The ladybird beetle, Cheilomenes sexmaculata (Fabricius), has been extending its distribution in and around urban areas at higher latitudes in Japan over the past 100 years. Between 2003 and 2011, we investigated the seasonal occurrence, aphid prey and population dynamics of this species in an urban park in Osaka City, central Japan. We found that C. sexmaculata completes three generations a year in Osaka. Overwintered adults emerge in March or April and produce two (or rarely one) generations by summer. Second-generation adults aestivate and subsequently produce another generation in autumn. This species feeds on five species of aphids that infest planted shrubs and alien weeds throughout the vegetative season. We analyzed the association between accumulated temperature and when overwintered adults first emerged. In addition, we determined the association between their time of emergence, peak abundance and last occurrence, and meteorological conditions. There was no association between the sum of effective temperatures and termination of adult overwintering. There was, however, an association between first occurrence and peak abundance, and climatic conditions, such as warm temperatures or low humidity. This species maintained a stable population in an urban park by becoming quiescent when climatic conditions were unfavourable or prey was scarce. We discussed these findings in relation to urban environmental factors, such as climate, food conditions and vegetation., Yasuko Kawakami, Kazuo Yamazaki, Kazunori Ohashi., and Obsahuje bibliografii
We conducted a comparative population genetic analysis of levels of genetic variation and its geographical structuring in three closely related species of grasshopper that co-occur in the Mediterranean Basin: Calliptamus italicus, C. barbarus and C. wattenwylianus. In the western part of their distributions 5 populations of C. italicus, 13 of C. barbarus and 10 of C. wattenwylianus were sampled. Bootstrap re-sampling of populations and microsatellite loci within each species indicated a lower level of genetic diversity and higher level of genetic differentiation in C. barbarus, which is less of an outbreak pest species than either of the other Calliptamus species studied. This may be due to lower effective sizes of non-outbreak populations and/or lower gene flow among them., Elodie Blanchet ... [et al.]., and Obsahuje seznam literatury
High host specificity and dependence on the host plants are common attributes of herbivorous insects. Their usage in ecosystem studies and landscape assessment is shown by examples from a group of Central European weevils and leaf beetles. Biodiversity can be assessed from the degree of completeness of present herbivore feeding guilds. Wingless species with narrow habitat requirements can be used as good bioindicators of relic natural habitats. and Pavel Špryňar, Jaromír Strejček.
Crypsis is the ability of an organism to avoid observation or detection by other organisms, either by predation strategy or antipredator adaptation. Many animals have evolved to visually resemble their surroundings by changing their colour. These changes can be experimentally provoked by altering physical parameters (such as humidity) during the development of the nymphs, and also depend on the type of food they consume. This report illustrates coloration changes of the Green Shield Bug (Palomena prasina) during autumn, on specimens caught at the nearby town of Vlašim (Central Bohemia). We recorded the shortest time for the imagos to change color (from bright green to uniform brown) as nine days in an experimental insecta - rium. The rate of color change was influenced by air temperature. The brown colour is evidently an indicator of the diapause. and Lubomír Hanel, Jana Hanelová.
In suitable habitats the population density of the Dice Snake (Natrix tessellata) can be obviously higher than the density of other central European snakes. Under such conditions the Dice Snakes can form larger aggregations of mating individuals, in which male-male mating competition takes place. Dice Snake mating aggregations observed in the Ohře river valley are described and the mating strategy of males and female is discussed. Special attention is paid to mating in above-ground positions, e.g. on trees. and Jiří Moravec.
Článek představuje jednu skupinu nosatcovitých brouků – zobonosky čeledí Attelabidae a Rhynchitidae. Těžištěm výskytu těchto brouků jsou tropické oblasti, v ČR žije 29 druhů. Zobonosky jsou typické tvorbou různě utvářených smotků na listech rostlin sloužících k vývoji larev, některé druhy napadají plody, pupeny a větvičky. Většina druhů je vázána na lesní biotopy, dále sady, zahrady nebo louky., This paper introduces a group of curculionid beetles – the Leaf Rolling Weevils of the families Attelabidae and Rhynchitidae. Most species are known from tropical regions, while in the Czech Republic 29 species are recorded. These beetles create various kinds of leaf rolls for their larvae; some species develop in fruits, buds or branches. Most species are associated with forest habitats, but they also live in orchards, gardens and on meadows., and Robert Stejskal, Filip Trnka.
There are 15 members of the Wolf Spiders genus Alopecosa in the Czech Republic, most of which are rare and stenoecious. Although they have been studied for a long time, we do not have much information about their biology and reproduction. Members of this genus show a large variability in courtship and copulatory behaviour., K zajímavým rodům slíďáků náleží rod Alopecosa, na území České republiky známe výskyt 15 druhů rodu. Ačkoli ojedinělé záznamy o biologii a taxonomii rodu máme sice už z 18. stol., jejich studium pokračuje zejména v dnešní době, kdy se do popředí dostává výzkum rozmnožování., and Pavel Just.
Life table data of natural enemies are often used to understand their population dynamics and estimate their potential role in the biological control of pests. Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) is an important pest of several crops and its intrinsic rate of population increase (rm) is 0.282 at 22°C. The life table parameters (immature mortality, developmental time, sex ratio of emerging adults, fecundity and longevity) of Praon volucre (Haliday) (Hymenoptera: Braconidae: Aphidiinae) parasitizing M. euphorbiae were estimated in a climatic chamber at 22 ± 1°C, RH 70 ± 10% and 12 h photophase. Immature mortality was 8.2%, developmental time of males and females was 13.9 and 14.4 days, respectively, and the sex ratio was 0.55 (= fraction of females). Parasitoid fecundity was 504 eggs and longevity 11 days. The net rate of reproduction (R0) was 207.5 females and the intrinsic rate of population increase (rm) 0.281 females/female/day. The time for doubling the population (TD) was 2.45 weeks. P. volucre has a population growth rate similar to that of its host M. euphorbiae and might therefore be a good candidate for the biological control of this aphid. and Juracy Caldeira Lins jr., Vanda Helena Paes Bueno, Diego Bastos Silva, Marcus Vinicius Sampaio, Joop C. van Lenteren.
Článek shrnuje dosavadní znalosti o pavoucích zimujících v ulitách suchozemských plžů v České republice. Jde o dvě studie - jedna ze zimy 2008/2009 (2 448 prázdných ulit tří druhů suchozemských plžů: suchomilka obecná (Xerolenta obvia), páskovka žíhaná (Cepaea vindobonensis) a hlemýžď zahradní (Helix pomatia)). Druhá studie byla provedena v zimním období 2010/2011 (přes 30 000 ulit, stejné druhy jako v předchozích letech plus druhy: skalnice kýlnatá (Helicigona lapicida) a plamatka lesní (Arianta arbustorum)). Prozatím jsou souhrnně zpracována data z první studie, z druhé jsou v článku zmíněny pouze faunisticky významnější nálezy. Naše zjištění potvrzují nálezy ze zahraničí, že v ulitách přezimuje, často hojně, celá řada druhů pavouků, které považujeme za vzácné. Asi nejvýznamnější druhy jsou: skálovka šestitečná (Phaeocedus braccatus), snovačka pětitečná (Euryopis quinqueguttata), skákavka dvoutečná (Sitticus penicillatus), zápřednice Pennyova (Cheiracanthium pennyi), zápřednice karmínová (Ch. montanum) a další., This article summarises our knowledge of overwintering spiders in land snail shells in the Czech Republic. The results of two studies, based on the survey of more than 32 000 shells of 5 species, confirmed that many spider species considered rare actually overwinter in shells, often in large numbers. The most important records include Phaeocedus braccatus, Euryopis quinqueguttata, Sitticus penicillatus, Cheiracanthium pennyi and Ch. montanum., and Jana Niedobová, Vladimír Hula, Ondřej Košulič.