   

___

r/UL 1

BULLETIN

THE TEXAS AGRICULTURAL EXPERIMENT STATION/ J. E. Miller, Director! Texas A&M University/ College Station, Texas

Liﬁinigg/

B-1161
February 1976

: f-“p.

‘Tex ( q   .
Effects of Temperature and Host 1531'??? M Unit/erg] 
on Population Dynamics of the Cotton Fleahoppeity,

Pseudatomoscelis seriatus
Michael I’. Gaylor and Winfield L. Sterling*

ABSTRACT

Host plants and temperature had a great inﬂuence
on population dynamics of the cotton ﬂeahopper,
Pseudatomoscelis seriatus (Reuter). The longest life ex-
pectancy calculated was 4.91 weeks for newly depo-
sited eggs at 23.9 degrees C (75 degrees F). Net repro-
ductive rates per generation (R0) ranged from about 40
for ﬂeahoppers reared on ﬂowering croton at 26.7
degrees C (80 degrees F) to 1.6 for ﬂeahoppers reared
on beans and potatoes at 35.0 degrees C (95 degrees F).
The shortest mean generation time (Tc) was 3.87 weeks
on ﬂowering croton at 26.7 degrees C, but comparable
values were obtained for groups of ﬂeahoppers reared
on spotted beebalm at 26.7 degrees C and on beans
and potatoes at 29.4 degrees C. A cotton ﬂeahopper
population reared on ﬂowering croton at 26.7 degrees
C for 10 weeks could theoretically increase to over
13,000 females for each female present at week one.

INTRODUCTION

Many studies have been conducted to determine
effects of environmental parameters on insect popula-
tion dynamics. The effects of temperature on the biol-
ogy of insects probably have been investigated as
thoroughly as the effects of any other environmental
parameter. However, most studies to determine ef-
fects of temperature on the biology of insects have
dealt with effects on developmental rates (Strong and
Sheldahl1970, Philipp and Watson 1971, Siddiqui and
Barlow 1972). Fewer papers have reported effects of
temperature on growth of insect populations (Birch
1953, Strong and Sheldahl 1970, Philipp and Watson
1971, Siddiqui and Barlow 1972). Effects of tempera-
ture on developmental rates, survival, and fecundity
of the cotton ﬂeahopper, Pseudatomoscelis seriatus (Re-
uter), were reported, by Gaylor and Sterling (1975).

It has long been ‘recognized that food may inﬂu-
ence insect biological processes (Andrewartha and
Birch 1954). However, quantitative studies dealing
with effects of host plants on insect development are
fewer than studies dealing with effects of temperature

*Graduate research assistant and associate professor, respectively.

(Van Emden and Way 1971). Brazzel and Martin (1957)
found that mortality of young larvae and fecundity of
female pink bollworms, Pectinophora gossypiella, were
inﬂuenced by the growth stage of the host plant.
Gaylor (1975) found that developmental rates,
mortality, and fecundity of the cotton ﬂeahopper were
inﬂuenced by species as well as growth stage of host
plant. Drooz (1971) reported that species and maturity
of host plants on which adult elm spanworms, En-
nomos subsignurius, fed affected fecundity, develop-
mental rates, and size of offspring in the F2 generation.
Maturity of the "ideal" host had less effect than matur-
ity of less ideal hosts.

Birch (1953) reported effects of two kinds of stored
grain on entire populations of two species of stored
grain pests. However, in Birch's study one pest was
not normally found in one of the grains. Similarly, the
other pest was not normally found in the second kind
of grain. Effects of ”normal” hosts onentire popula-
tions of insects have not been well studied.

The innate capacity for increase (rm) of insects has
been used as an indicator of population change (Birch
1953, Philipp and Watson 1971, Siddiqui and Barlow
1972). Andrewartha and Birch (1954) presented a sim-
ple approximation of rm. Laughlin (1965) called the
approximation the "capacity for increase,” rc, and
showed that it could be used as a valuable indicator of
population growth. The statistic, Tc, is calculated by
the log formula:

n: lOge R0
Tc
where R0: net reproductive rate per generation and
T¢= generation time. Strong and Sheldahl (1970) used
re to indicate the ”fitness" of the genotype to the envi-
ronment.

Values of re for a given population in a given envi-
ronment depend on fecundity, survival, and de-
velopmental rates of individuals in the population.
Effects of host plants on cotton ﬂeahopper fecundity,
survival, and developmental rates have been investi-

gated under various constant temperature conditions
(Gaylor 1975). However, effects of temperature and
host plants on growth of cotton ﬂeahopper popula-
tions have not been reported.

METHODS AND MATERIALS
Data used by Gaylor and Sterling (1975) to deter-
mine the effects of temperature and host plants on
development, fecundity, and mortality were used to
develop survivorship and age-specific fecundity
curves for the cotton ﬂeahopper. The way these data
were obtained has been described (Gaylor and Sterl-
ing 1975). Net reproductive rates, R0, generation
times, Tc, capacities for increase, n, and ﬁnite rates of
increase per day,)\, were calculated from survivorship
and age-speciﬁc fecundity curves.
Curves were developed for populations reared on
green beans and potatoes under 23.9, 26.7, 29.4, and
35.0 degrees C constant temperature regimens. Beans
and potatoes are not ”normal” ﬂeahopper food for
naturally occurring ﬁeld populations. However, de-
velopmental rates of ﬂeahoppers reared on beans and
potatoes (Gaylor and Sterling 1975) were comparable
to developmental rates of ﬂeahoppers reared on the
normal hosts, spotted beebalm, Monarda punctata L.,
cutleaf evening primrose, Oenothera laciniata Hill, and
cotton, Gossypium hirsutum L., in pre-ﬂowering
growth stages (Gaylor 1975). Survival rates were
much higher on beans and potatoes than on "nonnal”
hosts in pre-ﬂowering growth stages. Since survival to
the adult stage was very low on pre-ﬂowering spotted
beebahn, cutleaf primrose and cotton, fecundity on
these hosts was not determined. However, based on
survival and developmental rates, it appears that
population growth on beans and potatoes would be at
least as rapid as on pre-ﬂowering spotted beebalm,
primrose and cotton. Survivorship and age speciﬁc
fecundity curves also were developed for populations
reared on ﬂowering croton and ﬂowering spotted
beebalm at a constant 26.7 degrees C temperature
regimen.
Life expectancy tables were calculated for each
population in the manner reported by Deevey (1947)
and summarized by Southwood (1966).

RESULTS AND DISCUSSION

Much higher fecundity rates occurred in ﬂeahop-
per cohorts reared on ﬂowering croton and spotted
beebalm than’ in those reared onbeans and potatoes
(Figure 1). Peak egg deposition occurred earlier on
normal hosts than on beans and potatoes, and high
rates of egg deposition were maintained longer on
croton than on spotted beebalm. Not only were more
eggs deposited on normal hosts than on beans and
potatoes, but Gaylor (1975) reported a higher percent-
age of females (about 75 percent) became adults on
ﬂowering croton and spotted beebahn than was re-
ported (Gaylor and Sterling 1975) on beans and
potatoes (about 50 percent). Thus, the number of
female eggs deposited per female (mx) on beans and
potatoes was found by multiplying the total eggs dep-

2

  
 
  
   
    
    
  
 
 
  
   
   
  
 
  
   
 
 
 

i

osited by 0.50. On spotted beebalm and croton 1
values were obtained by multiplying the total num;
of eggs deposited by 0.75. ~
Peak egg deposition was lower on beans a
potatoes under a 29.4 degrees C temperature regim
than under other temperature regimens, but egg de’
osition occurred earlier under the 29.4 degrees C r g
men. Also, the percentage of adiilt ﬂeahoppers survi
ing during egg deposition was higher at the 29.4 d,
grees C regimen than in other temperatures. In 
cohorts some adult ﬂeahoppers survived for consid ]
able periods of time after the last egg was deposit__
Most of these surviving adults were unmated i v
viduals in individual cages. The unmated individu i
were included in survivorship (1x) curves because -
fects of mating and crowding on ﬂeahopper survival
test cages is unknown. V~
Gaylor and Sterling (1975) showed that so V’
ﬂeahoppers could survive for more than 10 wee 4
when reared on beans and potatoes at 23.9 degrees if
However, the longest life expectancy of ﬂeahoppe i
was obtained for a newly depositied egg on beans a 
potatoes at 23.9 degrees C (Table 1). '
Egg mortality was not determined until hatchin
Mean time from deposition to hatching for all coho ;
was between 2 and 3 weeks (Gaylor 1975). Thus, a
mortality was observed during week 1 in all cohort
Therefore, life expectancy during week 1 in all coho 5 a
was artiﬁcially high (Tables 1-6). Similarly, all e ;_
mortality, as well as early nymphal mortality, w
calculated as occurring during week 2. Therefore, 
expectancy in all cohorts was artiﬁcially low durin
week 2 (Tables 1-6).
High mortality occurred during egg and earl
nymphal life in all cohorts except those reared 0
beans and potatoes at 29.4 degrees C (Figure 1). Thus
life expectancy decreased for nymphs at the beginnin
of the 2nd week of life and increased during the 3r‘

TABLE 1. LIFE TABLE FOR COMPUTING LIFE EXPECTANCYjl
o|= COTTON FLEAHOPPERS REAR ED ON BEANS AND
POTATOES AT 23.9°cl/

X 1x dx ex
1 1000 0 4.91
2 1000 341 3.91
3 s59 1o 4.67
4 s49 10s 3.74
5 541 s2 3.3s
s 459 1s 2.90
7 as1 s2 2.39
s 299 119 1.90
9 1s0 so 1.s3

10 120 30 1 .50
11 90 s0 0.83
0.50

12 30 30

U X= pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of 1000 eggs; ex = expectation of further life in weeks.

100
75
5O
25

100
75
5O
25

1OO
75
5O

25

1OO
75
5O
25

1OO
75
5O
25

SURVIVAL RATE (Ix)

1OO
75
5O
25

Figure 1.

[T T 1 I I I I I

 

 

  
     

 
  
  
 

  

 

10.00

w| aEANss. POTATOES 7.50
m 35.o°c
5% ' |x 
6|  2.50
8: 0.00
' I I I I ‘ 10.00
w BEANS s. POTATOES 7.5O
g if“ 5.00
‘n '""'"' 2.50
o
8 0.00
I 1 I l 10.00
| BEANS a POTATOES 1 7.50
é‘. gomc q 5.00
5| 
B: 0.00
ll l l l l l l l l 
' BEANS a POTATOES 7.5O
§; ff“: 5.00
o: ""‘"" 2.50
E3‘ _\ 0.00
‘l | l I I I j l I l 
m|   FLOWERING SPOTTED BEEBALM 7.5O
i}: ' ffff 5.00
o: '""'"' 2.50
8| H Li? o0 
ll l : l l l l l I l 1Q,QQ
' FLOWERING CROTON 7.50

   

3, H  2¢>.7°c

ff o H‘ |x

0' mx....

9i

ll l l l 1 l 1 I L
j1O 2O 3O 4O 5O 6O 7O 8O 9O

DAYS

5.00
2.50
0.00

FEMALE EGGS PER FEMALE (mx)

Effects 0f temperature and host plants 0n cotton ﬂeahopper survival and age-specific fecundity rates. _ The survival rate (1 x)
is the percentage surviving, and mx values are the number of female eggs deposited per female.

3

TABLE 2. LIFE TABLE FOR COMPUTING LIFE EXPECTANCY
OF COTTON FLEAHOPPERS REAR ED 0N BEANS AND
POTATOES AT 26.7°cl/

X 1x dx ex
1 1000 0 4.67
2 1000 369 3.67
3 631 19 4.52
4 612 21 3.64
5 591 44 2.76
6 547 209 1.94
7 338 91 1.83
8 247 129 1.31
9 118 71 1.20
10 47 23 1.27
11 24 12 1.00
12 12 12 0.50

J X = pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of 1000 eggs; ex = expectation of further life in weeks.

TABLE s. LIFE TABLE FOR COMPUTING LIFE EXPECTANCY
OF COTTON FLEAHOPPERS REARED ON BEANS AND
POTATOES AT 29.4°cl/

X 1x dx ex

1 1000 0 4.40
2 1000 127 3.40
3 873 0 2.82
4 873 159 1.82
5 714 433 1.11
6 281 158 1.06
7 123 88 0.78
8 35 35 0.50

l! X = pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of 1000 eggs; ex = expectation of further life in weeks.

TABLE 4. LIFE TABLE FOR COMPUTING LIFE EXPECTANCY
OF COTTON FLEAHOPPERS REAR ED 0N BEANS AND
POTATOES AT 35.o°cl/

X 1x dx l ex

1 1000 0 2.59
2 1000 580 1.59
3 420 49 2.10
4 371 155 1.31
5 216 150 0.88
6 66 49 0.76
7 17 17 0.50

week of life. Fleahopper cohorts reared on beans and Y

potatoes at 29.4 degrees C did not experience high egg ;

and early nymphal mortality. In this cohort, life expec- 
tancy decreased as ﬂeahoppers aged. With one excep- 

tion, under all conditions tested, life expectancy was

greatest when nymphs had just emerged from eggs 
(Tables 1-6). Fkleahoppers reared on beans and g
potatoes at 29.4 degrees C (Table 3) were an exception »
and this was due to relatively high egg survival under _l

these conditions (Gaylor and Sterling 1975).

The host plant on which ﬂeahopper populations 

were reared had a great effect on ﬂeahopper reproduc-

tion rates. Net reproduction rates per generation ( ') §
were higher for populations reared on ﬂowering cro- .

ton than for cohorts reared on other hosts (Tables

7-12). The R0 value for populations reared on croton A

(Table 7) was almost 4 times greater than for popula-

tions reared on beans and potatoes at the same tem- 
perature (Table 10). The net reproductive rate also was f

much greater (about 2X) on ﬂowering spotted beebalm T

(Table 8) than on beans and potatoes under the same p,
temperature regimen. The R0 value was greater in the 
26.7 degrees C regimen than in all other temperatures ,

(Table 10). The lowest R0 value for ﬂeahoppers reared 5
on beans and potatoes (Table 12) was about 16 percent 

of the net reproduction rate at 26.7 degrees C on beans 

and potatoes (Table 10).

Mean generation times, Tc, also were affected by 

temperature and host plants. The T.- was about 1 week A '

longer on beans and potatoes at 23.9 degrees C (Table 

9) than on the same host at 26.7 degrees C (Table 10). 
The shortest generation time was on ﬂowering croton 
(Table 7), but comparable Tc values were observed on
spotted beebalm at 26.7 degrees C (Table 8) and on é

beans and potatoes at 29.4 degrees C (Table 11).

Using I'c as the criterion of suitability (Strong and l

Sheldahl 1970), ﬂowering croton was the best host 3

(Table 7), followed by ﬂowering spotted beebalm (Ta- 
ble 8). The most suitable temperature for populations 
reared on beans and potatoes was 26.7 degrees C 11

(Table 10).

TABLE s. LIFE TABLE FOR COMPUTING LIFE EXPECTANCY
OF COTTON FLEAHOPPERS REAR ED 0N FLOWERING
CROTON AT 2s.7°cl/

X 1x dx ex

1 1000 0 3.88
2 1000 - 361 2.88
3 639 44 3.22
4 595 102 2.42
5 493 280 1 .82
6 213 30 2.56
7 183 37 1.90
8 146 36 1.25
9 1 1O 1 10 0.50

U X = pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of 1000 eggs; ex = expectation of further life in weeks.

4

l/ X = pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of"1000 eggs; ex = expectation of further life in weeks.

   

‘ff-TABLE 6. LIFE TABLE FOR COMPUTING LIFE EXPECTANCY
f1 OF corrow FLEAHOPPEFIS REARED ON FLOWER mo
 SPOTTED BEEBALM AT 26.7°cll

X 1x dx ex

1 1000 0 3.25
2 1000 363 2.25
3 637 109 2.25
4 528 142 1.62
5 386 217 1.03
6 169 152 0.70
7 17 g 0 1.50
8 17 17 0.50

U X = pivotal age in weeks; 1x = number surviving at beginning of
age interval out of 1000 eggs; dx = number dying in age interval
out of 1000 eggs; ex = expectation of further life in weeks.

TABLE 7. LIFE AND AGE-SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REARED ON FLOWERING CROTON
AT 26.7°C

Pivotal age Proportion alive Y no. female eggs/
in weeks (X) from 100 eggs (1x) female/week (mx) 1xmx

1 .5 .639  
2.6 .639 0.45 0.28s
3.5 .556 43.65 24.2694
4.6 .406 37.13 16.0377
5.5 .222 0.00 0

R0 = 39.6961 y

R0 = Net reproductive rate per generation = Zixmx
Tc = Generation time in days =Z1xmxX/Z1xmx = 3.8725
rc = Capacity for increase = logeRo/Tc = 0.9500

A = Finite rate of increase per day = antilog rc = 2.5856

TABLE 8. LIFE AND AGE SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REARED ON FLOWEFIING SPOTTED

Finite rates of increase per female per day were
calculated by:

A = antilog r5

as described by Andrewartha and Birch (1954). Rates
of increase per week ranged from 1.3905 on beans and
potatoes at 23.9 degrees C (Table 9) to 2.5856 on ﬂow-
ering croton at 26.7 degrees C (Table 7).

Finite rates of increase for insect populations do
not remain constant for extended periods (Sterling
and Adkisson 1970). However, A values are useful in
demonstrating population growth rates under
speciﬁed conditions. Population growth potentials
under different conditions are clearly demonstrated
when ﬁnite rates of increase per week are extrapolated
over time. After 10 weeks at 26.7 degrees C on ﬂower-
ing croton, a ﬂeahopper population with a A value of
2.5856 would increase to over 13,000 females for each
female present at week 1 (Figure 2). After 10 weeks on
beans and potatoes at 26.7 degrees a population would
increase to less than 200 females for each female pre-
sent at week 1. The difference between potential popu-
lation size for fleahoppers reared on beans and
potatoes at 35.0 degrees C and 26.7 degrees C was
much less than the difference when reared on beans
and potatoes at 26.7 degrees C and reared on ﬂower-
ing croton at the same temperature. Thus, host plants
have a great inﬂuence on potential ﬂeahopper popula-
tion size.

Cotton fleahopper populations migrate from host
to host throughout the summer (Reinhard 1926,
Thomas 1936, Almand 1974). However, Eddy (1927)
reported that ﬂeahoppers could be found on croton
throughout the growing season. He concluded that
populations on croton might be a source of ﬂeahop-
pers for continual infestations in cotton. Results of the

TABLE 9. LIFE AND AGE SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REARED ON BEANS AND POTATOES
AT 23.9°C

Pivotal age Proportion alive X no. female eggs/
BEEBALM AT 261°C in weeks (X) from 100 eggs (1x) female/week (mx) 1xmx
Pivotal age Proportion alive Y no. female eggs/ 2.5 .659 - - - - - - - - --
in weeks IX) from 100 eggs (1x) female/week (mx) 1xmx 3.5 .597 - - - - - - - - --

4.5 .529 .76 .4020
1 .5 .659 -—-- ----- 5.5 .447 1 1 .10 4.9617
2.5 .661 ----- ----- 6.5 .381 2.14 0.8153
y? 3.5 .512 29.91 15.3139 7.5 .226 1.05 0.2373

“j 4.5 .306 29.13 8.9138 8.5 .154 0 0

5.5 .076 4.05 0.3078 9.5 .105 0 0

6.5 .028 0 0 10.5 .090 0 0

7.5 .028 0 0 1 1.5 .030 0 0
R0 = 24.5355 Flo = 6.4164

R0 = net reproductive rate per generation = Z1xmx
Tc =/'generation time in days = Z1xmxX/Z1xmx = 3.8884
rc = capacity for increase = logeBo/Tc = 0.8230

A = finite rate of increase per day = antilog rc = 2.2773

R0 = Net reproductive rate per generation = Z1xmx
Tc = generation time in days = Z1xmxX/Z1xmx = 5.6383
rc = Capacity for increase = logeRO/Tc = 0.3297

A = Finite rate of increase per day = antilog rc = 1.3905

10000_
1,000 _

100 r

NUMBERS OF FLEAHOPPERS

I 1 . .
WEEKS 1 ,2 3 4

Figure 2.

Exponential rates 0f increase for cotton ﬂeahopper populations reared under different temperature and host plant conditions. _

present study tend to support this conclusion, since
ﬂowering croton is a suitable host plant. However,
populations also may increase to high levels on other
native host plants such as spotted beebalm. Results of
the present study and earlier studies (Gaylor and

ACKNOWLEDGMENTS

35.0°C

BEANS a POT noes-

l l

5 c6

789

Sterling 1975) indicate that ﬂeahopper populations p‘
would not increase to high levels on cotton. Damaging ,
infestations probably result from migration into cotton  .

from native hosts.

Research herein is part of a Ph.D. dissertation
submitted in partial fulﬁllment of degree requirements
at Texas A&M University in cooperation with the Ag-
ricultural Research Service, USDA. This research was
supported in part by the National Science Foundation
and the Environmental Protection Agency, through a
grant (NSF GB-34718) to the University of California.

6

The ﬁndings, opinions, and recommendations ex- i
pressed herein are those of the authors and not neces- .
sarily those of the University of California, the Na- _'
tional Science Foundation or the Environmental Pro-  ,

tection Agency. This paper was approved for publica-

tion as Bulletin 1161 by Director, The Texas Agricul- ;_

tural Experiment Station, February 1976.

10

TABLE 10. LIFE AND AGE-SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REARED ON BEANS AND POTATOES
AT 267°C

Pivotal age Proportion alive Yno. female eggs/
in weeks (X) from 100 eggs (1x) female/week (mx) 1xmx

1 .5 .679  ---
2.5 .622 - - - - - - - - --
3.5 .601 1.93 1.1599
4.5 .569 11.34 6.4525
5.5 .448 5.36 2.4013
6.5 .327 0 0
7.5 .200 0 0
8.5 .082 o 0
9.5 .024 0 0

10.5 .024 0 0

11.5 .012 0 0

R0 = Net reproductive rate per generation = Z1xmx

Tc = Generation time in days =Z1xmxX/Z1xmx = 4.6240
rc = Capacity for increase = logeRO/Tc = 0.4983

X = Finite rate of increase per day = antilog rc = 1.6459

TABLE 11. LIFE AND AGE-SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REAR ED ON BEANS AND POTATOES
AT 29.4°C

Pivotal age Proportion alive Y no. female eggs/
in weeks (X) from 100 eggs (ix) female/week (mx) 1xmx

1 .5 .901  ----
2.5 .873 - - - - - - - - --
3.5 .873 5.43 4.7404
4.5 .515 3.28 1.6892
5.5 .179 0 0

6.5 .054 0 0

7.5 .036 0 o

R0 = Net reproductive rate per generation = Z1xmx
Tc = Generation time in days = Z1xmxX/Z1xmx = 3.7627
rc = Capacity for increase = IogeFio/Tc = 0.4946

l = Finite rate of increase per day = antilog rc = 1.6398

TABLE 12. LIFE AND AGE SPECIFIC FECUNDITY TABLE FOR
COTTON FLEAHOPPERS REARED ON BEANS AND POTATOES
AT 350°C

Pivotal age Proportion alive Y no. female eggs/
in weeks (X) from 100 eggs (1x) female/week (mx) 1xmx

 

?

1.5 .471 _ - 4 - - - - - - --
2.5 .403 - - - - - - - - --
3.5 .331 2.6100 .8639
4.5 .116 5.2400 .6078
5.5 .025 5.4000 .1350
6.5 .006 0 0

no = 1.6068

R0 = net reproductive rate per generation = Z1xmx

Tc = Generation time in days = Z1xmxX/Z1xmx = 4.0461
rc = Capacity for increase = IogeRo/"FC = 0.1172

A = Finite rate of increase per day = antilog rc I 1.1244

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the cotton ﬂeahopperin certain host plants. Ph.D. Dissertation.
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Andrewartha, H. G. and L. C. Birch. 1954. The distribution and
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Birch, L. C. 1953. The inﬂuence of temperature, moisture and food
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Brazzel, I. R. and D. F. Martin. 1957. Oviposition sites of the pink
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Drooz, A. T. 1971. The elm spanworrn (Lepidoptera: Geometridae):
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Eddy, C. O. 1927. The cotton ﬂeahopper. S. C. Agric. Exp. Stn. Bull.
235. 21 p.

Gaylor, M. I. 1975. Effects of temperature, host plants, photoperiod
and rainfall on population dynamics of the cotton fleahopper,
Pseudatomoscelis seriatus (Reuter). Ph.D. Dissertation. Texas
A&M University.

Gaylor, M. I. and W. L. Sterling. 1975. Effects of temperature on the
development, egg production, and survival of the cotton
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Laughlin, R. 1965. Capacity for increase: a useful population 
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