Mites - Pests of Ornamental Trees, Shrubs and Flowers - page 406

FRAXINUS

Eriophyes fraxinivorus Nalepa ( 1098 )
Ash inflorescence gall mite
A widespread species, causing a distinctive galling of
the inflorescences of ash ( Fraxinus excelsior ). The
mites overwinter in bark crevices. In the spring, they
invade the emerging inflorescences, depositing eggs and
producing a succession of overlapping generations
throughout the summer. The mites cause considerable
distortion, the flower clusters swelling into a series of
brownish lumps up to 20 mm across; galled flower
stalks may also coalesce. The galled inflorescences
remain attached to trees throughout the year and are
particularly obvious after leaf fall. Infestations are often
heavy on mature trees but any effect on vegetative
growth appears to be slight. Adult mites are c . 0.18 mm
long, with about 65 abdominal tergites and sternites,
and a pair of backwardly directed setae arising from
tubercles on the hind margin of the prodorsal shield.

Aculus epiphyllus (Nalepa) ( 1096-1097 )
Ash rust mite
This generally common mite causes extensive bronzing
of the foliage of ash ( Fraxinus excelsior ) and is often
present on nursery trees. In severe cases, the foliage
becomes brittle and distorted, and the tips of new shoots
turn black and die. Loss of terminal growth often results
in the forking of young trees, and this is a serious
problem in nurseries. The pale, yellowish, pear-shaped
mites are c . 0.15 mm long, with about 30 abdominal
tergites, and a pair of very short, backwardly directed
setae arising from widely spaced tubercles on the hind
margin of the prodorsal shield (cf. Tegonotus collaris ,
below). When present in large numbers, the mites are
clearly visible against the darker background of infested
leaves or bud scales.

Tegonotus collaris Nalepa
Often present on bronzed foliage of ash ( Fraxinus
excelsior ), usually in company with Aculus epiphyllus
(q.v.). The mites are c . 0.16 mm long and rather stumpy,
with about 13 broad, roof-like abdominal tergites, and a
pair of posteriorly directed setae arising from tubercles
on the hind margin of the prodorsal shield.

1096

FUCHSIA

Aculops fuchsiae Keifer
Fuchsia gall mite
This important pest of Fuchsia was first discovered in
1972 in Brazil. It has since been introduced into North
America and, more recently, France. In 2006, following
its arrival in Europe, the pest was found in the Channel
Islands (both Guernsey and Jersey). In 2007 it was also
discovered on fuchsia plants in southern England. The

1096 Ash rust mite ( Aculus epiphyllus ) damage to leaves of
Fraxinus .

1097 1098

1097 Ash rust mite ( Aculus epiphyllus ) damage to shoots of
Fraxinus .

1098 Galls of ash inflorescence gall mite ( Eriophyes
fraxinivorus ).