Pests and diseases of forestry in New Zealand
Paropsis charybdis, Eucalyptus tortoise beetle
Paropsis
charybdis adult
|
Defoliation
caused by Paropsis charybdis. This damage severely checks
growth and form.
|
Eucalyptus tortoise
beetle Paropsis charybdis
Paropsis charybdis,
the eucalyptus tortoise beetle, has been defoliating eucalypts in New
Zealand since just after the turn of last century.
This beetle is the most serious defoliater of eucalypts in New Zealand,
butis normally only a serious problem for one group of eucalypts,
those belonging to the subgenus called Symphyomyrtus. It can be quite
difficult to categorise levels of attack to each species because
sometimes strains within
a species are more susceptible.
The most severely attacked species include:
E.
globulus, E. viminalis, E. johnstonii, E. smithii, E. grandis, E.
deanei, E. guilfoylei,
E. macarthurii, E. longifolia, E. quadrangulata, E. dunnii, E.
resinifera,
E. scias, E. pellita, E. guilfoylei, E. leucoxylon and E. melliodora.
Other species sometimes subject to attack include
E. saligna,
E. botryoides, E. robusta, E. rummeryi, E. propinqua,
E. punctata, E. diversicolor, E. camaldulensis,
E. teretecornis, E. brookerana, E. nitens, E. bicostata, E. maidenii
and
E. ovata.
However, some species such as
E.nitens, which is not
usually attacked by
Paropsis,
can be subject to severe
attack and defoliation when in a plantation situation.
E.nitens is widely grown in New
Zealand for wood fibre in large plantations and
Paropsis is considered to be the
most serious threat to the industry.
Some eucalypts belonging to the other common subgenus,
Monocalyptus, (ashes and stringybarks) are browsed by the adult
beetles, resulting in minor, characteristic "scalloping" of older,
mature leaves, but without the more serious damage to new growth caused
by
Paropsis larvae. Such browsing is often seen on
E. fraxinoides,
E. muelleriana, E. obliqua, and E. regnans.
A parasitoid wasp
Ennogera nassaui gave good biological control
of
Paropsis charybdis after
it was
released in the 1980's. However, in recent years it, in turn, has been
parasitised by a hyperparasitoid,
Baeoanusia
albifuncle which has unfortunately arrived from Australia and
very
specifically attacks eggs of
P.
charybdis
already parasitised by
Ennogera. To further
complicate things, fortunately there is now another
parasitoid in New Zealand
Neopolycyctus
insectifurax
that also attacks
P. charybdis.
Although this insect affords some control over
P. charybdis, defoliation of
susceptible eucalypts remains high.
Many of the eucalypt species susceptible to
Paropsis
could be commercialised if an adequate level of control over
Paropsis was achieved. In particular, for warmer areas,
E.
scias red mahogany because of its quality timber suitable for high
value end uses and
E. quadrangulata white-topped box, for its
extremely durable timber, excellent form and fast
growth. Colder climate species such as
E. johnstonii, E. nitens
and
E.
globulus could regain favour if biological control of
Paropsis was to prove successful.
Dean Satchell
4/4/10
Eucalyptus
tortoise beetle
Forest and Timber Insects in New Zealand No. 10
PAROPSIS BIOLOGICAL CONTROL AGENTS HAD A
WHITE CHRISTMAS IN DUBLIN
Forest Health News 212, January 2011
CLEOBORA
MELLYI - WHAT IT IS UP TO THESE DAYS
From Forest Health News 193, March 2009
SPREAD
OF PAROPSIS
CHARYBDIS
PARASITOIDS INTO
THE SOUTH ISLAND
Forest Health News 182, March 2008
CURRENT
STATUS OF PAROPSIS CHARYBDIS IN THE CENTRAL NORTH ISLAND
Forest Health News 150, April 2005
Best
laid [biocontrol] plans…
Biosecurity 59, May 2005
Eucalyptus
tortoise beetle Paropsis charybdis
Update
From Forest Health News 141,
June 2004
CLEOBORA
ALIVE AND WELL IN THE SOUTH ISLAND
From Forest Health News 140, May 2004
PAROPSIS
UPDATE
From Forest Health News 130, June
2003
NEW INSECT THREATENS CONTROL OF
EUCALYPTUS TORTOISE BEETLE
Forest Health News 117,
April 2002
