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Unformatted text preview: Deformed wing virus associated with Tropilaelaps mercedesae infesting European honey bees ( Apis mellifera ) Eva Forsgren Æ Joachim R. de Miranda Æ Mats Isaksson Æ Shi Wei Æ Ingemar Fries Received: 24 June 2008 / Accepted: 8 October 2008 / Published online: 22 October 2008 Ó Springer Science+Business Media B.V. 2008 Abstract Mites in the genus Tropilaelaps (Acari: Laelapidae) are ectoparasites of the brood of honey bees ( Apis spp.). Different Tropilaelaps subspecies were originally described from Apis dorsata , but a host switch occurred to the Western honey bee, Apis mellifera , for which infestations can rapidly lead to colony death. Tropilaelaps is hence considered more dangerous to A. mellifera than the parasitic mite Varroa destructor . Honey bees are also infected by many different viruses, some of them associated with and vectored by V. destructor . In recent years, deformed wing virus (DWV) has become the most prevalent virus infection in honey bees associated with V. destructor . DWV is distributed world-wide, and found wherever the Varroa mite is found, although low levels of the virus can also be found in Varroa free colonies. The Varroa mite transmits viral particles when feeding on the haemolymph of pupae or adult bees. Both the Tropilaelaps mite and the Varroa mite feed on honey bee brood, but no observations of DWV in Tropilaelaps have so far been reported. In this study, quan- titative real-time RT-PCR was used to show the presence of DWV in infested brood and Tropilaelaps mercedesae mites collected in China, and to demonstrate a close quantitative association between mite-infested pupae of A. mellifera and DWV infec- tions. Phylogenetic analysis of the DWV sequences recovered from matching pupae and E. Forsgren ( & ) J. R. de Miranda I. Fries Department of Ecology, Swedish University of Agricultural Sciences, PO Box 7044, 75007 Uppsala, Sweden e-mail: [email protected] J. R. de Miranda School of Biological Sciences, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland M. Isaksson The National Veterinary Institute, Ulls va ¨g 2 B, 75189 Uppsala, Sweden S. Wei Institute of Apiculture, Chinese Academy of Agricultural Sciences, Xian Shan, 10000 Beijing, China 123 Exp Appl Acarol (2009) 47:87–97 DOI 10.1007/s10493-008-9204-4 mites revealed considerable DWV sequence heterogeneity and polymorphism. These polymorphisms appeared to be associated with the individual brood cell, rather than with a particular host. Keywords Tropilaelaps mercedesae Apis mellifera Deformed wing virus qRT-PCR Introduction Deformed wing virus (DWV) is a virus with a single positive-stranded RNA genome belonging to the genus Iflavirus (Lanzi et al. 2006 ). Overt DWV infections are a major cause for colony collapse of honey bees ( Apis mellifera ) worldwide. Virus infections (i.e....
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