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Central European Populations (central + european_population)
Selected AbstractsEffects of photoperiod and temperature on the development and diapause of the bark beetle Ips typographusJOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2007P. Dole Abstract:, Diapause was induced in a Central European population of Ips typographus grown at 20°C when the day length decreased below 16 h [50% diapause incidence occurred in the 14.7:9.3 h L:D (light:dark) regime]. The non-diapausing adults fed on days 2,6 and 10,14 after the ecdysis and swarmed after the second feeding bout with chorionated eggs in the ovaries and sperm in the spermiducts. Neither gonads nor the flight muscles matured and no swarming occurred in the diapausing adults. The development from egg to adult took about 34 days in both 18:6 h (no diapause) and 12:12 h L:D (diapause) regimes, but it was extended by up to 30% without diapause induction when only larvae or pupae were exposed to L:D 12:12 h. Diapause was induced in insects reared at L:D 12:12 h through the last larval and the pupal instars and/or in the adult stage. Temperature , 23°C prevented diapause induction at L:D 12:12 h but diapause occurred at L:D 14:10 h associated with 26:6°C thermoperiod. The effect of thermoperiods on the developmental rate requires further research. Exposure of the non-diapausing adults to 5°C for several days blocked feeding and evoked a diapause-like state, whereas diapausing adults fed and their gonads slowly developed at this temperature. Diapausing adults exposed in forest to low night temperatures and transferred in October to 20°C readily reproduced at 18:6, but not 12:12 h L:D photoperiods. After 2-months at 5°C and darkness, they became insensitive to the photoperiod, matured and most of them also swarmed at 20°C in the 12:12 h L:D regime. In a Scandinavian population, diapause occurred at 18:6 h L:D and was terminated either by exposure to 5°C or by very long photoperiod (L:D 20:4 h) combined with high temperature (23°C). [source] External morphology of a Slovenian population of pumpkinseed Lepomis gibbosus (L.) from a habitat with extreme thermal conditionsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2005umer Summary The external morphology and growth variability of morphometric characters of pumpkinseed (n = 141) from an oxbow (River Sava, Slovenia) that receives thermal effluent were examined using triple regression analysis. Differences in external morphology between pumpkinseed from the oxbow and both native North American (River Otonabee, Looncall Lake, Canada) and non-native Central European populations (side arms of the River Danube, Slovakia) were evaluated. Two possible morphotypes among adults were observed, whereas the morphology of juveniles appears rather uniform across geographical location (i.e. Otonabee, Looncall, Danube). This suggests that environmental conditions, i.e. epigenetical information, seem to be responsible for most of variability in pumpkinseed morphology, which represents a function of epigenetical mechanisms. However, further investigation into epigenetical interactions, especially early development, fecundity, number of spawning acts per season, parental care, egg size and age at maturation are necessary to test this hypothesis. [source] Chromosomal inversion polymorphism of Drosophila subobscura from south-eastern part of EuropeJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 4 2002G. Zivanovic Abstract Five Drosophila subobscura populations from south-eastern Europe were investigated with respect to chromosomal inversion polymorphism. They belong to central European populations and their gene arrangement frequencies are in accordance with latitudinal variation observed in this species. The new complex gene arrangement A2+8+9, found in one of the populations analysed, may be specific for the southern Balkan refugium. A general tendency of gene arrangement frequencies to exhibit some southern characteristics was found for some of the autosomal standard arrangements. Zusammenfassung Fünf Populationen von Drosophila suboscura aus dem Süwesten von Europa wurden hinsichtlich ihres chromosomalen Inversionspolymorphismus untersucht. Sie erweisen sich als zu den mitteleuropäischen Populationen gehörig und die Häufigkeiten der chromosomalen Inversionsstrukturen stimmen mit den breitenabhängigen Häufigkeitsklinen, die in dieser Art beobachtet werden, überein. Ein neuer komplexer Strukturtyp, A2+8+9, der in einer der untersuchten Populationen gefunden wurde, scheint für das Refugium im südlichen Balkan spezifisch zu sein. Eine allgemeine Tendenz der Häufigkeiten der Strukturtypen, sich in Richtung mehr südlichere Eigenschaften zu verändern, wurde für einige der Standardstrukturtypen der Autosomen gefunden. [source] Increase in mate availability without loss of self-incompatibility in the invasive species Senecio inaequidens (Asteraceae)OIKOS, Issue 2 2007Lucile Lafuma The evolution of the strength of self-incompatibility in Senecio inaequidens, a native of South Africa was investigated in relation to its invasion in Europe. Levels of self-incompatibility were estimated with hand-pollinations in five populations in greenhouse conditions. One population came from the native range of the species and four populations were sampled in Europe from two independent transects of colonization with old and recent populations. Contrary to Baker's law predictions, our results suggest that the species has a sporophytic self-incompatible system maintained in all populations. We suggest that the ability of S. inaequidens to colonize new sites with a self-incompatibility system is promoted by its ecological characteristics (perenniality, extended reproductive period, massive seed production, generalist pollinators). In addition, we found that mate availability was increased (1) in the introduced range compared to the native range, (2) in marginal versus central European populations. Possible explanations for this surprising result are discussed. [source] | ||||||||||