, Polydesmus angustus individuals born in the first part of the breeding season have a 1-year life cycle and those born later have a 2-year life cycle (cohort-splitting). In this study, 249 juveniles from four early broods (born in mid-July) and four late broods (born in September) were reared under similar laboratory conditions, to test for possible maternal influences on life-cycle duration. Development times of early- and late-born individuals were compared under four combinations of day length and temperature (16 h - 18°C, 16 h - 16°C, 12 h - 18°C and 12 h - 16°C). The results showed that development time varied significantly in response to day length, temperature and sex, but that of individuals in the early and late broods did not differ significantly (mean development times ± SE: 180 ± 6 and 183 ± 8 days, respectively). There were no significant interactions between birth period and other factors, indicating that the effects of day length, temperature and sex on development time were similar in early- and late-born individuals. This indicates that the extended life cycle of millipedes born late in the season is not maternally determined and that cohort-splitting is controlled entirely by the environmental conditions experienced by the offspring during their development. This conclusion is supported by the absence of significant variation in offspring live weight at birth measured at different times in the breeding season. The results are discussed in relation to the bet-hedging theory, which is often put forward to account for cohort-splitting in arthropods. In P. angustus, the results are consistent with either bet-hedging or adaptive plasticity, but further studies are required to decide which interpretation is correct. and Jean-François David, Jean-Jacques Geoffroy.