"Top 10 pests". Wisley, England: Royal Horticultural Society. 19 January 2011. Archived from the original on 9 October 2013. Retrieved 4 September 2014.
"Viburnum beetle". Wisley, England: Royal Horticultural Society. 2014. Retrieved 4 September 2014.
"Top 10 pests". Wisley, England: Royal Horticultural Society. 19 January 2011. Archived from the original on 9 October 2013. Retrieved 4 September 2014.