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1.
《Researches on Population Ecology》1983,25(2):336-352
Summary Numerical changes and distribution patterns of the pine needle gall midge,Thecodiplosis japonensis
Uchida etInouye, were studied during the period from 1978 to 1979 in a young plantation ofPinus thunbergii in Shiga Prefecture, Japan. The survivorship curve of this species was characterized by a low mortality of larvae in galls
and two high mortalities before the formation of galls and during the overwintering period in soil.
The within and between-trees distributions of eggs and larvae in galls were examined by using the
regression method. The egg distribution per shoot was aggregative both within and between host plants. The within-tree variations
in numbers of eggs per shoot were related to the differences in the abundance of available needles for oviposition per shoot
among the canopy layers. The between-tree variations reflected the heterogeneous emergence of adult females in the study plot.
The degree of aggregation increased from egg to gall stage in both within- and between-tree distributions and the increase
was explained by the different mortality of larvae within trees and the inversely density-dependent mortality between trees.
The distribution patterns in the soil habitat stages were examined by the patchness index (
). This species showed aggregative distributions in soil stages. There was a correlation in spatial patterns of adult emergence
between the successive generations.
The distribution properties of this species were discussed in connection with the population dynamics and the availability
of host plants in the study plot. 相似文献
2.
Density dependence depends on scale; at larval resource patch and at whole population 总被引:1,自引:0,他引:1
Midori Tuda 《Researches on Population Ecology》1993,35(2):261-271
Summary A previous study (Tuda and Shimada, 1993) has shown that the equilibrium population size of the azuki bean beetle was lower
at 32°C than at 30°C and that this difference was due to a reduced maximum population size of emerged progeny through inside-bean
process. In this paper, these results were analyzed further on the scale of the individual bean where interaction among larvae
took place. Per-bean numbers of deposited eggs, hatched eggs, and emerged adults have been recorded at seven different parental
densities under the two temperature conditions.
Three individual-bean-scale process hypotheses that may explain the reduced maximum emergence density on the whole population
scale are suggested: (1) a lower maximum emergence per bean at 32°C than at 30°C, if the bean scale and the wholepopulation
scale share the same density-dependent pattern in adult emergence, (2) a limited range of hatched egg number per bean at 32°C,
resulting from the adult oviposition process outside beans, and (3) different patterns of density-dependent emergence between
the two different scales.
This study showed that the inside-bean pattern of responses on the bean scale was a simple saturated curve at 30°C, but one
with a discontinuous decline at higher hatched egg densities at 32°C. On the contrary, during outside-bean process, the peak
number of hatched eggs decreased on this scale as observed on the wholepopulation scale. I discuss why the extracted factor
of inside-bean process on the whole-population in the previous study could not be applied to the bean-scale pattern. 相似文献
3.
Fusao Nakasuji 《Researches on Population Ecology》1982,24(1):157-173
Summary Survival rates and mortality factors of a migrant skipperParnara guttata were censused in paddy fields in 4 localities of central and western Japan during 1975–1980, and 10 life tables were developed
for 3 generations. Mortality rates of eggs, older larvae and pupae were high but those of younger larvae were very low. The
high mortality rate was caused by parasitoids. Ten primary and 6 secondary parasitoids were recorded. Out of three egg parasitoids,Telenomus sp. was predominant. Larval parasitoids,Apanteles baoris andPediobus mitsukurii which are specific to genusParnara were predominant in wet land habitat, i.e. paddy land. On the other hand, tachinid flies which have a wide host range and
a high searching ability were predominant in dry land habitats. Mortalities of eggs and pupae contribute more to the change
in the total mortality of immature stages than those of other stages. egg parasitoids which are the major mortality factor
of eggs acted density-dependently but larval and pupal parasitoids did not do so. The total mortality of immature stages occurred
more or less density-dependently. Larval density on rice plants scarecely affected the survival rate of larvae. 相似文献
4.
Summary
Luehdorfia butterflies lay eggs in clusters. Clones of their host plants (Asiasarum andHeterotropa) are distributed pacthily among the understory of deciduous forests. Groups ofLuehdorfia larvae often exhaust the clones and may wander over the forest floor seeking new clones. The highest mortality observed is
during this wandering period. To elucidate whyLuehdorfia butterflies lay eggs in clusters, a simulation experiment was made for hypothetical populations which lay eggs in clusters
or singly. Field data on larval mortality, consumption, density of host clones and leaf weight forLuehdorfia japonica were incorporated into the model. The predictions of the simulation were: (1) When the egg density is low, the single egg
type could leave many more pupae than the egg clustering type, but when the egg density is high, the former might leave smaller
number of pupae than the latter; and (2) There are optimal sizes of egg clusters for different egg densities and the optimal
size becomes larger as the egg density increased.
This work was supported in part by Grant-in-Aid No. 439017 and No. 56480039 from the Ministry of Education, Science and Culture,
Japan. 相似文献
5.
Summary Optimal clutch size of the chestnut gall-wasp,Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), was examined in galls on wild and resistant chestnut trees in 1988 and 1989. The rate
of escape success of newly-emerged adults from galls was an average of 60%, irrespective of cell numbers per gall. Dry mass
per cell of a gall (as an index of nutritive condition) decreased with increasing cell number per gall, but was proportional
to the mean number of mature eggs of new adults per gall. The number of cells per gall that occurred most frequently did not
agree with that attained by the maximum survival rate from young larva to adult emergence of the gall-wasp. This discrepancy
was examined from the viewpoint of three factors: 1) quality of offspring, 2) defensive response of the host plant causing
mortality of the gall-wasp before cell formation, and 3) fitness per gall vs. fitness per egg. It is concluded that the third
factor is most likely to be the one best in explaining the discrepancy. 相似文献
6.
Summary A series of increasing egg densities was obtained by releasing various numbers of femalePlodia interpunctella (Hübner) in rooms where dishes of moth rearing medium were evenly spaced on the floor. The number of larvae produced in each dish
was taken as an indication of the number of eggs that had been laid. At all egg densities, the eggs were aggregated, and most
of the distributions conformed quite well with the negative binormial, but the degree of aggregation denreased as mean egg
density increased. The implications of the results for the development of ware-house sampling strategies are discussed. 相似文献
7.
Myron P. Zalucki 《Researches on Population Ecology》1981,23(2):318-327
Summary The effects of age and weather conditions on egg laying inD. plexippus were determined for caged females. Age (measured in physiological time), temperature and solar radiation influence egg laying
in this species of butterfly. An algorithm taking these factors into account in presented and accounts for 88% of the daily
variation in egg laying. CagedD. plexippus begin to lay eggs six—seven days after emergence, peak egg production (about 60 eggs/♀) occurs about 15 days later. Females
continue to lay eggs throughout their adult life, which in a flight cage was about 40 days. This egg laying pattern is compared
with other published fecundity schedules. The effect and importance of a female being prevented from laying her eggs, on her
life-time egg production, is also discussed. 相似文献
8.
Masakazu Shiga 《Researches on Population Ecology》1977,18(2):284-301
Summary Stabilizing mechanism in population ofMalacosoma neustria testacea was investigated in a central part of Japan based on eight year survey.
Population fluctuation in each developmental stage in the experimental field was rather small, i.e., 5.9 times in egg and
85.0 times in female adult. Pupal weight negatively correlated with the densities of 5th instar larvae and prepupae (cocoons)
and correlation coefficient was highly significant in females. Population density was stabilized by density-dependent dispersal
of female moths in preovipositional period. Comparison between fecundity of emerged moths and that of actually oviposited
ones in the experimental field suggested that density-dependent dispersal took place as the result of density-dependent size
variation, i.e., small-sized female months have higher flying ability. This hypothesis was supported by the experiment in
which flying ability of newly emerged female moth was measured. Similar stabilizing mechanism is expected to occur in semelparous
or pro-ovigenic insects.
Contribution Ser. A, No. 64 from Fruit Tree Research Station, Ministry of Agriculture and Forestry, Japan 相似文献
9.
Summary The population dynamics ofPryeria sinica was investigated in an undisturbed area in 1976–1979. We analyzed the process stabilizing the local population by the life
table approach for immature stages and the mark-recapture method for the adult stage. Females usually layed about 130 eggs
in an egg-mass. The shape of the survivorship curve was convex and was characterized by a relatively low mortality in the
egg and larval stages and by a relatively high mortality in the prepupal and pupal stages. The low mortality in the early
stage seemed to be not only due to the peculiar life cycle of this species (larvae develop in early spring when natural enemies
are not active) but due to their protective nest-webs, larval warning coloration and repellent smell. The high mortality after
cocooning was caused by severe parasitization byAgrothereutes minousubae. The number of adult in the population varied by 2.10-fold, which was less than that of other gregarious moths. The life
table data and field observations suggest that adult female dispersal would have acted as a stabilizing factor, andA. minousubae as a conditioning factor on the dynamics of the moth population. 相似文献
10.
The effects of distance between hatching larvae on survival and development were investigated inMonochamus alternatus. Two newly-hatched larvae were inoculated intoPinus densiflora bolts at a distance of 2.5 cm or 10 cm, simultaneously or at an interval of 2 weeks. Some larvae were inoculated singly as
a control. When larvae were inoculated simultaneously, mortality of the closely-inoculated larvae was significantly higher
than that of distantly-inoculated larvae. Such high mortality was identified as due to conspecific bites. When the two larvae
were inoculated asynchronously, the first-inoculated larvae killed some second-inoculated larvae but were never killed by
them. Consequently, mortality was higher in second-inoculated larvae than in first-inoculated larvae. In particular, there
was a significant difference in mortality between them when the larvae had been inoculated closely. The mortality of second-inoculated
larvae was higher in the closely-inoculated group than in the distantly-inoculated group although there was no significant
difference between them. In the case of two simultaneously-inoculated larvae, the initial distance between them had no significant
effect on the development and growth in the early larval stage. When the larvae were inoculated asynchronously, the first-inoculated
larvae grew more quickly than singly-inoculated control larvae. 相似文献
11.
Naoya Osawa 《Researches on Population Ecology》1989,31(1):153-160
Summary Sibling (cannibalism among siblings) and non-sibling cannibalism (cannibalism among non-siblings) were studied in a natural
population of a lady beetle,Harmonia axyridis
Pallas.
Of all the eggs laid (n=2269), 24.76% (n=562) were killed by sibling cannibalism and 36.10% (n=819) were killed by non-sibling cannibalism. Sibling cannibalism occurred constantly and intensively in most egg batches
throughout the entire oviposition period. On the other hand, non-sibling cannibalism was more intense in the middle and late
oviposition periods, and when the egg batches were close to an aphid colony. This may be due to the high density ofH. axyridis larvae relative to aphid density in the middle and late oviposition periods and also the larvae searching intensively near
an aphid colony. 相似文献
12.
Summary Population dynamics ofHeliothis virescens (F.) andHeliothis zea (Boddie) (Lepidoptera: Noctuidae) eggs and larvae were studied for two years in a small plot of cotton,Gossypium hirsutum (L.). Due to morphological and ecological similarities, the pooledHeliothis population was considered for most of the analyses. Two generations ofHeliothis eggs and larvae were completed during each year. Stage recruitment was estimated for the eggs and larval instars 2–6, and
recruitment variances were estimated by a Monte Carlo method. A modified form of the Weibull distribution was developed and
used as a model to characterize survivorship curves for each of the fourHeliothis generations. A Type I survivorship curve (mortality rate increasing with age) was inferred for both Generation 1 (early season)
data sets, whereas a Type II survivorship curve (mortality rate constant and thus independent of age) was inferred for both
Generation 2 (late season) data sets. The shapes of the survivorship curves for the individualH. virescens andH. zea populations were inferred to be the same as those for the pooled populations. Analysis of the contributions of various factors
toHeliothis stage-specific mortality indicated that natural enemies (predators and parasites) and the availability of food for larvae
were responsible for between-generation differences in survivorship patterns. 相似文献
13.
Summary The population dynamics of an epilachnine beetle, which is closely related toEpilachna sparsa
Dieke (henceforth called “sp. C”) and feeds on bitter cucumberMomordica charantia, was studied by mark-recapture of adults and the construction of life tables. The study was repeated three times, i.e., March–May,
July–September and October–December in 1982, in Padang, Sumatra, Indonesia. After the establishment of the host plants, adults
of “sp. C” soon colonized, and each study period ended in the death of the plants due to defoliation by the larvae and adults.
The estimated mean length of residence of adults ranged from 6–11 days, but this was probably much shorter than the actual
longevity, because the adults were so active that they flew away, or dropped off the plants, when they were approached or
slightly disturbed. Life tables indicated that egg mortality ranged from 17.8–53.9%, and a parasitic waspTetrastichus sp. B made up 41.1–64.2% of egg mortality. Two wasps,Tetrastichus sp. C andPediobius foveolatus killed 1.2–19.4% (7.6–100%)* of 4th instars and only the latter species attacked the pupae, killing 24.6–59.1% (45.1–72.4%). Parasitism and starvation
by overcrowding contributed most to the total mortality from egg to adult emergence, which ranged from 89.4–99.5%. “Sp. C”
had a higher diversity and level of parasitism than the Japanese species,E. vigintioctopunctata. The high dispersal power of “sp. C”, coupled with the prolongedl
x−mx schedules shown under laboratory conditions, was advantageous for exploiting the food plant which was available throughout
the year, but was rather patchily distributed in space. 相似文献
14.
Syuniti Iwao 《Researches on Population Ecology》1970,12(1):100-110
Summary The contagiousness in the operation of mortality processes on the colonies of the western tent caterpillar,Malacosoma californicum pluviale, was analyzed from two different aspects: successive changes in the frequency distribution of the number of surviving individuals
per colony in the course of development, and the distribution pattern of the individuals killed by some biotic mortality factors.
Also, for a tachinid parasite,Tachinomyia similis, the analysis was made on the egg-laying pattern on colonies as well as on individual larvae. The methods of these analyses
were all based on the relation of mean crowding (m) on mean
.
A braconid parasite,Rogas sp., tended to kill few individuals together once it attacked a colony, but its effect on host colonies was rather equivalent
to the random removal of individuals from all the colonies. Diseases in the late-stage larvae before cocooning was contagious
in their action. Nuclear polyhedrosis virus seemed to have no basic contagiousness in its action, but it caused highly contagious
distribution of deaths among the colonies when its average incidence was high. A spore-formingBacillus had a tendency to kill several individuals once it appeared in a colony, but the distribution of its incidence (no. of times
it appeared per colony) was considered to be nearly at random.
The female ofTachinomyia tended to lay more than one egg successively on the same colony. It also attacked individual larvae with a definite tendency
for aggregation, which seemed to be resulted from the parasite’s preference to large hosts. When the number of eggs laid on
prefered hosts exceeded a certain threshold, however, the fly seemed to change its attention to less attractive, smaller individuals. 相似文献
15.
Summary Studies on the population dynamics of the fall webworm,Hyphantria cunea have been carried out at three survey stations and along selected roads in the urban area of Tokyo since 1966. Twelve survivorship
curves obtained during two years and 8 life tables show that the mortality rate in early developmental stages of the fall
webworm is remarkably low as compared with that of other lepidopterous defoliaters and the mortality rate in later developmental
stages is compensatory high. The low mortality rate in early stages is considered to be due to the protective role of the
nest-web and the lack of egg and larval parasites. All but one parasitic species emerge from prepupae and pupae. Spiders living
in the nest-web of the fall webworm play an important role in reducing the number of young larvae. Direct observations and
caging experiments showed that relatively high mortality during later larval stages is mainly due to predation by birds (in
the first generation) and wasps (in the second generation). The generation mortality in the survey stations always exceeded
the level where the population is kept at the steady state, and the outbreak of this moth is considered to be continued by
the immigration of adults from large trees growing in gardens on which the larvae can escape from predation pressure.
Contributions from JIBP-PT No. 51. A part of this study was supported by the special project research, ‘Studies on the dynamic
status of biosphere’, sponsored by the Ministry of Education. 相似文献
16.
Ei''ichi Shibata 《Researches on Population Ecology》1995,37(2):229-237
The inner bark of Japanese cedar,Cryptomeria japonica D. Don., is the main food of the sugi bark borer,Semanotus japonicus Lacordaire, but may also be involved in resistance to attack by the borer. I used newly hatched larvae to inoculate cedar
logs that had been cut 2-weeks to 12-months earlier, and undamaged living cedar trees. On living trees, all larvae were killed
by resin flow from the traumatic resin canals between the outer- and inner bark or between the inner bark and cambium. In
logs that were cut more than 4 months prior to inoculation, larvae were unable to complete development. In logs cut 2 weeks
prior to inoculation, almost all larvae were able to reach the adult stage but they were smaller in size than adults from
living trees damaged by this borer. These results suggest that poor nutrient conditions in the inner bark of logs affected
development and survival of the borer. Because of its nutritional advantage, living cedars provide a better environment for
the sugi bark borer. However, all larvae are killed by resin flow, suggesting that this insect is “in between” being primary
and secondary with respect to living trees, or a “weak” primary insect. The sugi bark borer seems to develop early in the
season so that early instar larvae encounter reduced amounts of resin flow and so that late-instar larvae feed mostly in summer
when nutrient levels in the inner bark are at their highest. 相似文献
17.
Seiji Tanaka 《Researches on Population Ecology》1994,36(2):137-143
Wing shedding or de-alation is a common phenomenon among crickets. Its significance and effects on other traits were examined
based on the results from experiments using artifical or natural de-alation. Artificial de-alation at adult emergence induces
rapid egg production and flight muscle histolysis in several species examined. However, natural de-alation does not always
shorten the pre-ovipositional period because it does not occur immediately after adult emergence and because oviposition starts
before de-alation. In some cases, naturally de-alated females produce more eggs than to intact females during early adult
life, but peak ovipositing activity occurs before de-alation. Therefore, retention of the hindwings does not suppress high
ovipositing activity in such cases. It appears that de-alation is a result rather than a causal factor in ending migration.
Ovarian development and flight muscle histolysis, which can be stimulated by de-alation, are controlled by the jevenile hormone,
but the mechanism inducing de-alation remains unknown. The possible factors leading to the evolution of de-alation are discussed. 相似文献
18.
Kenji Fujisaki 《Researches on Population Ecology》1993,35(2):171-181
Summary Reproduction and egg diapause of the oriental chinch bug,Cavelerius saccharivorus, in the subtropical winter season were investigated in relation to its wing polymorphism. Macropterous females collected
from the southern part of Okinawa Is. in the autumn season delayed their oviposition and were less fecund early in the adult
life period, but survived much longer than brachypterous females collected from the same locality. The total fecundity was
not significantly different between wing morphs. The diapause of eggs laid by brachypters tended to be terminated more easily
at a high temperature than that of eggs laid by macropters. This indicated that the eggs laid by macropters were more intense
in their diapause than those laid by brachypters. However, irrespective of the parental wing form, diapause showed considerable
variation in its intensity within and between clutches. 相似文献
19.
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
20.
K. Tanaka T. Watanabe H. Higuchi K. Miyamoto Y. Yusa T. Kiyonaga H. Kiyota Y. Suzuki T. Wada 《Researches on Population Ecology》1999,41(3):253-262
To examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint-marked snails of
15–20 mm shell height into 12 enclosures (pens) of 16 m2 at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent
of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density
dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg
masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than
3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however,
higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density.
The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult
density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering
period, was not significantly different among density treatments. These results suggest that snail density after the overwintering
period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate
the population of P. canaliculata in paddies.
Received: October 23, 1998 / Accepted: July 16, 1999 相似文献