Bewertung der Auswirkungen von Pflanzenschutzmitteln auf Regenwürmer

The fundamental data requirements for the authorization of plant protection products and the inclusion of active ingredients in Annex I of Council Directive 91/414/EEC are described in Annexes II and III of the Directive. The uniform principles for the registration of plant protection products in the Member States described in Annex VI of the Directive were primarily developed to assess the effects on the soil functions with regard to agriculture. A tiered approach was developed to assess the effects of plant protection products on earthworms based on the data requirements of Annex II and III of Directive 91/414/EEC. The risk is assessed using the effect-concentration evaluated in ecotoxicological tests and the predicted or calculated environmental concentration. To protect the whole range of naturally occurring species in terrestrial biocenosis assessment factors need to be considered.     

Male and female developmental differences in chemosensory investigations by African elephants (Loxodonta africana) approaching waterholes

Although communication is vital for members of a social species, the sexes may differ in the type and degree of information sought. In many polygynous societies, males search for reproductively active females and compete intrasexually for access to females with older males often being most successful. In social mammals, females may mature sooner than males and thus at an earlier age behave more like adults. This maturation may include the assessment of potential mates directly or via indicative signals. In this study, we observed the behavior of African elephants (Loxodonta africana) during their approach to waterholes. Waterholes provide an opportunity for elephants to investigate conspecific chemical signals from feces and urine, and each other. We examined the presence of sexual dimorphism in behaviors of the trunk that are indicative of olfactory investigation. We predicted that upon approach to a waterhole, adult males would show greater interest than females in conspecific chemical signals. Females were predicted and observed to exhibit adult-like rates of investigatory behavior at a younger age than males because females mature sooner. Adult males took the longest to reach the waterhole in the last 100 m of approach; they also demonstrated greater investigatory rates to conspecific feces. Each sex showed adult-type investigative behaviors with the trunk before the age of reproduction. Rather than showing a common chronological developmental pattern across sex, the exhibition of investigatory, chemosensory behaviors reflected sex-specific changes in reproductive development, perhaps reflective of the relative strength of intra- and intersexual selection on communication patterns.     

Gezeitenrhythmische Nahrungsaufnahme und Kotballenablage einer terrestrischen Milbe (Oribatei: Ameronothridae) im marinen Felslitoral

Feeding, locomotory and defecatory activity of the algivorous orbatid mite Ameronothrus marinus have been measured under defined conditions in the laboratory. Of terrestrial origin, these mites inhabit the intertidal zone of rocky shores along the North and Baltic Seas. Under daylight cycles found at the sampling site and in the absence of tides, feeding and defecation follow an endogenous rhythm with a spontaneous period of 12.3 h; in the tideless littoral of the Baltic Sea these activities are synchronized with diurnal cycles. Feeding and defecation follow a definite sequential pattern, repeated on the average every 4 h, i.e., 3 times between two high tides. The phase of this tidal feeding-defecation rhythm is determined by the onset of the high tide, and different patterns of this rhythm can be observed according to the tidal zones. Inhabitants of the lower eulittoral exposed to longer periods of submersion start feeding earlier, take up more food at one time before the beginning of high tide, quickly defecate part of the food undigested after feeding, and later produce other faecal pellets which contain the real remains of digestion. Inhabitants of the upper eulittoral, exposed to shorter periods of submersion, start feeding later and extend their feeding activity over the whole period of low tide; the difference between faecal pellets with digested and undigested contents is indistinct. The occurrence of these different types of faecal pellets in inhabitants of the intertidal zone is interpreted as a compensatory physiological adaptation resulting from increasing periods of submersion.     

Plant protection products: assessing the risk for terrestrial plants

The fundamental data requirements for the authorization of plant protection products and the inclusion of active ingredients in Annex I of Council Directive 91/414/EEC (Council Directive of 15 July 1991 referring to placing plant protection products on the market (91/414/EEC). Official Journal of European Communities L 230, 19 August 1991) are described in the Annexes II and III of this Directive. Definite instructions with regard to preconditions for implementation and methodology (guidelines) concerning investigations with terrestrial plants are deficient. In addition to that, the uniform principles for the registration of plant protection products in the Member States described in Annex VI of the directive do not include any criteria concerning the risk assessment for non-target plants. However, plant protection products often show effects on non-target plants which need to be assessed as a requirement for the authorisation of the product. Hence, the German Federal Environmental Agency has developed a tiered approach to assess the effects of plant protection products on non-terrestrial plants. The risk is assessed using the effect-concentration evaluated in ecotoxicological tests and the environmental concentration predicted by validated exposure models. To protect non-target plants in terrestrial ecosystems assessment factors need to be considered. In the future, the risk for terrestrial plants needs to be addressed, also with regard to the revision of the Annexes of Directive 91/414/EEC.