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1.
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
2.
Atsushi Kokubo 《Researches on Population Ecology》1965,7(1):23-34
Summary Annual changes in the population of the pine-moth,Dendrolimus spectabilis
Butler, were studied in Kashima district. The insect completes two generations in one year, and the adult emerges in early summer
and again in autumn.
The insect population showed fairly drastic fluctuations in the past years, and a conspicuous peak was recorded in three times,
in 1950, 1955 and 1961. It was noted in each of those three years that a great number of adults of the summer generation emerged
in autumn. The main reason for this great abundance of the insect population seemed to be high survival rate of the young
larvae in summer. It was suggested that the climate in July had powerful influence upon the survival f thos e young larvae.
The effects of natural enemies were usually the greatest on the egg population of the pine-moth in either generation. Much
greater number of insects in the overwintering generation was destroyed by parasites and diseases than in the summer generation.
Finally, a rapid increase of the insect population in autumn was considered to be caused by a combined effect of climatic
conditions and of natural enemies. 相似文献
3.
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
4.
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
5.
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
6.
Keiji Kanamitsu 《Researches on Population Ecology》1965,7(1):16-22
Summary A field population ofEvetria cristata was studied in 10 plots in 1962 and in 6 plots in 1963. These plots were divided into 2 or 3 groups of different population
levels of the shoot moth in respective years. The survival of the insect was then analysed in these different groups of plots.
The survival rate ofE. cristata from eggs to adults in the first generation was found always higher in the group with low population density, which indicates
the existence of some factors that affect the population more severely when the insect is more abundant.Lissonota evetriae andPediobius sp. seemed to have killed more proportion of the hosts where the shoot moth density was high. However, the total effect of
the all natural enemies was not always great in the plots with high density of the moth. The survival of the second generation
of the moth in 1963 was observed to be much higher at any population level than in the other generations. 相似文献
7.
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
8.
Masaya Matsumura 《Researches on Population Ecology》1996,38(1):19-25
A population census was conducted to describe the effects of the growth stage of rice on the population dynamics ofS. furcifera, in particular, on immigration, seasonal abundance, population growth rate, and wing-form expression. The number of immigrants
was highest on rice plants 17 to 30 days after transplanting (DAT), which suggested that immigrants prefer to settle or remain
more on rice plants at the tillering stage (approximately 20–30 DAT). Population growth rate from immigration to the 1st generation
decreased with an increase in rice plant age. In contrast, population growth rate from the 1st to 2nd generation was not influenced
by rice plant age and was negatively density-dependent. The percentage of macropters (flyers) was positively related to the
growth stage of rice when rice was in the vegetative or early part of the reproductive stage, and reached 100% at about 10
days before heading (booting stage). Threafter, most adult females molted into macropters regardless of population density.
The roles of host plant age and crowding effect on the population dynamics ofS. furcifera are discussed. 相似文献
9.
Omar Muhamad Ritsuko Tsukuda Yoko Oki Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1994,36(1):53-62
The larvae ofPlutella xylostella were fed on five wild crucifers,Capsella bursa-pastoris, Lepidium virginicum, Cardamine flexuosa, Rorippa indica, R. islandica and a crop, cabbage. The developmental period of the immature stages, adult longevity, preoviposition period, fecundity and
morphometrical characters of the adults were measured. The flight activity of the adults was also measured by the tethered
flight method. All the wild plants except forR. islandica were less suitable host plants than cabbage, and larvae which were fed on these less suitable plants emerged as smaller adults
with shorter wings. The smaller female adults had lower fecundity but a higher flight activity. Smaller adults measured in
terms of their pupal weight among individuals fed on the same host plant had longer wings. These smaller adults with longer
wing flew more actively. 相似文献
10.
《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
11.
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
12.
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
13.
A traditional subject for discussion in population debates is whether the world or any subdivisions of it are overpopulated. Some proclaim that we are indeed in a state of overpopulation, while others persistently deny this claim. However, statements which proclaim or deny overpopulation are almost never accompanied by satisfactory definitions as to what overpopulation means. This is most unsatisfactory, especially because whether or not overpopulation is a fact is often claimed to be crucial when it comes to the justification of population political recommendations. This article considers an argument from overpopulation, according to which overpopulation justifies policies which reduce population size; and an argument against overpopulation, according to which the fact that present problems can be handled without population reductions establishes that there is no state of overpopulation. Both arguments are rejected by clarifying possible definitions of overpopulation. 相似文献
14.
Summary The population dynamics of an epilachnine beetle, which is closely related toEpilachna sparsa
Dieke (henceforth called “sp. C”) and feeds on bitter cucumberMomordica charantia, was studied by mark-recapture of adults and the construction of life tables. The study was repeated three times, i.e., March–May,
July–September and October–December in 1982, in Padang, Sumatra, Indonesia. After the establishment of the host plants, adults
of “sp. C” soon colonized, and each study period ended in the death of the plants due to defoliation by the larvae and adults.
The estimated mean length of residence of adults ranged from 6–11 days, but this was probably much shorter than the actual
longevity, because the adults were so active that they flew away, or dropped off the plants, when they were approached or
slightly disturbed. Life tables indicated that egg mortality ranged from 17.8–53.9%, and a parasitic waspTetrastichus sp. B made up 41.1–64.2% of egg mortality. Two wasps,Tetrastichus sp. C andPediobius foveolatus killed 1.2–19.4% (7.6–100%)* of 4th instars and only the latter species attacked the pupae, killing 24.6–59.1% (45.1–72.4%). Parasitism and starvation
by overcrowding contributed most to the total mortality from egg to adult emergence, which ranged from 89.4–99.5%. “Sp. C”
had a higher diversity and level of parasitism than the Japanese species,E. vigintioctopunctata. The high dispersal power of “sp. C”, coupled with the prolongedl
x−mx schedules shown under laboratory conditions, was advantageous for exploiting the food plant which was available throughout
the year, but was rather patchily distributed in space. 相似文献
15.
Toshiyuki Nishida 《Researches on Population Ecology》1966,8(1):78-88
Summary This paper is concerned with some aspects of the ecology of the southern green stink bug,Nezara viridula, in Hawaii. Dispersal studies on adults showed an asymetrical dispersal pattern. The rate of plant to plant to movement by
the adults was 3.3–6.7 feet per day. Mortality studies showed that egg predation by ants,Pheidole megancephala, was as high as 80–90 per cent. Egg parasitism byTelenomus basalis was highest during February, 1965, and adult parasitism byTrichopoda pennipes was highest during July, 1964, to January of the following year. The population ofN. viridula declined during May, 1964, to May, 1965. This decline occurred simultaneously with the decline in the number of eggs produced
per female. It has been speculated that this reduction in egg production was caused by parasitism byT. pennipes.
Published with the approval of the Director of the Hawaii Agricultural Experiment Station as Technical Paper No. 816.
It is with great pleasure that I acknowledge with thanks the help that I received in various ways from the following: Dr.
WallaceC. Mitchell, Dr. MervinKamran., Mr HarryKaya and Mr. HitoshiKamasaki. 相似文献
16.
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
17.
T. S. Bellows Jr. M. Ortiz J. C. Owens E. W. Huddleston 《Researches on Population Ecology》1982,24(1):142-156
Summary A model is developed for the analysis of insect stage-frequency data which may be applied to populations with age-dependent
mortality. The analysis of stage-frequency data is divided into two steps. In the first step, the number of different mortality
rates and their values are estimated. The second step provides estimates of developmental rates and variances for each developmental
stage and in addition provides estimates of the number of recruits to each stage. The model may be used both in analysis and
prediction of insect stage frequencies. Hence, in addition to estimating developmental and mortality rates from stage-frequency
data, it may also be used as a simulation model for an insect population. The model is applied to two populations ofHemileuca oliviae
Cockerell, a lepidopterous pest of New Mexico grasslands. The model identifies, in the two populations, different mortality rates that
are related to plant productivity. 相似文献
18.
Mathematical procedures are given to estimate infestation totals and daily life stage arrivals, departures, and mortality
ofDendroctonus frontalis
Zimmermann for an infested tree in the field. These estimates are based on minimal sample data and are designed to utilize all available
information. Daily arrival estimates for larvae, pupae, and callow adults are obtained by indirect analysis without direct
observation of these stages. The procedures are applied to 147 infested trees, and the results are transformed to a common
time basis to obtain daily expectations by life stage for an “average” tree. These expectations suggest optimal times for
field sampling or relative times of sampling when optimal times are missed. Expected daily arrival distributions by life stage
for a single egg and a single attacking adult are given. Procedures are given for utilizing collateral information to obtain
an infestation total and daily arrival estimates for a boundary life stage. The results of this study are applicable to anyD. frontalis field study, and the procedures given are applicable to any bark inhabiting insect having similar habits. 相似文献
19.
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
20.
Koukichi Nagasaka 《Researches on Population Ecology》1991,33(1):115-128
Summary ThreeAthalia sawflies,A. japonica, A. rosae andA. infumata, feeding on cruciferous plants, coexist in Japan. However, it is not known what ecological strategies they use and what environmental
factors are crucial to such strategies. I attempted to explain these questions by examining the relationship between the spatio-temporal
distribution patterns of threeAthalia sawflies and their habitats in three districts (Lowland, Intermediate and Mountain).
The three sawflies have different spatio-temporal distribution patterns, though they usually used common cruciferous plants.A. japonica was abundant in spring and autumn but disappeared during summer in all the districts. In the Lowland, populations ofA. rosae andA. infumata, like that ofA. japonica, crashed in summer. HoweverA. rosae occurred mainly in summer in the Intermediate and Mountain. AlthoughA. infumata occurred in the same seasons asA. rosae in all districts, population levels ofA. infumata were always lower than those ofA. rosae.
The crucial factors controlling their population patterns were the availability of host plants and temperature. Population
crashes ofA. rosae andA. infumata were due to food depletion, and those ofA. japonica were due to heat stress. On the other hand, their population patterns may be interpreted as phenological synchronization
with their original host plants, though they all existed on common cruciferous plants.
The three sawflies may have evolved different strategies to escape from unfavorable habitat conditions. Such strategies are
speculated to be summer diapause inA. japonica, long distance migration inA. rosae, and local dispersal inA. infumata. 相似文献