Deformed+Wing+Virus

=**What is Deformed Wing Virus? **= Deformed Wing Virus (DWV) is the most recognised viral infection ( Rosenkranz et al. 2010 ). This virus leads to crippled wings and a shortened abdomen ( Rosenkranz et al. 2010 ). DWV is a honeybee viral pathogen ( Yue & Genersch 2005 ). The effects of this viral pathogen are not normally morphologically present unless they are symptoms of a viral infection during the pupal stage of development ( Martin 2001 ). When the pupae are infected the rate of mortality increases and their lifespan decreases ( Martin 2001 ). Conversely, infected adult bees do not have a reduced lifespan ( Martin 2001 ).

=**What does //Varroa // have to do with DWV? ** = //Varroa // destructor aid in the transmission of this virus to honey bees, and this often leads to __ Colony Collapse Disorder __( Yue & Genersch 2005 ). There have been instances in the UK and South Africa where DWV has been found to be present in colonies that are not affected by //Varroa// ( Martin 2001 ). A scientific study has revealed that the DWV was found to be present in the food source of larval honey bees ( Yue & Genersch 2005 ). Furthermore, in the study it was found that one hundred percent of crippled and asymptomatic German honey bees had DWV ( Yue & Genersch 2005 ). Conversely, sixty percent of Swedish honey bees were free of this virus ( Yue & Genersch 2005 ). The number of mites carrying the DWV was also found to vary between populations ( Yue & Genersch 2005 ). A study conducted in France revealed that DVW was the most frequently occurring virus in bee and //Varroa// mite samples collected from colonies ( Tentcheva et al. 2004 ). Another study indicated that there was no information published about DWV relating to bee colony deaths before the arrival of //Varroa// into bee colonies ( Sumpter and Martin 2004 ). At this point in time it is unknown how DWV leads to the morphological changes that occur with infections ( Yue & Genersch 2005 ). What is known is that all infected bees are carriers of DWV until they perish, and human interference through moving infected bees aids in its spread ( Martin 2001 ). . 

This image shows an adult honey bee that has been infected by Deformed Wing Virus. Source: Rosenkranz et al. 2010.

©Kirsty Pearson 2010