Potential adverse effect of endocrine disruptors at low doses

Chemical pollution, acute and chronic, can present a serious threat to living organisms, their health, and their biodiversity. Intensive use of pesticides has resulted in their presence in water, soil and air. Number of these chemicals can act as endocrine disrupting compounds, cause pollution of natural ecosystems and can adversely affect species diversity. Endocrine disrupting chemicals are emerging risk for human health and the environment. What makes endocrine disruptors so significant is that they are often more active at lower doses, far beneath of those which are traditional concern to toxicologists

Close relatives of Mediterranean endemorelict hoverflies (Diptera, Syrphidae) in South Africa : Morphological and molecular evidence in the Merodon melanocerus subgroup

An ongoing study of the genus Merodon Meigen, 1803 in the Republic of South Africa (RSA) has revealed the existence of new species related to M. melanocerus Bezzi, 1915. The M. melanocerus subgroup belongs to the Afrotropical lineage of the M. desuturinus group. Revision of all available material from museums and detailed analyses of newly -collected specimens from our own expeditions to RSA resulted in delimitation of five species: M. capensis Hurkmans sp. n., M. commutabilis Radenkovic et Vujic sp. n., M. drakonis Vujic et Radenkovic sp. n., M. flavocerus Hurkmans sp. n. and M. melanocerus. In addition to classical morphological characters, sequences of the mitochondrial COI gene are provided for four related taxa. Results of molecular phylogenetic analyses supports monophyly of the M. desuturinus group and confirmed delimitation between species. Links between Palaearctic and Afrotropical faunas of this group, as well as possible evolutionary paths, are discussed. Based on phylogenetic analyses, four lineages (putative subgenera) have been recognized within the genus Merodon; besides the three previously established ones, albifrons+desuturinus, aureus (sensu lato) and avidus-nigritarsis, one new lineage named natans is distinguished.Peer reviewe