The spidery web of
the Conifer Mite
As a neighbour there are hundreds of things we can do to
irritate the people next door. It could
be as simple as having a dog bark late at night, blocking their driveway, argue
over boundaries or have late night parties and treat their garden as a bottle depository.
One of the main reasons for falling out in estates or houses
with small gardens is planting leylandii hedging on boundaries or so close to
the neighbours house you eventually block out all of their light in the kitchen
and sap the nutrients and moisture from their garden.
Planting leylandii as a boundary has been a popular method
of irritation since the 1970’s and since leylandii can grow up to three feet in
one growing season it’s only a handful of years before you have your day in
court with the neighbours or at least being aware of their disapproving looks
through the ever growing boundary hedge as you take the shopping into the front
door.
There is help at hand though for anyone who have these
massive out of control boundaries. They are tiny and can be extremely
destructive. The conifer mite and
cypress aphids have taken full advantage of the growing number of hedges and
have spread unhindered since the 1980’s.
Up until recently you would have thought that the brown
patches on the hedges were down to over zealous cutting back – Once you cut off
the green growth of leylandii the green doesn’t grow back. This type of over trimming
will account for a number of brown patches but it’s these small insects that
are causing the main bulk of the problem. Most of them are so small the only tell-tale
sighs are the small spider web looking fibres on the brown leaves. There are
over 500 species of sap sucking aphids and a couple of them are having their
moment in the limelight.
The two most attracted to leylandii are the conifer mite and
cypress aphid.
Conifer Mites Oligonychus
ununguis -
These spider mites also love spruce, fir, juniper, pine,
hemlock and others. The infested trees display mottled foliage which may appear
brownish-grey, and needle loss may occur.
To confirm a mite infection, lightly tap the damaged
branches over a white paper and examining the paper for reddish-brown mites
which are about the size of pepper grains. In heavy infestations like in the
image, spider webbing may also be conspicuous. The actual mites are so small
they can harly be seen
2. Cypress aphids
-Cinara cupressivora
Damage caused by cypress or conifer aphid develops in late
spring and summer. It is found most often at the base of the hedge, but can
develop at any height. Large greyish greenfly are sometimes found, but the
hedge browning often develops long after the aphids have left the foliage.
Clues are left behind, including cast aphid skins and a black fungal growth
(sooty mould) that grows on the sugary honeydew excreted by the pest.
There are ways to minimize the infestations and plant damage
but generally the damage has been done by the time you see the brown patches
and the insects have moved on to pastures new. Chemical spraying would be
extremely costly, difficult to cover the entire area and pretty dangerous on a
large hedge. Some people put a hosepipe into the tee and flush out the insects
as they don’t like too much moisture.
Maybe the best way to control the spread of mites and aphids
would be to start taking the hedges out and replacing them with alternatives.
In Inishowen the best hedging we have is escallonia although this wouldn’t suit
colder inland areas and it also has a few problems of its own namely fungal
leaf spot.
There’s also the lovely slow growing box hedge which will
give a fine boundary but wouldn’t be too invasive or antisocial. These again
have a problem called the Box Tree Moth. It’s the caterpillars that do the
damage and they are spreading quickly with no predators at present. They were first
noticed in 2007 and since 2014 they have become more established with sightings
throughout the country.
It seems there are no complete solutions to neighbours
boundaries, even fencing needs looking after every year. For some the best
solution for happy neighbour relations is to avoid erecting boundaries all
together and have an open dialogue with the people across the way, not blocking
them out, just giving them the nod when you see them.
I’m all for that, as long as they don’t keep popping in for
cups of tea .
