bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 22, 2024
Abstract
The
hemlock
woolly
adelgid,
Adelges
tsugae
Annand
(Hemiptera:
Adelgidae)
has
distinct
native
and
invasive
populations
in
Canada.
On
Canada’s
west
coast
the
adelgid
is
a
insect
feeding
on
western
hemlock,
Tsuga
heterophylla
(Raf.)
Sarg.
mountain
mertensiana
(Bong.)
Carrière
(Pinaceae).
In
eastern
Canada,
an
species
that
attacks
kills
canadensis
(L.)
We
obtained
all
records
of
A.
institutional
public
databases
develop
updated
range
maps,
phenologies
dispersal
estimates
for
British
Columbia
Canada
’s
distribution
centred
around
lower
mainland
Vancouver
Island
but
with
interior
along
Pacific
have
been
poorly
explored
which
could
be
sources
biological
control
agents
to
manage
east.
invaded
southern
Nova
Scotia,
portions
Niagara
region
Ontario
as
far
Hamilton,
at
least
one
site
north
shore
Lake
Ontario.
No
found
New
Brunswick,
Quebec
or
Prince
Edward
Island.
Finaly,
we
estimated
rate
spread
Scotia
12.6
±
8.2
20.5
27.21
km/year.
The Canadian Entomologist,
Journal Year:
2025,
Volume and Issue:
157
Published: Jan. 1, 2025
Abstract
The
hemlock
woolly
adelgid,
Adelges
tsugae
Annand
(Hemiptera:
Adelgidae),
has
distinct
native
and
invasive
populations
in
Canada.
On
the
country’s
west
coast,
adelgid
is
a
insect
that
feeds
on
western
hemlock,
Tsuga
heterophylla
(Rafinesque-Schmaltz)
Sargent,
mountain
mertensiana
(Bongard)
Carrière
(Pinaceae).
In
eastern
Canada,
an
species
attacks
kills
canadensis
(Linnaeus)
We
obtained
all
Canadian
records
of
A.
institutional
public
databases,
developed
updated
range
maps
phenologies
for
British
Columbia
dispersal
estimates
Nova
Scotia.
Columbia,
’s
observed
distribution
centred
around
Lower
Mainland
Vancouver
Island
but
with
Interior
along
Pacific
coast
have
been
poorly
explored.
invaded
southern
Scotia,
portions
Niagara
region
Ontario
as
far
Hamilton,
at
least
one
site
north
shore
Lake
Ontario.
No
found
New
Brunswick,
Quebec,
or
Prince
Edward
Island,
Finally,
we
estimated
rate
spread
Scotia
12.6
±
8.2
to
20.5
27.21
km/year.
Journal of Forestry,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 29, 2025
Abstract
This
22-year
study
examined
the
impact
and
dispersal
of
hemlock
woolly
adelgid
(HWA)
elongate
scale
at
67
sites
in
southwest
Virginia.
A
stand
health
index
was
based
on
percent
foliage
density,
live
crown
ratio,
branches,
tips,
new
foliage,
trees
each
site.
At
beginning
study,
all
good.
After
22
years
had
declined
to
a
poor
condition
mortality
averaged
30%.
Differences
decline
were
found
among
three
physiographic
mountain
regions.
Analysis
variables
measured
indicated
that
positively
correlated
with
percentage
branches
infested
HWA,
diameter
breast
height
(dbh),
total
tree
basal
area
per
hectare
negatively
latitude.
Crown
inverse
Forest
Inventory
(FIA)
canopy
transparency
could
be
used
as
standalone
measurement.
Journal of Insect Science,
Journal Year:
2025,
Volume and Issue:
25(2)
Published: March 1, 2025
Abstract
Hybridization
between
eastern
and
western
lineages
of
the
biological
control
agent,
Leucotaraxis
argenticollis
(Zetterstedt)
(Diptera:
Chamaemyiidae),
was
demonstrated
in
laboratory.
The
lineage
is
abundant
on
hemlock
woolly
adelgid,
Adelges
tsugae
Annand
(Hemiptera:
Adelgidae)
North
America
while
a
genetically
distinct
feeds
mostly
pine
adelgids
Adelgidae:
Pineus
spp.).
Western
flies
have
been
released
but
establishment
has
not
observed.
When
reared
A.
laboratory,
many
L.
larvae
did
survive,
those
that
reach
pupariation,
21%
survived
to
adult
stage.
To
assess
hybridization,
females
were
placed
with
males
for
no-choice
mating.
They
produced
hybrid
offspring
8%
survival
stage
when
tsugae.
Further
investigation
fitness,
assortative
mating,
prey-seeking
strategies
would
aid
predicting
outcome
potential
hybridization
field.
Insects,
Journal Year:
2024,
Volume and Issue:
15(7), P. 486 - 486
Published: June 28, 2024
Life
tables
are
an
important
tool
to
forecast
the
performance
of
biological
control
agents
used
in
pest
management
programs,
and
they
often
assessed
terms
population
growth.
In
present
study,
suitability
aphids
Canadian Journal of Forest Research,
Journal Year:
2024,
Volume and Issue:
54(12), P. 1458 - 1470
Published: Aug. 7, 2024
The
hemlock
woolly
adelgid
(HWA),
Adelges
tsugae
Annand,
has
invaded
eastern
North
America
and
caused
significant
mortality
to
hemlock,
Tsuga
canadensis
(L.)
Carrière.
In
America,
HWA’s
range
is
theorized
be
limited
by
minimum
winter
temperatures.
As
climate
change
reduces
the
severity
of
winter,
risk
northward
expansion
HWA
increases.
This
study
used
maximum
entropy
species
distribution
modeling
in
conjunction
with
occurrence
records
future
projections
model
habitat
suitability
for
throughout
hemlock.
Species
models
were
created
present
climatic
conditions
using
both
historical
data
emissions
scenarios
mid-
late-century.
addition,
condition
reference
western
Asia
generated
comparison
current
earlier
predictions
potential
America.
Under
a
low
scenario,
will
capable
invading
almost
entire
end
century.
More
extreme
warming
result
more
rapid
northwards
shift
mid-century.
consequences
are
significant,
infestations
likely
become
widespread
severe
due
change.
Environmental Entomology,
Journal Year:
2023,
Volume and Issue:
52(6), P. 1008 - 1019
Published: Sept. 26, 2023
Abstract
In
hemlock
stands
within
eastern
US
forests,
classical
biological
control
has
been
one
of
the
main
strategies
used
to
manage
woolly
adelgid,
Adelges
tsugae
Annand.
Specialist
predator
species
may
offer
a
management
solution
help
regulate
A.
populations.
Pacific
Northwest,
suite
specialist
predators
focus
research
and
includes
2
silver
fly,
Leucotaraxis
argenticollis
(Zetterstedt)
piniperda
(Malloch)
(Diptera:
Chamaemyiidae).
spp.
phenology
documented
in
but
either
western
is
unknown
United
States.
This
study
sought
document
Le.
NY
2021
VA
2022.
Nylon
mesh
cages
were
applied
over
branches
infested
with
contain
adults.
Biweekly
monthly
branch
samples
taken
2022,
documenting
all
life
stages
that
observed.
adults
eggs
present
during
oviposition
stage
generations
tsugae.
addition,
larvae
when
ovisacs
had
while
nymphs
both
present.
These
observations
indicate
well
synchronized
Insects,
Journal Year:
2024,
Volume and Issue:
15(10), P. 751 - 751
Published: Sept. 28, 2024
Understanding
the
spatial
patterns
of
insect
pests
and
their
associations
with
environments
is
crucial
for
developing
effective
sampling
management
plans.
This
study
was
conducted
to
identify
optimal
units
hemlock
woolly
adelgid,
Adelges
tsugae
Annand
(Hemiptera:
Adelgidae)
characterize
its
distribution
in
(Tsuga
canadensis
(L.)
Carrière)
stands
West
Virginia,
USA.
To
determine
unit,
we
randomly
selected
24
branches
from
each
46
A.
tsugae-infested
trees.
The
locations
number
ovisacs
on
branch
were
recorded
coefficient
variation
used
choose
units.
tsugae,
three
1-ha
divided
into
100
grids,
ovisac
counts
taken
center
grid.
Semivariograms
analysis
by
distance
indices
(SADIE)
analyze
tsugae.
In
addition,
various
environmental
biological
factors
measured
explore
results
this
revealed
that
exhibited
aggregation
within
branches,
predominantly
at
tips,
a
50
cm
approximately
3
m
above
ground
unit.
evident,
positive
found
between
populations
including
aspect,
tree
diameter
breast
height,
height.
These
findings
offer
valuable
insights
