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1.
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
2.
T. S. Bellows Jr. 《Researches on Population Ecology》1985,27(1):55-64
Summary The effects of host age on parasitoid reproductive capacity are studied using the pteromalid parasitoidLariophagus distinguendus
F?rster and its bruchid hosts,Callosobruchus chinensis (L.) andC. maculatus (F.). A series of experiments were performed to investigate relationships between age and size of host parasitized and the
developmental period of pre-imaginal progeny, sex ratio, female size, longevity, fecundity and oviposition rate. There was
no effect of host size on preimaginal parasitoid developmental period. Sex ratio varied from less than 5% females from young
(small) hosts to 60% females from mature (large) hosts. Adult size, female longevity, fecundity, and oviposition rate were
also positively related to host age. Females provided mature hosts lived longer than those provided either young hosts or
no hosts, possibly because of an increased ability to host-feed from the larger hosts. The implications of these findings
to parasitoid population reproductive capacity and host-parasitoid synchrony are discussed. 相似文献
3.
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
4.
Summary We studied the stopping rule obeyed by the female parasitoid,Chrysocharis pentheus, in deciding when to leave the leaflet on which she is searching for larvae ofPhytomyza ranunculi. She seemed not to employ some stopping rules that have been suggested; i.e., a fixed-number rule and a fixed-time rule and
others. The stopping model formulated forDapsilarthra rufiventris parasitic on the same host species fitted well to the results. The model assumes that the searching female will deposit a
marking pheromone on the leaflet at a rate proportional to the search speed and will leave the leaflet when the amount of
the pheromone that has accumulated on the leaflet reaches the threshold,L. In this model,L denotes the amount of search effort spent on the leaflet. A comparison of the observed results with the predictions from
the model suggested thatL increased markedly at the first encounter with the mine (host), but less at later encounters.C. pentheus appears to employ a mixed strategy of a fixed search-effort and an area-concentrated search. This would confer an adaptive
advantage in foraging forP. ranunculi larvae, which are distributed in clumps among leaflets in the field. 相似文献
5.
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
6.
Summary Difficulty arises in applying marking-and-recapture methods to insects when the probability of recapture of marked individuals
is changed with advancing age, either due to detachment of the mark by moulting (in the case of larvae) or to changes in their
survival rate or their behaviour. A modification of the re-recapture method (Leslie
et al., 1953) has been devised to analyze the capture-recapture data of the 5th-instar larvae and adults ofNezara viridula L. Estimation of the rate of moulting to the adult stage is made with the aid of additional information on larval survival.
Migration rates of the larvae between the two halves of the census field is estimated byIwao's (1963) method. Through these analyses, the dynamic feature of the population during transition from the 5th instar to, adult
is revealed. Several problems involved in the application of marking-and-recapture methods to insect populations are discussed.
Contribution from the Entomological Laboratory, Kyoto University No. 392. 相似文献
7.
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
8.
Tuyosi Sugimoto Oscar P. J. M. Minkenberg Junji Takabayashi Marcel Dicke Joop C. van Lenteren 《Researches on Population Ecology》1990,32(2):381-389
Summary We studied the rules used by the female parasitoid,Dacnusa sibirica Telenga (Hymenoptera: Braconidae), for deciding when to leave a tomato leaflet on which she is searching for larvae of the
leafminer,Liriomyza bryoniae Kalt. (Diptera: Agromyzidae). Females would deposit a marking pheromone on the leaflet and would leave the leaflet when the
amount of the pheromone accumulated to the thresholdL, which is proportional to the amount of search effort on the leaflet.L appears to increase with host density since it rises after every encounter with a host (or mine).D. sibirica would employ an area-concentrated search, which is advantageous in foraging for hosts showing a clumped distribution. 相似文献
9.
Makoto Kato 《Researches on Population Ecology》1996,38(1):27-40
Population dynamics of a leafminer,Chromatomyia suikazurae (Agromyzidae, Diptera) and its parasitoid community were studied for ten years at seven natural populations along an altitudinal
gradient in Japan. This species which mines leaves of a forest shrub,Lonicera gracilipes (Caprifoliaceae), was attacked by 25 hymenopterous parasitoid species. Annually, the parasitoid community structure varied
less within a population than among populations. The seven parasitoid communities were clustered into three groups corresponding
to the altitudinal gradient: (a) lowland communities dominated by late-attacking, generalist pupal idiobiont eulophids and
with highest species diversity, (b) hillside communities dominated by an early-attacking, specialist larval-pupal koinobiont
braconid and (c) highland communities dominated by an early-attacking, generalist larval idiobiont eulophid. Annual changes
of the host larval densities among the local populations were largely synchronous rather than cyclic. Among these populations,
host density levels and mortality patterns greatly varied. By analyzing these inter-populational differences of host mortality
patterns, the following conclusions were drawn: (1) The host mortality patterns were determined by the host utilization patterns
of the locally dominant species. (2) The host pupal mortality but not larval mortality was related to species diversity but
not to species richness itself of each parasitoid community. (3) Density dependence was detected only in pupal mortality at
a lowland population dominated by late-attacking pupal parasitoids. These results suggest that interspecific interactions
of parasitoids add additive effects to host population dynamics dissimilarly among local populations with different parasitoid
communities. 相似文献
10.
Masakazu Shimada 《Researches on Population Ecology》1985,27(2):203-216
Summary Effects of niche shift in ecological time scale on the population dynamics of competing species were studied in the experimental
populations of two parasitoid wasp species,Anisopteromalus calandrae andHeterospilus prosopidis (both are solitary parasites), on a host, the azuki bean weevil,Callosobruchus chinensis. Four resource conditions were set up with combination of kind of bean (azuki or black eye), and host distribution (uniform
or clumped). In each resource condition, four developmental stages of hosts were provided as a resource spectrum for parasitoid
wasps.
Population dynamics of the two wasp populations were investigated in each resource condition in Multi-Generation Competitive
Systems (MGCS), in which fresh hosts of four developmental stages were periodically introduced and were parasitized competitively
by the two wasp species. Competitive coexistence of both wasps occurred in the azuki-clumped condition, where the peaks of
the resource utilization curves separated in the two species; pupae inA. calandrae and the early or late fourth instar inH. prosopidis, A. calandrae was eliminated in the azuki-uniform condition andH. prosopidis went extinct in two black eye conditions irrespective of host distributions. The degrees of overlap of the resource utilization
patterns of the two wasp species during population dynamics were not significantly different among resource conditions irrespective
of the results of coexistence or extinction. Even in the azuki-clumped condition, however, extinction ofA. calandrae was observed when resource partitioning could not be realized with only the late fourth instar larvae available to wasps.
Further analytical experiments showed that parasitizing ability ofA. calandrae increased with host density per bean with azuki beans, butA. calandrae could express higher parasitizing ability with black eye beans thanH. prosopidis irrespective of host density per bean.
The flexibility in parasitizing ability byA. calandrae for various host stages under different resource conditions was thought to be the major factor in determining the competitive
coexistence or the extinction of either species under different resource conditions. The present experiments also suggested
that different second-best host stages between competitors could be a major contributing factor to competitive coexistence. 相似文献
11.
Tsukasa Sunose 《Researches on Population Ecology》1985,27(2):287-300
Summary Yearly population fluctuations ofM. pustulae were investigated at 19 sites in Kyushu. In sites where a platygastrid is the only parasitoid of the midge, the percentage
parasitism was very low in the incipient stage of the outbreak of the midge populations. After the number of midges reached
a peak, the midge populations declined as the percentage parasitism increased, and then the outbreak ceased. On the other
hand, in several populations no outbreak was found and the percentage parasitism was constantly at a high level. Therefore,
the immediate cause for the outbreak seemed to be a decline of the percentage parasitism. Like the midge, the platygastrid
has one generation each year, and its females also emerge in spring to deposit their eggs within host eggs. The decline of
the percentage parasitism seemed to be mainly affected by the time lag between emergence periods ofM. pustulae and the platygastrid.
In the midge populations parasitized by both the platygastrid and a eulophid (Chrysonotomyia sp.), an extinction of the population was observed, resulting from parasitism by the latter,Chrysonotomyia sp. is polyphagous and multivoltine, and is a late parasitoid, as discussed byAskew (1975). When the density of the midges is very low, the platygastrid may leave the host eggs unparasitized, whileChrysonotomyia sp. may not, because the mature galls are conspicuous. 相似文献
12.
Summary Two experiments on the nymphal predation ofPodisus maculiventris were conducted usingSpodoptera litura larvae as prey.
First experiment: The predator nymphs divided into three groups were reared individually from second instar to adult in a
small vessel. Each nymph in the groups 1, 2 and 3 was allowed to attack the serially growing larvae (these were supplied at
the rate of one per day) from 3-, 5- and 7-day old after hatching, respectively. The first prey used for the group 1 was so
small that it was not only insufficient to satiate the predator but also was difficult to be searched out. But these disadvantages
were soon recuperated due to the rapid growth of the prey and all nymphs could survive to adults. The survival rate of third
and fourth instar nymphs in the group 3 was severely affected by vigorous counterattack of older prey larvae.
Second experiment: The predator nymphs were individually reared either in a small vessel or in a large one at various rates
of food supply (the prey larvae of 7-day old were used). The functional response curves obtained for each instar of the predator
took a saturation type within a certain range of the prey density. The saturation level specific to each instar was generally
higher for the predator reared in the large vessel than in the small one. The functional response of fourth and fifth instar
nymphs was accelerated at a high prey density,viz. 16 larvae per vessel. Even at the low rate of food supply,viz. one larva per day per predator, the predator nymphs could survive to adults, but the size of resultant adults were abnormally
small. 相似文献
13.
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
14.
Shuji Kaneko 《Researches on Population Ecology》1995,37(2):225-228
Successful multiparasitism by five parasitoid wasps of the scale insectNipponaclerda biwakoensis was investigated at a reed bed in Lake Biwa. The wasps were gregarious endoparasitoids consuming the entire body of the host.
The rate of successful multiparasitism for a parasitoid species was defined as the proportion of the number of individual
hosts from which the species emergedwith other species to the total number of hosts from which the species emerged. The rates were high for each parasitoid species,
ranging from 17 to 82%. Successful multiparasitism frequently involved two species with similar adult size, but rarely involved
species with different adult size. For four of the five species, the number of wasps per host was significantly less when
wasps emerged from a host with other species relative to when emerged alone. For the other one species, the number of wasps
was less, but the difference was not significant. With only one species, female wasps were significantly smaller when they
emerged from a host with other species relative to when emerged alone. 相似文献
15.
Midori Tuda 《Researches on Population Ecology》1996,38(2):133-140
The effects of spatial structure in terms of local capacity, or the maximum number of larvae surviving competition at resource
patches, and temporal structure in terms of the period vulnerable to parasitoid attack in host populations on the persistence
of host-parasitoid systems were quantitatively evaluated by laboratory experiments and well-parameterized model analyses.
One of two bruchid beetles,Callosobruchus maculatus andC. phaseoli, were used as a host with Heterospilus prosopidis used as the parasitoid.C. maculatus, in which few larvae survive competition to become adults in each bean, andC. phaseoli, in which many larvae become adults in each bean, along with two kinds of beans, the mung and the azuki, were combined to
construct four (2×2) resource-herbivorous host-parasitoid systems that differed in local capacity and vulnerable period. The
mung-C. maculatus system with the parasitoid was the most persistent, i.e., took the longest time for extinction of either the host or parasitoid
to occur. Since this resource-herbivorous host combination exhibited the lowest local capacity and the shortest vulnerable
period, these two conditions possibly promoted the persistence of the system. A model incorporating the host population structure
supported the observed persistence. Furthermore, the possible contribution of the timing of density-dependent competition
of the host on the host-parasitoid persistence is predicted. 相似文献
16.
Summary The zygaenidPryeria sinica
Moore and the ichneumonidAgrothereutes minousubae
Nakanishi form a one host—one parasitoid system in nature. Their seasonal life cycles were investigated by laboratory experiments and
field observations, and the life-cycle adaptation of the parasitoid to its host was examined.
The moth is univoltine. The larva hatches from mid-February to mid-March and feeds on leaf buds and young leaves of ever greenEuonymus japonicus
Thunb. The thermal constants for completing the 1st, 2nd, 3rd, 4th larval instars and prepupal stage were 85.6, 80.5, 85.2, 177,0
and 197.6 degree-days, respectively. The prepupa and pupa vulnerable to the attack by the parasitoid occurred from mid-April
to early May and from mid- to late May, respectively.
Diapause in the parasitoid is facultative and occurs in the eonymphal stage. The photoperiodic response for this diapause
was a long-day type with a critical photoperiod of 13 hr 40 min at 20°C, but it was not expressed at 25°C, most larvae entering
diapause irrespective of photoperiod. About 19, 120, 82 and 112 degree-days above 7°C were required to complete the egg, larval,
prepupal and pupal development, respectively. These data were superimposed on the photothermograph of Fukuoka, and it is predicted
that the 1st adult eclosion would occur in late April and the partial 2nd adult eclosion in early June. The prediction was
supported by field observations.
The adult eclosion of the parasitoid synchronized well with the apperance of prepupae and pupae of the moth. The parasitoid
has two types of seasonal life cycle, one generation and two generations a year. Both types have an extremely long dormant
period of 10–11 months due to aestivo-hibernation. This seasonal life cycle enables the parasitoid to maintain its population
when the host is in short supply. 相似文献
17.
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
18.
Takao Itino 《Researches on Population Ecology》1986,28(2):185-199
Summary I compared life tables between the solitary eumenid waspAnterhynchium flavomarginatum
Smith and the subsocial eumenid waspOrancistrocerus drewseni
Saussure in Kyoto, Japan, during 1980–1983. The subsocial eumenid is parthenogenetic in this study area. There were 9 identified mortality
factors in the solitary eumenid and 7 in the subsocial eumenid, 6 of which were common to the two eumenids. The important
differences of mortality between the two eumenids were seen in the egg, larval, and prepupal stages. In the egg stage, mortality
by the phorid flyMegaselia sp. was much lower in the subsocial eumenid (1.4%) than in the solitary eumenid (15.0%) likely because of the matenal care
of the subsocial eumenid (progressive provisioning and other related behavior), which reduced predation pressure. In the larval
stage, mortality by the miltogrammine flyAmobia distorta was also lower in the subsocial eumenid (8.1%) than in the solitary eumenid (23.8%) also probably because of the maternal
care of the subsocial eumenid. A comparison of mortality in the two eumenids between the stable, long continuing natural nest
sites and the additional temporal ones showed that the phorid fly remained near its birth place and parasitized stable nest
sites. The miltogrammine fly followed returning eumenid wasps and parasitized those nest sites that have a high host density.
In the prepupal stage, mortality by endogenous death was higher in the subsocial eumenid than in the solitary eumenid. Mortality
due to the rhipiphorid beetle was also higher in the subsocial eumenid probably due to more frequent flower-visits by the
subsocial eumenid.
The defense mechanism of the subsocial eumenid was discussed in relation to the evolution of subsociality.
Contribution to the ecological studies of the eumenid wasps. I. 相似文献
19.
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
20.
Summary Larvae of genusPieris in the northern part of Kyoto City are parasitized by two tachinid flies:Epicampocera succincta, a specialist on genusPieris, andCompsilura concinnata, a generalist with very wide host-range. We surveyed the parasitism rates ofPieris by both flies for two years at six study areas. In these study areas, there lived three host species in the genusPieris: P. rapae, P. melete, andP. napi, but neither tachinid parasitizedP. napi to any significant extent. In the mountainous district,P. rapae andP. melete coexisted and their populations were relatively continuous, while in the lowland, onlyP. rapae larvae were abundant in spring and autumn, but even they disappeared in summer. Parasitisms byE. succincta occurred mainly in mountainous district and never in the lowland.C. concinnata parasitizedPieris in all the areas, but its parasitisms occurred mainly in autumn.
We analyzed the factors affecting the spatial and temporal patterns of parasitism rates and presumed that the temporal discontinuity
of host population restricted the distribution of the specialist parasitoid. 相似文献