FECUNDITY, FERTILITY, AND LONGEVITY OF MATED
AND UNMATED SPINED SOLDIER BUG FEMALES 1.2
A. M. Baker and P. L. Lambdin 3
Department of Entomology end Plant Pathology
University of Tennessee
Knoxville, TN 37901
Abstract: Expressed fecundity occurred in Podisus maculiventris (Say) females always paired
with males and in those which had been paired for 48, 96. 144, and 192 h. Egg cluster size
frequencies and modes were not significantly different. among mated females. No significant
differences were found among the mean cumulative or daily fecundity rates for any females,
indicating that fecundity waR not affected by the amount of time they were paired with
males. There was no peak or subsequent daily decline in fertility corresponding to the
duration of the experimental period. Mean fertilities of never-paired and paired females
differed significantly. The nverage life spans of always paired and virgin females were
significantly different, but increasing paired time from 48 - 192 h did not contribute to
reduced longevity.
Key Words: Spined soldier bug, Podisus macuJiuenlris, insect rearing, penlotomid.
J. Agric. Entomol. 2(4): 378-382 (October 1985)
Podisus maculiuentris (Soy), the spined soldier bug, is an indigenous predator
commonly found throughout North America east of the Rocky Mountains. Although
this predator has been evaluated against several forest and field crop pests
(Waddill and Shepard 1975; )gnoffo et aL 1977; Marston et aL 1978; Ables and
McCommas 1982; Mukerji and LeRoux 1965), its effectiveness as a biocontrol
agent has not been well established. The potential value of P. maculiuentris as a
biocontrol agent has stimulated evaluation of various aspects of its life history and
bionomics ()<irkland 1897; Whitmarsh 1916; Landis 1937; Esselbeugh 1948;
Mukerji and LeRoux 1965, 1969a, 1969b; Warren and Wallis 1971).
In studies on the reproductive capacity of labortory-reared P. maculiuentris,
Couturier (1938) suggested that oviposition continued until death of the female
provided she was kept with a male. Mukerji and LeRoux (1965) found that
females became sexually mature within 24 h after adult emergence, could mate as
many as 7 to 10 times during a life span, and were polygnmous. They predicted
that the number of fertile eggs laid depended upon the number of rnatings and the
length of life. Warren and Wallis (1971) supported those findings and suggested
that removal of a male from a cage containing n fertile female would result in a
decrease followed by cessation of fertility.
Youther and McPherson (1975) found that multiple copulations by the brown
stink bug, Euschistus serous (Say), had no effect on fecundity or fertility over an 8 wk
period, and reported no significant differences in fecundity for females once­
mated, twice-mated, thrice-mated, and mated-far-life. Similar data were reported
for fecundity of once-mated and always-mated female rice stink bugs, Oebalus
pugnax (Fabricius) (Nilakhc 1976). Significant differences were found between
1 Podisus macufiuenlris (Say) (HEMIPTERA: Pentatomidae).
2 Received for publicati9n 16 Moy 1985; accepted 15 October 1985.
3 Graduate assistant.. and Professor, respectively. Uni..·. of Tenn. Knoxville, TN 37901.
378
BAKER and LAMBOrN: Reproducti\'ity and Longevity of P maculiuentris
379
fecundity of mated females and unmated females for the southern green stink bug,
Nezara uiridu.la- (Linnneus), (Mitchell and Mau 1969) and the brown stink bug
(Youth.r and McPherson 1975), but not for rice stink bug females (Nilakhe 1976).
In some species, a single copulatory act may provide the female with sufficient
sperm to fertilize most of the eggs produced and may be the stimulus for both
oogenesis and oviposition. Thornhill and Alcock (I983) indicated that in many
insects, including some pentatomids, a polygamous nature resulted from convenience,
not requiremenl
Unmated females of several species have been repolted to have longer liIespans
than their mated counterparts (Lener 1967; Mitchell and Mau 1969; and Youther
and McPherson 1975) with differences as great as 50% in some species.
The objective of this experiment was to determine the effect that variable
expOSUl'e periods with males had on fecundity, fertility, and longevity of spined
soldier bug females, as a means of establishing a more efficient rearing procedure
for the predator.
MATERIALS AND METHODS
Laboratory conditions used to rear P. maculiuentris were modified from those
established by Mukerji and LeRoux (1965). Colonies of the greater wax moth,
Galleria mellonella (Linnaeus), were maintained to provide a constant source of
live food. \Vax moth larvae were reared on a commercially prepared diel One
6th or 7th instar was provided daily to each spined soldier bug. Specimens were
reared in plastic petTi dishes (l00 X 15 mm) beneath an artificial light fixture.
Each dish contained a filter paper lining and a shell vial (12 X 35 mm) filled with
distilled water and plugged with cotton. The order in which petri dishes were
stacked was alternated daily throughout the experiment. All spined soldier bugs
were maintained at 27 - 30°F, 40 - 50% RH, and 16L:8D photophase.
Treatment groups consisted of 2-d-old adult P. maculiuentris females as follows:
treatment I, 10 females always paired with males; treatment 2, five females never
paired; treatments 3, 4, 5, and 6, five females each, paired with males for 48, 96,
144, and 192 h, respectively. The sample size was doubled in treatment 1 to
compensate for expected reductions in non-zero observations since always paired
females had a greater threat of male cannibalism. Those eggs occasionally laid
beyond the main group were considered part of the cluster. Eggs were removed
daily and transferred to a new dish where they were observed for ecIosion.
Tests were run for 35 d with each test replicated three times. Numbe,r of eggs
laid and number of eggs hatched were counted daily. Fecundity refers to expressed
fecundity rather than oocyte production while fertility refers to the actual
reproductive capacity 8S measured by the production of viable offspring. Longevity
was determined through daily observations and by recording the number of days
each insect lived.
All statistical values were computer generated by means of SAS82. Cluster size
frequencies and modes were calculated from number of eggs laid using a frequency
procedure to tabulate the number of times each cluster size occurred. Means and
ranges were calculated for each variable (number of eggs laid, number of eggs
hatched, number of days lived). Analysis of variance was done with a general linear
models procedure, and least significant ranges were calculated for each of the
variables using Duncan's new multiple range test for mean separation.
J. Agric. EntomoL Vol. 2, No.4 (1985)
380
RESULTS AND DISCUSSION
Expressed fecundity in females which had been paired for 48, 96, 144, or 192 h
ranged from 14.9 to 17.8 egg clusters and \Vas similar to that of 15.4 for always
paired females. Cluster size frequency for each group was within the range of 14
to 30 recorded earlier for always paired females (Mukerji and LeRoux 1965;
Lambdin and Lu 1984; Warren and Wallis 1971). Females in aU paired groups
copulated at least once and displayed regularly expressed fecundity. Absence of
copulation may account for the lack of regularly expressed fecundity in virgin females.
Their egg clusters contained greater numbers of eggs laid less frequently.
Infertility and periodic productivity influenced the relationship between cluster
size and cumulative fertility of mated females. Infertile females occurred in all
groups which had been paired with males. About 16 - 33% of the mated females
evaluated were infertile. All females had periods of productivity interspersed with
nonproductivity during the 35 d test. Average productive periods for all females
ranged from 1 - 16 d during which egg clusters were laid. Average non-productivity
periods lasted 1·2 d after which oviposition resumed (except for never paired
females where extended periods were noted). Virgin females had fewer productive
days than any of the paired female groups.
No significant differences (p > 0.05) were found among means of the si.",
treatment groups for daily fecundity or overall fecundity rates (Table 1). Mukerji
and LeRoux (1965) observed higher fecundity and fertility rates and longer life
spans for P. maculiuentris females maintained in the lab at 21°C. but mean daily
fecundity rates were similar to those we obtained. Although average life spans of
insects in their study were nearly 4 X longer than for insects in our study, total
fecundity was only about 25% greater. Our results more closely correspond to
those reported by Warren and Wallis (1971). The'virgin females were equally as
fecund as mated females. This was also obselved by Nilakhe (1976) for the rice
stink bug.
Table 1. Fecundity and fertility rates for Podisus maculiuentris (Say) females.
x No. eggs/dayt
Treatment-
Laid
always
never
48 h
96 h
144 h
192 h
7.7
5.3
9.6
9.6
9.8
7.3
a
a
a
a
a
a
Hatched
3.8
0.0
4.0
4.6
4.0
3.0
a
b
a
a
a
a
Cumulative x and range
Fecundity
270.2
197.3
334.5
292.9
367.0
257.4
a 38 - 526
a 14 - 464
a 147 - 483
a 66 - 504
a 79 - 577
a 31 - 196
Fertility
135.2 a
b
140.3 a
162.7 a
136.6 a
102.8 a
0 - 395
0 - 401
0 - 469
0 - 475
0 - 409
%
50
0
42
56
37
40
- Treatment represents the type of pairing (ie., always paired, never paired, or paired for 4a, 96, 144 or
192 h).
t Any two means followed by the same letter in columns are not significantly different (P= 0.05.
Duncan's New Multiple Range Test).
Mean fertility of never I}aired females was significantly different (p ~ 0.05)
from all other females. No significant differences (p ~ 0.05) occurred among mean
fertility rates of paired females which indicate that females paired for restricted
time periods had fertility rates comparable to always paired females. Our data
BAKER and LAMBDIN: Reproductivity and Longevity of P maculiucntris
381
indicated that fertility could be maintained for at least 4 wk as the result of
limited exposure to a male in the lab. This differs from earlier studies (Couturier
1938; Mukerji and LeRoux 1965; Warren and Wallis 1971) suggesting that the
presence of males was necessary for continued fertility in the lab and that a
decline in fertility would be evidenced if males were removed from females.
Although some females had marked periods of infertility near the end of the test
and others were infertile throughout, there was not a noticeable peak. or subsequent
daily decline in fertility contributable to the removal of males.
Fertility rates for insects within treatment groups ranged between 78 . 100% on
select days, but overall fertility rates for 35 d were lower (37 ~ 56%) than those
reported by Mukerji and Le Roux (1965). Youther nnd McPberson (1975) found
no significant differences in fertility rates for females of E. seruus with restricted
mating exposure and those mated for life. Harris and Todd (1980a,b) observed
numerous copulations by the southern green stink bug, but found similar fertility
rates between always mated females and females isolated after one copulation.
Podisus maculiuentris females exemplified those insects which display polygamous
behavior even though limited exposure to one male can provide sufficient spenn
for continued fertility (Thornhill nnd Alcock 1983).
No significant differences (p> 0.05) were indicated for longevity among means
of the four groups paired for res}ricted time periods, but a significant difference
between always paired and never paired females was found (Table 2). There was
no indication that increasing paired time would contribute to reduced longevity.
However, the slightly reduced longevity did affect fecundity and fertility rates.
Only always paired and never paired conditions had distinct effects on longevity.
Significant differences found in longevity between virgin and always paired females
verified earlier reports of such an occurrence (Couturier 1938; Mukerji and
LeRoux 1965).
Table 2. Longevity of Podisus maculiuentris (Say) females.
Treatmentalways
never
48 h
96 h
144 h
192 h
n
30
15
15
15
15
15
xt
25.7
35.0
31.9
28.3
33.5
28.1
c
a
ab
bc
ab
bc
-Treatment represents the type of pairing (ie., always paired, never paired, or paired for 48, 96, 144 or
192 h).
t Any two means foUowed by the same leiter are not significantly different (P= 0.05, Duncan's New
Multiple Range Test.).
Relationships between fecundity, fertility, longevity, and mating may have
important practical implications. OUf results suggested no advantages in rearing
continuously paired spined soldier bugs in the laboratory. Maintaining females
without males (after copulation) required less food and handling time, Also, the
threat of cannibalism was reduced by the minimal paired time. The incidence of
infertility. which appeared nearly constant for all pairing times, probably will not
be increased as a result of restricted paired time. The fecundity and fertility rates.
382
J. Agric. Entorool. Vol. 2, No.4 (1985)
incidence of infertility, and average lifespans recorded here may be helpful in
estimating potential production of offspring for use in mass release programs.
REFERENCES CITED
Ables, J. R., Ilod D. W. McCommas. 1982. Efficiency of Podisus maculiuentri,<; 8S a predator
of variegated cutworm on greenhouse cotton. J. Ga. Entoma!. Soc. 17: 204-206.
Couturier, A. 1938. Contribution a I'etude biologiquc de Podisus motu/juel/iris (Say) predal:cur
Americain du doryphore. Ann. des Epiphytics et de Phytogenetique. N.S. 4: 95·165.
Esselbaugh, C. O. 1948. Notes on the bionomics of some midwestern Pentatomidae.
EntorooL Amer. 28: 1-73.
Hurris, V. E., and J. W. Todd. 19808. Comparative fecundity, egg fertility and hatch among
wild-type nnd three laboratory reared generations of the southern green stinkbug, Nezam
viridula (L.) (Hemiptera: Pentatomidae). J. Ga. Entomo!' Soc. 15: 245-252.
Harris, V. E., and J. W. Todd. 1980b. Temporal and numerical patterns of reproductive
behavior in the sout.hern green stinkbug, Nezara uiridula (L.) (Hemiptera: Pentatomidae).
Entomol. Expel'. et Appl. 27: 105-116.
Ignoffo, C. M., C. Garcia, W. A. Dickerson, G. 1'. Schmidt., and K. D. Biever. 1977.
Imprisonment of entomophages to increase effectiveness: Evaluation of a concept. J.
Econ. EntomoL 70: 292·29·1.
Kirkland, A. H. 1897. Notes on the life history of certain predaceous Heteroptera. State Bull.
Agr. on Extermination of the Gypsy Moth. Appendix: 51-59.
Lambdin, P. L., and G. Q. Lu. 1984. External morphology of eggs of lhe spined soldier bug,
PodisUIl maculiverltris (Say). Proc. Wash. Entomo!. Soc. 86: 374-377.
Landis, B. J. 1937_ Insect hosts and nymphal development of PodisU-..<; maculiuentris (Say) and
Peril/us bioculatill (F). Bur. Entomo!. and PI. Quar., USDA. No.4: 252-259.
Lener, W. 1967. Sexual activity and longevity in the large milkweed bug, Oncopeltus fasciatus
(Hemiptera: Lygaeidae). Ann. EntomoL Soc. ArneI'. GO: 484-485.
Ivlarston, N. L., G. T. Schmidt, K. D. Biever, and W. A. Dickerson. 1978. Reaction of five
species of soybean caterpillars to attack by the predator Podi..'ws maculiveTltris. Environ.
Entomol. 7: 53-56.
Mitchell, W. C., and R. F. L. Mau. 1969_ Sexual activity and longevit.y of the southern green
stinkbug, Nezara uiriulda. Ann. Entomol. Soc. ArneI'. 62: 1246-1247.
Mukerji, M. K., and E. J. LeRoux. 1965. Laboratory rearing of a Quebec strain of the
Pentatomid predator, Podisus maculivenlri.<; (Say). Phytoprotection 46: 40-60.
Mukerji, M. K., and E. J. LeRoux. 1969a. A quantitative study of food consumption and
growth of Podisus maculiuentris (Hemiptera: Pentatomidae). Can. EntomoL 101: 387-403.
Mukerji, M. 1<., and E. J. LeRoux. 1969b. A study on energetics of Podisus maculiuefllris
(Hemiptera: Pentatomidae). Can. Entomol. 101: 449-459.
Nilakhe, S. S. 1976. Overwintering, survival, fecundity, and moting behavior of the rice
stinkbug. Ann. Entomol. Soc. Amer. 69: 717-720.
Thornhill, R., and J. Alcock. 1983. Evolution of Insect Mating Systems. Harvard Univ. Press.
Cambridge. 547 pp.
Waddill, V., and M. Shepard. 1975. Dispersal of Podisus maculiventris nymphs in soybeans.
Environ. Entoffiol. 4: 233-234.
Warren, L. 0., and G. Wallis. 1971. Biology of the spined soldier bug, Podisus maculiuentris
(Hemiptera: Pentatomidae). J. Ga. Entomol. Soc. 6: 110-115.
Whitmarsh, R. D. 1916. Life history notes on Apatetic:us cynicus and maculiventris. J. Econ.
Entomol. 9: 51-53.
Youther, M. L., and J. E. 1\'lcPherson. 1975. A study of fecundity, fertility, and halch in
Euschilltus seruus (Hemiptera: Pentatomidae) with notes on precopulatory and copulatory
behavior. Trans. Ill. State Acad. Sci. 68: 321-338.