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1.
Shun'ichi Makino Seiki Yamane Tsukasa Sunose Shigeyuki Aoki 《Researches on Population Ecology》1987,29(1):111-117
Summary Dispersion capabilities of new queens were studied in the two haplometrotic paper waspsPolistes riparius andP. snelleni. New queens were marked on the nests in the late summer and located in the next spring. Dispersion distances greatly varied
among queens: although a large part of recovered queens nested in close proximity to their natal sites, some did disperse
over 100–300 m. This suggests that queens' emigration from and immigration into the censused areas occurred to a substantial
extent. On the whole, these species exhibited a weaker “philopatric” tendency than those so far studied for dispersion distance,
and seem to have the potential for a long-distance dispersion. 相似文献
2.
Koukichi Nagasaka 《Researches on Population Ecology》1992,34(2):383-395
Summary This report assesses the primary factor for the evolution of summer diapause of the three species of sawfly,Athalia japonica, A. rosae andA. infumata that feed on cruciferous plants and coexist in the same area.A. japonica has two discrete spring and autumn generations, butA. rosae andA. infumata 5–6 generations. OnlyA. japonica enters summer diapause in response to the long daylengths in spring. Although these three sawflies usually feed on the same
cultivated crucifers, they differ markedly in the utilization of wild crucifers. They oviposit only on young leaves.A. japonica mainly usesCardamine plants which sprout in spring and autumn.A. rosae andA. infumata primarily use hosts with new leaves all the year round, i.e. cultivated crucifers andRorippa indica, respectively. The thermal threshold for development is lower inA. japonica than in the other two species. The low heat tolerance ofA. japonica is adapted only to cool shady habitats whereCardamine grows. Presumably, summer diapause ofA. japonica is adaptation to the deterioration of the primary host plants rather than unfavorable climatic conditions. This interpretation
is supported by the movement patterns of the threeAthalia sawflies, alternative means to escape from deteriorated habitat conditions. 相似文献
3.
Dynamics of the buried seeds and plant population of two dominant weeds, viz.,Emilia sonchifolia (Linn.) DC. andRichardsonia pilosa HBK were studied in the crop fields of Meghalaya, north-east India during radish and maize cropping and intervening fallow
periods. The total buried seed population ofR. pilosa was always larger than that ofE. sonchifolia, but the germinable fraction was invariably greater in the latter. A major portion (39–41%) of the viable (germinable+dormant)
seed population in both weeds was confined to the surface soil layer (0–5 cm). The viable seed population ofE. sonchifolia peaked during April, while that ofR. pilosa showed two peaks (during August and December). The survival pattern and half-lives of seedling cohorts showed, some differences
in the two weed species, but both being summer annuals, their populations behaved in a similar manner by showing higher seedling
recruitment (K) and survivorship (p) rates in the summer crop (maize) than in the winter crop (radish). However, the density of plants that could attain adulthood
was significantly higher inE. sonchifolia thanR. pilosa which might have resulted in greater seed input of the former to the soil leading to its greater abundance in the crop fields.
Supported by the University Grants Commission, New Delhi (Grants No. F. 3-37/87 SR II) 相似文献
4.
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
5.
Tamotsu Kusano 《Researches on Population Ecology》1982,24(2):329-344
Summary The postmetamorphic growth and survival of the salamanderHynobius nebulosus tokyoentis
Tago were surveyed in the study site located in Habu village of Hinodemachi, a suburb of Tokyo City, during 1975–1981. A laboratory
experiment on the growth rate of juveniles was conducted in parallel with the field survey. The result indicated that this
salamander grew at the rate of 8,mm in s.v.l. per year during the juvenile stage, but its growth rate decreased markedly as
low as 1.8 mm for males and 1.1 mm for females, once it had attained sexual maturity. According to the “capture-recapture”
procedure the annual survival rate after metamorphosis was found to be quite high; that is, approximately 0.7. By using the
growth rate of juveniles and the difference between the sizes at metamorphosis and sexual maturity, the age at first reproduction
was estimated to be 4 year for males and 5 year for females.
From the data obtained in this study, the intrinsic rates of increase (r) were calculated for various values of age at first reproduction under different survival schedules, and the relationship
between the age at first reproduction and fitness as measured byr was examined. The result indicated that an optimal age maximizing fitness always existed under respective survival schedules,
and the observed age at first reproduction of this salamandei was found to coincide well with the predicted optimal age. 相似文献
6.
C. Richard Terman 《Researches on Population Ecology》1999,41(3):299-304
Adults of wild white-footed mouse (Peromyscus leucopus noveboracensis) populations in southeastern Virginia have been shown to be reproductively suppressed during May–July compared with other
months of the reproductive season. The gonads and sex accessory glands are also significantly smaller during May–July than
at other times of the year. The causes of this early summer reproductive suppression are unknown. In this study, food (Agway
3000) that could not be hoarded was supplied in feeding stations on one-half the 11-ha wooded study area during 1990 and 1991.
Food consumption (g) was positively but not significantly correlated with population density (adults/ha) during both years.
Population density was higher during 1991 on the food-supplemented area than on the nonsupplemented area, but the statistical
significance was marginal. Mice of both sexes living on both areas during 1990 and 1991 exhibited significant reproductive
suppression during May–June. Further, mice of both sexes living on both areas during both years had significantly smaller
gonads and sex accessory glands during May–June compared with other months of the year. Thus, during both years, surplus food
did not prevent suppression of reproductive function in this wild population, and this phenomenon remains unexplained.
Received: November 4, 1998 / Accepted: October 5, 1999 相似文献
7.
Yukibumi Kaneko Keisuke Nakata Takashi Saitoh Nils Chr Stenseth Ottar N. Bj?rnstad 《Researches on Population Ecology》1998,40(1):21-37
The biology of the gray-sided voleClethrionomys rufocanus in Hokkaido, concerning taxonomy, morphology, phylogeny, distribution, and natural history, is reviewed. Applied issues in
forest management (damage, control and census) are also mentioned. AlthoughClethrionomys rufocanus of Hokkaido was originally identified as a distinct species,Evotomys (=nowClethrionomys) bedfordiae Thomas, 1905, current literature generally refers to the gray-sided vole of Hokkaido asClethrionomys rufocanus or asC. rufocanus bedfordiae (vernacular name, the Bedford’s red-backed vole). The gray-sided vole is the most common small mammal in Hokkaido. It inhabits
open areas as well as forests, and mainly feeds on green plants. The gray-sided vole has a high reproductive potential; litter
size: 4–7; gestation period: 18–19 days; maturation age: 30–60 days old. Although spring-born individuals usually attain sexual
maturity in their summer/fall of birth, their maturation is sometimes suppressed under high densities. The breeding season
is generally from April to October, but with some regional variation.Clethrionomys rufocanus has a rather specialized diet (folivorous), particularly during winter when it feeds on bamboo grass. Many predators specialize
on the grey-sided vole in Hokkaido; even the red fox, which is a typical generalist predator, selectively feeds on this vole.
Damage by voles’ eating bark used to be sever on forest plantations in Hokkaido. Censuses of small rodents have been carried
out for management purpose since 1954. 相似文献
8.
Summary Population dynamics and aggregation patterns of nine kinds of stored-grain mites were studied in two 7.5 tonne lots of hulled
(cv. Random) and hulless (cv. Terra) oat cultivars with 12–14% moisture content stored in two wooden bins in Manitoba, Canada
during 1978–84. Random oats harbored more mites than Terra oats.Lepidoglyphus destructor Schrank was the most common granivorous mite andCheyletus eruditus Shrank the most common predatory mite. Ecological data on a tydeid mite,Paratriophtydeus coineaui André, are presented for the first time. Because they were more abundant in Terra oats with higher fat acidity values (FAV)
than Random oats with lower FAVs,L. destructor andTarsonemus granarius Lindquist could be used as bioindicators of spoilage of stored oats. All species analyzed showed some significant difference
in their abundance at different depths in the grain bulk; some species showed depthxtime interaction. Aggregation patterns
indicated most mite species had overdispersed (clumped) distribution.T. granarius, andBlattisocius keegani Fox-Androlaelaps casalis Berlese had a distinct aggregation pattern in each oat cultivar.
Contribution No. 1373 from Agriculture Canada Research Station, Winnipeg, Manitoba, Canada R3T 2M9 相似文献
9.
Kazuyoshi Miyashita 《Researches on Population Ecology》1964,6(1):37-42
Summary A relationship between outbreaks of the oriental tussock moth,Euproctis flava, in Akita Prefecture and weather conditions have been analyzed in the present paper. The results obtained are summarized
as follows:
Outbreaks were, in most cases, observed at intervals of 7–9 years, and the population fluctuation was considered to be regular,
when small rises of population density were taken into consideration. The condition of low temperature and decreased percentage
of sunny hours in spring and summer has a great influence upon the occurrence of outbreaks, and a big outbreak seems to come
when a peak of the intrinsic population fluctuation occurs just simultaneously with such a weather condition. 相似文献
10.
Nobuhiko Suzuki 《Researches on Population Ecology》1986,28(1):69-83
Summary Resource exploitation by and intraspecific competition in larvae ofGastrophysa atrocyanea andGalerucella vittaticollis were investigated in field and laboratory experiments. Larvae of both species frequently suffered from food shortages in
the field. WhenG. atrocyanea larvae suffered from a food shortage, severe intraspecific competition occurred because of lack of predation and parasitism.
This exploitive competition was caused by a local food shortage of the host plant. Individuals survived by fast exploitation
when food became abundant (contest type competition). TheG. atrocyanea larvae were wasteful of the food resource, and no mechanism by which to economize on the utilization of the resource was
acquired because of their exploitation of the abundant resource. In contrast, theG. vittaticollis population probably is regulated by extrinsic factors such as predation and parasitism. Those larvae grew into smaller adults
than those ofG. atrocyanea under a food shortage, so that their wasted food consumption was lower than that ofG. atrocyanea. Although intraspecific competition was similar to that forG. atrocyanea, it was not as severe. The food forG. vittaticollis was apt to be appropriated by other wasteful exploitators such asG. atrocyanea, which was superior in resource exploitation; thereforeG. vittaticollis frequently suffered a food shortage. Consequently selection in relation to tolerance to starvation became more acute forG. vittaticollis than forG. atrocyanea, and individuals ofG. vittaticollis that could endure starvation better may have been selected. 相似文献
11.
Alison Woodcock Laura Camfield J. Allister McGregor Faith Martin 《Social indicators research》2009,94(1):135-171
The aim of this study was to validate an individualised measure of quality of life (WeDQoL-Goals-Thailand). Three hundred
and sixty-nine Thai people completed the WeDQoL by interview. Respondents rated (0–2) the perceived necessity for wellbeing
of 51 goals (goal necessity), then rated (0–3) their satisfaction with the same goals (goal satisfaction). Weighted goal attainment
(possible range 0–6) was computed (necessity x satisfaction). Psychometric validation used frequency distributions, Principal
Components Analysis (PCA), and Cronbach’s alpha. Analysis of variance, t-tests, Kruskal–Wallis, Mann–Whitney U, Spearman’s correlation and multiple regression explored socio-demographic, geographic and economic differences. Respondents
were aged 15–89 (mean 45.7, SD 18.0); 169 men, 200 women. For weighted goal attainment scores, PCA found a 44-item scale (α = 0.91) and three subscales (community/social/health, α = 0.90; house and home, α = 0.80; nuclear family, α = 0.81). Thai Individualised Goal Attainment (TIGA) scale and the three subscales were computed as the mean of contributing weighted goal attainment scores, after excluding
goals considered ‘not necessary’ to each individual. Unweighted and individualised scores differed significantly with socio-demographic,
geographic and economic indicators. In multiple regression, both Thai Unweighted Goal Satisfaction (TUGS) and TIGA scale scores were predicted by being married, living in the South and in a non-urban location. TIGA scores were also predicted by being over 25 years old. WeDQoL-Goals-Thailand has excellent psychometric properties. Individualised
scores reflect each person’s perspective on wellbeing and are sensitive to subgroup differences. However, unweighted satisfaction
scores give a broadly similar picture and involve less complex computation. 相似文献
12.
Koukichi Nagasaka 《Researches on Population Ecology》1992,34(1):1-14
Summary I compared the differences in the movement intensity of three species of sympatricAthalia sawflies,A. japonica, A. rosae andA. infumata feeding on cruciferous plants. Mark-release-recapture census was conducted to estimate movement distance, sex ratio and age
composition of adult sawflies. In addition, the sex ratio of newlyemerged adults was examined by rearing field-collected larvae
until adult emergence. Age composition and longevity of adults were estimated experimentally. The movement intensity was evaluated
mostly with the indirect information thus obtained.
Females moved more actively than males in all three sawflies.A. japonica females of all age classes moved actively in spring and autumn, but in summer they disappeared. Also,A. rosae females of all age classes moved actively in spring and autumn. In summer, in contrast withA. japonica, A. rosae females moved most actively among the three species in all seasons.A. infumata females, in particular the young females, moved most actively among the three species, exceptA rosae in summer.
The movement patterns of the three sawflies were deduced in relation to the spatio-temporal distributions of their habitats.
In spring and autumn, when host plants were abundant,A. japonica andA. rosae females were dispersed among the host patches within the census are. In summer, however, when host plants were scarce,A. japonica entered diapause, whereasA. rosae migrated to neighboring areas. On the other hand,A. infumata, in particular young famale, innately dispersed to seek for temporary host plants throughout the census seasons. 相似文献
13.
K. Tanaka T. Watanabe H. Higuchi K. Miyamoto Y. Yusa T. Kiyonaga H. Kiyota Y. Suzuki T. Wada 《Researches on Population Ecology》1999,41(3):253-262
To examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint-marked snails of
15–20 mm shell height into 12 enclosures (pens) of 16 m2 at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent
of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density
dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg
masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than
3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however,
higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density.
The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult
density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering
period, was not significantly different among density treatments. These results suggest that snail density after the overwintering
period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate
the population of P. canaliculata in paddies.
Received: October 23, 1998 / Accepted: July 16, 1999 相似文献
14.
We studied seasonal changes in the larval population structure, adult size, and autogeny (egg production without a bloodmeal)
of the mosquitoAedes togoi on the seacoast of northern Kyushu, Japan. The effects of temperature, photoperiod and food conditions on larval development,
adult size and autogeny were studied in the laboratory.Aedes togoi overwintered in both the egg and larval stages and was multivoltine. Adult size was greater in spring and autumn and smaller
in summer. Autogeny occurred in spring and autumn but not in summer. Autogenous females were larger than anautogenous females,
and larger autogenous females produced more eggs. Laboratory experiments showed that autogeny was promoted under low temperature
and short-day conditions which corresponded with spring/autumn conditions in the field. Experimental food limitation in the
larval stage greatly reduced adult size and autogenous egg production. In the field, large inter-pool variations in adult
size and autogeny rate probably resulted from variations in nutrient and crowding conditions. Seasonal autogeny ofAedes togoi was discussed in terms of life-history strategy under fluctuating environmental conditions where relative advantages of autogenous
and anautogenous reproduction alternate seasonally. 相似文献
15.
Tadashi Miyashita 《Researches on Population Ecology》1992,34(1):15-28
Summary Mean daily food consumption and total lifetime food consumption of the spider,Nephila clavata, were estimated in natural populations. Daily food consumption in the late adult stage was 27–150 mg wet weight, which was
nearly equivalent or slightly larger than that in other large web-building spiders. Considerable variation in food consumption
was found among habitats or years. The largest variation among habitats in the same year was 7 and 5 fold for daily and lifetime
consumption, respectively, while that among years in the same habitat was 3.5 and 2.5 for daily and lifetime consumption,
respectively. Feeding conditions evaluated from the food consumption per body weight of spiders declined during the period
from mid-July to mid-September in almost all the populations, which suggested that they faced to severe food limitation in
this period. 相似文献
16.
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
17.
Spatially extensive analysis of satellite, climate, and census data reveals human-environment interactions of regional or
continental concern in the United States. A grid-based principal components analysis of Bureau of Census variables revealed
two independent demographic phenomena, α-settlement reflecting traditional human settlement patterns and β-settlement describing relative population growth correlated with recent construction in non-agricultural areas, notably in coastal,
desert, and “recreational” counties and around expanding metropolitan areas. Regression tree analysis showed that β-settlement
was differentially associated with five distinct combinations of seasonality, summer heat or cool, intensity of agriculture,
and extent of “barren” land. Beta-settlement was greatest in coastal and desert areas, and coincided with national concentrations
of threatened and endangered species. 相似文献
18.
Yasuyuki Ishibashi Takashi Saitoh Syuiti Abe Michihiro C. Yoshida 《Researches on Population Ecology》1998,40(1):51-59
Kinship amongClethrionomys rufocanus was investigated during the winter of 1992/93 in a 3-ha enclosure using both molecular and catch-mark-release techniques.
Forty-six adult voles (22 males and 24 females) having high heterozygosities, which were collected from several natural populations,
were released into the enclosure on 29 September 1992. Most fall-born individuals of both sexes stayed in their natal site
during the non-breeding period (December–March), although reproductively active females dispersed during the fall breeding
season (October–November). These philopatric individuals aggregated and formed an maternal family in the winter. Several females
which failed to reproduce were solitary during this season. Some individuals which were derived from several families also
aggregated into a mixed lineage group. Survival rate of fall-born voles from earlier litters was higher than that from later
ones. Maternal families broke up soon after the onset of spring reproduction. Most females established a territory near the
wintering site and made a kincluster, in which close relatives neighbored each other. Maternal families in winter bring about
female kin-clusters in spring, which may influence reproductive output in the breeding season. 相似文献
19.
Sh?ichi F. Sakagami Kazuo Hoshikawa Hiromi Fukuda 《Researches on Population Ecology》1984,26(2):363-378
Summary Overwintering of two social halictine bees,Lasioglossum duplex (Dalla Torre) andL. problematicum (Blüthgen), was studied. InL. duplex many females stay near the old nests, each female preparing a hibernaculum separated from the natal nest. InL. problematicum most females overwinter communally within the natal nest. This difference in overwintering habits relates to the social structure
in the next spring.L. duplex is nearly always solitary in spring although later becoming eusocial, whereas many nests ofL. problematicum are polygynous, beginning in early spring.L. duplex overwinters much deeper (
) in the soil than doesL. problematicum (
), but both species are safe from drops in soil temperature, which is above 0°C even in midwinter, and the bees' supercooling
points are lower than −6°C. This cold resistance and the storage of sufficient food in the crop are reflected in the winter
survival, which is much higher (79%) than the rate of successful nests in the spring active phase (25%).
Bionomics of the eusocial halictine beeLasioglossum duplex VII.
Contribution No. 2654 from the Inst. Low Temp. Sci. 相似文献
20.
T. S. Bellows Jr. 《Researches on Population Ecology》1985,27(1):65-76
Summary Oviposition rates and related behaviours were quantified forLariophagus distinguendus
F?rster attackingCalosobruchus chinensis (L.) andC. maculatus (F.). Oviposition rates varied with parasitoid age; parasitoids aged 1–7 days laid approximately twice as many eggs per day
as those aged 8–14 days. Similar differences were noted in search rates and handling times; younger parasitoids had higher
attack rates and lower handling times than older parasitoids. Search rates and handling times also varied with the host stage
available for attack. Search rates were higher and handling times were lower on larger stages. The results are discussed with
reference to their impact on the dynamical behavior of insect parasitoid-host populations. 相似文献