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1.
The lifetime mating frequency of female butterflies is believed tobe dependent on the reproductive status of the males which
they have mated. This report assesses those status usingPieris rapae L. Multiple mating females mated males with a short time interval after the last mating or males with many mating records.
Such males, like small ones, produced small spermatophores during copulation, which may have resulted in high mating frequency
of those females. The males with short time interval after the last mating or those with many mating records also showed a
long mating duration. Alternative interpretations of the adaptive significance of this behavior for males are discussed. 相似文献
2.
Takayoshi Nishida 《Researches on Population Ecology》1993,35(1):45-56
Summary Spatial relationships of mate acquisition probability for individuals of both sexes of a gregariously-mating coreid bug,Colpula lativentris, were studied in relation to aggregation size. Operational sex ratio was always strongly male biased. Mate acquisition probability
of females was rather constant and independent of aggregation size, as predicted by an ideal free distribution. Moreover laboratory
experiments showed that both multiple mating and rearing density little affected female fecundity, suggesting ideal free distribution
of females in terms of reproductive success. On the other hand, mate acquisition probability of males was higher in larger
aggregations, where more receptive females were available. This male discrepancy from an ideal free distribution was similar
to the patterns predicted by an ideal free distribution under perceptual constraints (Abrahams, 1986), but not by that under
unequal competitive ability. 相似文献
3.
Kenji Fujisaki 《Researches on Population Ecology》1981,23(2):262-279
Summary The mating system of the winter cherry bug,Acanthocoris sordidus, was analyzed precisely. As a result, it was found that male adults of this species establish a small territory for mating
on the stem of host plant which harbors females. These males abandoned their territories soon after the disappearance of monopolized
females. Thus it was confirned that the cue for the territorial establishment of males is the presence of females per se on
the host plant. Moreover, most aggregations of adults observed on the host plant contained only a single male. This one-male
unit in the mating was named a harem. Harem holding males were usually big in body-size and had a high chance of copulations.
The defence behaviors of harem holding males, the mating disparity among males, and the oviposition habit of females in relation
to the mating system, were observed. The results obtained were discussed in relation to the sexual selection theories. 相似文献
4.
Eiichiro Urano 《Researches on Population Ecology》1985,27(2):393-412
Summary Settlement date, mating status, and breeding success of individually marked great reed warblers,Acrocephalus arundinaceus, were studied during the 1980–84 breeding seasons in Kahokugata, Ishikawa Prefecture, Japan. Twenty-five per cent of the
territorial males were polygynous, of which the majority were bigamous. The settling periods of both sexes were long, extending
for 65 days in males and 49 days in females. About 80% of males and females settled in the first half of the settling period,
and the settlement date of 28–54% males overlapped with that of females. Many of the late settlers were bachelors and the
males which mated earlier tended to be polygynous. The timing of a male's settlement is important in acquiring mates. Fifty-five
per cent of eggs laid were lost before fledging, mainly due to predation. The mean number of fledglings was 3.19 per primary
female, 2.41 per secondary female, and 2.80 per monogamous female. Comparison of the number of fledglings of females which
mated during the same period showed that the presence of another female in the same territory did not adversely affect the
breeding success of either of the polygynous females. Polygynous males have the advantage of decreasing the risk of breeding
failure under high predation pressure. 相似文献
5.
Reproductive behaviors related to habitat utilization were studied in males of the damsefly,Mnais nawai, which has two male forms, territorial orange-winged males (nawai) and non-territorial pale-orange-winged males (sahoi), at the upper part of a mountain stream where they partiallycoexist with a related species,Mnais pruinosa, which also has two male forms, territorial orange-winged males (esakii) and non-territorial hyaline-winged males (strigata). These two species showed parapatric distribution; the lower part of the stream was occupied byM. nawai, and the upper part byM. pruinosa. In the present study, cross-matings occurred between bothMnais species, although normal intraspecific matings occurred more frequently than cross-matings. Territorial males of both species copulated
with conspecific females that entered their territory and guarded the ovipositing females, probably to avoid sperm displacement
resulting from subsequent copulations. Severe competition for oviposition sites by territorial males even occurred between
the two species. On the other hand, non-territorial males of both species have alternative mating strategies (including several
tactics such as sneaking, takeover and interception). The possible benefits from conflict among territorial males of both
species is discussed. 相似文献
6.
Takayoshi Nishida 《Researches on Population Ecology》1994,36(2):209-218
Spatio-temporal variations of lifetime reproductive succes (LRS) of both male and female individuals of a coreid bugColpula lativentris were measured and analyzed using the multiple regression method of Arnold and Wade (1984a, b). The standardized variance
of LRS was larger in males than that in females as males often to secure mates for a long period whereas females could easily
find mates and oviposit simply dependent on ovarial maturation. LRS was partitioned into 4 consecutive fitness components:
(1) reproductive lifespan, (2) copulating efficiency, (3) guarding efficiency (for males) or oviposition efficiency (for females),
and (4) number of eggs per clutch. In males copulating efficiency was the largest determining factor of LRS, whereas in females
reproductive lifespan was the most important factor. Such tendencies were stable on both a yearly and local basis. Patterns
of relative contribution of natural selection (reproductive lifespan and number of eggs per clutch) and sexual selection (copulating
efficiency and guarding or oviposition efficiency) to LRS were clearly different between males and females. This sexual difference
is, at least to some extent, thought to be brought about by sexual selection among males for mating opportunity, though no
physical fight was observed among males. Directional selection on body length was found only in relation to the clutch size
of females because large females tended to lay larger clutches. No significant directional selection was found in other fitness
components. 相似文献
7.
Takatoshi Ueno 《Researches on Population Ecology》1999,41(1):47-57
Charnov's host-size model explains parasitoid host-size-dependent sex ratio as an adaptive consequence when there is a differential
effect of host size on the offspring fitness of parasitoid males versus females. This article tests the predictions and the
assumptions of the host-size model. The parasitoid wasp Pimpla nipponica Uchida (Hymenoptera: Ichneumonidae) laid more female eggs in larger or fresher host pupae when choice among hosts of different
sizes or ages was allowed. Then, whether an asymmetrical effect of host size and age on the fitness of females versus males
existed in P. nipponica was examined. Larger or fresher host pupae yielded larger wasps. Larger females lived longer, whereas male size did not influence
male longevity. Large males mated successfully with relatively large females but failed with small females, whereas small
males could mate successfully either with small or with large females. Thus, small-male advantages were found, and this held
true even under male–male competition. Ovariole and egg numbers at any one time did not differ among females of different
sizes. Larger females attained higher oviposition success and spent less time and energy for oviposition in hosts. Larger
females produced more eggs from a single host meal. Taken together, females gained more, and males lost more, by being large.
Host size and age thus asymmetrically affected the fitness of offspring males versus females through the relationships between
host size or hast age and wasp size, which means the basic assumption of the host-size model was satisfied. Therefore, sex
ratio control by P. nipponica in response to host size and age is adaptive.
Received: November 13, 1998 / Accepted: January 18, 1999 相似文献
8.
Kenji Fujisaki 《Researches on Population Ecology》1992,34(1):173-183
Summary A male fitness advantage to wing reduction was investigated for the oriental chinch bug,Cavelerius saccharivorus, which is wing dimorphic. Field surveys for the frequency of matings between wing morphs showed that the mating probability
was much higher in brachypterous males than in macropterous males in the early breeding season. Brachypterous males copulated
with not only brachypterous females but also macropterous females in this season. This led to a considerable rate (30%) of
insemination of macropterous females just before emigration even in the early breeding season. A rearing experiment for the
pre-reproductive period of females revealed that females mated with brachypterous males copulated and oviposited earlier than
females mated with macropterous males. These results indicate that there is a fitness advantage to wing reduction in the males
ofC. saccharivorus in terms of the earlier sexual maturation. 相似文献
9.
Reproductive behavior of the foam-nesting treefrog,Rhacophorus arboreus, is described. Oviposition was made either by an amplectant pair (a female, and an amplectant male) alone or by an amplectant
pair and other males (joiners). The snout-vent length of males and females was negatively correlated with the date of the
first appearance in the pond. The period of staying in the pond in males was longer than that in females. Physical body contacts
of other males, and encounter calls by ampletant males were frequently observed before oviposition with joiners. Snout-vent
length of the female and an amplectant male were positively correlated. Encounter calls by amplectant males were likely to
precede movement of females. There was no difference of snout-vent length between amplectant males and joiners. Females moved
the hindlimbs more frequently than males during oviposition. Amplectant males made encounter cells more frequently in oviposition
with joiners, than oviposition without joiners. The patterns of transitions between acts of females and amplectant males were
similar between oviposition with and without joiners. Females more frequently responded to amplectant males than joiners.
Both the duration of a bout of the movements of hindlimbs of females and the interval between the bouts were longer in oviposition
without joiners than that with joiners. The number of the movements per bout in oviposition without joiners was smaller than
that with joiners. Encounter calls by amplectant males during oviposition tended to precede the hindlimb movements of females. 相似文献
10.
Models are presented to investigate the population dynamic behavior of a pest population with the release of pheromone for
mating disruption. Three mechanisms of mating disruption are considered: (i) confusion of males, (ii) competition with female
pheromone trails yielding false trail following, (iii) emigration of males prior to mating. In addition, several refinements
to confusion are considered. Confusion and emigration of males were found to be very similar both quantitatively and dynamically;
also, a combination of both mechanisms was very little more efficient than either one separately. False trail following is
difficult to compare with the other two, since competition with wild females is involved and thus the total population size
enters the equations. Density dependence of the action of pheromones results in some cases in which mating disruption cannot
control the pest population. Similarly, aggregation of the pest population decreases the efficiency of the method unless the
pheromone action is density independent. Delayed mating of females makes control easier, and may constitute one mechanism
for mating disruption. 相似文献
11.
InMenida scotti aduts which mate during hibernation, we examined the effect of photoperiod on diapause induction in terms of the developmental
degree of reproductive organs and corpora allata. In a hibernating population, mating season and physiological changes related
to dipause were investigated. When newly emerged adults were reared under long- or short-day conditions, reservoir of the
ectodermal accessory gland and corpora allata in males developed, while the developments of ovary and corpora allata in females
were suppressed under both conditions. This suggests that diapause of this species is induced only in females independently
photoperiodic conditions during adult stage. In a hibernating population, mating was observed from early to late November
and from late March to early May. Observations of the development of reproductive organs and corpora allata suggest that diapause
is induced only in females in the former period, while both sexes are not in diapause in the latter period. 相似文献
12.
Reproductive success, copulation success, and mating success were measured for a population of male dragonflies,Orthetrum japonicum. Copulation success explained the greatest variation in reproductive success. The proportion of copulations followed by oviposition
was positively correlated with the number of oviposited eggs per mating. Directional selection on four morphological characters
was estimated. The effect of selection on correlated traits was comparable to that of direct selection. Directional selection
varied between traits and between episodes in a single trait. The probability that the observed directional selection on the
four morphological traits was expected under the condition of the selective neutrality of traits was not smaller than 5%. 相似文献
13.
Takayoshi Nishida 《Researches on Population Ecology》1989,31(2):211-224
Summary The mating system of the coreid bug,Colpula lativentris, was studied, and compared with those in other hemipteran bugs. Copulating pairs formed a compact aggregation on a shoot
of the Japanese knotweed,Polygonum cuspidatum, and there continued copulation and feeding for more than one day. This aggregation was defined as “a shoot aggregation”.
Other than this aggregation composed of copulating pairs, there were loose aggregations on the ground composed of males and
females not in copula. This loose aggregation was defined as “a ground aggregation”. Males searched for receptive females
mostly in a ground aggregation.
Sex ratio was constant and variance of sex ratio was also very small in any shoot aggregations and in large ground aggregations.
However, in small ground aggregations, sex ratio was strongly male biased and variance of sex ratio was fairly large. This
was because receptive females tended to leave a small ground aggregation and join a large one. These results suggest that
a male can attain higher mating success in a larger ground aggregation. 相似文献
14.
Yozo Koshiyama Hisaaki Tsumuki Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1996,38(1):51-56
Menida scotti (Puton) males have been shown to transfer secretions from their bulbus ejaculatorius and reservoir of ectodermal accessory
gland to females by mating during hibernation. In the present study, the major components of the secretions were found to
be proteins and lipids. To specify the female organ incorporating the male secretions, a radiotracer experiment in which the
male secretions were labeled by [14C]valine was conducted in nine tissues of females collected in the fall and spring of the hibernation period. Relatively high
radioactivities were detected in the haemolymph and the residual carcass (head, legs, air-sacs, exoskeleton, etc.) in the
fall females, and in CO2 gas evolved and carcasses in the spring females. The radioactivities in the fat body were significantly higher in the fall
mating females than in the spring mating females, and vice versa in the ovary. The radioactivities in six fractions (lipids,
proteins, glycogen, sugars, free amino acids and the residues) were also assayed in the five organs of females that had a
relatively high radioactivity. The highest radioactivity was detected in the protein fraction of the haemolymph in fall and
spring females. There were significant differences in the radioactivities incorporated into the lipid fractions of the carcass
between fall and spring females. 相似文献
15.
Michael F. Antolin 《Researches on Population Ecology》1999,41(1):29-37
Parasitoid sex ratios are influenced by mating systems, whether complete inbreeding, partial inbreeding, complete inbreeding
avoidance, or production of all-male broods by unmated females. Population genetic theory demonstrates that inbreeding is
possible in haplodiploids because the purging of deleterious and lethal mutations through haploid males reduces inbreeding
depression. However, this purging does not act quickly for deleterious mutations or female-limited traits (e.g., fecundity,
host searching, sex ratio). The relationship between sex ratio, inbreeding, and inbreeding depression has not been explored
in depth in parasitoids. The gregarious egg parasitoid, Trichogramma pretiosum Riley, collected from Riverside, CA (USA) produced a female-biased sex ratio of 0.24 (proportion of males). Six generations
of sibling mating in the laboratory uncovered considerable inbreeding depression (∼ 20%) in fecundity and sex ratio. A population
genetic study (based upon allozymes) showed the population was inbred (F
it = 0.246), which corresponds to 56.6% sib-mating. However, average relatedness among females emerging from the same host egg
was only 0.646, which is less than expected (0.75) if ovipositing females mate randomly. This lower relatedness could arise
from inbreeding avoidance, multiple mating by females, or superparasitism. A review of the literature in general shows relatively
low inbreeding depression in haplodiploid species, but indicates that inbreeding depression can be as high as that found in
Drosophila. Finally, mating systems and inbreeding depression are thought to evolve in concert (in plants), but similar dynamic models
of the joint evolution of sex ratio, mating systems, and inbreeding depression have not been developed for parasitoid wasps.
Received: November 13, 1998 /Accepted: January 8, 1999 相似文献
16.
Asymmetric mating preferences occur in two closely related species, if females of one species are highly selective against
males of the second, while females of the second show less selection against males of the first species. It has been suggested
that such asymmetry is an indicator of common ancestry between the two species, but actual observations are contradictory
and inconclusive. We developed a scenario of speciation history and asymmetric mating preference, incorporating invasion dynamicsvia frequency-dependent interspecific sexual competition. A newly isolated (derived) species may form at the periphery of the
ancestral species’ distribution by invading a new range. Only a few closely related species would be expected in the new area,
while many related species are expected to coexist with the ancestral species. In a peripherally derived species, female mating
preferences should be relaxed through sexual character release, owing to a lack of sympatric species and a scarcity of intraspecific
mating opportunities. Secondary contacts may then happen as: 1. repeated invasions, i.e. subsequent invasion by the ancestral
species into the new range or, 2. backward invasions, i.e. derived species incursions into the ancestral range. Repeated invasions
could lead to the coexistence of both the derived species and the newly invading ancestor. Backward invasions by the derived
species can succeed only when the derived females develop a strict mating discrimination against the ancestral males. We then
expect strong character displacement in the derived species. Thus, peripheral isolation and repeated invasions lead to the
relaxed female mating preferences in the derived species and backward invasions lead to stronger female mating preferences
in the derived species. This agrees withDrosophila data from Hawaii and the continents. Experimental data of theDrosophila arizonaemojavensis species cluster also support the hypothesis. 相似文献
17.
Summary Modelling studies are presented which describe the effect of lek mating on the control of a wild population by sterile male
release. The mixed leks are assumed to follow a Poisson-binomial distribution and the system includes three parts: territory
defense, matings inside a lek and matings outside a lek. The effects of parameters on the hatchability are discussed. Among
the parameters, sterile type effect (W
s
), female choice (f
s
) and mating competitiveness (C
m
) are the most important. The application to determining the effects of sterile male release and on the proportion of sterile
males required for eradication are also discussed. 相似文献
18.
Hidenori Ubukata 《Researches on Population Ecology》1984,26(2):285-301
Summary Females of an odonate species in which oviposition sites overlap with mating sites may adopt one or more of the following
strategies when they lay eggs except when they ‘trade’ mating for access to suitable oviposition sites or for services (guarding,
etc.) provided by males: (1) ovipositing at hidden places; (2) ovipositing at a time when males are neither patrolling nor
watching; (3) indicating non-receptivity by a behavioral display. The density of ovipositing females of the dragonfly,Cordulia aenea amurensis
Selys which was studied between 1970 and 1983 at a pond (H?rai-numa, Sapporo, Hokkaido) had a high negative correlation with the
distance from ‘entrance’ (a part of shore at which the arrival of most adults seems to have occurred). On the other hand,
oviposition was rarely observed at a sector being distant from entrance in spite of the inference that larval survivorship
was probably high at this sector. Most females oviposited among emergent vegetation in which approach of males to them was
difficult, and they scarcely traveled across the open water in search of oviposition sites. Therefore, most females of the
population studied were considered to adopt the first strategy. The second and third strategy were not adopted by the population
studied. Finally, the influences of some environmental factors and traits possessed by a species on the adoption of these
tactics or on the execution of the ‘trades’ were discussed.
Ecological studies ofCordulia aenea amurensis
Selys, VII.
This work was supported in part by a Grant-in-Aid for Special Project Research on Biological Aspects of Optimal Strategy and
Social Structure from the Japan Ministry of Education, Science and Culture. 相似文献
19.
Takayoshi Nishida 《Researches on Population Ecology》1992,34(2):373-382
Summary Based on variances in components of lifetime reproductive success (LRS), a new index of the intensity of sexual selection
was proposed mainly useful for interspecific comparisons. The index was defined as the male to female ratio of the standardized
variance in mating efficiency during mating period. The index can to a large extent exclude the effect from natural selection
which commonly act on both sexes in mating period and also from mortality in pre-reproductive period. This empirical measure
has some defects in the strict sense (i.e., dichotomy of natural and sexual selection), however, it enables interspecific
comparisons of the intensity of sexual selection among different taxonomic groups of animals with various mating systems and
mortality schedules. 相似文献
20.
Koh-ichi Takakura 《Researches on Population Ecology》1999,41(3):269-273
Mating behavior and the male's contribution to female fecundity were studied in the bean weevil Bruchidius dorsalis (Fahraeus) (Coleoptera: Bruchidae) in comparison with two other species, Callosobruchus chinensis (which infests stored beans) and Kytorhinus sharpianus (which feeds on wild legumes). Only females of B. dorsalis showed multiple mating and characteristic precopulatory behavior that appeared to solicit the male's nutritious secretion.
In contrast, all females of the other two species did not copulate multiply and did not show such precopulatory behavior.
In B. dorsalis, the decrement of male body weight just after copulation indicated that seminal fluid weighing as much as approximately 7%
of the male's body weight was transferred to the female. Fecundity was more than eight times higher in females that had copulated
ten times than in females that had copulated only once, indicating that males paid most of the nutritional cost of egg production.
These facts suggest that the sex role is reversed in B. dorsalis.
Received: May 22, 1998 / Accepted: July 19, 1999 相似文献