Five albinotic individuals of the Common Newts (Lissotriton vulgaris), including two paedomorphic females, were caught on 15th April 2013 in a water reservoir in the village Stará Lysá. this is the first record of paedomorphic albinos of newts in the Czech Republic. The behaviour of albinotic individuals was observed in a laboratory for a period of one month. and Oldřich Kopecký, Petr Hataš, Tomáš Holer.
Plachetnatky (čeleď Linyphiidae) jsou po skákavkách (Salticidae) druhově nejbohatší čeledí pavouků. V temperátních zónách, včetně České republiky, dokonce jde o pavoučí čeleď s největším počtem druhů. Jsou to lehcí pavouci, snadno a ochotně se šíří větrem. Jejich dobrá migrační schopnost je obzvlášť výhodná v mírných pásech, které musely být po každé době ledové znovu kolonizovány. Své české jméno dostaly plachetnatky podle lapací sítě - horizontálně upředené plachetky. Většina plachetnatek jsou drobné, nenápadně zbarvené druhy. Poměrně velká a pestře zbarvená plachetnatka keřová (Linyphia triangularis) představuje jednu z mála výjimek., The Common Hammock-Weaver is rather untypical member of the family Linyphiidae due to its large size and clear markings on the cephalothorax. It is found across a large part of the Palaearctic and occurs as a ‘generalist’ in damp forests, meadows, forest edges, parks and gardens. The web consists of a horizontal sheet and a network of loose ‘tripwires’. Mature examples of the species are found from August to October. Males show ‘mate guarding’ behaviour., and Milan Řezáč.
Plant volatiles can synergize the response to moth pheromone. Synthetic pheromone analogs, in turn, have the opposite effect in reducing pheromone attractiveness. To determine how these two types of stimuli interact and influence male moth behaviour, we performed wind tunnel experiments on the grapevine moth, Lobesia botrana. We noticed that a blend of host plant volatiles [(E)-β-caryophyllene, 1-hexanol, (Z)-3-hexenyl acetate and 1-octen-3-ol in a 100:20:10:5 ratio] significantly increased the response of males to an optimized blend of sex pheromone [(7E,9Z)-dodeca-7,9-dienyl acetate (E7,Z9-12:Ac), (7E,9Z)- dodeca-7,9-dienol (E7,Z9-12:OH) and (Z)-9-dodecenyl acetate (Z9-12:Ac)] in a 100:10:2 ratio. However, the response of males to the natural attractant was significantly reduced by two analogs [(9E,11Z)-tetradeca-9,11-dien-2-one (MK 2) and [(9E,11Z)-1,1,1-trifluoro-tetradeca-9,11-dien-2-one (TFMK 3)], of the major component of the sex pheromone of the insect (E7,Z9-12:Ac). When both stimuli were tested on males at pheromone:analog:plant volatile blend 1:100:1000 ratio, the plant blend offset the inhibitory effect induced by TFMK 3 but not that of MK 2. Our results show for the first time that under laboratory conditions plant volatiles can prevent inhibition by a pheromone analog., Albert Sans, Miguel Morán, Magí Riba, Ángel Guerrero, Jaume Roig, César Gemeno., and Obsahuje bibliografii
Lygus lineolaris (Palisot de Beauvois, 1818) (tarnished plant bug) is a serious pest of cotton (Gossypium hirsutum L.) in the Delta region as compared to cotton in the Hills region of the state of Mississippi in USA. The reason for this is unclear but it was hypothesized that the plant cell wall degrading polygalacturonase enzyme system in the salivary glands of L. lineolaris from the Delta could be better adapted for cotton, which is grown more predominantly in the Delta region than in the Hills region. Expression analysis of three primary polygalacturonase genes (LlPG1, LlPG2 and LlPG3) was conducted in laboratory reared and field collected populations of L. lineolaris. Assay of polygalacturonase enzyme activity was also conducted to compare wild collected populations. Initial laboratory and field data revealed gene expression differences in sex, age, region, and host plant which guided the direction of our subsequent study during 2013 and 2014. Based on the results of this study, we propose that the three genes studied may not be reflective of the entire polygalacturonase enzyme system and may not be solely responsible for the observed adaptation of L. lineolaris to cotton in the Delta region than in the Hills region. Analyses also revealed that the expression of the three targeted polygalacturonase genes was affected by the host plant from which the insects were collected and that adults had higher polygalacturonase expression than nymphs. Taken together, our results provide strong evidence for developmental stage specific and host plant based change in expression of PG genes in the salivary glands of L. lineolaris. This, however, was not reflected in total polygalacturonase enzyme activity which was not significantly different between regions, hosts, sex, or developmental stage., Daniel Fleming, Natraj Krishnan, Fred Musser., and Obsahuje bibliografii
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
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.