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1.
T. S. Bellows Jr. 《Researches on Population Ecology》1985,27(1):55-64
Summary The effects of host age on parasitoid reproductive capacity are studied using the pteromalid parasitoidLariophagus distinguendus
F?rster and its bruchid hosts,Callosobruchus chinensis (L.) andC. maculatus (F.). A series of experiments were performed to investigate relationships between age and size of host parasitized and the
developmental period of pre-imaginal progeny, sex ratio, female size, longevity, fecundity and oviposition rate. There was
no effect of host size on preimaginal parasitoid developmental period. Sex ratio varied from less than 5% females from young
(small) hosts to 60% females from mature (large) hosts. Adult size, female longevity, fecundity, and oviposition rate were
also positively related to host age. Females provided mature hosts lived longer than those provided either young hosts or
no hosts, possibly because of an increased ability to host-feed from the larger hosts. The implications of these findings
to parasitoid population reproductive capacity and host-parasitoid synchrony are discussed. 相似文献
2.
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
3.
Summary Experimental results, and interpretation, are presented which relate to oviposition behaviour in four species of parasitic
wasp (Hymenoptera: Chalcidoidea). All lay their eggs in pupae of the common house fly (Musca domestica) and of other flies associated with man. Probability models suggested byD. J. Daley for describing the avoidance of superparasitism are used to analyse the data. Certain of the models considered by previous
authors appear as specieal cases. A satisfactory fit was obtained either by assuming a fixed probability of oviposition in
an already parasitised pupa, or by using a model motivated by supposing that a female will tolerate without oviposition some
fixed number of visits to already parasitised pupae. A third model was considered which makes the probability depend on the
number of previous ovipositions in the pupae now visited. In all four species the presence of other females (with parasite:
host ratio unchanged) increased the probability of oviposition upon encountering an already parasitised pupa. In the presence
of other femalesSpalangia endius laid an increased number of eggs, whereas the other three species laid fewer eggs. 相似文献
4.
We examined the female-biased sex ratio of a trap-nesting wasp Trypoxylon malaisei considering the following factors: (1) local mate competition (LMC), (2) resource quality, (3) partial bivoltinism, and (4)
presence of constrained females. The sex ratio (expressed as male ratio) at emergence was strongly female biased, i.e., 0.30
and 0.19, in terms of the number and investment, respectively. To evaluate the primary sex ratio, we analyzed the data from
nests where all the offspring successfully emerged, excluding nests composed of single-sex offspring. The primary sex ratio
was also female biased, at 0.33 and 0.21, in terms of the number and investment, respectively. LMC was highly responsible
for the female-biased sex ratio because both the nonrandom oviposition sequence [females at inner cells and male(s) at outer
cells] and earlier emergence of males allowed sib-matings to occur. In contrast, the other three factors little affected the
female-biased sex ratio: the sex ratio was fairly constant when resource quality (nest size) varied, partial bivoltinism was
extremely rare or absent, and constrained females were absent or did not reproduce at all.
Received: June 19, 1998 / Accepted: January 18, 1999 相似文献
5.
Summary Individual differences in several reproductive parameters of femalePieris rapae were investigated in a controlled laboratory condition. Lifetime and age-specific fecundity showed considerable variability
between individuals. Larger females began oviposition at an earlier age than smaller ones, and larger females were more fecund
than smaller ones. Larger females laid a larger proportion of their eggs in the early stages of their reproductive lifetime,
whilst smaller females laid the larger proportion of their eggs later in their reproductive lifetime. The significance of
the variance in age-specific fecundity associated with female size is discussed with respect to the seasonal change in size
and habitat utilization of this species. 相似文献
6.
Wolbachia bacteria are obligatory intracellular parasites of arthropods and have been detected in about 70 species of parasitic wasps
and three parasitoid flies. Wolbachia are transmitted cytoplasmically (maternally) and modify host reproduction in different ways to enhance their own transmission:
parthenogenesis induction (PI), cytoplasmic incompatibility (CI), or feminization (F) of genetic males. Only PI and CI are
known in parasitoids. PI-Wolbachia cause thelytoky in otherwise arrhenotokous parasitoids by generating diploid (rather than haploid) unfertilized wasp eggs.
CI-Wolbachia cause incompatibility of crosses between infected males and uninfected females because the paternally derived chromosomes
fail to decondense and are destroyed after syngamy. More complex situations arise when hosts harbor multiple infections, which
can lead to bidirectional incompatibility and may be involved in parasitoid speciation. The relative fitness of infected and
uninfected hosts is important to the population dynamics of Wolbachia, and more data are needed. Evolutionary conflict should be common between host genes, Wolbachia genes, and other "selfish" genetic elements. Wolbachia-specific PCR primers are now available for several genes with different rates of evolution. These primers will permit rapid
screening in future studies of spatial and temporal patterns of single and multiple infection. Molecular phylogenies show
that CI- and PI-Wolbachia do not form discrete clades. In combination with experimental transfection data, this result suggests that host reproductive
alterations depend on the interaction between attributes of both Wolbachia and host. Moreover, Wolbachia isolates from closely related hosts do not usually cluster together, and phylogenies suggest that Wolbachia may have radiated after their arthropod hosts. Both results support considerable horizontal transmission of Wolbachia between host species over evolutionary time. Natural horizontal transmisson between parasitoids and their hosts, or with
entomoparasitic nematodes or ectoparasitic mites, remains a tantalizing but equivocal possibility.
Received: November 27, 1998 / Accepted: January 15, 1999 相似文献
7.
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
8.
Masakazu Shimada 《Researches on Population Ecology》1985,27(2):203-216
Summary Effects of niche shift in ecological time scale on the population dynamics of competing species were studied in the experimental
populations of two parasitoid wasp species,Anisopteromalus calandrae andHeterospilus prosopidis (both are solitary parasites), on a host, the azuki bean weevil,Callosobruchus chinensis. Four resource conditions were set up with combination of kind of bean (azuki or black eye), and host distribution (uniform
or clumped). In each resource condition, four developmental stages of hosts were provided as a resource spectrum for parasitoid
wasps.
Population dynamics of the two wasp populations were investigated in each resource condition in Multi-Generation Competitive
Systems (MGCS), in which fresh hosts of four developmental stages were periodically introduced and were parasitized competitively
by the two wasp species. Competitive coexistence of both wasps occurred in the azuki-clumped condition, where the peaks of
the resource utilization curves separated in the two species; pupae inA. calandrae and the early or late fourth instar inH. prosopidis, A. calandrae was eliminated in the azuki-uniform condition andH. prosopidis went extinct in two black eye conditions irrespective of host distributions. The degrees of overlap of the resource utilization
patterns of the two wasp species during population dynamics were not significantly different among resource conditions irrespective
of the results of coexistence or extinction. Even in the azuki-clumped condition, however, extinction ofA. calandrae was observed when resource partitioning could not be realized with only the late fourth instar larvae available to wasps.
Further analytical experiments showed that parasitizing ability ofA. calandrae increased with host density per bean with azuki beans, butA. calandrae could express higher parasitizing ability with black eye beans thanH. prosopidis irrespective of host density per bean.
The flexibility in parasitizing ability byA. calandrae for various host stages under different resource conditions was thought to be the major factor in determining the competitive
coexistence or the extinction of either species under different resource conditions. The present experiments also suggested
that different second-best host stages between competitors could be a major contributing factor to competitive coexistence. 相似文献
9.
Host-feeding and oviposition by parasitoids in relation to host stage: Consequences for parasitoid-host population dynamics 总被引:1,自引:0,他引:1
Summary Among parasitoids which host-feed destructively, there is a tendency for females to partition their feeding and oviposition
behaviour in relation to different host stages, feeding preferentially or exclusively on earlier host stages and ovipositing
preferentially or exclusively in (or on) later ones. We explored the dynamic implications of this behaviour for parasitoid-host
population dynamics, using modifications of the age-structured simulation models of Kidd and Jervis (1989, 1991).
Using the new versions of the models, we compared the situation where parasitoids practice host stage discrimination with
respect to feeding and oviposition, with the situation where they do not. Additionally, we examined the effects of host stage
discrimination on populations by (a) having generations either discrete or overlapping, (b) varying initial age structure,
(c) having varying degrees of density dependence acting on host adult mortality, and (d) varying parasitoid develoment times
in relation to the length of host development.
With either discrete or overlapping generations of the host population, a reduction in the parasitoid development time had
a destabilizing influence on the parasitoid-host population interaction. With discrete generations stage discrimination had
no effect on the risk of extinction, irrespective of either the degree of density dependence acting on the host population,
or the initial age structure of the host population. When parasitoid search was uncoupled from the insect's adult energy requirements,
the interaction was always unstable. With continuous generations, stage discrimination affected stability at certain parasitoid
development times, but not at others. The relative lengths of parasitoid and host development times also influenced the tendency
of the host population to show discrete or overlapping generations. 相似文献
10.
Masakazu Shimada 《Researches on Population Ecology》1999,41(1):69-79
Population dynamics and variability were examined in one-host–two-parasitoid experimental systems with different resource
distributions: resource-clumped and resource-sparse conditions. The system consists of a seed beetle host, Callosobruchus chinensis, and two parasitoid wasps, Anisopteromalus calandrae (Pteromalidae) and Heterospilus prosopidis (Braconidae). In the resource-clumped condition, suitable hosts for parasitism (the late fourth-instar larvae and pupae)
were clumped in 1 large resource patch, but they were scattered evenly among 16 small patches in the resource-sparse condition.
Population censuses were conducted at 10-day intervals in long-term cultures, renewing 10 g of azuki beans (Vigna angularis). In both resource conditions, the first period was a single-species system of C. chinensis only, and A. calandrae was added in the second period. The one-host–one-parasitoid system with C. chinensis and A. calandrae showed stable population dynamics with small fluctuations. After addition of H. prosopidis in the third period, two of three replicates persisted to day 800 in each resource condition, although one replicate in each
went to extinction at an immediate outbreak of the H. prosopidis population after the introduction. Population variabilities of C. chinensis and H. prosopidis were significantly higher and the mean population size of A. calandrae was significantly smaller in the resource-sparse condition than that in the resource-clumped one. A short-term experiment
on parasitism efficiencies revealed that H. prosopidis parasitized significantly more at a low host density in the resource-sparse condition than in the resource-clumped one. Mutual
interference of H. prosopidis was weak enough at low parasitoid densities but became abruptly stronger with high densities. Providing fresh hosts in a
mixture of already parasitized ones, host-searching behaviors of a parasitoid were recorded by video for 3 h and were compared
between the two wasp species. H. prosopidis could parasitize fresh hosts more efficiently than A. calandrae through frequent long-distance walks (walking to distant beans at one bout or outside a clump of beans with hosts and back
soon on a distant bean of the clump) after reencounters with parasitized hosts. Considering all the experimental results,
populations were judged to be more fragile and more likely to go to extinction in the resource-sparse condition than in the
resource-clumped one. A higher attacking efficiency of H. prosopidis destabilized population dynamics more in the resource-sparse condition.
Received: December 23, 1998 / Accepted: January 20, 1999 相似文献
11.
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
12.
Motoaki Kinoshita Eiiti Kasuya Tetsukazu Yahara 《Researches on Population Ecology》1998,40(2):239-242
The sex ratio of the pollinator fig wasp,Blastophaga nipponica Grandi (Agaonidae), was examined in an experiment manipulating the number of foundresses. The sex ratio ofB. nipponica was conditional on the number of foundresses and corresponded to the qualitative prediction of the local mate competition
(LMC) theory that the proportion of males increases as foundress number increases. However, the sex ratio ofB. nipponica was consistently more female-biased than predicted by extended LMC theories that incorporated effects of inbreeding, and
these deviations were statistically significant. Plausible factors that would make predictions more female-biased are discussed. 相似文献
13.
Summary Lifetime mating success of males in a natural population of the papilionid butterfly,Atrophaneura alcinous, was investigated and causes of the variation were examined. The most successful males mated with 5 females, whereas about
73% of the males failed to mate. Body size of males was not correlated with their eclosion date, longevity and lifetime mating
success. There was no trade-off between mating success and longevity, and long-lived males had a disproportionately high mating
success. Although number of available females per male per day was not variable among males with different longevities, long-lived
males had higher mating efficiency. Time interval between matings by non-virgin males was shorter than that from eclosion
to the first mating. High lifetime mating success of long-lived males was strongly related to their mating experience, not
to their ageper se. 相似文献
14.
Kenji Fujisaki 《Researches on Population Ecology》1993,35(2):317-324
Summary Genetic correlations of the wing form and the relative wing length between females and males were estimated in the oriental
chinch bug,Cavelerius saccharivorus, by calculating the correlation between the sexes of the proportion macropterous or the mean relative wing length in full-sib
families obtained from different wing forms of parents emerged in a high density population. There was a significantly positive
genetic correlation between the sexes in both the proportion macropterous and the mean relative wing length. However, the
appearance rate of macropters tended to be much lower in males than in females under the rearing conditions which promote
the appearance of macropters. This was evident especially in the offspring of brachypterous parents. These indicated that
inC. saccharivorus the wing polymorphism of males is not a simple result of the genetic correlation of wing morphology between the two sexes.
It was considered that both of the female and male fitness advantages to wing reduction, as well as the genetic correlation
between the sexes, would influence the evolution of wing polymorphism in this species. 相似文献
15.
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
16.
K. L. Heong 《Researches on Population Ecology》1981,23(1):177-191
Summary The functional response parameters of the parasitoid,Anisopteromalus calandrae (Howard) to the third instar, the fourth instar and the pupae ofCallosobruchus maculatus (F.) were estimated from the Random Parasitoid Equation. By modifying this equation for a two host situation and using the
parameters estimated above, a no switch model could be obtained. This model was then used to test for switching. In the preference
experiments where two stages of the host were presented to the female parasitoid, a definite preference for the fourth instar
followed by the pupa and the third instar, respectively was shown. There was, however, no evidence of switching. There was
also no evidence that the data fitted the no switch models which suggests that when the parasitoid is searching in an environment
with two or more hosts, its searching behaviour is more complex. 相似文献
17.
Summary Male and female prairie deermice housed singly from weaning (21 days) until 40 days of age had urine from one of the following
sources applied daily to their nostrils: sexually mature laboratory population males or females, and sexually mature breeder
males or females from our laboratory colony. Other males and females were treated with water. Records were obtained of the
weights of the tests, seminal vesicles and bacula of males and the ovaries and uteri of females at 40 days of age.
The major results of this study were as follow: Female urine from sexually mature and inhibited population or isolated mice
stimulated the development of the male reproductive organs significantly more than water or male urine. Male urine applied
to young males did not differentially affect the weights of their reproductive organs compared with water and thus showed
no inhibition effects.
The reproductive organs of females treated with male urine did not differ significantly in weight from those of females treated
with female urine. Females treated with water developed significantly larger uteri than those treated with urine from sexually
mature population females (P≤0.02), inhibited population females (P<0.001) and inhibited population males (P<0.007). 相似文献
18.
Toshiya Masumoto Shintaro Nomakuchi Kouji Sawada 《Researches on Population Ecology》1993,35(2):241-250
Summary We investigated how the distribution pattern of eggs and larval on the host plant,Turritus glabra, was influenced by the oviposition behavior of the pierid butterflyAnthocharis scolymus. Females searched for the host plants visually and they frequently approached taller host plants with sparse surrounding
vegetation. After encountering host plants, oviposition behavior of females was independent of host plant characteristics
such as height, density, and type of surrounding vegetation. A female laid eggs singly on a host plants. Most females appeared
to lay their eggs regardless of the presense of eggs on the host plant. Consequently egg and larva tended to be abundant on
conspicuous host plants as measured by height or relative isolation from other plants. However, overcrowding of eggs on an
individual host decreased the survival rate of larvae. 相似文献
19.
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
20.
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