Browsing by Subject "Verbreitung"

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    Elucidating the megadiversity of Chalcidoidea (Hymenoptera) with a multi-taxonomic approach
    (2022) Haas, Michael; Krogmann, Lars
    With over 22,500 described and up to 500,000 estimated species, the jewel wasps (Chalcidoidea: Hymenoptera) are among the most species-rich insect lineages. Their evolutionary success is tightly linked to their parasitoid biology, having evolved to utilize a wide array of different arthropod hosts. Additionally, secondary phytophagy evolved several times within this superfamily. Although new approaches are employed in integrative taxonomic research, progress to decipher the megadiversity of this taxon, including their evolution, is still limited. With this work, the diversity of the superfamily is studied at two evolutionary key points in time. The evolutionary origin of Chalcidoidea is investigated in the Cretaceous and the resulting diversity since then is examined in the present. Different systematic levels will be elucidated with the help of integrative taxonomic methods. In the first chapter, the fossil origins of jewel wasps are addressed, around the middle of the Cretaceous period 110 million years ago. The morphology of a putative early chalcidoid specimen is studied, as it is highly informative for chalcidoid evolution due to its age. Based on those results, its phylogenetic placement is critically examined. The specimen is assumed to be one of the oldest described chalcidoid fossils, Parviformosus wohlrabeae Barling et al., 2013. It is a key fossil because of its age and putative assignment to the polyphyletic family Pteromalidae and could therefore be a valuable voucher for dating modern phylogenies. A precise redescription of the fossil was conducted and its morphology and phylogenetic position was discussed. No synapomorphic characters could be identified, warranting an inclusion in an already established chalcidoid family. In fact, none of the autapomorphies for Chalcidoidea could be recognized, necessitating a revised systematic placement in the Proctotrupomorpha. In the second chapter, several fossils in amber are described that grant insights in the early evolution of Chalcidoidea and the morphological diversity of Cretaceous lineages. Morphological characters are studied to answer the question of plesiomorphic character states in Chalcidoidea, aiding to understand their early evolution. The phylogenetic placement of these fossils is discussed, to provide hypotheses on the diversification of the superfamily, which so far has only few fossil representatives described from this time. Four fossils are made scientifically available that were found in 99 million year old Burmese amber. Those specimens are described in a new, extinct family, the Diversinitidae. This family exhibits a unique combination of plesiomorphic characters, not present in any other chalcidoid taxon, but lacks apomorphic characters. In total, three new genera and three new species are delimited and described. Phylogenetically relevant characters like the fully developed funicular segments, possessing multiporous plate sensilla, or the peg like cerci that improve our understanding of the early evolution of Chalcidoidea, are discussed based on the newly established family. A phylogenetic analysis based on morphological characters was performed. This analysis supported the monophyly of Diversinitidae, but left its exact systematic position within Chalcidoidea open. In the third chapter the focus shifts from the early evolution of Chalcidoidea towards the extant fauna, representing the diversity evolved since the Cretaceous. Exemplary, in the speciose family Pteromalidae the unknown diversity is examined to better understand the undiscovered species richness of parasitoid wasps. DNA barcoding is used to record and help identify previously unknown genera and species in Germany. Compared to the already known pteromalid fauna, 17 genera and 41 species are added as new records for Germany and the males of two species are described anew. The identified DNA barcodes were made available to enable the genetic identification of those species that have a high potential as indicators for nature conservation efforts due to their high host specificity. In the fourth chapter, the pertinent problem of cryptic diversity in Chalcidoidea is investigated. Via an extensive integrative taxonomic approach, the morphological species hypothesis is tested for one of the most abundant pteromalid species in Europe, Spintherus dubius. In this example, the benefit of combining different methods for species discovery and delimitation is highlighted. Genetic analyses of S. dubius reveal discrepancies between the morphological species concept and molecular data, indicating two potential species instead of one. The usage of an advanced morphological method, the multivariate ratio analysis, results in a confirmation of the molecular results, also exposing distinctive morphological characters per taxonomic unit. The examination of the host spectrum through rearing experiments further substantiates these findings, by revealing different host parasitoid affiliations. Altogether, this thesis showed that it is necessary to combine methods and examine different evolutionary points in time, to better understand the diversity of parasitoid lineages. Fossil taxa are important study subjects to examine the character evolution of any taxon, laying the base for phylogenetic research. The study of Diversinitidae highlights the plasticity of character states in Chalcidoidea, also providing evidence for plesiomorphic states. Their encompassing description and the redescription of P. wohlrabeae allow their incorporation into phylogenetic studies, to serve as solid anchor points in dating lineages and morphological evolution on the way towards extant diversity. Examining the extant fauna of Pteromalidae revealed the amount of diversity of species, for which the biology is often unknown. It is shown that molecular methods aid in the discovery of this diversity, opening possibilities for further research. It is affirmed that hidden diversity is even pertinent in abundant, well known species, with S. dubius being an example of cryptic diversity unveiled by integrative taxonomy.
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    Modeling population dynamics and dispersion of Codling moth Cydia pomonella L. (Lepidoptera, Tortricidae)
    (2009) Gharehkhani, Gholamhossein; Zebitz, Claus P. W.
    The study of insect dispersal plays an essential role in estimating the spread of damage caused by a newly invaded pest or the spatial distribution of an insect during the active period in growing season. Moreover concerning dispersal, quantitative information performs a crucial role in the evaluation and implementation of pest control. Since rearing clean and healthy insects in sufficient numbers is the most important prerequisite for many basic research programs and for developing pest control strategies, mass rearing of the Codling moth on the artificial diet carried out as the first step at optimum conditions. With regard to the fundamental function of feeding and pre-releasing handling on insect biological attributes, we intended to evaluate the individual marking influence on longevity of Codling moths in the next step. For this purpose, one day old adult male and female moths were kept three and five minutes at -20°C to make them motionless, then immediately marked individually with felt tip pens and coded by the different colors, maintained under optimum condition and checked daily for 13 days. The proposed linear model accounted for 89 % of the variations. Numbing and marking process influenced of the moths longevity regardless of their sex while the duration of the anesthetize does not affect the survival of moths meaningfully. Regarding the obstacles associated with egg and pupa storage of Codling moth, we examined the possibility of adult moth?s storage in low temperature in order to evaluate its effect on longevity of moths. Adult 12-24 h old male and female moths were treated separately and maintained in 4 ◦C and (0:24 h, L:D) photoperiod during the entire adult life. The survival rate evaluated with two days interval throughout 27 days. The effects of day and treatment were significant. It seems that the female moths tolerate the cold condition better and further than the male moths and live longer. Additionally the proposed models accounted for 71 % and 57 % of the variations for male and females respectively as verified more affection and debility of the males by the storage condition. Disadvantages of individual marking led us to test the mass marking and it?s influence on the survival of the moths. One-day-old moths were marked with fluorescent powder. Mortality of the males and females recorded daily for a 20 days period. Results indicated that the effects of the sex, the replications and interaction of them were significant as well as the effect of the day. The model accounted for 96 % of the variations. This study indicated that male and female moths were influenced by the fluorescent powder. Findings of this study may facilitate the improvement of mark-release experiment results and interpretation more precisely in particular for dispersal studies. In the field experiments, firstly trade off trap structure in assessing the horizontal and vertical distribution of Codling moth carried out as well as outward and inward dispersal. Three different types of the traps including Delta pheromone traps, Delta Pear ester trap and Cylinder shape Pear ester traps were used in the research station of the Hohenheim University. Ninety six traps were suspended in eight compass directions in order of four traps per direction, at three heights in random arrangement in outward dispersal. In inward dispersal study the traps arrangement and number was the same but dissimilarly the releasing site was from borders of directions SW, NW, W, E, and SE. The traps were checked daily and followed nine days after release. Results demonstrated no significant differences between three types of traps in attracting the marked and feral females ?Fn?. Meanwhile significant dissimilarity in marked and feral male ?Mn? catches were traced. Reaction of the moths to the traps elevation was not similar in the vertical distribution study. whereas marked female moths exhibited significant differences to different heights, marked and feral male and ?Fn? moths revealed no difference reaction to traps in different heights.In horizontal distribution study marked female moths ?Fr? exhibited significant differences. It is revealed that dominant directions for marked and feral moths were different. Concerning inward distribution, both marked male ?Mr? and female demonstrated significant differences in their direction and distances. In regard to this findings and priceless and effortless manufacturing of the Cylinder traps, utilization of this trap in mark-release-recapture studies of female and male Codling moths is recommended. Effect of apple cultivar on pheromone and Pear ester trap efficiency studied as the next tread. In this experiment 32 Delta pheromone traps and 32 Cylinder-shape Pear ester traps impartially mounted on different varieties of apple trees. Artificially reared and marked 24 to 26 h old moths were released at 1 m height from a central point. Among the simple effects the most important explanatory variable for the response variables ?Mn? and ?Fn? moths was sampling dates of moths, while the variety and distance from the releasing point for ?Mn? and the variety and trap height for ?Fn? were the second and third influential variables respectively. Moreover among the nested effects the interaction of distance-height-variety was the most influential one for ?Mn? likewise the interactions of date, release point, direction and trap height with the variety were the most influential for ?Fn?. For the ?Mr? and ?Fr? moths releasing date was the most important influential variable, while the trap type and variety for ?Mr? and variety and trap height for the ?Fr? were the second and third influential variables respectively. Current study revealed that dispersal of the feral and marked-released male and female Codling moths influenced by host cultivars distinctly and decidedly. Meanwhile, quantifying these relationships and propose distinct model for marked and feral male and female moths are the exclusive characteristics of present findings. The next stage of present study related to study of climatic factors on dispersal of Codling moth. In this study, Hohenheim station climatic data were used. Several climatic elements including temperature, relative humidity, precipitation, wind speed in two different heights (2.5 m and 10 m), Day Degree, twilight temperature, wind speed and precipitation were utilized in the analysis. Diversity and high number of variables led us to use AIC method for selecting of appropriate regressors and fitted model. The main regressors that inföuenced the ?Fr? were flight height, ageing, twilight wind speed (2.5 m heights) and precipitation. For the ?Mr? the same regressors plus the distance from the releasing point were the best subset. In the case of the feral moths the flight height, relative humidity, Day Degree, twilight temperature and wind speed were the best subset regressors. Comprehensively we concluded that present study provides new knowledge in basic as well as in applied science. Twilight temperature, rainfall, wind speed and Day Degree impress the distribution of the moths in a superior way than the circadian weather data. This knowledge could mitigate confusion which arises from observations of erratic flight patterns and could lead to fewer treatment decision errors in the future. Also may accelerate and strengthen forecasting programs of this key pest as well as the related management tactics. The combination of mark-release-recapture and diffusion models have been shown to be effective for measuring insect dispersal. We attempted to measure the Codling moth dispersal using traps placed at different distances and heights. Diffusion coefficient calculated for horizontal and vertical dispersal of male and female moths distinctly using direct and indirect methods and resulting models were compared. We fitted the non-linear regression using the iterative process and estimating the parameters accuracy were tested according to the default asymptotic 95 % confidence intervals calculation in non-linear regression. Considering the overall models, suitability of three factors fitted models was more convincible than that of two factors model particularly for male moths. Meanwhile we found great difference in the diffusion coeffcient of direct and indirect methods. Regardless of the model type, the R2 was relatively high in our experiments which evaluate how well the model fits data. We have shown that the diffusion model leads to powerful techniques for the analysis of dispersal data at least for one economically important insect. In conclusion, the present study provides an estimate of population spread by Codling moth using estimated rates of reproduction and dispersal, quantified the association between various key factors and Codling moth movement for the first time using the diffusion model. By including additional parameter to the diffusion model the predictive explanatory potential of this method was improved for dispersal studies at least for a cosmopolitan and critical insect.