Studies of insect population under field conditions to establish survival rates, longevity and dispersal rates are rare in the literature. These types of studies are important and can be used to inform studies of the effects of landscape composition and configuration on levels of biodiversity. Here the Cantharidae beetle, Rhagonycha fulva is studied under field conditions to derive estimates of daily survival rates for both males and females as well as local dispersal rates. Survival was studied at two sites, one in Wales and another in England, whilst dispersal was examined only at the Welsh site. Beetles were marked using different coloured enamel paints at the mid-point of a 200 m linear transect. The beetles were almost exclusively found (and marked) on common hogweed, Heracleum sphondylium. No difference in survival was found between males and females at both of the sites. The survival rates found at the two sites also did not differ. The overall daily survival rate was 0.771 equating with a median longevity of 4.37 days. Casual observations yielded a small number of marked individuals in excess of 400 m away from the point of marking. Movement of males along the transect differed from females. Marked females were never found far from the point of marking whilst males moved further away with time. This difference in behaviour is discussed in terms of hypothesized insect dispersal behaviour following emergence as mobile adults., Laura E. Rodwell, Jennifer J. Day, Christopher W. Foster, Graham J. Holloway., and Obsahuje bibliografii
The negative effects of continuous light (CL) seen in tomato plants are often claimed to be linked to effects of offsetting the diurnal rhythm. In this study we tested whether a short-term daily temperature drop prevents the decreased photosynthetic performance seen in tomato plants grown under CL. Tomato (Lycopersicon esculentum Mill.) plantlets were grown at constant temperature of 26°C under 16-h day (16D) or 24-h day (24D) at 150 μmol m-2 s-1 PPFD. Some 24D plants were treated daily by 2 h temperature drop from 26 to 10°C (24D+DROP). Physiological disorder, such as severe leaf chlorosis, a large decrease in net photosynthetic rate, maximal quantum yield of PSII photochemistry, and the effective quantum yield of PSII photochemistry were observed in 24D, but not in 16D and 24D+DROP plants. The daily 2-h drop in temperature eliminated a negative effect of CL on photosynthesis and prevented the development of leaf chlorosis in tomato plants. This could be due to a change in carbohydrate metabolism as the short drop in temperature might allow maintenance of the diurnal rhythms., E. N. Ikkonen, T. G. Shibaeva, E. Rosenqvist, C.-O. Ottosen., and Obsahuje seznam literatury
Tree hyraxes - genus Dendrohyrax - are among the least known mammals. in this review we summarize all known facts on their ecology and ethology. According to the Zoological Information Management System the only two zoos worldwide currently holding these animals are found in the Czech Republic. Therefore, also the information on their husbandry is included. and Jan Pluháček, Yveta Svobodová.
Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the midgut of four of five species of adult damselflies (Zygoptera) from a non-irrigated restored semipermanent wetland located in Stillwater, Oklahoma, USA. Of the four infected damselfly species, prevalence and mean abundance was highest for the southern spreadwing, Lestes disjunctus australis Walker (10%, 0.2 ± 0.8) and lowest for the familiar bluet, Enallagma civile (Hagen) (2.5%, 0.04 ± 0.3); whereas mean intensities were lowest for the citrine forktail, Ischnura hastata (Say) (1.5 ± 0.5) and the eastern forktail, Ischnura verticalis (Say) (1.0 ± 0). This is the first record of larvae of S. trispinosum from damselflies. Serpinema trispinosum adults have been reported from 18 species of North and Central American freshwater turtles, whereas microcrustaceans such as copepods serve as intermediate hosts and snails, fish and amphibians serve as paratenic hosts in this nematode's life cycle. However, dietary studies of the 18 species of freshwater turtles reported as definitive hosts for S. trispinosum indicate that aquatic insects including damselflies are more commonly reported in turtle diets than are fish or amphibians. Additionally, unlike snails and amphibians, larval damselflies predominantly feed on microcrustaceans, and our observation of S. trispinosum infecting damselflies may reflect the importance of these insects as paratenic hosts. In the present study, we provide new host information and measurements for third-stage larvae of S. trispinosum from damselfly hosts along with measurements for adult male and female S. trispinosum from turtle hosts from Oklahoma, USA., Crystal M. Wiles, Matthew G. Bolek., and Obsahuje bibliografii
V práci je prezentovaná moderná paradigma darvinovskej evolúcie, ktorá ju chápe ako univerzálny optimalizačný algoritmus, aplikovateľný nielen v biologických vedách, ale aj v roznych oblastiach tak exaktných, ako aj sociálnych a behaviorálnych vied., Vladimír Kvasnička, Jiří Pospíchal., and Obsahuje bibliografii