Vasates quadripedes Maple Bladder Gall Mite in Worcestershire
J.J. Day (John Day)
The gall mite Vasetes quadripedes is native to North America. It is parasitic on the leaves North American maples including Silver Maple Acer saccharinum; Sugar Maple Acer saccharum; Red Maple, Acer rubrum. The mite causes red pustules up to 5mm high normally on the upperside of the leaves (Figs. 1 & 2). They are well established on the leaves by June, when much of the leaf surface may be infested. They become black later in the season.
The first British record for the gall was in London (Wurzell 2002) but is now known to be spreading across the country (Dr.M.Redfern pers.comm.). The only host known in Britain is the Silver Maple Acer saccharinum (Redfern & Shirley, 2011). The Silver Maple is a native of Eastern North America from Ontario to Florida. It was first introduced into Britain in 1725 (Sell & Murrell, 2009). It is commonly planted, in parks and gardens as an ornamental tree.
Worcestershire’s first record for the gall came in August 2008 when it was noted by J.J.Day from a park in Droitwich. There were no further records until June 2011 when three new sites were located, by J J Day (2) & G H Green (1), from widely spaced areas of the county (SO83, SO84, SO96). Two more sites were also located in the same year in SO85 & SP06; the latter site is in VC38 Warwickshire (Table 1.)
Both young and mature trees have been noted as hosts in Worcestershire. The gall is unmistakeable and Silver Maples anywhere in the county should be checked as potential hosts.
Table 1. Worcestershire Records of Vasates quadripedes
|Site||Grid Reference||Date||Recorder||Host||Vice County|
|Eldersfield - Linkend Road||SO81743077||Jun-11||J J Day||Young tree <10years||vc37|
|Droitwich - St Peters Park||SO902629||Jun-11||J J Day||Large tree||vc37|
|Redditch - Matchborough||SP071664||Jul-11||J J Day||Tree 30-40 years||vc38|
|Worcester - County Hall||SO876542||Oct-11||J J Day||Tree 30-40 years||vc37|
|Droitwich - Celvestune Way Park||SO886624||Aug-08||J J Day||Large tree||vc37|
|Earls Croome - Garden Centre||SO863421||Jun-11||G H Green||Young tree||vc37|
Redfern, M & Shirley, P. 2011. P. British Plant Galls. Field Studies Council, Preston Montford.
Sell, P. & Murrell, Gina. 2009. Flora of Great Britain & Ireland Vol. 3.
Fig. 1. Vasates quadripedes on Acer saccharinum 14th June 2011, Earls Croome, Worcestershire SO863421. G.H.Green
Fig. 2. Vasates quadripedes on Acer saccharinum 11th June 2012, Eldersfield, Worcestershire, SO81743077. G.H.Green