HAVE a desperate request. We have a beautiful 10-year-old Peruvian
Pepper tree and for the second time in three years, it is losing
its leaves. The first time it did so was in summer and then its
twigs died and snapped off. We thought it was dead, then it burst
with new growth and covered itself with a copious layer of leaf.
Now it's doing it again, in spite of plenty of rain. The only comment
I can make is that the lawn underneath it is thick with moss. Please
sounds like your pepper tree is suffering from a pest first found
in Auckland a few years ago, but which is now quite widespread.
It's a sap-sucking psyllid from South America called Calypha
schini, which seems to attack only pepper trees, particularly
the Peruvian species, Schinus molle.
Moss in the lawn beneath
your tree suggests the possibility of poor drainage, but the main
reason for leaf loss at odd times of the year will be the psyllid.
The adult is a tiny winged insect about the size of an aphid which
can travel quite long distances, particularly in a breeze, but it's
the larvae that cause all the damage. They establish themselves
in pits on the underside of a leaf, causing blister-like lumps to
appear on the upper surface. They feed on the sap and, if an infestation
is severe enough, the plant can be so debilitated that leaves drop
and shoots die back, as you've discovered.
Healthy trees may recover,
but are often attacked again. In some parts of the country even
mature pepper trees have been so badly affected they have had to
be cut down. Spraying with a systemic insecticide, such as Rogor
100 or Orthene, as soon as blisters appear on the leaves, could
help control the pest, but I wouldn't recommend it as the hazards
of spraying a large tree are too great. I'm sorry to say the days
of Peruvian pepper tree being a good tree for certain parts of the
country are numbered.
Interestingly, the Brazilian
pepper tree (Schinus terebinthifolius) seems to be relatively
unaffected, but it doesn't have the graceful foliage and attractive
gnarled trunk and branches of its Peruvian cousin.
Gardener, Issue 133, 2003, Page 28
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.