Galleria mellonella larvae spin protective tubes, which they use until they finish feeding, when they spin cocoons. A feeding choice experiment showed that some of the silk produced by feeding larvae was consumed in addition to the standard diet (STD). To determine the effect of feeding on silk, last instar larvae were fed for 24 h on foods based on STD but modified by replacing the dry milk component (10% of the diet) with equal amounts of different kinds of silk. While each control larva consumed 21 ± 0.5 mg of the STD and produced 4.5 ± 0.1 mg of silk, larvae that ate the food that contained larval silk consumed 10 ± 0.4 mg of food and produced 6.1 ± 0.1 mg silk; the percentage ratio of silk produced to diet consumed was 21% and 61%, respectively. A more pronounced reduction in food consumption occurred when larvae were supplied with Galleria "cocoon" silk or the sericin fraction of such silk, and only 3.8 mg/larva was ingested of the diet containing Bombyx mori cocoon silk or its sericin fraction. Silk production expressed in terms of percentage of diet consumed was always higher than that recorded for larvae fed STD. We conclude that G. mellonella larvae recycle part of the silk that they produce during feeding. Presence of silk in the diet reduces food intake but increases the ratio of silk production to diet consumption. Sericin fraction of the cocoon silk seems to deter feeding., Haq Abdul Shaik, Archana Mishra, František Sehnal., and Obsahuje bibliografii
Chlorophyll fluorescence serves as a proxy photosynthesis measure under different climatic conditions. The objective of the study was to predict PSII quantum yield using greenhouse microclimate data to monitor plant conditions under various climates. Multilayer leaf model was applied to model fluorescence emission from actinic light-adapted (F') leaves, maximum fluorescence from light-adapted (Fm') leaves, PSII-operating efficiency (Fq'/Fm'), and electron transport rate (ETR). A linear function was used to approximate F' from several measurements under constant and variable light conditions. Model performance was evaluated by comparing the differences between the root mean square error (RMSE) and mean square error (MSE) of observed and predicted values. The model exhibited predictive success for Fq'/Fm' and ETR under different temperature and light conditions with lower RMSE and MSE. However, prediction of F' and Fm' was poor due to a weak relationship under constant (R2 = 0.48) and variable (R2 = 0.35) light., E. Janka, O. Körner, E. Rosenqvist, C.-O. Ottosen., and Obsahuje bibliografii
Na hustě osídleném ostrově Srí Lanka se zachovalo necelých 5 % primárních deštných lesů. Část z nich je chráněna v biosférické rezervaci Sinharaja na jihozápadě země. Vysoký stupeň endemismu je typický pro flóru i faunu rezervace. Různorodé rostlinné formace, které se plynule mění od nížin až po submontánní stupeň, představují refugium pro mnohé vzácné a ohrožené druhy živočichů - více než 50 % z nich je endemických. Protože o toto chráněné území projevuje zájem stále větší počet turistů, lze předpokládat, že nebude v budoucnu ohroženo exploatací a bude i nadále spravováno podle nejnovějších poznatků ekologů. I proto je pro návštěvníky zpřístupněna jen nepatrná část rezervace., Only 5 % of primary rainforests have been preserved on the densely populated island of Sri Lanka. Some rainforests are preserved within the biosphere reserve Sinharaja in the southwest of the country, with a high degree of flora and fauna endemism. Various plant formations, changing from lowlands up to the submontaneous level, provide a refuge for rare and endangered species of animals (more than 50 % endemic). Due to rising tourism, the area likely will not be much exploited and will be managed according to the latest ecological knowledge., and Jozef Májsky.
Molekulární metody umožnily studovat šíření rostlin v povodí Labe. Druhy šířené vodou (zevar, stulík) migrují především jednosměrně podél řek. Bylo prokázáno i šíření mezi říčními systémy, častější je u druhů šířících se také větrem (rákos, orobinec). Klonální šíření mezi populacemi není u těchto studovaných druhů rostlin tak běžné, jak se dosud předpokládalo., Molecular approaches have allowed for the study of plant dispersal in the catchment area of the River Elbe. Plants dispersed by water (Bur-reed, Pond Lily) migrated mainly unidirectionally along streams. Dispersal among river systems was also detected and is more common among plants with wind dispersal (Common Reed, Cattail). Clonal dispersal does not seem to be as common in the studied species as previously suggested., and Tomáš Fér.
Male dimorphism in insects is often accompanied by alternative mating tactics, which may, together with morphological traits, determine fitness of the different male morphs. Fitness consequences of male head horn size, male-male competition and male nest-staying behaviour were experimentally assessed in Copris acutidens, in which major and minor males can co-occur in nests. Possible differences in their reproductive behaviour and breeding success were assayed in a breeding experiment, in which females were paired with one major male, one minor male, or a pair of major and minor males. The advantage of major males staying in a nest along with a rival male is that major males are reproductively more successful than minor males in this species. The weight of dung transported into nests was significantly less in rearing containers containing two males than in those with a single male of either morph, although it did not differ between major and minor males when kept alone. The results indicate that the presence of a rival male negatively affects male provisioning due to interference from rival males. In contrast, in the present study, an increased incidence of male nest-staying behaviour was recorded in the two- male and one minor male treatment than in the one major male treatment. These results indicate that because of the risk of sperm competition, major males stay longer in nests if a rival male is present. Furthermore, minor males (which are subject to a higher risk of sperm competition) stay longer than major males in nests without a rival male. In other words, the present study revealed an alternative behaviour during the post-copulatory stage associated with horn dimorphism and the presence or absence of a rival male., Mayumi Akamine., and Obsahuje bibliografii
The ongoing process of climate change will result in higher temperatures during winter and therefore might increase the survival of overwintering invertebrates. However, the process may also lead to a reduction in snow cover and expose overwintering invertebrates to lower temperatures, which could result in higher mortality. During a field experiment, I investigated the effects of a reduction in snow cover on the survival of the ant Temnothorax crassispinus, which overwinters in nests located on the ground. Ant colonies differed in the survival rate of the workers in the experimental (from which snow cover was removed) and control group. In the control group, the survival rate was unrelated to colony size. However, in the experimental group, from which snow was removed after each heavy snowfall, worker survival was lower in small colonies. Such colony size related mortality may affect the fusion of colonies before winter. and Sławomir Mitrus.
Pro rok 2013 se stal evropským pavoukem roku sklípkánek hnědý (Atypus affinis). Jde o jednoho ze tří druhů sklípkanů vyskytujících se v České republice. V článku popisuji morfologii, způsob života, stanovištní nároky a rozšíření sklípkánka hnědého. Je naším nejhojnějším zástupcem rodu, vyskytuje se na suchých osluněných kamenitých stráních s řídkou stromovou vegetací. Jeho stanoviště nejsou bezprostředně ohrožena sílícím zarůstáním krajiny., The Purse-Web Spider (Atypus affinis) became the European Spider of the Year 2013. The genus Atypus comprises three species in Europe. The morphology, natural history, habitat requirements and distribution of A. affinis are described. In Central Europe, it is the most common Atypus species and it occurs on dry sunny rocky slopes with sparse woody vegetation. These habitats do not tend to be overgrown by expansive tree or grass species., and Milan Řezáč.
Ray-finned fishes (Actinopterygii) are by far the most diversified group of vertebrates on Earth, and there are currently more than 32500 valid species in about 500 families and 72 orders. The diversity of ray-finned fishes has increased dramatically during their evolution, particularly in the modern group of Percomorpha. This also includes high morphological diversity of body shapes. However, in many cases similar morphological structures have evolved in different groups independently (by convergence). Recently, fish phylogeny has been reconstructed based on molecular genetic data, including whole genome sequencing. In this issue we present two articles on general relationships among the main lineages of fishes and the current version of the phylogeny of the ray-finned fishes. and Zuzana Musilová.