Research Square (Research Square),
Journal Year:
2022,
Volume and Issue:
unknown
Published: Aug. 23, 2022
Abstract
The
present
study
examined
the
acute
and
chronic
toxicity
of
neonicotinoid
insecticides
imidacloprid
thiamethoxam
in
neotropical
amphibian
species
from
Pampa
region
Argentina.
median
lethal
concentration
after
96h
exposure
(96h-LC50)
ranged
between
11.28
>
71.2
mg/L
amongst
all
development
stages
tested;
indicating
that
these
pesticides
are
unlikely
to
cause
wild.
subchronic
was
also
low,
with
21d-LC50
values
ranging
27.15
mg/L.
However,
developing
tadpoles
Rhinella
arenarum
stage
27
until
completion
metamorphosis
showed
treated
animals
a
significant
reduction
metamorphic
success
together
smaller
size
at
an
asymmetry
length
left
right
front
arms.
These
effects,
which
observed
starting
lowest
tested
(9
mg/L),
suggest
effect
on
hypothalamic-pituitary-thyroid
(HPT)
axis.
Given
effects
can
clearly
impair
performance
survival
wild,
further
studies
employing
same
experimental
approach
but
looking
lower
environmentally-relevant
concentrations
needed.
Scientific Reports,
Journal Year:
2021,
Volume and Issue:
11(1)
Published: Feb. 3, 2021
Abstract
Neonicotinoids
are
neurotoxic
systemic
insecticides
applied
extensively
worldwide.
The
impacts
of
common
neonicotinoids
like
imidacloprid
on
non-target
invertebrate
pollinators
have
been
widely
studied,
however
effects
vertebrate
received
little
attention.
Here,
we
describe
the
first
study
evaluating
short-term
(3
d)
exposure
to
a
range
environmentally
relevant
concentrations
(
$${0.2}\,\upmu
\hbox
{g
g}^{-1}$$
0.2μg-1
$${2.5}\,\upmu
g}^{-1}\cdot$$
2.5·
Body
Weight)
wild-caught
ruby-throated
hummingbirds.
Within
2
h
exposure,
hummingbirds
exhibited
significant
depression
in
energy
expenditure
(up
$$25\%
\pm
11\%$$
25%±11
).
We
did
not
observe
foraging
behaviour
measured
subsequent
4
h,
although
effect
size
estimate
was
large
(0.29).
also
analyzed
tissues
collected
24
after
final
dose
and
immune
response
or
cholinesterase
activity,
this
may
be
related
our
small
sample
size.
determined
that
excrete
quickly
(elimination
half-life
$$2.1\hbox
{
h}
0.1\hbox
h}$$
2.1h0.1
)
relative
other
bird
species.
Hummingbirds
high
energetic
demands
store
relatively
energy,
especially
during
migration
breeding
seasons.
Therefore,
changes
their
metabolism
following
exposures
observed
herein
could
bear
important
survivorship
consequences
for
Global Ecology and Conservation,
Journal Year:
2020,
Volume and Issue:
24, P. e01292 - e01292
Published: Sept. 28, 2020
Neonicotinoids
are
one
of
the
most
widely
used
classes
insecticides
in
world.
The
neonicotinoid
imidacloprid
is
commonly
applied
to
hemlock
(Tsuga
spp.)
stands
eastern
North
America
reduce
tree
mortality
from
infestations
invasive
woolly
adelgid
(HWA;
Adelges
tsugae).
While
laboratory
and
mesocosm
studies
have
determined
that
can
bioaccumulate
anurans
cause
sublethal
effects,
no
field
investigated
whether
salamanders
or
insects
streams
adjacent
HWA
treatments
if
effects
detectable
wild
salamanders.
We
assessed
relationships
between
exposure
stream
salamander
health
West
Virginia,
USA,
using
concentration
stress
hormone
corticosterone
body
condition
indices
(BCI)
as
response
variables.
Of
107
Desmognathus
11
sites
tested
for
bioaccumulation,
we
detected
47
15
benthic
macroinvertebrate
samples
tested,
imidacloprid,
imidacloprid-urea,
imidacloprid-olefin
15,
13,
1
sample,
respectively.
Based
on
115
sampled
at
responses,
increased
with
water.
For
802
48
sites,
BCI
decreased
water
increased,
but
explanatory
power
was
low.
Our
study
suggests
chronic
leaching
treated
into
has
potential
negatively
affect
aquatic
organisms
may
provide
a
route
higher
trophic
levels.
Conservation Physiology,
Journal Year:
2023,
Volume and Issue:
11(1)
Published: Jan. 1, 2023
Global
change
exposes
wildlife
to
a
variety
of
environmental
stressors
and
is
affecting
biodiversity
worldwide,
with
amphibian
population
declines
being
at
the
forefront
global
crisis.
The
use
non-invasive
methods
determine
physiological
state
in
response
therefore
an
important
advance
field
conservation
physiology.
glucocorticoid
hormone
corticosterone
(CORT)
one
useful
biomarker
assess
stress
amphibians,
sampling
water-borne
(WB)
CORT
novel,
collection
technique.
Here,
we
tested
whether
WB
can
serve
as
valid
proxy
organismal
levels
larvae
common
frog
(
Journal of Toxicology and Environmental Health,
Journal Year:
2022,
Volume and Issue:
85(24), P. 1019 - 1039
Published: Nov. 24, 2022
The
present
study
examined
the
acute
and
chronic
toxicity
of
neonicotinoid
insecticides
imidacloprid
(IMI)
thiamethoxam
(TIA)
on
neotropical
amphibian
species
Rhinella
arenarum,
fernandezae
Scinax
granulatus.
median
lethal
concentration
after
96
hr
exposure
(96
hr-LC50)
ranged
between
11.28
>71.2
mg/L
amongst
all
development
stages
tested,
indicating
that
these
pesticides
are
not
likely
to
produce
in
wild.
subchronic
was
also
low,
with
21
day-LC50
values
ranging
27.15
mg/L.
However,
tadpoles
arenarum
exposed
from
stage
27
until
completion
metamorphosis
presented
a
significantly
lower
metamorphic
success
rate
together
smaller
size
at
metamorphosis,
starting
lowest
tested.
Although
number
studies
previously
effects
neonicotinoids
tadpoles,
investigations
focused
time
reported
variety
results
including
retardation,
acceleration
or
lack
effect.
Here,
data
demonstrated
predominantly
impacts
through
reduction
transformation
body
weight,
rather
than
by
affecting
timings
metamorphosis.
By
closely
monitoring
progression
different
stages,
impairment
occur
during
transition
39
42,
suggesting
an
effect
thyroid
system.
An
asymmetry
length
arms
observed
metamorphs
treated
thiamethoxam.
Overall,
indicate
thiamethoxam,
conceivably
other
neonicotinoids,
have
potential
impair
amphibians
diminish
their
performance
survival
