共查询到20条相似文献,搜索用时 125 毫秒
1.
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
2.
Tuyosi Sugimoto 《Researches on Population Ecology》1978,19(2):197-208
Summary The present paper studies how the female parasite ofKratochviliana sp. visits and attacks its host larvae of Ranunculus leaf mining fly,P. ranunculi at a single leaf visit. The parasite visited its hosts at random on the leaf. The frequency of host visits was independent
of the host density and the proportion of hosts survived from the parasite attack, in a leaf and its distribution was expressed
as a single straight line. It almost always attacked living hosts at the first host visit after isolated from them for one
day but with the rate of about 0.5 at the subsequent visits. In consequence, the relationships of the number of host attacks
and killed hosts to the host density drew satulated curves in each. A model of host attack by this parasite at its single
leaf visit was formulated by modifyingBakker
et al.'s model (1972) basing upon these observations and the attack avoidance by the parasite to already attacked hosts previously
reported.
Ecological studies on the relationship between Ranunculus leaf mining fly,Phytomyza ranunculi
Schrank (Diptera; Agromyzidae) and its parasite,Kratochviliana sp. (Hymenoptera; Eulophidae) from the viewpoint of spatial structure II.
This paper constitutes a part of the Doctoral Thesis presented to the College of Agriculture, Kyoto University by the present
author. 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.
Summary AsMatsumoto andHuffaker (1973) concluded that their initial universe size was too small for the proper separation of the effects of host density
and dispersion on parasite performance, a larger universe of 38 1/2″ (length) ×38 1/2″ (width) ×3″ (height) was used.
When individual parasites were exposed to fixed densities and dispersion patterns of host, they displayed an overall decrease
in the parasitization rate when compared to the small universe. In all cases aHolling-type response resulted.
When a group of 10 parasites per test was employed a Nicholsonian type of response resulted.
In an experimentally confined space, the parasites displayed a mutual behavioral interference resulting in emigration which
accelerated as the parasite density increased.
These studies were conducted as a partial fulfillment in the Ph. D. program of one of us (B. M. Matsumoto) and is a part of a broad investigation into the processes operating in the dynamics of arthropod populations under grants
toC. B. Huffaker from the U. S. Public Health Service, National Institutes of Health and the U. S. Department of Agriculture. 相似文献
5.
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
6.
Summary A series of experiments were carried out with the endophagous egg parasiteTelenomus fariai on its hostTriatoma phyllosoma pallidipennis to determine the possible role of intraspecific competition by the parasite progeny in population regulation of the parasite.
Eight parasite densities (1, 3, 5, 10, 20, 30, 40, and 50 individuals per vial) were used, and the design of sequentially
sacrificed replicates applied. Survivorship curves for each density indicated smaller number of progeny per host at higher
densities, and the shapes of the curves suggested a relatively early mortality process.Morris' linear regression technique for determining within-generation density-dependence was used, and the results showed that only
larval mortality could be identified as density dependent. The same technique applied within the larval stage proved that
only mortality of larvae in their second, third, and fourth day of development were responsible for population regulation.
The applicability of the technique, as well as the relevance of the results for natural population, is discussed. 相似文献
7.
Mutsunori Tokeshi 《Researches on Population Ecology》1995,37(1):43-48
The mathematical basis of a widely-known variance-mean power relationship of ecological populations was examined. It is shown
that the log variance (S
2)—log mean, (m) plot is virtually delimited by two lines logS
2=logn+2 logm and logS
2=logm, thus increasing the chance that a linear regression line can be successfully fitted, without a profoundly behavioural background.
This makes difficult the task of interpreting a successful fit of the power law regression and its parameterb in a biologically meaningful manner. In comparison with the power law regression, Iwao'sm
*-m regression is structurally less constrained, i.e. has a wider spatial region in which data points can scatter. This suggests
that a comparison between the two methods in terms of how good a fit is achieved for a particular data set is largely meaningless,
since the power law regression may inherently produce a better fit due to its constrained spatial entity. Furthermore, it
could be argued that a successful fit in Iwao's method, when found, is less taxed with mathematical arterfacts and perhaps
more clearly linked to some biological mechanisms underlying spatial dispersion of populations. 相似文献
8.
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
9.
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
10.
This is the first follow up study measuring quality of life among abused women who have left their abusive partner. The women
(n = 22) answered a questionnaire while staying at women’s shelter and one year later. The aim was to examine long-term effects
of intimate partner violence against women on health-related quality of life. Health-related quality of life was measured
using the SF-36 Health Survey and the WHOQOL-BREF. The meantime for living in a violent partnership was 11 years, most of
the women had children under 10 years living with them, low income and were on sickness absence or disability pension. About
half of the women had experienced threats of violence and 6 had experienced violent acts after leaving their partner. SF-36
scores after one year were significantly better in vitality (t-test, P < 0.001), mental health (t-test P < 0.001) and social domains (t-test, P < 0.04). WHOQOL-BREF scores did not change significantly from baseline, showing that the SF-36 showed more responsiveness
in this population. Regression analysis showed that serious physical violence reported at baseline predicted significantly
less improvement in physical and mental health and role-emotional in the SF-36 and in social relationships and environmental
health in the WHOQOL-BREF. High psychological violence at baseline predicted significantly less improvement in mental health
in the SF-36 and in social relationships and environmental health in the WHOQOL-BREF. 相似文献
11.
Pierre-Alexandre Landry Fran?ois-Joseph Lapointe 《Researches on Population Ecology》1999,41(3):263-268
A survey of the genetic variability in deer mouse populations was performed using specimens collected from six different
islands on a lake covering approximately 50 km2. Random amplified polymorphic DNA (RAPD) was used to measure the extent of the genetic differences in this insular system.
An analysis of molecular variance (AMOVA) revealed that populations are clearly separated at this microgeographic scale (F
st
= 0.13863; P < 0.001). The homogeneity of molecular variance test (HOMOVA) indicated that within-population levels vary greatly (B
p
= 0.76831; P < 0.001). The within-population molecular variance was found to be mainly correlated with the accessibility of the islands,
computed as the inverse of the geographic distance separating an island from the lakeshore (r = 0.916; P < 0.003).
Received: March 5, 1999 / Accepted: July 16, 1999 相似文献
12.
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
13.
Summary Dispersions and resource utilization of primary and secondary parasitoids developing in non-depletable primary host populations
were determined for an aphid-parasitoid community occurring on strawberries. Analyses of dispersions based onGreen's coefficient andLloyd's Patchiness Index indicated parasitized aphids were highly aggregated initially, became less aggregated as density increased,
and remained aggregated following collapse of the aphid populations. The “index of aggregation” values calculated usingTaylor's Power Law concurred with results from the other indices, and the similarity of the regression coefficients from both seasons
suggests that the index of aggregation may be characteristic for communities as well as species. Analysis withIwao's regression of mean crowding on the mean generated similar results when population data were stratified temporally, and
also indicated that the individual was the basic unit of the population.
In a non-depletable environment, oviposition of individuals exhibiting an aggregated dispersion pattern within clumps of hosts
provides primary parasitoids with a suitable trade-off between energy utilization or genetic potential, and losses associated
with hyperparasitism. 相似文献
14.
Tock H. Chua 《Researches on Population Ecology》1992,34(2):285-292
Summary The effect of body size, as measured by the head width, of the femaleBactrocera sp. Malaysian A (kept separately in sexual pairs) on the demographic parameters was investigated in the laboratory under
ambient conditions of 28–30°C, 78–85% RH and natural photoperiod. Body size was shown to influence significantly all the demographic
parameters. The expectation of life of females at eclosion from pupae was respectively for head widths of 1.6, 1.8, 1.9, 2.0
and 2.1 mm: 76.2, 73.4, 73.8, 102.4 and 115.2 days. The mean number of eggs laid per female in its life time was respectively:
86.4±48.7, 181.8±56.1, 229.7±72.6, 364.3±69.4 and 477.5±109.3 which was significantly different from one another (F=3.73,P<0.05) especially the two smaller sizes from the two larger sizes. The regression line for total eggs laid (Y) against head width (X) wasY=785.2X−1208.7 (R
2=0.35,P<0.001). The net reproductive rate (R
0) was respectively 15.8, 34.0, 43.5, 66.9 and 88.8 eggs, while the intrinsic rate of increase (r) was respectivley 0.0435, 0.0538, 0.0670, 0.0665 and 0.0711. The results confirm that for mass rearing purposes, larger females
which produce more offspring are to be preferred. 相似文献
15.
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
16.
J. N. Ayertey 《Researches on Population Ecology》1980,22(1):101-116
Summary This paper describes a series of experiments conducted to determine whySitophilus zeamais
Mots. andSitotroga cerealella (Oliv.) could not survive together in maize cultures in the laboratory. The effect ofS. zeamais on different developmental stages ofS. cerealella was investigated. The presence of adultS. zeamais slightly affected moth copulation, egg laying and moth eggs in a mixed culture, but large numbers of developing moths inside
maize grains were killed by the adult weevil through feeding on the grains. The major cause of elimination ofS. cerealella byS. zeamais from mixed cultures was therefore found to be damage to the immature moths in grain and such moth mortality increased as
the developing moths became bigger in the grains. A weevil: grain ratio of approximately 1.4∶1 was found to be the critical
weevil density at which the moth disappeared from the mixed cultures. 相似文献
17.
Takayuki Ohgushi 《Researches on Population Ecology》1988,30(1):57-68
Summary The relationships between egg predation of an herbivorous lady beetleEpilachna niponica (Lewis) and its predator, the earwigAnechura harmandi (Burr), were examined in both time and space. In spite of little annual, changes in egg densities, egg mortality due to predation
varied considerably. There was no, clear relationship between the earwig density and the proportionate predation over the
five years. The seasonal occurrence of earwig nymphs on thistle plants, however, was closely synchronized with that of egg
predation. Predator attacks on the beetle occurred in a time-restricted manner. Thus, later cohorts mostly escape from heavy
predatory pressure. No spatially density-depent egg predation was detected at the level of either thistle plants or thistle
patches. Furthermore, there was no indication of aggregative behaviour of the earwig in response to local egg density. The
earwig density was more likely to be associated with particular localities with sandy deposits available for its nest site. 相似文献
18.
《Women and birth : journal of the Australian College of Midwives》2022,35(6):619-627
Background and ProblemExisting healthcare systems have been put under immense pressure during the COVID-19 pandemic. Disruptions in essential maternal and newborn services have come from even high-income countries within the World Health Organization (WHO) European Region.AimTo describe the quality of care during pregnancy and childbirth, as reported by the women themselves, during the COVID-19 pandemic in Sweden, using the WHO ‘Standards for improving quality of maternal and newborn care in health facilities’.MethodsUsing an anonymous, online questionnaire, women ≥18 years were invited to participate if they had given birth in Sweden from March 1, 2020 to June 30, 2021. The quality of maternal and newborn care was measured using 40 questions across four domains: provision of care, experience of care, availability of human/physical resources, and organisational changes due to COVID-19.FindingsOf the 5003 women included, n = 4528 experienced labour. Of these, 46.7% perceived a poorer quality of maternal and newborn care due to the COVID-19. Fundal pressure was applied in 22.2% of instrumental vaginal births, 36.8% received inadequate breastfeeding support and 6.9% reported some form of abuse. Findings were worse in women undergoing prelabour Caesarean section (CS) (n = 475). Multivariate analysis showed significant associations of the quality of maternal and newborn care to year of birth (P < 0.001), parity (P < 0.001), no pharmacological pain relief (P < 0.001), prelabour CS (P < 0.001), emergency CS (P < 0.001) and overall satisfaction (P < 0.001).ConclusionConsiderable gaps over many key quality measures and deviations from women-centred care were noted. Findings were worse in women with prelabour CS. Actions to promote high-quality, evidence-based and respectful care during childbirth for all mothers are urgently needed. 相似文献
19.
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
20.
Of the biotic factors potentially affecting the foraging behavior of pit-building antlion larvae,Myrmeleon bore
Tjeder, we focussed on the density effects and examined experimentally influences of larval density on pit construction behavior,
spatial distribution and pit relocation rate. Moreover the mechanism of mutual interference among larvae was examined.
相似文献
1. | After releasing 2, 5, 10, 15, 20 and 30 third instar larvae ofM. bore at the center of each container (30×30×10 cm3) filled with sand, we measured number of pits, pit diameter and position of pit base. |
2. | More than 80% of antlion larvae at each density always constructed pits, and the rates of larvae that had not constructed pits rose in proportion to the density. Pit size was approximately constant independent of the density. |
3. | The density ofM. bore larvae clearly affected the residence time of the pits, i.e. more larvae frequently relocate pits with increasing larval density. |
4. | To analyze the spatial distribution pattern of the larvae in a container, nearest neighbor distance (NND) was measured. Comparison between the observed NND and the expected value for NND in random distribution obtained from computer simulation suggested that high larval density produced a uniform distribution owing to their mutual interference. |
5. | The result of an experiment to examine the mechanism of mutual interference among larvae showed that frequent dropping of sand into a pit tossed by neighbor antlion larvae causes a pit-relocation. |