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1.
R. N. Coulson P. E. Pulley D. N. Pope W. S. Fargo L. J. Edson 《Researches on Population Ecology》1980,22(1):117-135
Summary Infestations ofDendroctonus frontalis
Zimm. are often observed to enlarge continuously by the colonization of new hosts in a pattern similar to a forest fire. This pattern
of infestation growth presents unique problems in quantitatively estimating populations ofD. frontalis. Beetle populations on each infested tree in an infestation go through five processes: attack, oviposition, reemergence,
survivorship, and emergence. These processes, which have been described mathematically in the literature, each take several
days for completion. In order to follow the distribution and abundance ofD. frontalis throughout the course of development of a spot, we need a daily estimate of the number of beetles involved in each process
on every tree. Since it is not practical to sample each tree daily, we developed a procedure whereby quantitative estimation
procedures for within-tree populations were used in combination with the mathematical models for the life processes to produce
a daily record of the number of adults successfully attacking trees, the number of eggs oviposited, the number of beetles
reemerging, number of beetles surviving within the trees, and the number of beetles emerging. These daily estimates were then
summarized for all trees in the spot for the duration of the infestation.
The daily record of populations ofD. frontalis, used with information on infestation geometry, were suggested to be of value in describing and elucidating several important
facets of population dynamics including dispersal patterns within infestations, between tree beetle loss (mortality), and
time lags among the various population processes. The information reported can be used to develop simulation models of population
dynamics or to validate existing models.
Texas Agric. Experiment Stn. TA No. 14689. 相似文献
2.
Summary Dispersal, immigration and emigration rates, horizontal and vertical survivorship and absolute population size were estimated
for micropopulations ofAn. culicifacies, An. stephensi andAn. subpictus at a series of cattle sheds in rural Punjab Province, Pakistan, during November 1979 and May 1980 using capture-mark-release-recapture
and dissection methods. Dispersal was temperature-related, with populations more vagile during May. Mean dispersal distance
per individual was low for all species. More than 70% of all recaptures were taken at the point of release and the longest
detected flight was 1250 meters.
Horizontal survivorship was greater during November and was always less than vertical survivorship calculated from dissection
agegrading data. Survivorship during the nulliparous period was greater than survivorship throughout total life, indicating
the survivorship curve may be slightly sigmoid. Daily population sizes of endemic and immigrating females and males were calculated
usingBailey's (1952) modification of the Lincoln Index, with the daily captures adjusted for immigration which was highest in May. Daily
additions to the indoor resting population exclusive of immigrants were estimated using the method ofManly andParr (1968). The relationship of the present findings to malaria transmission and genetic control were discussed. 相似文献
3.
Summary A statistical and graphic study is presented of the wastage of eggs byVenturia (=Nemeritis) canescens when searching singly and in groups of 10 among hosts at four different host densities in laboratory universes as described
byHuffaker andMatsumoto (preceding paper of this journal). The host insect was the fluour mothAnagasta kühniella and the host densities used were 10, 30, 100 and 200 per universe. Intensity of egg wastage due to superparasitim varied
significantly according to host density, and between the two parasite densities employed, 1 and 10, using bothF-tests and chi-square tests. Plots ofk-factor analysis on this egg wastage showed high negative correlations with host density, and the raw data for single parasites
was well represented by a parabola while that for the grouped parasites departed from this relationship only at the lowest
host density.
These studies were conducted as a part of a general investigation into the processes operating in the population dynamics
of arthropods under grants from the National Institutes of Health, U. S. Public Health Service (#A10-1611), and the National
Science Foundation and Environmental Protection Agency (NSF DEB7504223) to the University of California. The findings, opinions
and recommendations expressed herein are those of the authors and not necessarily those of the University of California, the
National Institutes of Health, the National Science Foundation or the Environmental Protection Agency. 相似文献
4.
Chobei Imai 《Researches on Population Ecology》1984,26(2):353-362
Summary The population dynamics of the housefly,Musca domestica, on patchy and unstable habitats consisting of refuse was investigated at a waste disposal site by using sticky flypaper
and mark-release-recapture technique (Jolly-Seber's method). The newly disposed garbage was favorable for breeding of the flies for about one month after being disposed, while
a mixture of garbage and ash from incinerated refuse was less favorable. On the garbage under favorable conditions, the rates
of population increase was 1.25–2.82 per day, and approximately 1300–1500 flies were produced per square meter within the
available period of one month. The rapid decrease in the fly density was observed just after the appearance of high density
peaks. The mark-release-recapture study suggested that this rapid decrease would be mainly due to the density-dependent emigration
of adult flies from the patchy habitats. The emigration was also activated when the time after garbage disposition became
long. 相似文献
5.
Summary The functional response ofPseudogonatopus flavifemur E & H (Hym., Dryinidae) was investigated by offering hosts (brown planthopper) at densities ranging from 8 to 160 per cage.
The response curve was found to be sigmoid, i. e.Holling's (1959) Type III curve. In experiments involving 310 hosts per cage distributed unevenly in 5 densities (10, 20, 40, 80
and 160 per hill), and a different female parasite density each time (viz. 1, 2, 4, 8 or 16 per cage), the behavioral response
was described well by the “random predator equation” ofRoyama (1971) andRoger (1972), which is a convex exponential curve. The area of discovery (a) decreased with an increase in female parasite density (P), and the relationship was described by the equation: loga=−1.0099−0.3638 logP. There was an apparent increase in handling time per host as the number of female parasites increased. Superparasitism, a
rare phenomenon under natural conditions, was often observed in the laboratory. The potential ofP. flavifemur as a biocontrol agent of the brown planthopper is discussed. 相似文献
6.
Chobei Imai 《Researches on Population Ecology》1987,29(1):129-146
Summary Susceptible houseflies,Musca domestica, were released at a waste disposal site to control insecticide resistance in a field housefly population. In the first experiment,
a total of 163,000 pupae of the susceptible Takatsuki strain were released in October–November 1977. LD50 values to fenitrothion and diazinon decreased to about one-sixth in April 1978, five months after the releases, of those
before the releases. For the second experiment, a susceptible colony was derived by cross and backcross between a white-eyed
substrain of the Takatsuki and a field colony. This susceptible colony consisted of whiteeyed flies with low activity and
normal-eyed flies bearing no or one white eye gene. The results of large cage experiments suggested that the normal-eyed males
of the susceptible colony had half the mating competitiveness of wild males. Approximately 31,000–46,000 susceptible pupae
were used in each of five releases from October to November 1980. The population number of each sex, estimated by a mark-release-recapture
method, increased from 12,000 in late September to 35,000–43,000 in middle November and then decreased to 5,000–8,000 in early
December. The frequency of field-collected males bearing one white eye gene and those bearing one male determining factor,
which were characteristics of the susceptible colony released, increased gradually during the period of releases. The susceptibility
of the field population to fenitrothion and diazinon was examined five times in the period from September to December 1980.
With time, the dosage-mortality regression gradually shifted towards that of the susceptible colony after starting the releases.
LD50 values to fenitrothion and diazinon decreased to about one-sixth and one-fifth, respectively, in June 1981, six months after
the second series of susceptible fly releases, of those before the releases. Ratios of the wild flies to the released fiies
were estimated to be between 4.7∶1 and 9.8∶1 in males and between 3.0∶1 and 3.9∶1 in females by taking the quality of the
released colony and the population parameters of the field houseflies into consideration. Under several assumptions, the manner
of resistant phenotype reduction was discussed, based on the dosage-mortality regressions and the ratios of released flies.
These results showed that the releases of susceptible flies were successful in suppression of insecticide resistance in the
field housefly population. 相似文献
7.
The outbreak mechanisms of the green rice leafhopper,Nephotettix cincticeps Uhler, in northern Japan
Intraspecific regulatory processes keep the population ofNephotettix cincticeps stable at a low density in southern Japan. In northern Japan, however, the yearly population density of the insect fluctuates
violently, and large outbreaks occasionally take place. To clarify the difference in the population dynamics between the two
regions, we analyzed light-trap and sweep-net sampling records from prefectural and national agricultural experimental stations.
The survival rate of the overwintering population decreased with increases in the period of continuous snow cover (PCSC) in
the north, and initial population densities in the years of long PCSC were too low for populations to reach equilibrium density
by the end of the active breeding season. This made yearly population fluctuations in the north much larger than in the south.
The equilibrium density in the north was higher than in the south. The higher equilibrium density presumably permits the higher
population density and larger yearly population fluctuations in the north. A major factor responsible for the difference in
equilibrium densities between the two regions is the difference in heading dates of the host plant (rice). Qualitative differences
among rice plant varieties, and among biotypes ofN. cincticeps, may also be important. 相似文献
8.
Alan J. Sawyer 《Researches on Population Ecology》1989,31(1):11-24
Summary
Taylor's power law,s
2
=am
b
, provides a precise summary of the relationship between sample variance (s
2
) and sample mean (m) for many organisms. The coefficientb has been interpreted as an index of aggregation, with a characteristic value for a given species in a particular environment,
and has been thought to be independent of the sample unit. Simulation studies were conducted that demonstrate that the value
ofb may vary with the size of the sample unit in quadrat sampling, and this relationship, in turn, depends on the underlying
spatial distribution of the population. For example, simulated populations with hierarchical aggregation on a large scale
produced values ofb that increased with the size of the sample unit. In contrast, for a simulated population with randomly distributed clusters
of individuals, the value ofb eventually decreased with increasing quadrat size, as sample counts became more uniform. A single value ofTaylor'sb, determined with a particular sample unit, provides neither a fixed index of aggregation nor a complete picture of a species'
spatial distribution. Rather, it describes a consistent relationship between sample variance and sample mean over a range
of densities, on a spatial scale related to the size of the sample unit. This relationship may reflect, but not uniquely define,
density-dependent population and behavioral processes governing the spatial distribution of the organism. Interpretation ofTaylor'sb for a particular organism should be qualified by reference to the sample unit, and comparisons should not be made between
cases in which different sample units were used. Whenever possible, a range of sample units should be used to provide information
about the pattern of distribution of a population on various spatial scales. 相似文献
9.
Summary Time-specific life tables were constructed for three pea aphid,Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), populations using a modification ofHughes' analytical procedure. All populations were studied on second-growth alfalfa (mid-June to mid-July) in south central Wisconsin;
data for two populations were collected during 1980, and data for the third population were collected during 1982. The intrinsic
rate of increase (r
m) estimated on a physiological time (day-degree) scale under field conditions but in the absence of natural enemies, provided
a reliable estimate of potential population growth rate and was used in preference toHughes' approach of estimating potential population growth rates directly from stage structure data. Emigration by adult alatae and
fungal disease were the major sources ofA. pisum mortality in each of the three populations studied. These factors were most important because of their impact on reducing
birth rates within the local population. Parasitism was never greater than 9 percent. Mortality attributable to predation
ranged from 0.0 to about 30.0%; however, even at the highest predator densitiesA. pisum populations increased exponentially. 相似文献
10.
Summary A marking-and-recapture study of a population of overwintered adults ofEpilachna sparsa orientalis was carried out in a small farm containing potatoes and egg-plants. The experiment involved a single release and five recapture
samplings during May–June. The data were analysed byLeslie's re-recapture method. Assumption of randomness of sampling proved to be well satisfied.
Survival rate of the overwintered adult population was maintained as high as 90 per cent per week or more until early June,
and then it declined rapidly towards the end of June. Initially overwintered adults exclusively lived on potato plants, but
half of the population alive in mid June migrated to nearby egg-plants. Emigration out of the experimental field, however,
seemed not to be occurring.
Recapture data of marked individuals in the potato field indicate that majority of the individuals stayed within a radius
of 3 m, at least for 2 weeks. Similar data taken from another field also suggest that their mobility was far restricted as
compared with random movement within the field.
Some comparisons were made between the population behaviours of overwintered adults ofE. sparsa orientalis andE. vigintioctomaculata.
Contribution from the Entomological Laboratory, Kyoto University, No. 371. 相似文献
11.
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
12.
《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
13.
William K. Reisen Farida Mahmood Tauheeda Parveen 《Researches on Population Ecology》1979,21(1):12-29
Summary A mark-release-recapture experiment to estimate population survivorship and absolute size was performed with wild-caughtAn. subpictus adults at the village of Khano-Harni, Lahore District, Punjab Province, Pakistan during September 1978, the end of the monsoon
rainy season, when temporal population abundance was maximized. Daily survival rate estimated from the recapture sequence
of marked adults was low, males=0.192 and females=0.343. Survivorship for females estimated by several vertical age-grading
procedures ranged from 0.347 to 0.628. Both stage- and age-specific life tables were calculated from vertical age-grading
data determined by the dilatation method. Female and male population size was estimated byBailey’s modification of theLincoln Index and was found to average 4478.4 and 6106.8, respectively. The bionomics, survivorship and population size ofAn. subpictus in the Lahore are indicated that this species was probably not important in the transmission of human malaria. 相似文献
14.
Boyd Collier 《Researches on Population Ecology》1968,10(1):99-104
Summary High and low emigration rates through a laboratory system were selected for in populations of house flies (Musca domestica L.). Emigration consisted of movement of flies from on plastic box to another by way of a connecting tube. Selection was
carried out by first dividing a wild population of flies into two lines and then selecting for movement from the box in one
line and against movement from the box in the other line. The selection experiment was performed twice. In both experiments
a statistically significant difference between the two strains was obtained in three to four generations of selection. In
the second experiment, after 5 genrations the mean number of high emigration rate flies emigrating in 1 hour was 4.37 times
the mean number of low emigration rate flies and in 24 hours was 2.81 times the number of low emigration rate flies. The second
experiment was terminated after 6 generations, but the first experiment was continued for 35 generations. In this case, divergence
ceased in roughly 15 generations.
The possible relevance of the findings to laboratory population experiments in which spatial discontinuities are included
is discussed.
This study was supported by a research grant of the National Science Foundation (Environmental Biology GB 4567) to Prof. DavidPimentel. The author wishes to thank Prof.Pimentel for his aid and encouragement. 相似文献
15.
Shiro Kobayashi 《Researches on Population Ecology》1965,7(2):109-117
Summary To investigate the relation between the distribution pattern of eggs and the parental density in the common cabbage butterfly,Pieris rapae crucivora, the countings of egg number per plant were made on both cabbage plants cultivated in the farm and planted in the net house
in which the female butterflies were released at various densities.
The frequency distribution of eggs fits well to the negative binomial excepting the cases where they agree withPoisson series, and the degree of aggregation expressed as the reciprocal of the parameter, 1/k, tends to decrease as the egg or parental density increases. At the same parental density, however, the distribution of eggs
can be described by the negative binomial with a common parameter,k
c, regardless of the difference in the density of laid eggs.
In the case where a single female butterfly lays eggs, the spatial pattern of egg distribution is always lean, while its frequencies
conform toPoisson or the negative binomial series. This lean changes toward patchy with increasing the parental density.
From these results, it is concluded that the degree of aggregation in the distribution of eggs decreases with the increase
of the parental density. 相似文献
16.
Summary Population behaviour of adults and 5th-instar nymphs ofNezara viridula L. was analysed by means of the marking-and-recapture method in an early-planted paddy field. The field contained five varieties
of rice which differend in growth states. It was estimated that a total of more, than 7,000 adults of the first generation,
in which at least 3,000 were females, invaded the field from early July to middle August. Egg-mass census data, however, indicated
that only 10 per cent or less of the females participated in egg-laying. This was largely due to the, low rate of adult survival.
The adults preferred younger plants, for both feeding and oviposition.
The method described byIwao
et al. (1966) permitted estimate that 3,300–3,400 of the 5 th-instar nymphs and 1,100–1,200 of the adults of the second generation
were produced from 298 egg-masses (25, 700 eggs); while 95–6 per cent of the individuals were thought to have died before
reaching adulthood. Most of the 5 th-instar nymphs moved less than 4 m in three days as long as the condition of food plants
remained suitable, but they tended to move more towards younger plants when those on which they lived became too mature. The
apparent survival rate of the second generation adults was very low, probably due both to a rapid emigration and a high mortality
of newly-emerged adults. 相似文献
17.
Kazuo Nakamura 《Researches on Population Ecology》1968,10(1):45-53
Summary An wolf spider,Lycosa pseudoannulata, collected from the field were reared in test tubes supplied with fruit flies as the food, and the number and weight of fruit
flies killed per unit time and the weight of residuum of killed flies were recorded. When the cumulative number of flies killed
by a spider was plotted against time after the beginning of food supply, the angle of the curve obtained decreased gradually
until a constant value. In this time, it seems that the gut of spider had saturated with food and the increase rate of number
of flies killed reflects the rate of food disappeared from gut by assimilation and egestion. The amount of ingestion was obtained
by subtracting the weight of residuum and the gain of live weight of the spider from the weight of killed flies. After the
gut has saturated, the amount of food remained in the gut is considered to be equal to the capacity of gut, which is an essential
factor in the study of predation. The amount of food disappearance from gut was also estimated.
There was a linear relationship between the log body weight of spiders and the log capacity of gut. The linear relationship
was also seen between the log total amount of ingestion and the log total amount of food disappeared from gut. 相似文献
18.
T. H. Chua 《Researches on Population Ecology》1977,19(1):125-139
Summary Studies on populations ofBrevicoryne brassicae (L.), its parasites and hyperparasites were carried out by actual counting in the sprouts field and by sticky and water traps.B. brassicae was found to be attacked by one primary parasite,Diaretiella rapae (McIntosh), which in turn is parasitized byAlloxysta brassicae (Ashm.),Asaphes vulgaris
Walker,A. suspensus (Nees),Pachyneuron minutissimum (F?rster) andDendrocerus carpenterii (Curtis). The aphid population in the field was started by immigrant alates which were found flying too early to be synchronized
with the sprouts plants. SimilarlyD. rapae was not synchronized with the aphids although many individuals could have been carried into a plot through parasitized immigrant
alates, of which less than 30% were found parasitized. Because of high hyperparasitism (especially byA. brassicae)D. rapae was not able to maintain a high rate of parasitism to curb the aphid population growth. The maximum percentage mummies being
27.8%, while the maximum, percentage parasitism being 56.6% recorded only during the early 1974 season (mean=12.9%). The decline
of aphid population from September onwards was largely due to the cold weather, Syrphid predation and occasionally fungal
attack. The high rate of hyperparasitism byA. brassicae is attributed to its better synchronization withD. rapae. The mean percentage of parasite that emerged from mummies collected during 1973–74 wereD. rapae 31.3%,A. brassicae 64.3%,A. vulgaris andA. suspensus 4.3%,D. carpenterii 0.2% andP. minutissimum 0.1%. 相似文献
19.
Katsumi Togashi 《Researches on Population Ecology》1990,32(1):1-13
Summary Newly-emerged adults ofMonochamus alternatus aged 1 to 5 days were code-numbered with lacquer paint and released by placing them on the trunks of one or two trees in
aPinus thunbergii stand at weekly intervals during the beetle emergence period from 1980 to 1983. Beetles were captured at weekly intervals
from one week after the first day of release. Determinations were made on the distance and direction of beetle dispersal during
a week after release and analysed by a method of Inoue (1978). When the stand canopy was closed, the rate of beetle’s stay
on trees was 0.56 per week. The beetles dispersed at random by walk and flight. When the pine stand was sparse, the rate of
beetle’s stay on trees was 0.02–0.30 per week. They dispersed at random by flight. The average distances traversed were estimated
to be 7.1–37.8 m for the first week after emergence. Using other method, the average distance traversed was estimated to be
10–20 m for each week through the first 3 weeks after release. The results of stepwise multiple regression analysis and a
simple field experiment suggested that the dispersal of newly-emerged beetles was affected by stand density, number of beetles
emerging from individual dead trees, maximum air temperature, and precipitation. 相似文献
20.
Kazuhiko Kosuda 《Researches on Population Ecology》1981,23(2):379-386
Summary Competition experiments between a lac+ prototroph and a lac− auxotroph ofEscherichia coli were conducted by serial transfer procedure on four levels of sugar concentration. Changes of the relative frequencies of
both genotypes were followed and the relative fitness was estimated. Fitness was proved to be density-dependent. No explicit
dependence of fitness upon genotype frequencies could be detected by the simple method ofKosuda (1981). 相似文献