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Group Title: Mimeo report - North Florida Research and Education Center ; 87-6
Title: Soybean seed protein, oil levels and stink bug genotypes in relation to weight, development and survival of southern green stink bug
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Permanent Link: http://ufdc.ufl.edu/UF00066061/00001
 Material Information
Title: Soybean seed protein, oil levels and stink bug genotypes in relation to weight, development and survival of southern green stink bug
Series Title: Research report (North Florida Research and Education Center (Quincy, Fla.))
Physical Description: 6 leaves : ; 28 cm.
Language: English
Creator: Calhoun, D. S ( D. Steven )
Funderburk, J. E ( Joseph E. ), 1954-
Teare, I. D ( Iwan Dale ), 1931-
North Florida research and Education Center (Quincy, Fla.)
Publisher: North Florida Reseach and Education Center
Place of Publication: Quincy Fla
Publication Date: 1987
 Subjects
Subject: Nezara viridula   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references.
Statement of Responsibility: by D.S. Calhoun, J.E. Funderbunk, and I.D. Teare.
General Note: Cover title.
 Record Information
Bibliographic ID: UF00066061
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 70003068

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SOYBEAN SEED PROTEIN, OIL LEVELS AND STINK BUG GENOTYPES

IN RELATION TO WEIGHT, DEVELOPMENT AND SURVIVAL

OF SOUTHERN GREEN STINK BUG







D. S. Calhoun, J. E. Funderburk, and I. D. Teare











University of Florida

North Florida Research and Education Center

Route 3 Box 4370

Quincy, Florida 32351









SOYBEAN SEED PROTEIN, OIL LEVELS AND STINK BUG GENOTYPES


IN RELATION TO WEIGHT, DEVELOPMENT AND SURVIVAL

OF SOUTHERN GREEN STINK BUG1/


D. S. Calhoun, J. E. Funderburk, and I. D. Teare2/



ABSTRACT
The influence of soybean seed protein and oil level on developmental time,
weight, and survival of southern green stink bug, Nezara viridula (L.), was
examined. Nymphs were reared from first instar to adult on a diet of rewetted
soybean seeds. The three soybean genotypes included in these experiments
ranged in protein content from 39 to 47% and in oil content from 15 to 22%.
The randomized complete block design used in the study considered nymphs from
a single egg mass (full sibs) as a block to remove the effect of stink bug
genotype in the analyses. Developmental times and weights of adults and
nymphs were similar to those reported by other researchers. Diet had a small
but significant effect on developmental time to second, third, and fourth
instar, with higher protein (lower oil) resulting in decreased developmental
time. Maximum differences from hatch to adult were only 2 days. Development-
al time, however, from hatch to fifth instar and adult was not significantly
affected by diet. Males and females had similar developmental times. Diet
had no effect on weights of nymphs, but a highly significant effect on adult
weights. Increasing seed protein resulted in greater adult weights of both
males and females. Females were significantly heavier than males from fourth
instar to adult. Stink bug genotype (blocks) significantly affected develop-
mental time and weight of all nymphal instars and adults. Survival was not
affected by diet or stink bug genotype.


Index Words: Nezara viridula, insect rearing, insect dietetics, insect geno-
type











Contribution from the Inst. of Food and Agric. Sci. Florida Exp. Stn., Univ.
of Florida, and the North Florida Res. and Educ. Ctr., Quincy, FL 32351.
Research Report NF 87-6.

3/Graduate Student of Agronomy, Assistant Professor of Entomology, and
Research Scholar/Scientist of Agronomy, respectively, Univ. of Florida.










INTRODUCTION


Plant breeders have for many years tried to increase oil and protein
content in soybean. A measure of success has been achieved in selecting for
high protein (Brim and Burton 1979) or high oil content (Burton and Brim
1981). However, the components are competitive, and selection for an
increased percentage of one results in decreased percentage of the other.

The relationship between seed yield and increased protein or oil content
has been the subject of much research, but the influence of altered nutrient
composition on insect pests of soybean has not been considered. Host nutrient
content has been shown to affect insect pests of other plants in terms of
feeding behavior, larval survival, adult weight, fecundity, and population
density (e.g., Schoonhoven 1972, Shaw and Little 1972, Bronson and Simpson
1966). Changes in protein and oil content may affect the biology of soybean
pests.

In the southeastern U.S., southern green stink bug (SGSB) Nezara viridula
(L.), is frequently a serious pest of soybean, reducing yield, seed quality,
and germination (Todd and Turnipseed 1974). Kester and Smith (1984) found
that diet affects adult female weight and fecundity of SGSB. Diets in the
study consisted of different species rather than nutrient content within a
single plant species.

The purpose of our study was to evaluate the impact of modifying soybean
seed protein content (and consequently oil content) on the biology of SGSB.
The specific objective was to quantify the influence of soybean seed protein
on developmental time, weight, and survival of male and female SGSB from first
instar to adult.

MATERIALS AND METHODS

Experimental design was a randomized complete block, with 10 SGSB per
treatment in each of 4 blocks. Blocks consisted of nymphs from a single egg
mass (each block from a different egg mass) shelved together in the incubator.
Thus, blocks accounted for genetic differences among the egg-mass cohorts.
Treatment diets were mature seed of the following soybean genotypes: 1)
non-nodulating 'Hardy', 2) normal 'Hardy', and 3) breeding line FL67-3673 with
low, intermediate, and high protein and high, intermediate, and low oil;
respectively. Seed of the three soybean genotypes included in the experiment
ranged in protein content from 39 to 47% and in oil content from 15 to 22%.
Seeds were placed on wet filter paper and refrigerated for 24 h to soften them
before offering to nymphs.

Egg masses were collected from soybean plants in the field. Within 24h
after hatching, each nymph was placed in a covered 100xl5mm petri dish which
had been lined with a moist filter paper and supplied with a single seed of
the appropriate genotype. Filter paper liners were pre-treated with benomyl
(100mg of a 50WP formulation in 100ml of water applied to 100 papers and
dried) to eliminate mold growth. Upon reaching fourth instar, nymphs were
transferred to 500 ml glass containers with benomyl-treated filter papers
lining the inside bottoms. Vertical paper strips were hung in the 500 ml
containers to aid in molting. Stink bugs were maintained at 25oC and 14:10
photoperiod for the duration of the life cycle. Observations were made and










seeds changed every 24h. Each nymph was weighed within 24h of molting, and
filter paper liners replaced. Data for each SGSB consisted of days to and
weight of each life stage and survival.

Treatments in the analyses involving days from hatching to each life
stage and weight of each life stage were a factorial arrangement of SGSB sex
and soybean seed protein/oil level. Treatment and block effects were
determined by analysis of variance, with treatment sum of squares partitioned
into the main effects of sex and seed composition and the interaction of
sex*seed composition. The effect of diet on survival was analyzed similarly
although no effect of sex was included.

RESULTS AND DISCUSSION

The effect of block, which was due primarily to genetic differences among
egg-mass cohorts, was highly significant in all cases. Since egg-mass cohorts
represent full sib families, there was a high degree of genetic similarity
within each cohort. This method of blocking removed a large amount of other-
wise random error. Thus, it was possible to detect treatment differences
which would have been masked by genetic differences without "cohort blocking".

Survival to adult was similar for each seed protein level. Survival for
high, medium, and low protein diets was 67.5, 72.5, and 65.0%, respectively.

Mean developmental times to second, third, fouth, and fifth instar and to
adult for males and females are given for each seed protein level in Table 1.
There was no effect of sex on developmental time at any life stage, and no
effect of sex*seed composition interaction on developmental rate. Seed protein
level had a small but significant effect on males and females for days
required to reach second, third and fourth instar, with increased protein
resulting in reduced time to each life stage. The effect on days to second
instar is surprising, because it is thought that first instar nymphs do not
feed (Bowling 1980). We have no explanation for this phenomenon, but note
that the difference is a maximum of 0.4 days. The maximum difference between
developmental times was 2 days for the third and fourth instar. By the fifth
instar there was no detectable difference in developmental time due to
treatment variables.

Mean weights at third, fourth and fifth instar and adult are given for
each protein level in Table 2. The effect of sex on weight was detectable
from the the third instar to adult, with adult males weighing an average of
77% as much as adult females. The effect of diet on weight was significant
only at the adult stage, with higher protein (lower oil) diets resulting in
heavier adults. Kester and Smith (1984) found a significant effect of diet
during the fifth stadium on adult weight of female SGSB.

Developmental rate and weight were affected by SGSB genotype, and blocking
according to individual egg masses reduced random error due to individual
genetic differences in our experiment. Similar designs would improve pre-
cision in future experiments involving SGSB biology and may be beneficial in
reducing random error in experiments involving insects in general.

Male and female SGSB had similar developmental times, but different
weights from fourth instar to adult. Diet had a small effect on developmental










time from hatch through fourth instar, with higher protein (lower oil) result-
ing in decreased developmental time. Increasing seed protein also resulted in
greater weights of adult males and females. Females reared on high protein
seeds weighed > 10% more than females reared on seeds with standard protein
content. Though we did not measure fecundity in this study, it is reasonable
to assume that heavier females are more fecund. Changes in soybean seed
composition obviously will affect the biology of pests, and this should be a
consideration when breeding for increased seed protein or oil.


LITERATURE CITED

Bowling, C. C. 1980. The stylet sheath as an indicator of feeding activity by
the southern green stink bug on soybeans. J. Econ. Entomol. 73:1-3.

Brim, C. A., and J. W. Burton. 1979. Recurrent selection in soybean. I.
Selection for increased percent protein in seed. Crop Sci. 19:494-498.

Burton, J. W., and C. A. Brim. 1981. Recurrent selection in soybean. II.
Selection for increased percent oil in seed. Crop Sci. 21:31-34.

Bronson, T. F., and R. G. Simpson. 1966. Effects of nitrogen deficient hosts
and crowding on the corn leaf aphid. J. Econ. Entomol. 59:290-293.

Harris, V. E., and J. W. Todd. 1980. Duration of immature stages of the
southern green stink bug, Nezara viridula, with a comparative review of
previous studies. J. Georgia Entomol. Soc. 15:109-114.

Kester, K. M., and C. M. Smith. 1984. Effects of diet on growth, fecundity and
duration of tethered flight of Nezara viridula. Entomol. Exp. Appl.
35:75-81.

McPherson, R. M., L. D. Newsom, and B. F. Farthing. 1979. Evaluation of four
stink bug species from three genera affecting soybean yield and quality
in Louisiana. J. Econ. Entomol. 72:188-194.

Schoonhoven, L. M. 1972. Some aspects of host selection and feeding in
phytophagaous insects, pp.557-566. In J. G. Rodreguez (ed.) Insect and
Mite Nutrition. North-Holland Pub. Co.

Shaw, G.G., and G. H. A. Little. 1972. Effect of high urea fertilization of
balsam fir trees on spruce budworm development. p.589-597. In J. G.
Rodreguez (ed.) Insect and Mite Nutrition. North-Holland Pub. Co.

Todd, J. W., and S. G. Turnipseed. 1974. Effects of southern green stink bug
damage on yield and quality of soybean. J. Econ. Entomol. 67:421-426.



ACKNOWLEDGEMENTS

The authors would like to express appreciation to Drs. K. Hinson, D. C.
Herzog, and A. R. Zimet for their invaluable help in supplying materials and
technical guidance for this research.










Table 1. Mean number of days at 250C from hatch to second, third, fourth,
and fifth instar and to adult for southern green stink bugs
according to sex and diet of soybean seed at three protein levels.

MEAN NO. DAYS TO DEVELOP (+SE)
SEX, PROTEIN LEVEL INSTAR II INSTAR III INSTAR IV INSTAR V ADULT

MALES
HIGH PROTEIN 3.3(0.2) 9.1(0.2) 13.6(0.3) 20.0(0.6) 28.3(0.7)
MEDIUM PROTEIN 3.6(0.2) 9.6(0.2) 14.5(0.4) 20.4(0.5) 28.7(0.6)
LOW PROTEIN 3.7(0.2) 10.4(0.6) 15.2(0.8) 20.7(0.6) 29.5(0.8)
FEMALES
HIGH PROTEIN 3.4(0.2) 8.6(0.2) 13.3(0.2) 19.3(0.4) 28.7(0.9)
MEDIUM PROTEIN 3.6(0.3) 9.4(0.3) 14.2(0.4) 21.6(0.8) 31.2(1.1)
LOW PROTEIN 3.7(0.3) 10.8(0.8) 15.2(1.1) 20.3(0.6) 29.9(1.2)
ANOVA SOURCE
SEX(ldf) NS NS NS NS NS
PROTEIN LEVEL(2df) ** NS NS
SEX*PROTEIN LEVEL(2df) NS NS NS NS NS
BLOCK(3df) ** ** ** ** **
NS = not significant at the 0.05 level according to an F test
* = P < 0.05 according to an F test
** = P < 0.01 according to an F test



Table 2. Mean weights (mg) of third instar, fourth instar, fifth instar,
and adult southern green stink bugs according to sex and diet of
soybean seed at three protein levels.
WEIGHT IN mg (+SE)
SEX, PROTEIN LEVEL INSTAR III INSTAR IV INSTAR V ADULT
MALES
HIGH PROTEIN 5.2(0.3) 16.7(1.2) 54.7(3.2) 131.2(3.6)
MEDIUM PROTEIN 4.3(0.3) 15.1(1.3) 50.5(3.3) 126.3(4.1)
LOW PROTEIN 5.0(0.4) 15.2(1.0) 55.7(5.2) 124.3(6.7)
FEMALES
HIGH PROTEIN 4.6(0.5) 19.3(1.2) 62.0(4.0) 182.2(8.6)-
MEDIUM PROTEIN 4.4(0.4) 16.6(2.0) 60.9(5.8) 160.5(9.1)
LOW PROTEIN 5.5(0.6) 17.6(1.5) 60.1(4.8) 153.0(9.5)
ANOVA SOURCE
SEX(ldf) NS ** ** **
PROTEIN LEVEL(2df) NS NS NS *
SEX*PROTEIN LEVEL(2df) NS NS NS NS
BLOCK(3df) ** ** ** **
NS = not significant at the 0.05 level according to an F test
* = P < 0.05 according to an F test
** = P < 0.01 according to an F test




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