AN ABSTRACT OF THE THESIS OF
JOHN ALBERT GILL
(Name of student)
in
Fisheries and Wildlife
for the
M. S.
(Degree)
presented on
i
'iI
(Date)
(Major)
TITLE: TOLERANCE OF TWO POPULATIONS OF
RING-NECKED PHEA
Abstract approved:
ii
Redacted for Privacy
'B.
J, Verts
Levels of tolerance to DDT in two populations of ring-necked
pheasants (Phasianus coichicus) were investigated during 1966-68.
One population inhabited an area which received agricultural applica-
tions of DDT for 8 years; the other inhabited an area which had no
history of agricultural applications of DDT, Contradictory results
as to the more tolerant population were obtained from two preliminary experiments in which capsules containing technical DDT were
administered to small numbers of birds. A third experiment was
designed to resolve this inconsistency
Median lethal concentrations
of technical DDT in diets of week-old chicks were determined. The
following pairs of groups (from the treated-area and the control-area)
were tested: (1) first-generation progeny whose parents were captive
1.5 years, (2) second-generation progeny whose parents were reared
in captivity (from adults captured in the wild), and (3) first-generation
progeny whose parents were captive O 5 year. Dose-mortality data
were analyzed by pooled regression analysis and analysis of variance.
Results indicated that progeny of control-area parentage were significantly more tolerant to DDT than progeny of treated-area parentage (P<O. 0Z5). Levels of tolerance to DDT appeared to be inherent
characteristics of the populations occupying the two areas because
they did not appear directly related to amounts of DDT-residues
passed to young through the eggs, to the length of time that parents
were in captivity, or to the number of generations that birds were
maintained in captivity. Observed differences in tolerance to DDT
did not appear to be related to the intensity or duration of agricultural applicatons of DDT on the treated area. These conclusions did
not preclude the possibility that DDT acted as a selective force on
populations of pheasants occupying the treated area. Differences in
levels of tolerance to DDT in populations occupying the two areas
may have been greater prior to the use of DDT on the treated area.
If tolerances of adjacent populations to insecticides differ as much
as was detected in this study, caution must be used in determining
levels of toxicity of insecticides to wildlife species.
Tolerance of Two Populations of
Ring-necked Pheasants to DDT
by
VEII'i:
Redacted for Privacy
Assistant Pr4'fessor of Wildlife Ecology
in charge of major
Redacted for Privacy
head of Department of Fisheries and Wildlife
Redacted for Privacy
Dean of Graduate School
iate thesis is presented
June 12, 1969
1red by Cpal Cirossnicklaus for
John Albert Gill
ACKNOWLEDGEMENTS
Gratitude is extended to Dr. B. J. Verts, Assistant Professor,
Department of Fisheries and Wildlife, for guidance in the conduct of
this research and in the writing of this thesis.
Appreciation is expressed to my wife, Jennifer, for typing
reports associated with this research and for providing encouragement.
Gratefully acknowledged are Joseph Capizzi, Entomology
Extension Agent, for a contribution of technical-grade DDT and Mrs.
Freya Hermann, School of Pharmacy, Oregon State University, for
assembling capsules of DDT. Dr. R. R. Claeys and his technicians
in the Department of Agricultural Chemistry, Oregon State Univer-
sity, determined DDT-residue levels in samples by gas chromatogr aphy.
N. 0. Taylor, Assistant County Extension Agent, Umatilla
County, helped locate suitable study areas.
J. F. Ely, Oregon State Game Commission, obtained access
to farm lands and provided facilities so that wild pheasants could be
captured and handled. D. F. Kirkpatrick and his staff at the Oregon
State Game Commission Pheasant Farm provided facilities and ad-
vice, and helped care for pheasants.
T. E. Morse, J. A. Chapman, G. S. Lind, and M. R. Bethers
helped capture wild pheasants. T. M. Connolly, D. E. Trethewey,
R. A. Powers, T. W. McCormick, andM. P. Connolly assisted with
maintaining pheasants in captivity and rearing chicks for experimen-
tal purposes. B. H. Gill, E. G. Silovsky, M. A. Moran, W. L.
Jordan, and D. J. Langowski helped collect data.
Dr. W. S. Overton, Department of Statistics, Oregon State
University, suggested appropriate statistical treatment of data on
dose-mortality relationships.
TABLE OF CONTENTS
INTRODUCTION
STUDY AREAS
Treated Area
Control Area
ME THODS
Experiment 1
Experiment 2
Experiment 3
RESULTS
Experiment 1
Experiment 2
Experiment 3
3
3
3
6
7
8
8
ii
11
11
14
DISC USSI ON
18
BIBLIOGRAPHY
20
APPENDIX
22
LIST OF TABLES
Page
Table
1.
2.
3.
4.
Levels of DDT-residues in ppm in brains and livers of
8-week old pheasants of treated-area and control-area
parentage.
14
Median lethal concentrations of technical DDT to
week-old pheasants.
15
Analysis of variance of median lethal concentrations
of technical DDT to three groups of pheasant chicks
from each treated-area and control-area parentage.
15
Residues in ppm ofp,'-DDT and p,'-DDE in eggs
17
laid by parents of chicks used in Experiment 3.
Appendix
Table
1.
Chemical names of compounds mentioned in this thesis.
22
LIST OF FIGURES
Figure
1
2
3
Outline map of the treated area with total pounds ci
technical DDT applied per acre indicated for the various
fields, 196L67.
Survivorship of ten female pheasants from each the
treated area and the control area when administered
capsules containing 100+3 mg technical DDT via glass
tube on alternate evenings until death ensued,
4
12
Survivorship of 20 pheasants 8-weeks old (males and
females) from each treated-area and controlarea
4
parents when administered capsules containing 0±0 3
mg echnical DDT and 90+2. 7 mg lactose on consecutive
mornings until death ensued,
13
Median lethal concentrations of technical DDT in ppm
to three groups of pheasant chicks of each treated-area
parentage and control-area parentage.
16
TOLERANCE OF TWO POPULATIONS OF
RING-NECKED PHEASANTS TO DDT'
INTRODUCTION
This is a report on levels of tolerance to DDT exhibited by two
populations of ring-necked pheasants (Phasianus colchicus). One population inhabited an area which received agricultural applications of
DDT for 8 years; the other inhabited an area which had no history of
agricultural applications of DDT.
Populations of numerous species exposed to certain insecticides
become more tolerant of the toxic effects of these compounds. Sev-
eral species of aquatic and semi-aquatic vertebrates apparently developed resistance through selection by insecticides for several gen-
erations (Vinsonetal., 1963; Ferguson etal., 1964; Ferguson and
Bingham, 1966; Ferguson and Gilbert, 1967). Increases in tolerance
of fishes ranged from none for populations exposed to DDT (Ferguson
etal., 1964) to 1, 500-fold for populations exposed to endrin
(Ferguson, 1968). Cross-resistance to related insecticides was
detected in several fishes (Boyd and Ferguson, 1964; Ferguson, 1968).
Increased sensitivity, the converse of resistance, was observed in
the first generation of sheep shead minnows (Cyprinodon variegatus)
whose parents were survivors of DDT tests (Holland etal., 1966).
'Chemical names of all insecticides (or compounds of insecticidal origin) mentioned are presented in the Appendix, Table 1.
2
The latter authors did not offer an explanation for the phenomenon.
Two species of terrestrial vertebrates exhibited resistance to
insecticides, In the laboratory, a DDT-resistant strain of white mice
(Mus musculus dome sticus) was developed by breeding survivors of
median lethal doses (LD50) for nine generations (Ozburn and Morrison,
1962).
These mice were 1.7 times as resistant as mice from a colony
not selected for DDT-resistance. Cross-resistance to lindane and
dieldrin was detected among mice selected for resistance to DDT
(Ozburn and Morrison, 1964). Wild pine mice (Pitymys pinetorurn)
exposed to agricultural applications of endrin exhibited a 12-fold
resistance to that chemical (Webb and Horsfall, 1967). Resistance
may have been induced in the pine mice through prior exposure to
the toxicant rather than acquired through selection by action of the
toxicant on their populations.
This research was initiated to explore the possibility of insecticide-resistance in avian populations. The ring-necked pheasant was
selected for the investigation because it inhabited agricultural lands,
high levels of insecticide residues were reported to accumulate in its
tissues (Keith and Hunt, 1966; Hunt, 1966), its reproduction was
demonstrably reduced by exposure to insecticides (De Witt, 1955,
1956; Genelly and Rudd, 1956; Azevedo etal., 1965), and it was
known to be relatively easy to capture and maintain in captivity.
3
STUDY AREAS
Treated Area
The treated area, a ranch owned by the Key-Wallace families,
was located 6 miles west of Milton- Freewater (in T 6 N, R. 34 E. ),
Umatilla County, Oregon. From 1955 to present, the predominant
crops were alfalfa grown for seed, and wheat, Alfalfa crops were
sprayed with varying amounts of DDT (Figure 1), toxaphene, Kelthane,
Systox, malathion, Dibrom, and Cygon to control insect pests such as
lygus bugs (Lygus sppj, pea aphids (Acyrtho siphon pisum), and two-
spotted spider mites (Tetranychus urticae). In the interval 196 1-67,
approximately 10, 500 pounds of DDT were applied to 804 acres of the
1, 219-acre ranch
A composite sample of soil (three cores 6 inches
deep and 1 inch in diameter from each of the treated fields) averaged
1. 123 ppm E' P -DDT, 0.249 ppm o, ' -DDT, 0. 127 ppm
,
' -DDD,
and 0ZO3 ppm E,E'-DDE
Control Area
The control area, 5 miles east of Pendleton (in T
2 N, R 3
E,) on the Umatilla Indian Reservation, Umatilla County, Oregon, was
35 miles from the treated area. Dry-land culture of wheat was pracliced on the area. According to the Umatilla Indian Agent no toxi-
cants were applied on the reservation, however, treatment of seed
2.
9.0(2)
\\ 9O(2)
5)
Pt
9.0
15.5(43
IN4J
I3.5(3
I?.5(5)
B.5(3)
8.5(3)
11.0(3)
8.5(3)
Jas
13.0(4)
I
22.0(6)
I
22.0(6)
175(5)
zFIELDS IN WHICH PHEASANTS
WERE CAPTURED
Figure 1. Outline map of the treated area with total pounds of technical DDT applied per acre indicated for the various fields, 1961-67.
Numbers of years in which one or more applications of DOT were made are in parentheses.
5
wheat with small quantities of dieldrin or aidrin for control of
depredations by Great Basin wire worms (Ctenicera pruinina) is a
common practice in the area (N. 0. Taylor, Assistant County Extension Agent, per sonal communication)
METHODS
Adult pheasants, captured on both study areas by nightlighting
(Labisky, 1959, 1968), were either tested for tolerance to DDT or
used to produce young which were tested. After capture, pheasants
were placed in crates and transported to Oregon State University
where they were transferred to pens. The pheasants were maintamed on Purina Game Bird F and M Chow until subjected to experi-
mentation or until the reproductive season. During the reproductive
season, they were supplied Purina Game Bird Breeder Layena and
crushed oyster she1ls
During the laying season, eggs were collected daily, marked to
identify parentage, and cleaned with a moist cloth. Eggs were placed
in egg flats and sealed in plastic sacks from which air was evacuated
by use of a venturi. The flats of eggs, stored at 553 F on an incline
of approximately 300, were turned at approximately 8-hour intervals
to prevent membranes from adhering to the eggshells.
Eggs were incubated in forced-draft incubators at the Oregon
State Game Commission Pheasant Farm. Chicks were brooded at
the Pheasant Farm until they were subjected to experimentation or
until brooding was no longer required.
7
Experiment 1
Ten female pheasants were captured on each the treated area
and the control area in December 1966 and held in captivity prior to
initiation of Experiment 1 for 17 and 9 days, respectively. Gelatin
capsules containing 100±3 rng technical DDT in crystalline form were
administered orally via glass tube on alternate evenings until death
ensued.
The formulation of technical DDT contained 71. 3 percent
E,R-DDT, 11.2 percent o,E-DDT, 4.0percent,'-DDD, 1.5 percent p,p' -DDE, and 12,0 percent inert ingredients.
Birds were observed at least every 12 hours for symptoms of
toxic effects of DDT. Individuals alive 48 hours after receiving the
previous capsules were administered additional capsules, thus, as
length of survival increased, dosage increased, Days of survival
were considered a measure of tolerance.
A source of variation was the amount of insecticide residues
accumulated by pheasants from the treated area prior to Experiment
1 and mobilized during the experiment. This variation was avoided
in subsequent experiments by using progeny of birds from the study
areas. Progeny of birds from both areas were raised in identical
conditions, and their exposure to insecticides was minimized.
E:i
Experiment 2
Methods of this experiment were essentially those of Experiment 1 with the following exceptions: (1) there were 20 progeny
(males and females, 8-weeks old) of the first generation in each
group from pheasants captured on the study areas in March 1967,
(2) capsules contained 10±0. 3 mg DDT (same formulation as DDT
used in Experiment 1) plus 90±2. 7 mg lactose which facilitated prepa-
ration of the capsules, and (3) capsules were administered on consecutive mornings. Again, days of survival were considered a
measure of tolerance
Brains of four poults and livers of two poults from each treatedarea and control-area parentage were analyzed by gas chromatography
to determine the levels of DDT. residues prior to Experiment 2,
ExDeriment 3
Experiment 3 consisted of three pairs of dose-mortality experiments with week-old pheasants of both sexes, The following pairs
of groups (treated-area and control-area) were compared: (1) firstgeneration progeny whose parents were captive 1.5 years, (2) secondgeneration progeny whose parents were reared in captivity from wildcaught adults, and (3) first-generation progeny whose parents were
captive 0,5 year.
The median lethal concentration of DDT (LC50) for each group
was determined according to procedures established by Heath and
Stickel (1965).
Technical DDT (same formulation as DDT used in
Experiments 1 and 2), weighed in mg, was dissolved in 20-g portions of corn oil, Solutions of various concentration were then
mixed with separate 980-g lots of Purina Turkey Startena.
Levels
of DDT in the resulting mixtures were expressed directly as parts
per million (ppm) of DDT in the diets.
Concentrations of DDT fol-
lowed geometric progressions with 3-6 dosage levels for each experimental group and 18-25 chicks subjected to each dosage level.
Food
and water were provided ad libitum; toxic food was provided for 5
days then noncontaminated food was supplied for 3 days. Chicks
which died during the 8-day period were considered to have died
from the toxic effects of DDT, Accidental mortality was measured
by use of control groups consisting of progeny of control-area pheasants which were captive 0. 5 year; 12 chicks received the basic diet
and 12 received the basic ration with 20 g corn oil per kg.
Percentages of chicks which died at each dosage level during
the 8-day test period were plotted against concentrations of DDT in
the diets. Slopes of lines fitted to these points by inspection were
judged to be similar. Therefore, slopes were calculated by pooling
data from the three groups of birds of treated-area parentage and
from the three groups of birds of control-area parentage. A line with
10
the calculated slope was drawn through coordinates of the mean DDT-
concentration fed and the mean percent mortality for each of the six
groups of birds, The LC50 for each group of pheasants was the value
on the abscissa perpendicular to the intercept of the dose-mortality
line and the 50 percent mortality line,
Analysis of variance was used to determine if DDT-tolerance
was associated primarily with the stocks (generations of the chicks
plus the length of time their parents were captive) or with the area
on which parentage of the chicks originated.
To determine exposure of chicks to the various analogs of DDT
prior to and during Experiment 3, other than amounts intentionally
added to the diets, the following items were chemically analyzed:
(1) eggs with histories identical to those from which the experimental
chicks hatched, (2) two 7-day-old chicks of parents from the control
area held captive 0 5 years, (3) a sample of the ration with corn oil
(no insecticide), and (4) two 15-day-old chicks of the same parentage
after the 8-day test in which they consumed the basic ration with corn
oil (no insecticide) for 5 days,
11
RESULTS
Experiment 1
Contrary to expectation, pheasants from the control area survived longer than pheasants from the treated area. Birds from the
control area survived an average of 8 0 days, whereas birds from
the treated area survived an average of 5 8 days (Figure Z). Three
birds from the control area survived at least 1.5 days longer than
any birds from the treated area.
Experiment 2
First-generation progeny of pheasants from the treated area
survived an average of 2 0 days longer than offspring of birds from
the control area (Figure 3). The longest-lived poult of treated-area
parents survived 5 0 days longer than the longest-lived poult of
control-area parents.
The amount of DDT-residues accumulated by progeny of
treated-area parents prior to Experiment 2 was not believed to
affect their tolerances to DDT. Residues of DDT were low in brains
and livers of poults whose parents were from both the treated area
or the control area (Table 1).
(I)
0
>
>
U)
cr'°
Ui
ID
z
ru
DAYS
Figure 2. Survivorship of ten female pheasant from each the treated area and the control area when administered capsules
containing 100±3 mg technical DDT via ginss tube on alternate evenings until death ensued.
13
20
Ii
C,)
0
>
Ci)
cr
LU
m
z
2
4
6
8
10
12
14
16
DAYS
Figure 3. Survivorship of 20 pheasants 8-weeks old (males and
females) from each treated-area and control-area parents
when administered capsules containing 10+0. 3 mg
technical DDT and 90±2. 7 mg lactose on consecutive
mornings until death ensued.
14
Table 1,
Levels of DDT-residues in ppm in brains and livers of
8-week-old pheasants of treated-area and control-area
par entage.
Analog
of
DDT
Treated Area
Brain**
Liver*
,pT-DDE
0.0170
0.2195
0.0201
0.0066
0.0104
--
Control Area
Brain
Liver
0.0343
0.2245
0.0621
0.0105
0.0080
--
Average value in livers of two poults
*Average value in brains of four poults
Experiment 3
Progeny of control-area parentage apparently were more resistant to the toxic effects of DDT than progeny from treated-area parentage (Table 2 and Figure 4), The LC50 of the least resistant group
of progeny from control-area parentage was 45 ppm greater than
the LC50 of the most resistant group from treated-area parentage.
Analysis of variance indicated that the LC50? s of chicks from control-
area parentage were significantly greater (P< 0.025) than the
LC50Ts
of chicks from treated-area parentage (Table 3). None of the chicks
died in the control groups, therefore no adjustments were required
to compensate for accidental mortality.
It was believed that exposure of the test birds to DDT prior to
and during Experiment 3 (from sources other than amounts intention-
ally added to their diets) did not affect DDT-tolerance of any
15
Table 2. Median lethal concentrations of technical DDT to week-old
pheasants.
No. Years
Parents Were
Generation
Captive
Calculated LC50 in ppm
Pheasants from Pheasants from
Treated-area
Parentage
Control-area
Parentage
F1
1.5
776
906
F2
1.0
816
911
F1
0.5
861
1,023
Reared in captivity
Table 3. Analysis of variance of median lethal concentrations of
technical DDT to three groups of pheasant chicks from
each treated-area and control-area parentage.
Source of Variation
Area on Which
d. f.
SS
MS
Computed F
1
24, 962. 0
24, 962. 0
44. 5*
11, 246.0
1, 123.0
5, 623.0
561.5
10.0
Parents were Captured
Stocks**
2
Area X Stocks
2
--
*Statistically significant (P<0. 025).
Effects of the generations of the chicks plus effects of
the length of time their parents were captive.
**Stocks
100
90
>I-
80
-J
70
cr
60
0
/
50
I
z
w
0
w
a-
40
30
20
Jo
0
-
-i--I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
II
I
I
I
II
I
I
I
I
II
I
I
I
I
II
I
I
I
Ii
I
I
.YY.
V.
00000
0CD 0 0000000
0
(DCD 0
oJ
N-
cj
Ø
y,
CJ
0)
o, 00i
CJ
DOSE
Figure 4. Median lethal concentrations of technical DDT in ppm to three groups of pheasant chicks of each treated-area parentage
(T) and control-area parentage (C).
T1. C1 = First-generation progeny of parent captive 1. 5 years.
T2, C2 = Second-generation progeny of parenti reared in captivity.
T3, C3 = First-generation progeny of parenti captive 0. 5 year.
17
particular group(s) of chicks. All eggs tested were low in DDTresidues (Table 4). Overlapping values for residues indicated that
DDT-residues were not associated with levels of DDT-tolerances.
Two 7-day-old chicks of parents held captive 0. 5 year from the con-
trol area contained an average of 0. 119 ppm , p -DDT, 0, 072 ppm
-DDE, 0.036 ppm o, ' -DDT, and no detectable p, E -DDD. A
,
sample of the ration with corn oil contained 0.281 ppm E R' -DDT,
0,008 ppm
' -DDE, 0.059 ppm
p -DDT, and 0.020 ppm
p -DDD.
Two chicks of the same parentage after the 8-day experiment, in
which they consumed the basic ration with corn oil (no insecticide)
for 5 days, contained an average of 0,400
ppm
,
ppm,DDT, 0.162
p' -DDE, 0. 253 ppm o, E -DDT, and no detectable p, E.' -DDD.
It was believed that quantities of the analogs of DDT from sources
other than amounts intentionally added to the diets did not materially
alter the determinations of the toxicities.
Table 4. Residues in ppm of p, p' -DDT and p, p -DDE in eggs laid
by parents of chicks used in Experiment 3.
No. Years
Parents Were
Captive
Generation
F1
F1
Eggs from Treated-area
Parentage
E,'-DDE
£,E'-DDT
1.5
0,0045
1. 0**
0.0057
0,0165
0.5
*Average value in two eggs
**Reared in captivity
0.0038
0.0092
0.0173
Eggs from Control-area
Parentage
2,-DDT
0.0303
0.0051
0.0329
0.0203
0.0054
0,0288
DISCUSSION
Results of Experiment 1 suggested that ring-necked pheasants
from an area treated with DDT for 8 years were less tolerant of the
toxic effects of DDT than pheasants from an area which had no history
of agricultural applications of DDT. Results of Experiment 2 suggested that progeny of pheasants from the treated area were more
tolerant than progeny of pheasants from the control area, essentially
the converse of Experiment 1. Expe riment 3 was designed because of
the contradictory re suits of these two experiments. Re suits of Lxperiment 3 indicated that progeny of pheasants from the treated area
were significantly less tolerant of the effects of DDT than progeny of
pheasants from the control area.
Differences in levels of tolerance to DDT exhibited by pheasants
from the two areas did not appear to be directly related to levels of
DDT-residues passed to young through the eggs (Table 4), to the
length of time that parents were in captivity (Table 3), or to the num-
ber of generations that birds were maintained in captivity (Table 3).
Thus, levels of tolerance to DDT appeared to be inherent character-.
istics of the populations occupying the two areas. The possibility of
inte rchange between the se populations was remote; the study areas
were 35 miles apart, and much of the intervening habitat was unsuitable for ring-necked pheasants.
The mechanisms by which these differences in tolerance to DDT
19
developed were unknown. Because pheasants from the treated area
were less tolerant than birds from the control area, it was adomatic
that these differences were not the result of DDT-pressure on popula-
tions of pheasants on the treated area. Thus, it was probable that
the observed differences were unrelated to the intensity or duration
of agricultural applications of DDT on the treated area.
These conclusions do not preclude the possibility of DDT acting
as a selective force on populations of pheasants occupying the treated
area. Differences in levels of tolerance to DDT in populations occupying the two areas may have been greater prior to the use of DDT
on the treated area. After 8 years of exposure to agricultural applications of DDT, the tolerance of the pheasant population on the treat-
ed area was 12 to 19 percent lower than the tolerance of the population on the control area. If selection for pheasants more tolerant to
DDT is occurring on the treated area, continued use of this insectidde on the treated area eventually should produce a population whose
tolerance to DDT would approach or surpass that of the population on
the control area
If tolerances to insecticides of adjacent population differ by as
much as 19 percent, and if those differences are not related to prior
exposure of the populations to those insecticides, it is obvious that
caution should be exercised in interpreting established levels of
toxicity of insecticides to wildlife species
BIBLIOGRAPHY
American Chemical Society. 1968, Chemical abstracts subject
index, July-December 1967, 2 vol. 3817 pp.
Azevedo, J. A., Jr., E. G. Hunt and L. A. Woods, Jr.
1965.
Physiological effects of DDT on pheasants. California Fish
and Game 51(4):276-293.
Boyd, C. E. and D. E. Ferguson. 1964. Spectrum of crossresistance to insecticides in the mosquito fish, Gambusia
affinis. Mosquito News 24(l):19-Zl.
De Witt, J. B.
1955. Effects of chlorinated hydrocarbon insecticides upon quail and pheasants. Journal of Agricultural and
Food Chemistry 3(8):672-676.
1956. Chronic toxicity to quail and pheasants of
some chlorinated insecticides. Journal of Agricultural and
Food Chemistry 4(1O):863-866.
Ferguson, D. E. 1968. Characteristics and significance of resistance to insecticides in fishes. In: Reservoir Fishery Resources Symposium, Athens, Georgia. 1967. 531-536.
(Reprint)
Ferguson, D, E. and C. R. Bingham. 1966. Endrin resistance in
the yellow bullhead, Ictalurus natalis. Transactions of the
American Fisheries Society 95(3):325-326.
Ferguson, D. E., D. D. Culley, W. D. Cotton and R. P. Dodds.
1964. Resistance to chlorinated hydrocarbon insecticides in
three species of freshwater fish. Bioscience 14(l1):43-44.
Ferguson, D. E. and Caroline G. Gilbert. 1967. Tolerances of
three species of anuran amphibians to five chlorinated hydrocarbon insecticides. Journal of the Mississippi Academy of
Sciences 13:135-138.
Effects of DDT, toxaphene
and dieldrin on pheasant reproduction. Auk 73(4):529-539.
Genelly, R. E. and R. L. Rudd.
1956.
21
Heath, R. G. and Lucille F. Stickel. 1965. Protocol for testing the
acute and relative toxicity of pesticides to penned birds. In:
The effects of pesticides on fish and wildlife. Washington, D. C.
77 p. (U. S. Fish and Wildlife Service. Circular 226)
Holland, H. T., D. L. Coppage and P. A. Butler.
Increased
sensitivity to pesticides in sheepshead minnows. Transactions
of the American Fisheries Society 95(1):110-112.
1966.
Hunt, E. G. 1966. Studies of pheasant-insecticide relationships.
Journal of Applied Ecology, sup., 3:113-123.
1966. Levels of insecticide residues
in fish and wildlife in California. Transactions of the North
American Wildlife and Natural Resources Conference 3 1:150-
Keith, J. 0. and E. G. Hunt.
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APPENDIX
22
APPENDIX
Table 1. Chemical names of compounds mentioned in this thesis.*
Chemical Name
Compound
Aidrin
1, 4:5, 8-dimethanonapthalene, 1, 2, 3,4, 10, 10, hexachloro-1, 4, 4a, 5, 8, 80-hexahydro-endo, exo
Cygon
0, 0.-dimethyl ester, S-ester with 2-mercapto-Nmethylacetamide
Dibrom
1, 2-dibromo-2, 2-dichloroethyl dimethyl ester
Dieldrin
1, 4:5, 8-dimethanonaphthalene, 1, 2, 3, 4, 10, l0
hexachloro-6, 7-epoxy-i, 4, -4a, 5, 6, 7, 8, 8aoctahydro-endo, exo
Endrin
1, 4:5, 8-dimethanonaphthalene, 1, 2, 3, 4, 10, 10hexachloro-6, 7-epoxy-i, 4, -4a, 5, 6, 7, 8, Saoctahydro-endo, endo
Keithane
b enzhydrol, 4, 4'- dichloro-a - (trichloromethyl )-
Lindane
cyclohexane, 1, 2, 3, 4, 5, 6-hexachioro(V-isomer)
Malathion
diethyl ester, S-ester with 0, 0-dimethyl
phosphorodithioate
o,
' -
DDT
ethane, 1, 1, 1-trichioro- 2- (o-chlorophenyl)- 2(p- chiorophenyl)-
-
DDD
ethane, 1, 1 -dichloro- 2, 2-bis(p-chlorophenyl )-
-
DDE
ethylene, 1, 1-dichioro- 2, 2-bis(p-chlorophenyl)-
'-DDT
Systox
ethane, 1, 1, 1-trichloro-2, 2-bis(p-chlorophenyl)-
mixture of 0-[2-(ethylthio)ethyl]0, 0-dimethyl
ester and S- [2-(ethylthio )ethyl] 0, 0-dimethyl
ester
Technical DDT
ethane, 1, 1, 1 -trichloro- 2, 2-bis(p- chlorophenyl)-
(See formulation in text.
Toxaphene
chlorinated camphene containing 67-69% chlorine
*Chemical nomenclature follows that of American Chemical Society (1968).