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Aquatic toxicology of cypermethrin. III. Fate and biological effects of spray drift deposits in fresh water adjacent to agricultural land
Aquatic Toxicology, 2 (19X?) 253-270
Elsevier
Biomedical
253
Press
AQUATIC TOXICOLOGY OF CYPERMETHRIN. III. FATE AND
BIOLOGICAL EFFECTS OF SPRAY DRIFT DEPOSITS IN FRESH WATER ADJACENT TO AGRICULTURAL LAND
N.O. CROSSLAND. S.W. SHIRES
and D. BENNETT
Shell Restwrch Limited, Sittingbourne Research Centre, Sittingbourne, Kent, ME9 8AC, England 29 October
(Received
Fields of sugar beet and potatoes using tractor-mounted and concentrations
25 January
1981; rcceptd
in the U.K.
1982)
were treated with cypermethrin
1
at a dosage of 7Og. ha
sprayers. Deposits of spray drift on three adjacent pond srlrfaces were very small in subsurface
water were near IO or below the limits of detection.
There were no
detectable residues in fish and there were no effects on the aquatic fauna except on the surface of one corner of o:le of the ponds where knockdown, belonging to certain species of air-breathing Vineyards
in France
cypermcthrirl
on Ae
concentrations
pg.1~
were treated surf
but
invertebrate
24 h later drift
I .7
11g. I
their
mistblo\\er<.
1soonafter
a few hours. The resulting concentration-time
profile\
Deposits of mp.
numbers
1112 and
spraying, decreasing to for cypermerhrln
less thau those required IO cause mortalities of invertebrate\.
increase in the numbers of live arthropod\
spraying
1 using
streams were in the range 0.04-0.45
in subsurtace water Here in the ranpe OA-
1 within
was observed among a few individuals
at dosages of 30 or 45 g. ha
: of three adjacent
stream hater were considerably marked
but no mortality, insects.
in rhc
There \\a, a
in the stream draft during the iir
weke similar
IO those in pre-treatment
had no detectable effect on population
sample\.
tnhanced
denritie:, of benrhic ~n\rrrchrate\.
The choice of tria, sites, the conditions of spraying and fhc dosage:; uvzd acre all dcGpnrd 11) incrca\e the risk of contamination
of natural
Haterbodies
with cypermethrin
expected to occur under normal conditions of agricultural cypermethrm
could be detected in adjacent
uaterbodie5
conciuded that spray drift from ground-based hazard
to aquatic
organisms,
to a higher lekel than \rould
112
WC. h\en W. onl! \sry lo\! conicntrnricbn* L~I and biologlA
rffectr
applications o!‘cypermethrin
despite the high toxicity
OI c)perrnethrln
uere in~igntfi~ant.
II N;L\
is unliked> to be a +gnll~~aru IO \uch organlvnr
w 111~
laboratory. Key words: cypermethrin;
spray drift; pond\;
stream5
INTRODUCTION
It has been shown in the laboratory that the insecticidecypermethrin [RIPCORD*, NRDC 149, [R,S]-a+cyano-3-pherroxybenzyl(IR, IS, cis, rrur~~)-3-(2,2-dichloroviIl~l)2,2-dimethyl cyclcpropanecarboxylate] is highly toxic to certain species of fish.
*RIPCORD
is a Shell trademark.
0166-445X/62/oo8o-0000/$02.72
(5’ Elsevier Biomedical Press
254
aquatic insects and Crustacea (Stephenson, 1982). However, in pond experiments sensitive species of fish survived when the pond surfaces were oversprayed with a dosage of 100 g-ha-r (Crossland, 1982; Crossland and Stephenson, 19801. From these results it was concluded that there is a negligable risk of direct toxicity to fish associated with the normal agricultural use of cypermethrin. On the other hand it was thought that there might be a risk of toxicity to aquatic crustaceans and certain species of aquatic insects. The environmental monitoring programme described here was therefore undertaken to determine the amounts of contamination in ponds and streams adjacent to agricultural land treated to control insect pests and to investigate the possibility of effects of such contamination on freshwater invertebrates. A preliminary survey of farms in the U.K. was carried out to locate ponds that would be exposed to a high risk of contamination from spray drift. In the county of Suffolk two farms were seb:ted that had large fields of sugar beet or potatoes enclosing or adjacent to smalii ponds. In this region two insecticide applications per annum are applied by tractor-mounted boom-and-nozzle spraying equipment for control of aphids. .4 preliminary survey in the south of France was carried out to locate drainage ditches and streams that would be exposed to a high risk of contamination from spray drift. Three vineyards with adjacent streams were chosen in the Languedoc region of southern France. In this region three insecticide applications per annum are applied in vineyards by mistblowers to control caterpillars of the tortrix moth,
Three ponds situated on two different farms near Stowmarker, Suffolk. U.K. ww selected to investigate spray drift from boom-and-nozzle applications (Figs. 1 and 3. The applications were carried out by farm staff so that the conditions of spplicatron \rould be the same as those in normal commercial usage. One of these (Pond A) was located in the north-west corner of a 19ha field dikided into equal areas of sugar beet and potatoes. Approximately one-third of its perimeter was adjacent to the crop. A thin stand of small bushes and trees partially \creened the pond from the field. The surface area of the pond was about 950 rn: and its maximum depth was 1.4 m. 4 second pond (Pond B) was located near the southern edge of the same field and %a.~entirely surrounded by crops. Much of the perimeter of the pond was screened from the field by bushes and trees but there were a few gaps in the screen of vegetation. The distance between the edge of the pond and the crops was generally lesz than 2 m. The surface area of the pond was about 250 mz and its maximum depth was 1.6 m.
The third pond (Pand C) was located on the north-west botmdar~ OI’ ;I XLha r’icld sugar beet. Approximatcty nw-Lhirds of’ ids perimctcr %\a!, adja!
of
256 Pond 0
Pond C
0 0 0
drift
platrr
,4” \ depthcontowslcml -,
-+m
route of boom sprayerr
Fig. 2. Sketch of farm ponds showing positions of drift
plates.
applicaticns except that the operator was asked to spray as close as possible to the edges of the ponds and around the whole of the perimeters, if accessible to the tractor, even though these were not alwa.ys adjacent to the crops. Spray drift deposits were collected on horizontally-placed, aluminium-foil plates, 250 mm squr-e. Ten such plates in a series were,placed within the crops, near to the edge of the water or over the surface o,f the water. Their lay-out on or near fhe ponds is illustrated in Fig. 2. Spray deposits were washed from the foils with acetone
and the deposits from each series of 10 foils were combined before storage and analysis. Water samples from the surface of the ponds were removed using stainless-steel fine mesh discs, area 0.0093 m*, mesh no. 200, Five such discs were used for each sample. The average mass of water collected per five disc; was 2.95 g (range 2.7-3.2 g) and thus the depth of each surface sample was calculated to be 0.06 mm. Subsurface water samples were taken from a depth of 20-30 cm using a glassstoppered Erlenmeyer flask which was opened beneath the surface. It was then restoppered, removed from the water and wiped free of water adhering to the glass. Each water sample comprised five IOO-ml subsamples which were combined in a separating funnel. After extraction with hexane and drying with anhydrous sodium sulphate the samples were stored for analysis in the laboratory. In the laboratory the hexane extracts were analyzed by gas-liquid chromatography with electron-capture detection (glclec). Fish for residue analysis were removed from two of the three ponds. They were collected either by using rod and line or with an electrofishing method, and were deep-frozen within l-3 h of capture. In the laboratory whole fish were macerated and cyperm~thrin was extracted with a mixture of hexane and acetone. The extracts were then analysed by glc/ec. Subsamples of the zooplankton were collected using a IOO-mm diameter Perspex tube immersed to a depth of 0.5 m. Four such subsamples were combined to give one sample. Immediately after collection each sample was passed through a 150-#cm mesh sieve and the zooplankters were collected and stored for examination in the laboratory. ~acroinvert~brates were sampled using a sweep-net with a 950.pm mesh bag. Each sample was taken by sweeping through a distance of 10 m in the water. Vineyards in France
Two streams and a drainage ditch adjacent to three vineyards in the Languedoc region of France were selected to investigate spray drift from mistblower applications, The applications were carried out by the farmers so that the conditions of application would be the same as those in normal commercial usage. One of the streams (Stream A, Fig. 3). situated on the southern boundary of a 1.3-ha vineyard, was a tributary of the River Orb and was subject to periodic inundation by storm water. The stony bed of this stream varied from 2 to 12 m in width and its depth was 5 to 50 cm in alternating short riffles and longer pools. The maximum flow rate in May was 0.5 rn. set-’ and the volumetric discharge was 3 m3. min- I. In July the flow rate in riffle sections was similarly about 0.5 m . set _ ’ but the volumetric discharge was very much less than in May. In late July. i.e. after the second insecticide application, the stream bed dried up. The edge of the vineyard adjacent to the stream was 114 m long. Along much of this length the stream was
‘Ch
Edge of vmeya~~d --
_
_
-__ -
-
--
+
-
_ _,-
-
1
1 f
0
_-_-------_---_
--
h
0
0 -
-I
0 0
__-_----_---__---
1
I +
0
-_---
--, -. __*- -
--
114 Ill
CLJ
0 -----_--_. -
-
.-
--
0 1
I
of - _ -.-- .A
--.+-
0 Edge of vineyard
-
Ke\
00 x
Aluminlum
x
foil plates
water samplus invertebrate drift nets invertebrate quadrat samples
Ill --+
t IP 3. SIICin
water surface route of mistblower
France bhoxmg po\ltion\
OI ~amphng deice\
V
partially screened from the vineyard by a 2 m high bank. bushes and small trees. Stream B, situated on the southern boundary of a 3.Gha vineyard, also had a stony bed and consisted of riffle and pool sections but was much smaller, its width varying from 0.25 to 1.5 m and its depth from 5 to 20 cm. Maximum flow rate was 0.4 m . set ’ and volumetric discharge was 0.4 rn>. min ‘. This stream dried up in July before the second insecticide application was carried out. The edge of the vineyard adjacent to the stream was 270 m tong. Along much of this length the stream was partially screened from the vineyard by a l-m high bank, bushes and small trees. The drainage ditch was situated along the western and northern edges of a 1.O-ha vineyard. Its width var,ed from 0.2-2.0 m, its depth from 5-25 cm and its flow rate was approximately 0.01-0.03 m . set I. The ditch dried up in July before the second insecticide application ?vas carried out. There was no screening canopy of vegetation between the ditch and the adjacent vineyard but the banks and much of its surface \verc o\‘ergrown with grasses. flag iris (Iris sp.) and water crowfoot (Ranuncvllts sp.). Two of the vineyards, adjacent to streams, were treated at a dosage of 30 g. ha ’ using a 5% EC formulation of cypermethrin (Fig. 4). One of then, adjacent to a drainage ditch (Fig. S), was treated with a dosage of 45 g. ha I. The formulation wnh diluted wi!h water and applied at a rate of 400 I. ha ’ by mistblowers fitted nith a fixed or a swinging head discharging at a height of 3 m. A11three vineyards kteere
Fig. 5. The drainage ditch at Marseillan, Languedoc.
sprayed three times with cypermethrin., at intervals of 6 wk between May and August but because of prevailing draught conditions only the first application was monitored at all three sites. The second application was monitored at only one site, Stream A, where water was still flowing down the stream in duly. However, even this stream had dried up in August when the third application was carried out. Spray drift deposits were coilected on ahtminium-foil plates as described previously for the U.K. trials. A typical lay-out of sampling piates in a vineyard and an adjacent stream is illustrated in Fg. 3. Water samples from the two streams and from the draina,ge ditch were generally taken from sampling stations situated timmediately downstream from the treated vineyards.
261
Kick-samples of benthic invertebrates from the streams were collected with a sweep-net from within 0.2%m2 quadrats placed on the stream bed. After placing the quadrat on the stream bed the sediments were vigorously disturbed and material retained in the net was passed through a 500-pm mesh sieve. Animals and debris retained on the sieve were collected and stored for examination in the laboratory. Sweep-net samples of invertebrates were taken from the drainage ditch using a sweep-net with a 950-pm mesh bag. Samples of invertebrates in the stream drift were collected in 200-pm mesh nylon bags mounted on an adjustable framework of steel rods. A pair of drift nets was used to sample an area of stream 0.5 m wide, representing 50-100% of the total stream flow.
RESULTS
Arable crops in U.K.
Deposits L\f cypermethrin on the soil surface within sugar beet and potatoes treated with a dosage of 70 g. ha- I (= 7 mg . m 2) were between 4.2 and 6.6 mg. m -? (Table I). Deposits on pond surfaces were generally in the range 4-20x IO s rng,m-?, i.e. four to five orders of magnitude less than those in the crops, The one notable exception, when the deposit was 28 x 10 ? mg. m :, occurred during the second application when this relatively high deposit was found on a series of plates situated in an exposed corner of a pond immediately adjacent to the sprayed field. Very low concentrations (6-23 pg. I I) of cypermethrin lvere present in 10 out of I4 surface water samples collected immediately after treatment of the crops (Table 11). After 24 h cypermethrin \*as present (6 ,Q 1 I) in only one of 14 surface \\ater samples. Maximum concentrations in subsurface water tended to occur during the period O-5 h after treatment of the crops (Table II). The highest concentrations, 0.03-0.07 PE * 1 I, were recorded in Pond A 5 h after the second applicaiion. After 24 h the concentration in this pond had declined to a level belo\\ the limit of detection (0.01 pg. l- I)_ In 9 out of I4 samples collected 24 h after treatment the concentration t\as 10.01 /Lg.1 I and in the other 5 samples was in the range 0.01-0.03 pg. I I. Thirty-five rudd (Scurdinius er_vrhrophthaimzcs) and 15 Crucian carp (CamsGus cm&us) removed from two of the ponds were analgsed for cypermethrin (Table IT). There were no detectable residues in anv of these fish; limit of detection 5 rg.kg ‘. The most abundant groups of zooplankton in the ponds \vere Cyclopoida, Calanoida, Ostracoda and Chydoridae (Table 111). Their numbers fluctuated considerably but none of the changes in density could be attributed to the effects of insecticide spraying in adjacent fields.
TABLE1 hlosc of cypuzkcthrin deposited on ahtminium-foil plates in arable crops and on surface of adjacent pandr. SireandsunpP
Surfrce deposit (mg . m -2)
station P
1st Application
--2nd Application
PondA In crop near pond Nearsideofpond
6.3 0.14 x IO-3
5.8 28 x 10-S
centre of pond Far side of pond
0.10 x 10-J 0.14 x 10-3
4 0.01 x 10-3
Pond B In crop near pond
rc 0.02 x 10-3
6.6
5.8 0.23 x 10-r 0.54x IO-3
Perimeter of pond Centre of pond Pond C Im crop near pond Near side of pond Far side of pond
-_
1.8 x to-3
0.16 x IO-J
4.2
No datd
0.17 x 10-3 0.09 x IO--’
0.10 x lo-’
0.04 x 10
-3
TABLE II Concentrations of cypermethrin in samplesof water and fish collected from ponds (number of samples in parentheses). Site and treatment
-
Time after application
(h)
Surface water
Subsurface water
Fish
048*t-‘)
M3~l-V
(c9.k9
7. 9, 23 55. 12. 13
aO.fDI (3) ~0.101. 0.02, 0.02
-
Pond A 1st application
0 5 24
2nd application
55,
55, 6
0.102, 0.02. 0.03
0
55, 13, 21
zco.01 (3)
5 24
IO, 16, 26
SO.01 (3)
55 (6)
0.03, 0.05, 0.07
72
a5 (3)
Pond B 0 5 24
6, 13 8, I5 I5 (2)
SO.01 (2)
0 5 24
55. 6 5, 6 55 (2)
0.03 (2) so.01. 0.01 10.01 (2)
1st application
0 5 24
55 (2) 8, I1 55 (2)
SO.01 (2) 0.01, 0.02 zGo.01, 0.01
2nd application
0
9, I2
5 24
5, 5 15 (2)
1st application
2nd application
o.D4, 0.05 ~0.01,0.03
Pond C
55 (3)
0.01 (2) 0.02 (2) zco.01, 0.01
s5 (3)
‘1
nauplii
nauplii
I = times of insecticide
Chydoridae
Cqpepod
Cyclopoida
applications.
(1%53) 143 (IOl-203) 196 (117-330)
7
(5-198)
(l-18) 5 (l-17) 70 (43-l 13) 35
6
( 170-693)
W-362)
(3-18) 31
(67-I 10) 85 (52- 139) 343
108 (78-149) 96 (67.. 138) 181
500
(341-733) 86
371
(513-741)
(334-653) 617
(259-532)
446 (276-721) 235 (162-340)
55
(65- 105) I2 (7720) (35-71) 5 (I-21)
50
83
8 13.-19)
II (2-47)
4 (l-17)
(89-152) 445 (209-944)
30 (22~m41) I16
(83-291)
I56
470 (421-524)
(42-72) 531 (425-663)
3
20 (14.-29)
-
523 (271- 1011)
(lO3-iO4)
(55 105) 145
76
(276-452)
355
927 (849-1013)
423 (229-782)
I9 :I2-30)
36
(26-49) 467
2
from ponds (95% confidence
33
I’
in samples
(23-48)
0
ot zooplankters
C.rlanoida
Pmd C’
Ostracoda
Chaoboridae
Copepod
Pond B Cyclopoida
Copepod
Cyclopoida
Calanoida
nauplii
(days)
Pond A
Tie
Mean numbers
18
4
183)
(71-304)
(8-40) 148
18
(7-25)
14
(4-31)
II
34 (25-47) I82 (100-331)
(O-19) 0
(ISI
(262-488) I66
358
(11-B)
9
I2
5
2
?.
(O-2) 10 (6-16) Cl
I
(4-54)
16
(12-43)
(3-9) 23
(l-6)
(l-6)
(O-2)
(l-7) I8 (8-39) I
3
(9-70)
26
(l-13) I6 (8-32)
(l-11) 5
(2-12) 4
6
(l-4)
(7-l 1)
(S-17) 205 (128-328) 2
4
28’
(2-9) 191 (113-323) 5
27
limits in parentheses).
4
Sl
8 (4-15)
(I-3)
(8-W 2
18
3 (O-12) 48 (11-205)
5 (2-12)
9 (5-17)
(l-5)
(2-6) 167 (97-289) 2
29
121
(O-2)
(O-3) 17 (12-25) I
(3-50) I
13
(14-27)
5 (2-11) 19
2
(O-56)
12 (2-74) 7
(I-IO) 2 (O-II)
3
5 (3-10)
(l-3)
1 (O-3) 51
7
(388-w)
(88-155: 499
(3-12) 61
I70 (104-276) II
10
N-26)
I2
35
(7-12)
30
264 ‘rABLE IV IGmbers of invertebiates in sweep-net samples from ponds.
‘Time (days)
0
I+
2
34 794 16 145 IS 41 6 I6 272
I2 79 0 I6 I9 a 3 5 123
-9
.-..
27
201
35 --
Pond A
G.astropoda O#gochaeta Hirudinca Asellidae Notonectidae Corixidae Coleoptera
Ephemeroptera Chironomidae Diversity index Evenness Species richness
2.Q 0.48 4.2
51 7s 21 II6 II I6 8 9 448
2.4 0.58 4.1
22 951 I2 I64 I6 17 7 9 251
2.1 0.53 3.9
I.7 0.42 4.0
IO Ill 136 IS8 33 18 54 9s II8 3.1 0.77 4.0
I3 354 53 83 I9 2 8 56 254 2.5 0.61 4.1
41 603 59 288 41 22 I9 292 I88 2.6 0.62 4.2
Pond B
Oligochaeta Hirudinea Asellidae Notonectidae Corixidae Coleoptera Chironomidae Chaoboridae
I 0 20 I7 I4 3 38 412 I.1 0.37
Diversity index Evenness Species richness
8 0 IS3 60 4s I2 40 IO64
204 I 5 5 9 8 154 596 I.6 0.43 3.8
3.0
24 9 5s 4 I9 6 28 832
I.4 0.39 3.5
I .O 0.31 3.3
3 29 374 9 36 9 99 II80 I.5 0.39 3.9
I 7 385 I2 86 I3 loo0 1612 I.7 0.46 3.6
6 13 296 2 54 I2 301 R29 I.8 0.54 3.3
Pond C 9
Gastropoda Asellidae Corixidae Coleoptera Ephemeroptera Chironomidae
I 9 7 76 174
47 IO 34 6 IS3 261
2.0 0.50 3.9
Diversity index Evenness Species richne.ss
i= times of insecticide applicatbns. Data
oblained
from
sweep-net
is 3 21 5 56 I86
2.3 0.59 3.9
E86 136 40 46 151 358
2.4 0.58 4.1
collections
3.1 0.71 4.3
5 7 I97 6 169 IO3 2.2 0.55 3.9
of macroinvertebrates
2 4 14s 3 72 82 2.1 0.58 3.7
I’4 IO6 46 231 I26 2.1 0.67 4.1
in the ponds
are
given in Table IV. There were no marked redGctions in the numbers of arly of the groups of macroinvertebrates in any of the three ponds. No visible effects on invertebrates or fish were observed except in one corner of Pond A immediately after the second insecticide application. During the first few
265
hours aftl*r this treatment some pond skaters (Gerris sp.), one water-boatman (Noionecru sp.) and two rat-tailed maggots (Erisfdis sp.) were found immobilized on the surface of the pond. Several of these affected insects were collected and placed in beakers containing pond water. All had recovered by the following day. Vinqvards in France
Deposits of cypermethrin on the soil surface in vineyards treated by mistblowers at a dosage of 30 g. ha - ’ ( = 3 mg - m - *) were between 0.65 and 2.1 mg .m - ? (Table V). In the vineyard treated with 45 g. ha- I the deposit was 2.9 mg .m - 2. Spray drift deposits on the surface of adjacent streams were in the range 0.04-0.45 mg .m 2. Concentrations of cypermethrin in the surface water of streams soon after spraying were in the range 140-1010 pg. I -I (Table VI). These relatively high concentrations decreased to 20 pg. I ’ or less within 3 h after the completion of spraying. Maximum concentrations of cypermethrin in subsurface water of streams soon after spraying were in she range 0.4-I .7 fig. I - I. However, these had general11 decreased to 5 0.1 pg. I - ’ a few hours later. Numbers of live invertebrates collected in drift-nets placed in streams adjacent to treated vineyards are given in Tables VII and VIII. The results show that there was a considerable increase in the numbers of Gammaridae, Ephemeroptera, Coleoptera and Hemiptera in the invertebrate drift during the first 2 h after spraying, with a peak occurring about 2 h after spraying. Samples taken either 24 or 48 h after spraying contained numbers of invertebrates that were similar to those in prrtreatment samples, TABLE V Moss of cypermethrin deposited watcrbodies.
------
Trial site and dosage
---.
I
Stream A 30 g. ha
1
g . ha
Second application
Stream B 30
g . ha
-
1
First application Drainage
ditch 45
First application ___-
g
foil plate\
--_--..._._ __~
Sampling
ha
1
in \mcyardr
_~__.__. position (see Fig. 3)
_.
and on *urIacc
ot ad~;~cm
~_~ .._~_~_. Surface depobit (mg
Top of stream bank
( .h ( .J6
Over middle of stream
0.06Y
Far edge of stream bed
0.001
In the vineyard
First application
Stream A 30
on aluminium
In the vineyard
I .o
Edge of the vineyard
P.80
Over middle of stream
0.037
Far edge of stream bed
0.001
In the vineyard
2.1
Over the stream
0.45
In the vineyard
2.9
Top of ditch bank
I .v
Over middle of ditch
O.?l
m
2)
TABLB VI C~tfone
of cypermethrln in water adjacem to treated VhIeyards.
Trial site and
Sampling position
trcatmm
and time(h)
Cypermethrln concentration fj~g. I -
Giwe Stream A w)a.ba-r First appiicadon
- I
Downstream, near edpc of sprayed
+ +2 Upstream, near
_. I
Second application
edge of sprayed field
+
Downslream, near
SO.01 10
0.02
+3 +6 +26
10 3 2
0.03 0.04 0.03
1010
SO.01 0.52
IO ;D
0.05 0.04
s zi
t 3 +6 +26
ZG
+33
Drainqc
ditch
Downstream. near
J5g.ha
1
edge of sprayed field
First application
I + 0.5
Downstream, near edge of sprayed field
I.7 0.09 0.09 0.11
I
- I * 0.5
edge of sprayed field
410 110 ;:0
I
Stream A u)g.ha-r
1)
Subsurface water so.01
4?0
0 + 0.5
Befd
SlrearnBU)g.ha-1 Firsl application
film
2
0.03
10
so.01
-
I40
+ I + 2 + 4
:10 “.) ..L
50.02 0.40 0.22 0.20 O.OR
- I + 0.5 t 1 + 2
so.01
+ 3.5 + 24
0.09 0.04
50.01 0.17 0.04
TABLE VII Numbers of invertebrates in the stream drift (Stream A. first application). Time from spraying Gammaridae Ephcmeroptcra Coleoptera (h) -
II00 Of0
0
I
I 102 2 10 3 4a IO 49 --_-
29 9 0 0
-Diptera
0 14
I5 67
422 166
218
527 95 3
585 687
171
0
25
-_
261
TABLE Vlll Numbers of invertebrates in the stream drift (Stream B, first application). Time from spraying (h) -1510
0
-16
- 2to-1to oto Ito 2to 3to 26 to
Ephemeroptera
1 0
I 2 3 4 27
0 6 198 144 30 IO I2
Coleoptera 51 27 13 240 636 328 229 68
Hemiptera 1
I 0 8 120 42 16 2
-Diptera 725 284 898 2463 10364 5913 3648 584
TABLE IX Mean numbers of invertebrates per five sweep-net samples from the drainage ditch (95% confidence limits in parentheses). Family or Order --Asellidae Coleoptera Diptera Mollusca Oligochaeta Total Shannon-Wiener diversity index Evenness Species richness
Pre-treatment (17 May 1979)
Post-treatment (19 May 1979)
34( 7-156) IS ( 9-23) 6( l-27) 167 (30-891) 7 ( O-94) 280 (71-1103)
18 ( 9-36) 7 ( 2-18) a( 1-5) 67 (2 I-208) I I O-7) I16 (58-233)
1.79 0.40 4.46
--.
2.04 0.51 4.00
TABLE X Mean numbers of invertebrates per five kick-samples from Stream A. first application (95% confidence limits in oarentheses).
Taxon
Pre-treatment 120 May 1979)
Post-treatment 122 May 1979)
Ephemeroptera Diptera Coleoptera Oligochaeta Tots) Shp tnon-Wiener diversity index Species richness Evenness
3 ( O-18) 600 (267-1347) 20 ( 13-29)
4( 1-8) 1083 (369-3176) 24 ( 13-45) 164 ( 21-1248) 1460 (509-4180)
58 ( I-2076) 950 (442-2040)
1.7 4.2 0.41
1.7 4.4 0.38
XI
197
(2)
(3.81-4.25) 0.61 (0.57-0.68)
4.36
( 4.09-4.52)
( 0.57-0.71)
Species richness 0.65
(2.19-2.58) 3.95
( 2.35-3.17)
Shannon-Wiener diversity index
Evenness
772 ( 417-3429) 2.39
II73 ( 1254-2507) 2.85
Tixal
u-5)
I
104 ( 52-209)
Hirudinea (
53 ( 20-141)
I-IO)
(
(
4- 10)
( 298-1093) 20 ( 12-34) 4
571
( 62-192)
109
Station
(4 July 1979)
856 ( 492-1491) 107 ( 64-180) 7
( 150-258)
(I)
Pre-treatment
Station
from Stream
241 ( 149-387)
._
per five kick-samples
Mollusca
Hemiptera
Coleoptera
Diptera
of invertebrates
indices).
Ephemeroptera
Taxon
community
Mean numbers
TABLE
68
l-9)
( t
3-21)
(0.64-0.81)
(3.59-4.17) 0.73
372 ( 142-982) 2.82 (2.68-3. IO) 3.87
i
9
( 39-221)
92
33 15-70) 4
( 25-183) 149 ( 42-529)
(3)
application
Station
A, second
O-8)
2
124 68-227)
1493 734-3040)
241 182-318)
(I)
55-230)
0.63 ( 0.53-0.71)
(
3.94 3.70-4.09)
2.49 ( 1.98-2.91)
2460 ( 1463-4137)
(
112
245 ( 162-370)
(
(
(
(
Station
(2)
O-16)
3
31-240)
86
(0.61-0.81)
0.70
(3.32-3.81)
(2.10-2.78) 3.57
909 ( 377-2192) 2.51
(
(
29-86) 10 ( 2-41)
(
612 ( 245- 1525) 50
I24 ( 49-314)
Station
(6 July 1979)
limits tn parenfheur;-
Post-treatment
(95% confidence
(3)
;,-91)
13-613) 39
89
(0.59-0.73)
0.66
!3.91-4.17)
(I .95-2.94) 3.98
527 ( 219-956) 2.63
(
(
68-220) 72 ( 47-109) 8 ( 4-15)
(
IO? ( 49-211) 139
Station
ranges in parentheses
for
269
Numbers of invertebrates collected in sweep-net samples from the drainage ditch and in kick samples from Stream A are given in Tables IX, X, and XI. Species richness, evenness and diversity indices were calculated for each of the samples collected immediately before and after treatment of the vineyards. The results show that the treatments had no effect on the abundance of individual species or on the community structure of benthic invertebrates.
DISCUSSION
In five out of the six tractor-mounted spray applications to arable crops the amount of spray deposited on pond surfaces adjacent to treated crops was only O.OOl-0.01% of the deposits on soil surfaces in adjacent fields, even though the sprayers passed within 1 or 2 m of the ponds. The deposits on pond surfaces are remarkably low when compared with spray drift deposits on adjacent soil surfaces. It is well established that most droplets contained in spray drift are relatively small ( ~60 pm) and tend to remain airborne under conditions of minor atmospheric turbulence. Since the surfaces of the farm ponds were below the level of the surrounding a;sble land there would be a tendency for spray drift to pass over rather than fall out onto pond surfaces. The only biological effect observed in any of the ponds was associated with a relatively high deposit of 28 x 10-j rngarnm2 found on the surface of one of them following the second application of cypermethrin. This was associated with the knockdown, but no mortality, among a few individuals belonging to insect species that inhabit the surface or come to the surface to breathe. The mistblowers described in this paper are designed to apply insecticide to rows of vines situated from I to 10 m distant from the applicators. The majority of droplets are much smaller than those used in boom-and-nozzle applications, they are emitted at a greater velocity from a higher elevation and therefore the quantity of insecticide drifting outside o,f the target area i: proportionally greater. The quantity of cypermethrin deposited on the soil surface within treated vineyards varied from 0.69 to 2.9 mg . m-‘. The average deposit of cypermethrin on the surface of adjacent streams was of the order of S-IO% of the deposit in the vineyards. However, where stream surfaces were unprotected by high banks or riparian vegetation the drift deposit was up to 2030 of that in the vineyard (or 10Wo of the nominal dosage expressed in g. m ?). Maximum concentrations of cypermethrin in subsurface water of the streams were in the range 0.4- 1.7 pg. I - ’ and these occurred within 0.5 h of spraying. These concentrations decreased rapidly soon after treatment because of dilution b!, untreated water from upstream. The :esulting concentration-time profiles for cypermethrin in the stream water were corlsiderably less than those required to cause mortalities of invertebrates.
210
The use of drift nets provided a very sensitive method of detecting effects ot pyrethroid contamination on aquatic invertebrates in flowing water. Relatively large numbers of gammarids, mayfly larvae and water beetles were caught in drift nets soon after mistblower treatments of adjacent vineyards. Peak numbers occurred between one and two hours after completion of spraying. Thereafter, the numbers caught in drift nets decreased and were no greater than background levels 24-48 h after treatment. There was no indication that any of the invertebrates affected by pyrethroid contamination of streams subsequently died. On the contrary when individuals caught in the drift nets were placed in uncontaminated water contained in beakers they behaved normally and fully recovered from the temporary effects caused by very low concentrations of cypermethrin in water. Furthermore, enhanced invertebrate drift had no detectable effect on population densities of benthic invertebrates. Thus overall impact of cypermethrin contamination of streams adjacent to vineyards resulted in, at worst, only minor and temporary effects on the invertebrate fauna. The areas chosen for these studies were selected such that insecticide contamination of natural waters adjacent to agricultural land was most likely to ‘irccur. In fact it was necessary to carry out rather extensive surveys in order to locate a sufficient number of ponds and watercourses that were in very close proximity to treated crops. After the first application of cypermethrin to arable crops in the U.K. it was clear that there were no biological effects of any kind in adjacent ponds. It was therefore decided to instruct the farmers to sipray the insecticide as close as possible to the edges of the ponds and around the whole of the perimeters, if accessible to the tractors. Despite these measures, contamination of pond surfaces with cypermethrin was remarkably low and the only observed effect was the knockdown of a few individual insects in the corner of one of the ponds. Similarly, the dosages used to treat vines in France (up to 45 g-ha- I) and the proximity of lhe spraying to the watercourses were factors that tended to increase the risk of contamination of watercourses with cypermethrin. In most agricultural arcas contamination of natural waters by spray drift from ground based spraying equipment is likely to be less than that reported in this paper. It follows that spray drift from such applications of cypermethrin is unlikely to be a significant hazard to aquatic organisms, despite its high toxicity in the laboratory. REFERENCES Crossland. N.0 , I982 Aquatic toxicology of cypermethrin. II. Fate and biological effects in pond experiments. Quai. Tkcol. 2. 205-222. Crossland, N.0 and R.R. Stephenson, 198~. lhe role of pond studies in assessingthe hazard of toxic chemicals to freshwater xosystems. Proc. 1979 BCK Conference, 2, 453-459. Stephenson. R.p , 1982. Aquatic toxicology of cypermethrin. I. Acute toxicity to some freshwater fish and invertebra:cs in laboratory tests. Aquat. Toxicol. 2, 175-185.
Elsevier
Biomedical
253
Press
AQUATIC TOXICOLOGY OF CYPERMETHRIN. III. FATE AND
BIOLOGICAL EFFECTS OF SPRAY DRIFT DEPOSITS IN FRESH WATER ADJACENT TO AGRICULTURAL LAND
N.O. CROSSLAND. S.W. SHIRES
and D. BENNETT
Shell Restwrch Limited, Sittingbourne Research Centre, Sittingbourne, Kent, ME9 8AC, England 29 October
(Received
Fields of sugar beet and potatoes using tractor-mounted and concentrations
25 January
1981; rcceptd
in the U.K.
1982)
were treated with cypermethrin
1
at a dosage of 7Og. ha
sprayers. Deposits of spray drift on three adjacent pond srlrfaces were very small in subsurface
water were near IO or below the limits of detection.
There were no
detectable residues in fish and there were no effects on the aquatic fauna except on the surface of one corner of o:le of the ponds where knockdown, belonging to certain species of air-breathing Vineyards
in France
cypermcthrirl
on Ae
concentrations
pg.1~
were treated surf
but
invertebrate
24 h later drift
I .7
11g. I
their
mistblo\\er<.
1soonafter
a few hours. The resulting concentration-time
profile\
Deposits of mp.
numbers
1112 and
spraying, decreasing to for cypermerhrln
less thau those required IO cause mortalities of invertebrate\.
increase in the numbers of live arthropod\
spraying
1 using
streams were in the range 0.04-0.45
in subsurtace water Here in the ranpe OA-
1 within
was observed among a few individuals
at dosages of 30 or 45 g. ha
: of three adjacent
stream hater were considerably marked
but no mortality, insects.
in rhc
There \\a, a
in the stream draft during the iir
weke similar
IO those in pre-treatment
had no detectable effect on population
sample\.
tnhanced
denritie:, of benrhic ~n\rrrchrate\.
The choice of tria, sites, the conditions of spraying and fhc dosage:; uvzd acre all dcGpnrd 11) incrca\e the risk of contamination
of natural
Haterbodies
with cypermethrin
expected to occur under normal conditions of agricultural cypermethrm
could be detected in adjacent
uaterbodie5
conciuded that spray drift from ground-based hazard
to aquatic
organisms,
to a higher lekel than \rould
112
WC. h\en W. onl! \sry lo\! conicntrnricbn* L~I and biologlA
rffectr
applications o!‘cypermethrin
despite the high toxicity
OI c)perrnethrln
uere in~igntfi~ant.
II N;L\
is unliked> to be a +gnll~~aru IO \uch organlvnr
w 111~
laboratory. Key words: cypermethrin;
spray drift; pond\;
stream5
INTRODUCTION
It has been shown in the laboratory that the insecticidecypermethrin [RIPCORD*, NRDC 149, [R,S]-a+cyano-3-pherroxybenzyl(IR, IS, cis, rrur~~)-3-(2,2-dichloroviIl~l)2,2-dimethyl cyclcpropanecarboxylate] is highly toxic to certain species of fish.
*RIPCORD
is a Shell trademark.
0166-445X/62/oo8o-0000/$02.72
(5’ Elsevier Biomedical Press
254
aquatic insects and Crustacea (Stephenson, 1982). However, in pond experiments sensitive species of fish survived when the pond surfaces were oversprayed with a dosage of 100 g-ha-r (Crossland, 1982; Crossland and Stephenson, 19801. From these results it was concluded that there is a negligable risk of direct toxicity to fish associated with the normal agricultural use of cypermethrin. On the other hand it was thought that there might be a risk of toxicity to aquatic crustaceans and certain species of aquatic insects. The environmental monitoring programme described here was therefore undertaken to determine the amounts of contamination in ponds and streams adjacent to agricultural land treated to control insect pests and to investigate the possibility of effects of such contamination on freshwater invertebrates. A preliminary survey of farms in the U.K. was carried out to locate ponds that would be exposed to a high risk of contamination from spray drift. In the county of Suffolk two farms were seb:ted that had large fields of sugar beet or potatoes enclosing or adjacent to smalii ponds. In this region two insecticide applications per annum are applied by tractor-mounted boom-and-nozzle spraying equipment for control of aphids. .4 preliminary survey in the south of France was carried out to locate drainage ditches and streams that would be exposed to a high risk of contamination from spray drift. Three vineyards with adjacent streams were chosen in the Languedoc region of southern France. In this region three insecticide applications per annum are applied in vineyards by mistblowers to control caterpillars of the tortrix moth,
Three ponds situated on two different farms near Stowmarker, Suffolk. U.K. ww selected to investigate spray drift from boom-and-nozzle applications (Figs. 1 and 3. The applications were carried out by farm staff so that the conditions of spplicatron \rould be the same as those in normal commercial usage. One of these (Pond A) was located in the north-west corner of a 19ha field dikided into equal areas of sugar beet and potatoes. Approximately one-third of its perimeter was adjacent to the crop. A thin stand of small bushes and trees partially \creened the pond from the field. The surface area of the pond was about 950 rn: and its maximum depth was 1.4 m. 4 second pond (Pond B) was located near the southern edge of the same field and %a.~entirely surrounded by crops. Much of the perimeter of the pond was screened from the field by bushes and trees but there were a few gaps in the screen of vegetation. The distance between the edge of the pond and the crops was generally lesz than 2 m. The surface area of the pond was about 250 mz and its maximum depth was 1.6 m.
The third pond (Pand C) was located on the north-west botmdar~ OI’ ;I XLha r’icld sugar beet. Approximatcty nw-Lhirds of’ ids perimctcr %\a!, adja
of
256 Pond 0
Pond C
0 0 0
drift
platrr
,4” \ depthcontowslcml -,
-+m
route of boom sprayerr
Fig. 2. Sketch of farm ponds showing positions of drift
plates.
applicaticns except that the operator was asked to spray as close as possible to the edges of the ponds and around the whole of the perimeters, if accessible to the tractor, even though these were not alwa.ys adjacent to the crops. Spray drift deposits were collected on horizontally-placed, aluminium-foil plates, 250 mm squr-e. Ten such plates in a series were,placed within the crops, near to the edge of the water or over the surface o,f the water. Their lay-out on or near fhe ponds is illustrated in Fig. 2. Spray deposits were washed from the foils with acetone
and the deposits from each series of 10 foils were combined before storage and analysis. Water samples from the surface of the ponds were removed using stainless-steel fine mesh discs, area 0.0093 m*, mesh no. 200, Five such discs were used for each sample. The average mass of water collected per five disc; was 2.95 g (range 2.7-3.2 g) and thus the depth of each surface sample was calculated to be 0.06 mm. Subsurface water samples were taken from a depth of 20-30 cm using a glassstoppered Erlenmeyer flask which was opened beneath the surface. It was then restoppered, removed from the water and wiped free of water adhering to the glass. Each water sample comprised five IOO-ml subsamples which were combined in a separating funnel. After extraction with hexane and drying with anhydrous sodium sulphate the samples were stored for analysis in the laboratory. In the laboratory the hexane extracts were analyzed by gas-liquid chromatography with electron-capture detection (glclec). Fish for residue analysis were removed from two of the three ponds. They were collected either by using rod and line or with an electrofishing method, and were deep-frozen within l-3 h of capture. In the laboratory whole fish were macerated and cyperm~thrin was extracted with a mixture of hexane and acetone. The extracts were then analysed by glc/ec. Subsamples of the zooplankton were collected using a IOO-mm diameter Perspex tube immersed to a depth of 0.5 m. Four such subsamples were combined to give one sample. Immediately after collection each sample was passed through a 150-#cm mesh sieve and the zooplankters were collected and stored for examination in the laboratory. ~acroinvert~brates were sampled using a sweep-net with a 950.pm mesh bag. Each sample was taken by sweeping through a distance of 10 m in the water. Vineyards in France
Two streams and a drainage ditch adjacent to three vineyards in the Languedoc region of France were selected to investigate spray drift from mistblower applications, The applications were carried out by the farmers so that the conditions of application would be the same as those in normal commercial usage. One of the streams (Stream A, Fig. 3). situated on the southern boundary of a 1.3-ha vineyard, was a tributary of the River Orb and was subject to periodic inundation by storm water. The stony bed of this stream varied from 2 to 12 m in width and its depth was 5 to 50 cm in alternating short riffles and longer pools. The maximum flow rate in May was 0.5 rn. set-’ and the volumetric discharge was 3 m3. min- I. In July the flow rate in riffle sections was similarly about 0.5 m . set _ ’ but the volumetric discharge was very much less than in May. In late July. i.e. after the second insecticide application, the stream bed dried up. The edge of the vineyard adjacent to the stream was 114 m long. Along much of this length the stream was
‘Ch
Edge of vmeya~~d --
_
_
-__ -
-
--
+
-
_ _,-
-
1
1 f
0
_-_-------_---_
--
h
0
0 -
-I
0 0
__-_----_---__---
1
I +
0
-_---
--, -. __*- -
--
114 Ill
CLJ
0 -----_--_. -
-
.-
--
0 1
I
of - _ -.-- .A
--.+-
0 Edge of vineyard
-
Ke\
00 x
Aluminlum
x
foil plates
water samplus invertebrate drift nets invertebrate quadrat samples
Ill --+
t IP 3. SIICin
water surface route of mistblower
France bhoxmg po\ltion\
OI ~amphng deice\
V
partially screened from the vineyard by a 2 m high bank. bushes and small trees. Stream B, situated on the southern boundary of a 3.Gha vineyard, also had a stony bed and consisted of riffle and pool sections but was much smaller, its width varying from 0.25 to 1.5 m and its depth from 5 to 20 cm. Maximum flow rate was 0.4 m . set ’ and volumetric discharge was 0.4 rn>. min ‘. This stream dried up in July before the second insecticide application was carried out. The edge of the vineyard adjacent to the stream was 270 m tong. Along much of this length the stream was partially screened from the vineyard by a l-m high bank, bushes and small trees. The drainage ditch was situated along the western and northern edges of a 1.O-ha vineyard. Its width var,ed from 0.2-2.0 m, its depth from 5-25 cm and its flow rate was approximately 0.01-0.03 m . set I. The ditch dried up in July before the second insecticide application ?vas carried out. There was no screening canopy of vegetation between the ditch and the adjacent vineyard but the banks and much of its surface \verc o\‘ergrown with grasses. flag iris (Iris sp.) and water crowfoot (Ranuncvllts sp.). Two of the vineyards, adjacent to streams, were treated at a dosage of 30 g. ha ’ using a 5% EC formulation of cypermethrin (Fig. 4). One of then, adjacent to a drainage ditch (Fig. S), was treated with a dosage of 45 g. ha I. The formulation wnh diluted wi!h water and applied at a rate of 400 I. ha ’ by mistblowers fitted nith a fixed or a swinging head discharging at a height of 3 m. A11three vineyards kteere
Fig. 5. The drainage ditch at Marseillan, Languedoc.
sprayed three times with cypermethrin., at intervals of 6 wk between May and August but because of prevailing draught conditions only the first application was monitored at all three sites. The second application was monitored at only one site, Stream A, where water was still flowing down the stream in duly. However, even this stream had dried up in August when the third application was carried out. Spray drift deposits were coilected on ahtminium-foil plates as described previously for the U.K. trials. A typical lay-out of sampling piates in a vineyard and an adjacent stream is illustrated in Fg. 3. Water samples from the two streams and from the draina,ge ditch were generally taken from sampling stations situated timmediately downstream from the treated vineyards.
261
Kick-samples of benthic invertebrates from the streams were collected with a sweep-net from within 0.2%m2 quadrats placed on the stream bed. After placing the quadrat on the stream bed the sediments were vigorously disturbed and material retained in the net was passed through a 500-pm mesh sieve. Animals and debris retained on the sieve were collected and stored for examination in the laboratory. Sweep-net samples of invertebrates were taken from the drainage ditch using a sweep-net with a 950-pm mesh bag. Samples of invertebrates in the stream drift were collected in 200-pm mesh nylon bags mounted on an adjustable framework of steel rods. A pair of drift nets was used to sample an area of stream 0.5 m wide, representing 50-100% of the total stream flow.
RESULTS
Arable crops in U.K.
Deposits L\f cypermethrin on the soil surface within sugar beet and potatoes treated with a dosage of 70 g. ha- I (= 7 mg . m 2) were between 4.2 and 6.6 mg. m -? (Table I). Deposits on pond surfaces were generally in the range 4-20x IO s rng,m-?, i.e. four to five orders of magnitude less than those in the crops, The one notable exception, when the deposit was 28 x 10 ? mg. m :, occurred during the second application when this relatively high deposit was found on a series of plates situated in an exposed corner of a pond immediately adjacent to the sprayed field. Very low concentrations (6-23 pg. I I) of cypermethrin lvere present in 10 out of I4 surface water samples collected immediately after treatment of the crops (Table 11). After 24 h cypermethrin \*as present (6 ,Q 1 I) in only one of 14 surface \\ater samples. Maximum concentrations in subsurface water tended to occur during the period O-5 h after treatment of the crops (Table II). The highest concentrations, 0.03-0.07 PE * 1 I, were recorded in Pond A 5 h after the second applicaiion. After 24 h the concentration in this pond had declined to a level belo\\ the limit of detection (0.01 pg. l- I)_ In 9 out of I4 samples collected 24 h after treatment the concentration t\as 10.01 /Lg.1 I and in the other 5 samples was in the range 0.01-0.03 pg. I I. Thirty-five rudd (Scurdinius er_vrhrophthaimzcs) and 15 Crucian carp (CamsGus cm&us) removed from two of the ponds were analgsed for cypermethrin (Table IT). There were no detectable residues in anv of these fish; limit of detection 5 rg.kg ‘. The most abundant groups of zooplankton in the ponds \vere Cyclopoida, Calanoida, Ostracoda and Chydoridae (Table 111). Their numbers fluctuated considerably but none of the changes in density could be attributed to the effects of insecticide spraying in adjacent fields.
TABLE1 hlosc of cypuzkcthrin deposited on ahtminium-foil plates in arable crops and on surface of adjacent pandr. SireandsunpP
Surfrce deposit (mg . m -2)
station P
1st Application
--2nd Application
PondA In crop near pond Nearsideofpond
6.3 0.14 x IO-3
5.8 28 x 10-S
centre of pond Far side of pond
0.10 x 10-J 0.14 x 10-3
4 0.01 x 10-3
Pond B In crop near pond
rc 0.02 x 10-3
6.6
5.8 0.23 x 10-r 0.54x IO-3
Perimeter of pond Centre of pond Pond C Im crop near pond Near side of pond Far side of pond
-_
1.8 x to-3
0.16 x IO-J
4.2
No datd
0.17 x 10-3 0.09 x IO--’
0.10 x lo-’
0.04 x 10
-3
TABLE II Concentrations of cypermethrin in samplesof water and fish collected from ponds (number of samples in parentheses). Site and treatment
-
Time after application
(h)
Surface water
Subsurface water
Fish
048*t-‘)
M3~l-V
(c9.k9
7. 9, 23 55. 12. 13
aO.fDI (3) ~0.101. 0.02, 0.02
-
Pond A 1st application
0 5 24
2nd application
55,
55, 6
0.102, 0.02. 0.03
0
55, 13, 21
zco.01 (3)
5 24
IO, 16, 26
SO.01 (3)
55 (6)
0.03, 0.05, 0.07
72
a5 (3)
Pond B 0 5 24
6, 13 8, I5 I5 (2)
SO.01 (2)
0 5 24
55. 6 5, 6 55 (2)
0.03 (2) so.01. 0.01 10.01 (2)
1st application
0 5 24
55 (2) 8, I1 55 (2)
SO.01 (2) 0.01, 0.02 zGo.01, 0.01
2nd application
0
9, I2
5 24
5, 5 15 (2)
1st application
2nd application
o.D4, 0.05 ~0.01,0.03
Pond C
55 (3)
0.01 (2) 0.02 (2) zco.01, 0.01
s5 (3)
‘1
nauplii
nauplii
I = times of insecticide
Chydoridae
Cqpepod
Cyclopoida
applications.
(1%53) 143 (IOl-203) 196 (117-330)
7
(5-198)
(l-18) 5 (l-17) 70 (43-l 13) 35
6
( 170-693)
W-362)
(3-18) 31
(67-I 10) 85 (52- 139) 343
108 (78-149) 96 (67.. 138) 181
500
(341-733) 86
371
(513-741)
(334-653) 617
(259-532)
446 (276-721) 235 (162-340)
55
(65- 105) I2 (7720) (35-71) 5 (I-21)
50
83
8 13.-19)
II (2-47)
4 (l-17)
(89-152) 445 (209-944)
30 (22~m41) I16
(83-291)
I56
470 (421-524)
(42-72) 531 (425-663)
3
20 (14.-29)
-
523 (271- 1011)
(lO3-iO4)
(55 105) 145
76
(276-452)
355
927 (849-1013)
423 (229-782)
I9 :I2-30)
36
(26-49) 467
2
from ponds (95% confidence
33
I’
in samples
(23-48)
0
ot zooplankters
C.rlanoida
Pmd C’
Ostracoda
Chaoboridae
Copepod
Pond B Cyclopoida
Copepod
Cyclopoida
Calanoida
nauplii
(days)
Pond A
Tie
Mean numbers
18
4
183)
(71-304)
(8-40) 148
18
(7-25)
14
(4-31)
II
34 (25-47) I82 (100-331)
(O-19) 0
(ISI
(262-488) I66
358
(11-B)
9
I2
5
2
?.
(O-2) 10 (6-16) Cl
I
(4-54)
16
(12-43)
(3-9) 23
(l-6)
(l-6)
(O-2)
(l-7) I8 (8-39) I
3
(9-70)
26
(l-13) I6 (8-32)
(l-11) 5
(2-12) 4
6
(l-4)
(7-l 1)
(S-17) 205 (128-328) 2
4
28’
(2-9) 191 (113-323) 5
27
limits in parentheses).
4
Sl
8 (4-15)
(I-3)
(8-W 2
18
3 (O-12) 48 (11-205)
5 (2-12)
9 (5-17)
(l-5)
(2-6) 167 (97-289) 2
29
121
(O-2)
(O-3) 17 (12-25) I
(3-50) I
13
(14-27)
5 (2-11) 19
2
(O-56)
12 (2-74) 7
(I-IO) 2 (O-II)
3
5 (3-10)
(l-3)
1 (O-3) 51
7
(388-w)
(88-155: 499
(3-12) 61
I70 (104-276) II
10
N-26)
I2
35
(7-12)
30
264 ‘rABLE IV IGmbers of invertebiates in sweep-net samples from ponds.
‘Time (days)
0
I+
2
34 794 16 145 IS 41 6 I6 272
I2 79 0 I6 I9 a 3 5 123
-9
.-..
27
201
35 --
Pond A
G.astropoda O#gochaeta Hirudinca Asellidae Notonectidae Corixidae Coleoptera
Ephemeroptera Chironomidae Diversity index Evenness Species richness
2.Q 0.48 4.2
51 7s 21 II6 II I6 8 9 448
2.4 0.58 4.1
22 951 I2 I64 I6 17 7 9 251
2.1 0.53 3.9
I.7 0.42 4.0
IO Ill 136 IS8 33 18 54 9s II8 3.1 0.77 4.0
I3 354 53 83 I9 2 8 56 254 2.5 0.61 4.1
41 603 59 288 41 22 I9 292 I88 2.6 0.62 4.2
Pond B
Oligochaeta Hirudinea Asellidae Notonectidae Corixidae Coleoptera Chironomidae Chaoboridae
I 0 20 I7 I4 3 38 412 I.1 0.37
Diversity index Evenness Species richness
8 0 IS3 60 4s I2 40 IO64
204 I 5 5 9 8 154 596 I.6 0.43 3.8
3.0
24 9 5s 4 I9 6 28 832
I.4 0.39 3.5
I .O 0.31 3.3
3 29 374 9 36 9 99 II80 I.5 0.39 3.9
I 7 385 I2 86 I3 loo0 1612 I.7 0.46 3.6
6 13 296 2 54 I2 301 R29 I.8 0.54 3.3
Pond C 9
Gastropoda Asellidae Corixidae Coleoptera Ephemeroptera Chironomidae
I 9 7 76 174
47 IO 34 6 IS3 261
2.0 0.50 3.9
Diversity index Evenness Species richne.ss
i= times of insecticide applicatbns. Data
oblained
from
sweep-net
is 3 21 5 56 I86
2.3 0.59 3.9
E86 136 40 46 151 358
2.4 0.58 4.1
collections
3.1 0.71 4.3
5 7 I97 6 169 IO3 2.2 0.55 3.9
of macroinvertebrates
2 4 14s 3 72 82 2.1 0.58 3.7
I’4 IO6 46 231 I26 2.1 0.67 4.1
in the ponds
are
given in Table IV. There were no marked redGctions in the numbers of arly of the groups of macroinvertebrates in any of the three ponds. No visible effects on invertebrates or fish were observed except in one corner of Pond A immediately after the second insecticide application. During the first few
265
hours aftl*r this treatment some pond skaters (Gerris sp.), one water-boatman (Noionecru sp.) and two rat-tailed maggots (Erisfdis sp.) were found immobilized on the surface of the pond. Several of these affected insects were collected and placed in beakers containing pond water. All had recovered by the following day. Vinqvards in France
Deposits of cypermethrin on the soil surface in vineyards treated by mistblowers at a dosage of 30 g. ha - ’ ( = 3 mg - m - *) were between 0.65 and 2.1 mg .m - ? (Table V). In the vineyard treated with 45 g. ha- I the deposit was 2.9 mg .m - 2. Spray drift deposits on the surface of adjacent streams were in the range 0.04-0.45 mg .m 2. Concentrations of cypermethrin in the surface water of streams soon after spraying were in the range 140-1010 pg. I -I (Table VI). These relatively high concentrations decreased to 20 pg. I ’ or less within 3 h after the completion of spraying. Maximum concentrations of cypermethrin in subsurface water of streams soon after spraying were in she range 0.4-I .7 fig. I - I. However, these had general11 decreased to 5 0.1 pg. I - ’ a few hours later. Numbers of live invertebrates collected in drift-nets placed in streams adjacent to treated vineyards are given in Tables VII and VIII. The results show that there was a considerable increase in the numbers of Gammaridae, Ephemeroptera, Coleoptera and Hemiptera in the invertebrate drift during the first 2 h after spraying, with a peak occurring about 2 h after spraying. Samples taken either 24 or 48 h after spraying contained numbers of invertebrates that were similar to those in prrtreatment samples, TABLE V Moss of cypermethrin deposited watcrbodies.
------
Trial site and dosage
---.
I
Stream A 30 g. ha
1
g . ha
Second application
Stream B 30
g . ha
-
1
First application Drainage
ditch 45
First application ___-
g
foil plate\
--_--..._._ __~
Sampling
ha
1
in \mcyardr
_~__.__. position (see Fig. 3)
_.
and on *urIacc
ot ad~;~cm
~_~ .._~_~_. Surface depobit (mg
Top of stream bank
( .h ( .J6
Over middle of stream
0.06Y
Far edge of stream bed
0.001
In the vineyard
First application
Stream A 30
on aluminium
In the vineyard
I .o
Edge of the vineyard
P.80
Over middle of stream
0.037
Far edge of stream bed
0.001
In the vineyard
2.1
Over the stream
0.45
In the vineyard
2.9
Top of ditch bank
I .v
Over middle of ditch
O.?l
m
2)
TABLB VI C~tfone
of cypermethrln in water adjacem to treated VhIeyards.
Trial site and
Sampling position
trcatmm
and time(h)
Cypermethrln concentration fj~g. I -
Giwe Stream A w)a.ba-r First appiicadon
- I
Downstream, near edpc of sprayed
+ +2 Upstream, near
_. I
Second application
edge of sprayed field
+
Downslream, near
SO.01 10
0.02
+3 +6 +26
10 3 2
0.03 0.04 0.03
1010
SO.01 0.52
IO ;D
0.05 0.04
s zi
t 3 +6 +26
ZG
+33
Drainqc
ditch
Downstream. near
J5g.ha
1
edge of sprayed field
First application
I + 0.5
Downstream, near edge of sprayed field
I.7 0.09 0.09 0.11
I
- I * 0.5
edge of sprayed field
410 110 ;:0
I
Stream A u)g.ha-r
1)
Subsurface water so.01
4?0
0 + 0.5
Befd
SlrearnBU)g.ha-1 Firsl application
film
2
0.03
10
so.01
-
I40
+ I + 2 + 4
:10 “.) ..L
50.02 0.40 0.22 0.20 O.OR
- I + 0.5 t 1 + 2
so.01
+ 3.5 + 24
0.09 0.04
50.01 0.17 0.04
TABLE VII Numbers of invertebrates in the stream drift (Stream A. first application). Time from spraying Gammaridae Ephcmeroptcra Coleoptera (h) -
II00 Of0
0
I
I 102 2 10 3 4a IO 49 --_-
29 9 0 0
-Diptera
0 14
I5 67
422 166
218
527 95 3
585 687
171
0
25
-_
261
TABLE Vlll Numbers of invertebrates in the stream drift (Stream B, first application). Time from spraying (h) -1510
0
-16
- 2to-1to oto Ito 2to 3to 26 to
Ephemeroptera
1 0
I 2 3 4 27
0 6 198 144 30 IO I2
Coleoptera 51 27 13 240 636 328 229 68
Hemiptera 1
I 0 8 120 42 16 2
-Diptera 725 284 898 2463 10364 5913 3648 584
TABLE IX Mean numbers of invertebrates per five sweep-net samples from the drainage ditch (95% confidence limits in parentheses). Family or Order --Asellidae Coleoptera Diptera Mollusca Oligochaeta Total Shannon-Wiener diversity index Evenness Species richness
Pre-treatment (17 May 1979)
Post-treatment (19 May 1979)
34( 7-156) IS ( 9-23) 6( l-27) 167 (30-891) 7 ( O-94) 280 (71-1103)
18 ( 9-36) 7 ( 2-18) a( 1-5) 67 (2 I-208) I I O-7) I16 (58-233)
1.79 0.40 4.46
--.
2.04 0.51 4.00
TABLE X Mean numbers of invertebrates per five kick-samples from Stream A. first application (95% confidence limits in oarentheses).
Taxon
Pre-treatment 120 May 1979)
Post-treatment 122 May 1979)
Ephemeroptera Diptera Coleoptera Oligochaeta Tots) Shp tnon-Wiener diversity index Species richness Evenness
3 ( O-18) 600 (267-1347) 20 ( 13-29)
4( 1-8) 1083 (369-3176) 24 ( 13-45) 164 ( 21-1248) 1460 (509-4180)
58 ( I-2076) 950 (442-2040)
1.7 4.2 0.41
1.7 4.4 0.38
XI
197
(2)
(3.81-4.25) 0.61 (0.57-0.68)
4.36
( 4.09-4.52)
( 0.57-0.71)
Species richness 0.65
(2.19-2.58) 3.95
( 2.35-3.17)
Shannon-Wiener diversity index
Evenness
772 ( 417-3429) 2.39
II73 ( 1254-2507) 2.85
Tixal
u-5)
I
104 ( 52-209)
Hirudinea (
53 ( 20-141)
I-IO)
(
(
4- 10)
( 298-1093) 20 ( 12-34) 4
571
( 62-192)
109
Station
(4 July 1979)
856 ( 492-1491) 107 ( 64-180) 7
( 150-258)
(I)
Pre-treatment
Station
from Stream
241 ( 149-387)
._
per five kick-samples
Mollusca
Hemiptera
Coleoptera
Diptera
of invertebrates
indices).
Ephemeroptera
Taxon
community
Mean numbers
TABLE
68
l-9)
( t
3-21)
(0.64-0.81)
(3.59-4.17) 0.73
372 ( 142-982) 2.82 (2.68-3. IO) 3.87
i
9
( 39-221)
92
33 15-70) 4
( 25-183) 149 ( 42-529)
(3)
application
Station
A, second
O-8)
2
124 68-227)
1493 734-3040)
241 182-318)
(I)
55-230)
0.63 ( 0.53-0.71)
(
3.94 3.70-4.09)
2.49 ( 1.98-2.91)
2460 ( 1463-4137)
(
112
245 ( 162-370)
(
(
(
(
Station
(2)
O-16)
3
31-240)
86
(0.61-0.81)
0.70
(3.32-3.81)
(2.10-2.78) 3.57
909 ( 377-2192) 2.51
(
(
29-86) 10 ( 2-41)
(
612 ( 245- 1525) 50
I24 ( 49-314)
Station
(6 July 1979)
limits tn parenfheur;-
Post-treatment
(95% confidence
(3)
;,-91)
13-613) 39
89
(0.59-0.73)
0.66
!3.91-4.17)
(I .95-2.94) 3.98
527 ( 219-956) 2.63
(
(
68-220) 72 ( 47-109) 8 ( 4-15)
(
IO? ( 49-211) 139
Station
ranges in parentheses
for
269
Numbers of invertebrates collected in sweep-net samples from the drainage ditch and in kick samples from Stream A are given in Tables IX, X, and XI. Species richness, evenness and diversity indices were calculated for each of the samples collected immediately before and after treatment of the vineyards. The results show that the treatments had no effect on the abundance of individual species or on the community structure of benthic invertebrates.
DISCUSSION
In five out of the six tractor-mounted spray applications to arable crops the amount of spray deposited on pond surfaces adjacent to treated crops was only O.OOl-0.01% of the deposits on soil surfaces in adjacent fields, even though the sprayers passed within 1 or 2 m of the ponds. The deposits on pond surfaces are remarkably low when compared with spray drift deposits on adjacent soil surfaces. It is well established that most droplets contained in spray drift are relatively small ( ~60 pm) and tend to remain airborne under conditions of minor atmospheric turbulence. Since the surfaces of the farm ponds were below the level of the surrounding a;sble land there would be a tendency for spray drift to pass over rather than fall out onto pond surfaces. The only biological effect observed in any of the ponds was associated with a relatively high deposit of 28 x 10-j rngarnm2 found on the surface of one of them following the second application of cypermethrin. This was associated with the knockdown, but no mortality, among a few individuals belonging to insect species that inhabit the surface or come to the surface to breathe. The mistblowers described in this paper are designed to apply insecticide to rows of vines situated from I to 10 m distant from the applicators. The majority of droplets are much smaller than those used in boom-and-nozzle applications, they are emitted at a greater velocity from a higher elevation and therefore the quantity of insecticide drifting outside o,f the target area i: proportionally greater. The quantity of cypermethrin deposited on the soil surface within treated vineyards varied from 0.69 to 2.9 mg . m-‘. The average deposit of cypermethrin on the surface of adjacent streams was of the order of S-IO% of the deposit in the vineyards. However, where stream surfaces were unprotected by high banks or riparian vegetation the drift deposit was up to 2030 of that in the vineyard (or 10Wo of the nominal dosage expressed in g. m ?). Maximum concentrations of cypermethrin in subsurface water of the streams were in the range 0.4- 1.7 pg. I - ’ and these occurred within 0.5 h of spraying. These concentrations decreased rapidly soon after treatment because of dilution b!, untreated water from upstream. The :esulting concentration-time profiles for cypermethrin in the stream water were corlsiderably less than those required to cause mortalities of invertebrates.
210
The use of drift nets provided a very sensitive method of detecting effects ot pyrethroid contamination on aquatic invertebrates in flowing water. Relatively large numbers of gammarids, mayfly larvae and water beetles were caught in drift nets soon after mistblower treatments of adjacent vineyards. Peak numbers occurred between one and two hours after completion of spraying. Thereafter, the numbers caught in drift nets decreased and were no greater than background levels 24-48 h after treatment. There was no indication that any of the invertebrates affected by pyrethroid contamination of streams subsequently died. On the contrary when individuals caught in the drift nets were placed in uncontaminated water contained in beakers they behaved normally and fully recovered from the temporary effects caused by very low concentrations of cypermethrin in water. Furthermore, enhanced invertebrate drift had no detectable effect on population densities of benthic invertebrates. Thus overall impact of cypermethrin contamination of streams adjacent to vineyards resulted in, at worst, only minor and temporary effects on the invertebrate fauna. The areas chosen for these studies were selected such that insecticide contamination of natural waters adjacent to agricultural land was most likely to ‘irccur. In fact it was necessary to carry out rather extensive surveys in order to locate a sufficient number of ponds and watercourses that were in very close proximity to treated crops. After the first application of cypermethrin to arable crops in the U.K. it was clear that there were no biological effects of any kind in adjacent ponds. It was therefore decided to instruct the farmers to sipray the insecticide as close as possible to the edges of the ponds and around the whole of the perimeters, if accessible to the tractors. Despite these measures, contamination of pond surfaces with cypermethrin was remarkably low and the only observed effect was the knockdown of a few individual insects in the corner of one of the ponds. Similarly, the dosages used to treat vines in France (up to 45 g-ha- I) and the proximity of lhe spraying to the watercourses were factors that tended to increase the risk of contamination of watercourses with cypermethrin. In most agricultural arcas contamination of natural waters by spray drift from ground based spraying equipment is likely to be less than that reported in this paper. It follows that spray drift from such applications of cypermethrin is unlikely to be a significant hazard to aquatic organisms, despite its high toxicity in the laboratory. REFERENCES Crossland. N.0 , I982 Aquatic toxicology of cypermethrin. II. Fate and biological effects in pond experiments. Quai. Tkcol. 2. 205-222. Crossland, N.0 and R.R. Stephenson, 198~. lhe role of pond studies in assessingthe hazard of toxic chemicals to freshwater xosystems. Proc. 1979 BCK Conference, 2, 453-459. Stephenson. R.p , 1982. Aquatic toxicology of cypermethrin. I. Acute toxicity to some freshwater fish and invertebra:cs in laboratory tests. Aquat. Toxicol. 2, 175-185.