Prüfung der Auswirkungen von Pflanzenschutzmitteln auf Laufkäfer

The testing procedure for the effects of pesticides on carabid beetles is described and examples are given for important factors, e.g. temperature, type of soil, testing method and physiology of the test animal, which can influence the results of such tests. Risk assessment for pesticides, therefore, has to be carried out by experts. Additionally, a monitoring of effects should be carried out after the registration process in certain cases.     

Comparing aquatic risk assessment methods for the photosynthesis-inhibiting herbicides metribuzin and metamitron

Three different risk assessment procedures are described that aim to protect freshwater habitats from risks of the photosynthesis-inhibiting herbicides metribuzin and metamitron. These procedures are (1) the first-tier approach, based on standard toxicity tests and the application of an assessment factor, (2) the Species Sensitivity Distribution (SSD) approach, based on laboratory tests with a wider array of species and the application of a statistical model to calculate the HCx (the Hazardous Concentration for x% of the species), and (3) the model ecosystem approach, based on the evaluation of treatment-related effects in field enclosures. A comparison of the risk assessment procedures reveals that the first-tier approach is the most conservative for metamitron and metribuzin, and that HC5 values (and even HC10 values) based on acute EC50 values of algae and aquatic vascular plants may be used to derive maximum permissible concentrations for single applications. For both compounds these HC5 values were very similar to the ecological threshold concentrations in the enclosure studies. In contrast to model ecosystem experiments, however, HCx values based on lab toxicity tests do not provide information on the recovery potential of sensitive endpoints and on indirect effects, which may be important for regulatory decision-making. In the enclosure study, indirect effects of metribuzin on invertebrate populations were observed at an exposure concentration that was approximately 20 times lower than the corresponding HC5 value based on lab toxicity data for aquatic invertebrates.     

Timing of eclosion in marine insects on Mediterranean shores – studies on Clunio mediterraneus, C. ponticus and Thalassomyia frauenfeldi (Diptera: Chironomidae)

In three Clunio stocks, two from the Mediterranean Sea (Banyuls, Rovinj) and one from the Black Sea (Sosopol), an identical circasemilunar eclosion pattern in combination with a circadian eclosion time of day was evoked in breeding experiments under an artificial moonlight cycle (four nights of 0.3 lux every 30 d, 12 h light:12 h dark). The eclosion peaks occurred on days with artificial moonlight and approximately 2 weeks later, and with regard to the time of day between mid-night and lights-on. In spite of the weak tidal amplitudes on Mediterranean shores, extreme low water levels occur when a nocturnal low-water time coincides on days around full and new moon (spring-tide situation) with winds from land to sea. Field observations at Banyuls and Rovinj agree with the experimental results. In contrast to Clunio spp. adults (life span only a few hours), Thalassomyia frauenfeldi adults (life span up to several days in the laboratory) demonstrated an unsynchronized eclosion pattern in the experiments (no lunar concentration, wide diurnal eclosion gate). Although inhabiting the same intertidal area, T. frauenfeldi walking on exposed intertidal substrates can delay egg-deposition for days and can probably wait for favorable low water levels. The taxonomical status of European Clunio populations is reviewed; minute morphological distinctions are presented for C. mediterraneus in the otherwise morphologically uniform, but ecophysiologically differentiated genus. Received: 15 May 1997 / Accepted: 16 June 1997     

Deposition of dust with active substances in pesticides from treated seeds in adjacent fields during drilling: disentangling the effects of various factors using an 8-year field experiment

Environmental Science and Pollution Research - The side effects from the use of plant protection products and their potential effects on non-target arthropods (NTAs) such as honey bees, other...     

Entwicklung der Ökotoxikologie von Pflanzenschutzmitteln in den letzten 25 Jahren: Von ersten Diskussionen über Prüforganismen zur probabilistischen Risikoanalyse

In Europe as well as in Germany a remarkable development within the last 25 years took place in the assessment of ecotoxicological effects of Plant Protection Products (PPPs). The starting point was a comparative, retrospective toxicity testing of some selected indicator species. Then, first attempts of a quantitative, prospective hazard and risk assessment with relevant exposure evaluations were made. Currently a probabilistic risk analysis on the landscape level is discussed.Based on personal experiences within the last decades this contribution will highlight the different developments of the ecotoxicological evaluation of PPPs. At first, the selection of suitable test species and the development of suitable standardized test methods was the main task. Thereafter, the discussions focused more on long-term, chronic effects instead of solely acute ones, the development of focused higher tier studies adjusted to better address the specific properties of a PPP and/or the specific concerns resulting from its application, as well as multi-species and ecosystem approaches. With the availability of suitable computer based models a more precise exposure calculation was possible, which allows a more realistic exposure assessment instead of simple worstcase assumptions. Current discussions focus on probabilistic exposure assessments at a local scale.All these developments took place regardless of the insufficient (political) definition of the protection goal and — as a consequence — the need and extent of appropriate safety factors. The development of ecotoxicology was mostly driven by political trends in Europe, mainly by the harmonized registration of PPPs under the still valid Annexes II and III (1996) of the EU Directive 91/414 and the thereby initiated further progression. In the context of this development more and more scientists were offered interesting job opportunities.