Seasonal dynamics of biting midges (Diptera: Ceratopogonidae, Culicoides spp.) on dairy farms of Central Germany during the 2007/2008 epidemic of bluetongue

Abstract

The unforeseen outbreak of bluetongue in north-western Europe in August 2006 raised the question, which Culicoides spp. were involved in the transmission of bluetongue virus (BTV). Based on the decision 2007/20/EU of December 2006, a large-scale entomological surveillance programme was initiated in the five affected EU member states including Germany. This paper reports on the entomological findings obtained from March/April 2007 to May 2008 at 15 sampling sites in the federal states of Lower Saxony (eastern region), Mecklenburg-Western Pomerania, Brandenburg and Saxony-Anhalt: The number of captured biting midges in one trap varied from none or few Culicoides during winter (December 2007 to April 2008) to up to more than 12,500 individuals during summer and autumn. Catches of the C. obsoletus group were consistently higher than those of the C. pulicaris group. C. imicola, the principal afro-asiatic vector of BTV, was not detected. High numbers of midges were caught inside the cattle sheds. Eleven pools of biting midges were RT-PCR-positive to BTV-8 including pools of non-engorged midges of the C. obsoletus and of the C. pulicaris groups. The first BTV-genome positive pool of midges was detected in August 2007; the remaining genome-positive pools were detected during October and November 2007.

An appraisal of current and new techniques intended to protect bulls against Culicoides and other haematophagous nematocera: the case of Schmergow, Brandenburg, Germany

“…As for C. obsoletus it appeared that deltamethrin did not markedly change the percentage of successful feeds. During the German Federal Monitoring Programme of biting midges in 2007, catches were performed on 15 dairy farms in Brandenburg, Lower Saxony, Mecklenburg-Vorpommern and Saxony-Anhalt (Clausen et al 2009). Most catches indicated a clear dominance of C. obsoletus contrary to the findings in this study.…”

Monitoring of biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) on farms in Sweden during the emergence of the 2008 epidemic of bluetongue

“…The former three species also accounted for 98-99% of Culicoides captured in a cattle shed and a sheepfold in Belgium (Zimmer et al 2008a). At cattle farms in western, central and southern Germany, Culicoides species belonging to the C. obsoletus group were most abundant, while species of the C. pulicaris group were second (Mehlhorn et al 2009;Clausen et al 2009;Hörbrand and Geier 2009). …”

Bluetongue disease in Germany (2007–2008): monitoring of entomological aspects

“…The 10 papers following this introducing overview in the present volume of the journal Vorsprach et al 2009;Balczun et al 2009;Kiel et al 2009;Kiehl et al 2009;Bartsch et al 2009;Clausen et al 2009;Stephan et al 2009;Bauer et al 2009;Hörbrand and Geier 2009) describe the results obtained during this monitoring program, which ran from the end of March 2007 until the end of May 2008.…”

“…Evaluating these main results of the entomological monitoring and the fact that many wild ruminants have also been infected with BTV, it becomes evident that bluetongue disease has become endemic in Central Europe, and that only constant effort including vaccination and perhaps also insecticidal protection of cattle and sheep will keep the economical losses at a reasonable level. The following papers (1-10) in this journal will contribute more details obtained from this worldwide unique entomological monitoring: Bartsch et al 2009;Bauer et al 2009;Clausen et al 2009;Hörbrand and Geier 2009;Kiehl et al 2009;Mehlhorn et al 2009;Kiel et al 2009;Vorsprach et al 2009;Balczun et al 2009.…”