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The potter wasp Eumenes coronatus on the move (Hymenoptera: Vespidae) The first record of Eumenus coronatus in the Netherlands dates back from 1954. After that the species was not recorded until 1988. Since then many specimens were collected in the southern part of the country. In 2004 a female was caught near Arnhem in the central part of the Netherlands. Based on the observed northward expansion in Germany it is expected that Eumenes coronatus will push further northward in the future.

Uitbreiding van het areaal van de mosdiertjes Tricellaria inopinata en Bugula simplex in het noordoosten van de Atlantische Oceaan (Bryozoa: Cheilostomatida) In 2000 werd het mosdiertje Tricellaria inopinata op twee plaatsen bij Goes (Zeeland) aangetroffen. De soort is in 1985 beschreven aan de hand van materiaal van Venetië, waar ze kennelijk door scheepvaart is geïntroduceerd. Tricellaria inopinata is afkomstig uit het noorden van de Stille Oceaan. De soort komt nu ook in Zuid-Australië, Nieuw-Zeeland, Japan en Taiwan voor, en is daar waarschijnlijk geïntroduceerd. In 1996 werd deze soort voor het eerst aan de Atlantische kust van Europa waargenomen, in Galicië (NW Spanje). Waarschijnlijk tussen 1996 en 1998 koloniseerde de soort Zuid-Engeland in de omgeving van Wight. Naar aanleiding van de vondst bij Goes werd een onderzoek ingesteld naar de struikvormige mosdiertjes van (jacht)havens in Frankrijk, België en Nederland. Vastzittende kolonies van T. inopinata werden aangetroffen bij Scharendijke, Burghsluis, Bruinisse, Neeltje Jans, Colijnsplaat, Kats, Goes en Breskens in Nederland, Blankenberge en Oostende in België en Hendaye in Zuidwest-Frankrijk. De soort werd aangetroffen op (begroeiing van) pontons en jachten in jachthavens en in het Goesse Meer vooral op wieren. In Zuidwest- Nederland was de soort reeds zodanig wijdverspreid en talrijk in 2000, dat de introductie waarschijnlijk al in 1999 of eerder plaatsvond. Waarschijnlijk zal de soort in België en Nederland beperkt blijven tot (jacht)havens en binnenwateren met een voldoende hoog zoutgehalte, vanaf circa 25 ‰. In de Grevelingen zal zich naar verwachting een grote populatie ontwikkelen. Tijdens het onderzoek

New and rare flies for the Dutch fauna (Diptera) In this paper an overview is given of the author’s captures of rare and interesting Diptera, mainly from the years 1997-2000. In total 36 species from ten families are presented, of which four are new to the Dutch fauna (marked with an *), Empis confusa Loew, 1865 (Empididae), Temnosira ambusta (Meigen, 1826) (Pallopteridae), Chetostoma curvinerve Rondani, 1856 (Tephritidae) and Tephritis separata Rondani, 1871 (Tephritidae).

The expansion of Conocephalus discolor in the southern part of the province of Limburg (Orthoptera: Tettigoniidae) The range of Conocephalus discolor (Thunberg, 1815) in northwestern Europe and Britain has expanded substantially during the last decades. The species is known from the Netherlands since 1990 but was not found in the southern part of the province of Limburg until 1997. In 1997, triggered by an accidental find of a population in his neighbourhood, the author became highly interested and started investigating the distribution of C. discolor in these surroundings. The localities both where the species has been observed and those where it not has been found, are mapped. It became clear that the species is common between Kerkrade and Geleen. This area, covering a former coalmining-district, is quite urbanised and except for a few more natural sites not extensively examined before. The habitat ranges from dry to slightly wet, referring consistently to rough grassland with or without coarse herbaceous vegetation. These habitats are quite often presented by urban wasteland, roadside verges and railway lines, neglected fields and meadows, river banks, pools and pits. The species was not found in dry heathland. The number of observed individuals per site ranged from a single specimen to florishing populations. At a few sites a single or a few individuals were found in a habitat patch as small as 100 m2 or even less. The species was found together with a number of other Orthoptera, sometimes only with the most common ones as Chorthippus parallelus and C. biguttulus. In 20 of the 54 localities visited by the author, C. discolor was found together with P. falcata, which is also expanding its range and in seven localities together with the related C. dorsalis. The number of localities, density and size of some populations do suggest that C. discolor is already present since a number of years in this part of Limburg. However, as the localities with C. discolor become scarcer towards the western part of the study area, it i

Interesting new records of hoverflies in TheNetherlands (Diptera: Syrphidae) The preliminary distribution atlas of the Dutch hoverflies (NJN 1998) marked the start of the Syrphidae recording scheme (1998-2002). This publication has proven to be a major stimulus for the study of this interesting group of flies. Many interesting new data from field and collection work have become known since 1998. In this paper a selection of published and unpublished records is summarized. At the end of the project all available knowledge on Dutch hoverflies will be compiled in the Dutch Syrphidae atlas.

The expansion of the range of the spider Argiope bruennichi in the Netherlands (Araneae: Araneidae) Argiope bruennichi (Scopoli, 1772) is one of the biggest and most colourful spiders in Europe and therefore easy to recognise, even by non-specialists. The species has expanded its range in Germany and Belgium for several decades now and reached the south of The Netherlands in 1980. After the discovery of the first female in the south of the province of Limburg more specimens were found in this region in subsequent years. Later the species was discovered near Herkenbosch, about 30 kilometres to the north. Over the last years the expansion continued rapidly and now almost 300 records are brought together. The species has become widespread in the southern and eastern part of The Netherlands. In 1995 a leap of some 70 kilometres was made, from Limburg to the southern parts of the Veluwe. The years 1998 and 1999 were very good for Argiope, both with over 80 records per year. It is suggested that this expansion is related to the warm and sunny summers in the nineties.