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1.
A. J. Hayes 《Researches on Population Ecology》1988,30(1):13-24
Summary The numerical response of adult femaleT. pyri feeding on different levels of ERM larvae, and at a range of temperatures was examined. The duration of the pre-oviposition
period decreased as larval consumption increased, and the rate of oviposition was linearly related to the rate of consumption
of larvae. Mathematical models were used to describe these relationships in terms of temperature and consumption of ERM larvae.
The results were discussed in relation to the nature of theT. pyri/ERM interaction in New Zealand apple orchards. 相似文献
2.
We studied seasonal changes in the larval population structure, adult size, and autogeny (egg production without a bloodmeal)
of the mosquitoAedes togoi on the seacoast of northern Kyushu, Japan. The effects of temperature, photoperiod and food conditions on larval development,
adult size and autogeny were studied in the laboratory.Aedes togoi overwintered in both the egg and larval stages and was multivoltine. Adult size was greater in spring and autumn and smaller
in summer. Autogeny occurred in spring and autumn but not in summer. Autogenous females were larger than anautogenous females,
and larger autogenous females produced more eggs. Laboratory experiments showed that autogeny was promoted under low temperature
and short-day conditions which corresponded with spring/autumn conditions in the field. Experimental food limitation in the
larval stage greatly reduced adult size and autogenous egg production. In the field, large inter-pool variations in adult
size and autogeny rate probably resulted from variations in nutrient and crowding conditions. Seasonal autogeny ofAedes togoi was discussed in terms of life-history strategy under fluctuating environmental conditions where relative advantages of autogenous
and anautogenous reproduction alternate seasonally. 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.
Ronald A. Nussbaum 《Researches on Population Ecology》1987,29(1):27-44
Summary The safe harbor hypothesis includes the suggestion that parental care causes the embryonic stage to be the safest harbor,
and, therefore, egg size will increase in populations with parental care to decrease the duration of subsequent, higher risk
stages. Neither the safe habor hypothesis nor r and K theory seem adequate to explain the correlation between egg size and
the presence/absence of parental care among salamanders, a group in which there is a further correlation between the larval
(hatchling) habitat and egg size/parental care. Pond-breeding salamanders generally have small eggs and lack parental care,
and stream-breeding salamanders generally have large eggs and parental care. I argue that the fundamental difference in the
food available to hatchling salamanders between lentic (plankton-rich) and lotic (plankton-poor) environments selects for
relatively lower parental investment in the lentic environment. From the standpoint of parental fitness, small (more numerous)
hatchlings have a greater payoff where the available food is mall and dense (zooplankton in lentic environments), and large
hatchlings are selectively advantageous where the food is of large size and less dense (benthic invertebrates in lotic environments).
Selection for larger hatchlings in lotic environments results in longer embryonic periods and,ceteris paribus, greater total embryonic mortality. Embryo hiding and guarding have evolved among lotic-breeding salamanders as compensatory
mechanisms to reduce the rate of embryonic mortality. In this view, parental care is a consequence of selection for larger
egg size and not an umbrella that allows egg size to increase, contrary to the safe harbor hypothesis.
The relationship between variance in parental investment and food available to offspring, developed here for salamanders,
may be of general significance. YosiakiIt?, a critic of r and K theory, independently arrived at a similar conclusion from a broader data base. 相似文献
5.
Summary Two species of tortoise beetles,Aspidomorpha miliaris (AM) andA. sanctaecrucis (AS) feeding on a shrub-like morning glory,Ipomoea carnea, were reared under laboratory conditions to study their survivorship and fertility schedules. AM and AS required 34–39 days
and 30–37, respectively, for the development of the immature stages. The mean longevity of the males was 88.4 days in AM and
63.8 in AS, and that of females was 87.9 days in AM and 83.3 in AS. The mean length of the pre-reproductive period (27.2 days
in AM and 33.8 in AS) was much longer than that of the post-reproductive period (10.9 days in AM and 14.3 in AS). Females
laid eggs at a nearly constant rate throughout their reproductive period. The reproductive valueV
x
/V
0
of the two species remained high for most of their adult life, as a result of prolonged survivorship and fertility periods.
The total number of eggs produced per female was 442.9 (AM) and 80.1 (AS). The intrinsic rate of natural increaser was 0.070 (AM) and 0.044 (AS) per capita per day. The prolonged reproductive schedules, coupled with strong dispersal power,
of these species no doubt have an adaptive value for living in highly disturbed tropical environments, where rainfall is ample
but unpredictable and food resources are available throughout the year in a wide area, but distributed in widely flung patches.
Contributions to the knowledge of population dynamics of tortoise beetles in Sumatra 3.
Contribution No. 33 of Sumatra Nature Study (Entomology).
Partly supported by Grants from Japan Society for Promotion of Science for JSPS-DGHE Scientific Cooperation (1980, 1982) and
Grants-in-Aid for Overseas Scientific Survey from Ministry of Education, Science and Culture of Japan (Nos. 56041027 and 58041030). 相似文献
6.
Summary The functional response ofCyrtorhinus lividipennis feeding on brown planthopper (BPH) and green leafhopper (GLH) eggs was found to be Holling’s Type II. The Random Predator
Equation fitted the data satisfactorily. Using Manly’s preference index, α, both the male and femaleC. lividipennis were found to prefer BPH eggs. There was, however, no evidence of switching and the ratio of the respective searching efficiencies
could account for the preference. 相似文献
7.
Yoichi Shirai 《Researches on Population Ecology》1995,37(2):269-277
Plutella xylostella in the temperate zone shows a clear seasonal change in adult body size. In the laboratory, large and small moths were produced
during immature stages at 15°C and 25°C, respectively. These moths were then used to evaluate longevity, age-specific flight
ability, flight ability of mated and unmated females, and the influence of flight experience on the subsequent reproductive
success. The large moths lived longer and displayed a greater flight ability over 3 weeks. Irrespective of body size, unmated
females flew for a longer time than mated females, and flight experience affected their subsequent reproductive success. Females
of both sizes mated and laid eggs soon after emergence, without any obvious pre-reproductive period. More flight experience
did not delay oviposition, but did reduce egg production. It is likely that large moths with a longer adult life span and
greater flight ability are better fitted for long-distance flight and more fecund than small ones. These experimental results
may explain why long-distance migration ofP. xylostella is mostly seen during cool seasons, when relatively large moths with long forewing appear in the field. 相似文献
8.
Shiro Kobayashi 《Researches on Population Ecology》1966,8(1):51-59
Summary The process generating the negative binomial in the distribution pattern of eggs of the common cabbage butterfly,Pieris rapae crucivora, was investigated by releasing the female adults in a net house where cabbages were planted.
The distribution of butterflies visited and laid an egg or more per plant followed thePoisson series under the uniform light condition, while that of eggs laid per visit conformed to the logarithmic distribution. From
these results, it may be concluded that the negative binomial arises from compounding of thePoisson and the logarithmic distribution. The observed frequency of eggs found per plant fitted to the negative binomial with parameter
thus computed theoretically.
The change in the degree of aggregation with the increase of the parental density was considered in connection with the above
results.
Aided by a grant from Scientific Research Expenditure of the Ministry of Education. 相似文献
9.
Summary We studied the interpecific competition between 2 species of predatory aquatic bugs,Diplonychus japonicus andD. major by conducting a field experiment. We set up 3 types of experimental plots in the paddy fields whereD. major predominated. The two plots contained single species of eitherD. japonicus orD. major, respectively, and one plot had both species in equal number. We compared the development and the reproductive performance
between plots in each species.
InD. japonicus, the number of eggs and early instar nymphs were significantly smaller in the plots containing both species than in the monospecific
plots. However, the numbers of late instar nymphs and newly emerged adults were not significantly different between plots.
The proportions of starved nymphs in both plots were larger than those in theD. japonicus's natural habitats. The final densities of adults in both plots were lower than those in the natural habitats. These results
suggest that lower density ofD. japonicus in these paddy fields is due to the lack of available food for nymphs rather than the effects of interspecific competition
withD. major.
InD. major, significant differences were not found in the number of eggs, each instar nymphs and adults. These results suggest that
the effects of interspecific competition did not affect the reproductive performance ofD. major. 相似文献
10.
T. S. Bellows Jr. 《Researches on Population Ecology》1985,27(1):65-76
Summary Oviposition rates and related behaviours were quantified forLariophagus distinguendus
F?rster attackingCalosobruchus chinensis (L.) andC. maculatus (F.). Oviposition rates varied with parasitoid age; parasitoids aged 1–7 days laid approximately twice as many eggs per day
as those aged 8–14 days. Similar differences were noted in search rates and handling times; younger parasitoids had higher
attack rates and lower handling times than older parasitoids. Search rates and handling times also varied with the host stage
available for attack. Search rates were higher and handling times were lower on larger stages. The results are discussed with
reference to their impact on the dynamical behavior of insect parasitoid-host populations. 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
Mun Il Ryoo 《Researches on Population Ecology》1986,28(1):17-26
Summary The basic components of the predation ofPhytoseiulus persimilis
Athias-Henriot feeding upon eggs ofTetranychus urticae
Koch were studied in an open system where the predator could disperse freely.
The type of the functional response of the predator to the density of its prey was the same as that studied so far in a closed
system, i.e.,Holling's Type 2. The search rate of the predator, however, was much lower in comparison with the result from a closed system. The
oviposition of the predator per day was only weakly related to prey densities higher than 10 per leaf disc. But the emigration
rate was inversely dependent upon the initial prey density up to 60 per leaf disc. The searching behaviour of the predator
was influenced by both the web density spun byT. urticae and the density of the prey: the predator searched for its prey intensively only after it had contact with web. Mutual interference
was observed in prey consumption, but not in the emigration rate. The emigration rate was largely dependent upon the prey
density available per predator. 相似文献
18.
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
19.
Tatsuto Kajimura I Nyoman Widiarta Kazuya Nagai Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1995,37(2):219-224
The reproduction ofSogatella furcifera was investigated in a chemically fertilized rice field and an organically farmed field. In the latter, the density of immigrants
was significantly higher, while the settling rate of female adults and the survival rate of immature stages of ensuing generations
were lower. The number of eggs laid by a female of the invading and following generations was smaller, and the percentage
of brachypterous females in the next generation was also lower. Consequently, the density of nymphs and adults in the ensuing
generations decreased in the organically farmed field. For an experimental comparison, potted rice plants were cultivated
using seedlings and soil from the chemically fertilized or the organically farmed fields. WhenSogatella furcifera was reared on these plants, both the reproductive rate and the appearance rate of brachypterous female adults were lower
in the organic treatment. Egg hatchability was also lower in the organic treatment. This experiment suggested that a specific
nutritional condition in rice plants suppressed the population ofS. furcifera in the organically farmed field. 相似文献
20.
Sibling cannibalism in the ladybird beetleHarmonia axyridis: Fitness consequences for mother and offspring 总被引:1,自引:0,他引:1
Naoya Osawa 《Researches on Population Ecology》1992,34(1):45-55
Summary The adaptive significance of sibling cannibalism was analyzed in the ladybird beetleHarmonia axyridis at two prey densities. Possible costs and benefits were considered from three points of view: the mother, the cannibal and
the victim. Cannibals ate both infertile and fertile eggs, thereby increasing in body length and survival rate with the intensity
of sibling cannibalism. The cannibalistic trait was clearly beneficial to the cannibal when aphid density was low. However,
it was not always beneficial when aphid density was high and the victims were full siblings. The altruistic behavior of being
a victim was beneficial only when the victim was cannibalized by full siblings at low aphid density. The mother attained almost
equal fitness at low aphid density, regardless of the intensity of sibling cannibalism. This suggests that sibling cannibalism
is not maladaptive for the mother. At high aphid density, however, mother’s fitness decreased with the intensity of sibling
cannibalism, indicating that sibling cannibalism is maladaptive for the mother when larval food availability is high. 相似文献