Neonicotinoid Pesticides and Bees - The Food and Environment ...

Compound tested
Species
Imidacloprid
(98%)
Apis mellifera L.
Imidacloprid
Apis mellifera
carnica
Imidacloprid
(Confidor)
Apis mellifera
Study type Test dose Test
duration
Lab study / oral
exposure / adults
Lab study / oral
exposure / adults
Lab study / oral
exposure / adults
µL/bee/d
2 - 32 ng/bee
12 and 0.12
ng/bee
(25mg/L and
250µg/L in
30% sucrose
solution with
0.5µL fed to
each 15-6d old
bee with
micropipette)
1 ppb
(1/10 LD)
100, 500 ppb
at single dose
(20µL) and ad
libitum (in 50%
sucrose)
Short (30 s
to 3 min) -
mid (15 to
60 min) and
long term
(24 h)
Sampled
treated 7d
old bees 1d
and7d after
treatment
Recorded at
0 - 30 mins;
30 - 60
mins;
1 - 2 h; 6.5 -
7 h; 23 -
23.5h
Endpoints Results Notes (study
reference in figure
Olfactory
learning (PER)
Size and
morphology of
HPG on 8- and
14-days-old
affected at 48µg/kg. In
summer bees significant
impairment occurred at
12µg/kg and all higher
doses
Significant increase of
cytochrome oxydase (CO)
in mushroom bodies.
No significant on PER to
sucrose solution alone.
Impairment of medium
term olfactory learning at
highest dose No effect on
short (0 s - 3 min) and
long (24 h) term of OL
No effects
Neonicotinoid pesticides and bees Page 55 of 133
Report to Syngenta Ltd
bees
Activity Mobility significantly
reduced with effects
starting at 30 - 60 min
after ingestion and
disappearing after a few
hours
Suggested effects could
result in reduced capacity
to communicate.
20)
Reference
(8) Decourtye et
al (2004a)
(9) Heylen et al
(2011)
(10)
Medrzycki et al
(2003)
Imidacloprid Lab study / oral 500ng/kg (in Exposure24 Hypopharyngeal Significant HPG acinus (11) Smodis Skerl