Harmful
bugs
are
appearing
with
increasing
frequency
in
greenhouse
horticulture
due
to
the
reduced
use
of
broad-spectrum
plant
protection
products.
Most
cases
involve
infestations
of
the
hairy
bug
Lygus
rugulipennis,
the
nettle
bug
Liocoris
tripustulatus,
and
the
green
apple
bug
Lygocoris
pabulinus
(Figure
1.1).
According
to
researchers
from
WUR,
the
biggest
problems
occur
in
chrysanthemum,
gerbera,
sweet
pepper,
cucumber,
and
aubergine
crops.
In
peppers
and
aubergines,
these
bugs
can
establish
themselves
and
build
up
a
population.
In
chrysanthemums,
this
is
still
unclear.
The
bugs
feed
on
plant
parts,
causing
flower
deformities,
flower
abortion,
and
sucking
damage
to
fruits.
Chemical
control
of
these
bugs
often
comes
too
late
and
is
also
undesirable
due
to
the
disruption
of
the
overall
biological
control
system.
Researchers
at
WUR
explain
more.
Figure
1.1.
In
addition
to
native
harmful
bugs,
problems
have
arisen
with
the
establishment
of
exotic
bugs.
In
tomatoes,
the
Mediterranean
bug
Nesidiocoris
tenuis
(also
known
as
Nesi)
causes
many
issues.
Chemical
control
is
extremely
difficult
because
these
treatments
also
strongly
affect
the
predatory
bug
Macrolophus
pygmaeus,
leading
to
other
pests,
such
as
whitefly
and
Tuta
absoluta,
getting
out
of
control.
Another
increasingly
common
exotic
pest
is
the
southern
green
shield
bug
Nezara
viridula.
Most
reports
of
problems
come
from
pepper
cultivation,
where
these
bugs
quickly
cause
damage
due
to
their
preference
for
fruits.
This
bug
is
also
difficult
to
control
selectively
because
of
the
side
effects
of
pesticides
on
beneficial
predatory
bugs
like
Orius
and
Macrolophus.
Besides
N.
viridula,
the
brown
marmorated
shield
bug
Halyomorpha
halys
is
also
advancing
in
Europe.
In
Italy,
this
bug
is
already
causing
significant
damage
in
horticulture,
including
tunnel-grown
vegetables.
In
the
Netherlands,
this
bug
was
first
found
in
Limburg
in
2020.
Due
to
climate
change,
this
species
could
also
become
established
in
northern
Europe.
Harmful
bugs
With
the
increase
in
native
and
exotic
harmful
bugs
(Figure
1.1)
and
the
reduced
scope
for
chemical
control,
there
is
a
need
to
develop
alternative
non-chemical
methods
of
control.
Within
the
PPP
“Functional
Biodiversity
in
and
around
the
greenhouse”
(TKI-LWV
19162),
four
years
of
research
were
conducted
on
the
control
of
two
species
of
harmful
bugs:
the
hairy
bug
L.
rugulipennis
and
the
southern
green
shield
bug
N.
viridula.
New
non-chemical
ways
The
aim
of
this
project
was
to
develop
new
non-chemical
methods
of
control
for
both
pest
bugs.
For
the
hairy
bug,
the
research
focused
on
predicting
fly-ins,
manipulating
the
behavior
of
fly-in
bugs
with
attractants
and
repellents
(push-pull),
and
deploying
selective
biological
agents
based
on
entomopathogenic
fungi.
Research
on
the
southern
green
shield
bug
focused
on
improving
signaling
with
decoy
plants
and
pheromone
traps,
as
well
as
biological
control
with
predatory
bugs,
parasitic
wasps,
and
entomopathogenic
fungi.
This
WUR
report
presents
the
results
of
these
studies.
