Environmental Engineering Reference
In-Depth Information
Overall, the bird community residing within the treated citrus fi elds was considered
to be highly viable.
The results of the 3 fi eld studies in citrus orchards indicated that fl owable CPY
applied at rates comparable to the maximum rate allowed by the label for Lorsban
Advanced (i.e., 6.17 kg ha
−1
(5.6 lb ai A
−1
) for use in oranges) had no signifi cant
adverse effects on birds. As with the corn fi eld studies, the citrus fi eld studies indicate
that LiquidPARAM may be overestimating avian risks in citrus orchards (Table
5
).
Apple
. Dursban 75 WG was applied to three apple orchards at a rate of 0.95 kg ha
−1
(0.86 lb ai A
−1
) (Wilkens et al.
2008
). Three applications were made to the fi rst
orchard with the fi rst and second applications being 14-d apart and the second and
third being 28-d apart. Two applications were made to the other two orchards, 14-d
apart. Telemetric surveys, visual bird observations, carcass searches, and nest obser-
vations were used to quantify the effects of CPY. Radio-tagged birds were tracked
for 3-d prior to applications and for 7-d following applications. Birds spent approxi-
mately half of their time in the study plots. No tracked birds exhibited signs of
toxicity. A total of 3,616 bird observations were made during the study period and
no birds exhibited any behavioral abnormalities or signs of toxicity. Only one dead
bird was found during the study period. The authors concluded that this death
resulted from a collision with a power transmission line. However, the applications
did reduce populations of foliage-dwelling pest and non-target arthropods by
approximately 87%. There were no signifi cant effects to birds in the apple fi eld
study, because the application rates in the fi eld study were approximately half that
used in the modeling exercise. Therefore, it cannot be determined whether
LiquidPARAM overestimated risks to the blue grosbeak (Table
5
) or not.
Grape
. Dursban 480 EC was applied twice at a rate of 0.36 kg ha
−1
(0.32 lb ai A
−1
)
with a 15-d interval to a vineyard in Puy du Maupas, near Puymeras, Vaucluse,
Southern France (Brown et al.
2007
). The vineyard consisted of eight adjacent
fi elds, with grass growing between the planted rows. The property also contained
scrub, woodland, garden, and grassy areas. The area was searched for carcasses of
birds prior to each application of CPY and 1, 3 and 7-d following each application.
Three to 4-d prior to each application, mist nests were placed in the vineyard and
along the boundaries. Collected birds were banded, sexed, measured, and radio-
tagged. Tagged birds were tracked for several days prior to treatment and for up to
10-d following treatment. The locations of birds were used to estimate the proportion
of time spent on the treated fi elds and to determine if the birds were alive.
Monitoring of the radio-tagged birds indicated that birds spent a maximum of
20% of their time on the treated fi elds. Only Cirl buntings (
Emberiza cirlus
), black
redstarts (
Phoenicurus ochruros
), stonechats (
Saxicola
sp.), and jays (unknown
species name) spent more than 5% of their time there. Birds on the treated crop for
the greatest proportion of time were alive at the end of the tracking period. Only one
radio-tagged bird was found dead during the monitoring period and, because only a
leg was found, it is unlikely that mortality was the result of CPY. Untagged birds
found dead during the study had residues of CPY on skin and feather residue levels
that were consistent with contact with the treated crop (0.27-1.3 mg ai kg
−1
bwt).
Analysis of AChE activity in the brain of a dead robin (
Erithacus rubecula
) showed
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