共查询到20条相似文献,搜索用时 31 毫秒
1.
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
2.
Summary Populations of the two-spotted spider mite,Tetranychus urticae Koch collected from various localities and from various host plants in Japan showed wide variations in diapause attribute.
Diapause percentages at 18°C/9L15D varied from nearly 100% in the north to 0% in the south-west. At intermediate latitudes
the mites showed wide inter-population variations. Populations on herbaceous hosts in vinyl- or glass-houses gave significantly
lower incidence of diapause than those on roses and deciduous fruit trees. Presence of winter hosts and better host quality
under protected environments seemed to favour non-diapausing mites.
The temperature threshold for diapause expression also varied widely among local populations. Northern populations consistently
had higher and less variable thresholds than populations at intermediate latitudes with thresholds between 15 and 18°C. Inbred
lines derived from a population in Kyoto exhibited a wide variation in diapause percentage at 18°C. These results show that
diapause inT. urticae is a quantitative threshold trait and that populations in central Japan consist of a variety of genotypes with different
diapause traits. This might provide a genetic source for adaptation to local and temporal variations in environmental conditions. 相似文献
3.
Berend Aukema 《Researches on Population Ecology》1995,37(1):105-110
A review of data on the background of wing dimorphism in carabid beetles (Coleoptera: Carabidae) and especially of the closely
relatedCalathus cinctus andC. melanocephalus is given. In bothCalathus species wing dimorphism is inherited in a simple Mendelian fashion with the brachypterous condition dominant, but inC. melanocephalus the expression of the long winged genotype is under environmental control as well. The development of long winged phenotypes
in the latter species is favoured by relatively favourable environmental conditions, such as high temperatures and a high
food-supply. The higher fecundity of the larger and heavier long winged females of both species may compensate for losses
of long winged phenotypes by flight activities. The evolutionary significance of both types of inheritance is discussed in
relation to dispersal. The ‘fixed type’ as found inC. cinctus is considered an opportunistic short term ‘between sites strategy’, whereas the ‘dynamic type’ ofC. melanocephalus represents a flexible long term ‘within sites strategy’. 相似文献
4.
I Nyoman Widiarta Kenji Fujisaki Fusao Nakasuji 《Researches on Population Ecology》1991,33(2):257-267
Summary The three year (1988–1990) life tables ofNephotettix cincticeps were constructed, and the daily survival rate and longevity of female adults were estimated by Hokyo and Kiritani’s (1967)
method for the overwintering and the first-generations on the foxtail grass in Okayama, southwestern Japan. The life tables
and the population parameter values estimated were compared with those in the other generations on rice. The FARMCOP suction
sampler was employed to survey the population density.
The durations of pre-ovarial maturation of female adults of the 1st generation on foxtail grass and rice seedling were similar.
Longevity of adults of the overwintering and the first generations which emerged on the wild host was longer than that of
the other generations (2nd and 3rd generations) on the rice plants. Fecundity of females decreased successively as the generation
proceeded and it became lowest in the final 3rd generation.
Only about 3.5 percent of first-instar nymphs of the 1st generation emerged as adults in the fallow field. The survival rate
of nymphs on foxtail grass was always lower in comparison with that on rice plants. However, the survival rates of nymphs
on foxtail grass and rice seedling were not significantly different from each other under laboratory conditions. In the fields,
senescence of foxtail grass occurred in the midst of nymphal period of the 1st generation. The survival rate of nymphs on
foxtail grass decreased with the increasing in the nymphal density. Abundance of spiders during the 1st generation was higher
than that in the early stage of rice plants. 相似文献
5.
John T. Trumble 《Researches on Population Ecology》1985,27(2):277-285
Summary The influence of pesticide application on the within-field distribution of arthropods was investigated forTetranychus urticae, the twospotted spider mite, on strawberries. Analyses of dispersions based onGreen's coefficient,Iwao's regression of mean crowding on the mean, andTaylor's power law all indicated that mite populations were highly aggregated initially. As densities increased, more of the avialable
niches were filled, leading to a less clumped dispersion. However, pesticide applications causing greater than 99.9% mortality
acted in a nearly density independant fashion and, although the originating populations were similar in number, did not produce
dispersions equivalent to the initial migrants. As a result, ignoring these changes by developing sampling plans based on
dispersion indices which generated a single slope for an entire data set, led to statistical errors that invalidated the sampling
programs. In order to accurately reflect the field biology of the spidermites, sampling plans for pre and post-treatment populations
were substantially different.
The impact of such changes in dispersion were graphically demonstrated using both sequential and binomial sampling techniques.
Both methods showed that fewer samples were necessary to estimate densities at a given precision level for post-treatment
populations. Also, these techniques indicated that post-treatment populations had similar, but significantly different, dispersions.
The implications of changes in pre and post-treatment dispersions, as well as problems associated with inconsistant dispersions
following pesticide use, are discussed. 相似文献
6.
Summary ‘Predator-foolhardiness’ (Lloyd andDybas, 1966b) in an epidemic population of the sugarcane cicada,Mogannia minuta was tested by counting the number of successful and failed trials of hand-capturing of adults in the centre and periphery
of a heavily infested area. Males frequently failed to escape from capture in the outbreak area but they did not in the peripheral
zone. Females could escape well irrespective of the density. It was considered that the ‘predator-foolhardiness’ of males
is not due to genetic differentiation through the process of outbreak but to the effect of massive chorus on the escape behaviour.
The work was supported in part by Grant-in-Aid No. 439017 from the Ministry of Education, Science and Culture. 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.
Katsumi Togashi 《Researches on Population Ecology》1990,32(1):1-13
Summary Newly-emerged adults ofMonochamus alternatus aged 1 to 5 days were code-numbered with lacquer paint and released by placing them on the trunks of one or two trees in
aPinus thunbergii stand at weekly intervals during the beetle emergence period from 1980 to 1983. Beetles were captured at weekly intervals
from one week after the first day of release. Determinations were made on the distance and direction of beetle dispersal during
a week after release and analysed by a method of Inoue (1978). When the stand canopy was closed, the rate of beetle’s stay
on trees was 0.56 per week. The beetles dispersed at random by walk and flight. When the pine stand was sparse, the rate of
beetle’s stay on trees was 0.02–0.30 per week. They dispersed at random by flight. The average distances traversed were estimated
to be 7.1–37.8 m for the first week after emergence. Using other method, the average distance traversed was estimated to be
10–20 m for each week through the first 3 weeks after release. The results of stepwise multiple regression analysis and a
simple field experiment suggested that the dispersal of newly-emerged beetles was affected by stand density, number of beetles
emerging from individual dead trees, maximum air temperature, and precipitation. 相似文献
9.
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
10.
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
11.
Somchai Isichaikul Koichi Fujimura Toshihide Ichikawa 《Researches on Population Ecology》1994,36(1):23-28
Nymphs ofNilaparvata lugens were experimentally reared from the 2nd instar in a cage covering part of the leaf sheath of an individual rice plant grown
in a Wagner pot. Plants were covered with the cage from the water surface of the pot to 10 cm above the surface (lower cage-group)
or from 10 cm to 20 cm above the surface (upper cage-group). Temperatures measured at three different parts of the cage remained
fairly constant in both groups at around 25°C (23.7–25.2°C in mean value). In the lower cage-group, relative humidities measured
at the three heights in the cage in (76.3–90.5% in mean value) markedly increased with the approach to the water surface.
The nymphs of this group, particularly during the molting period, aggregated close to the surface. Eighty-two percent of the
released nymphs emerged in this group. Relative humidities measured at three heights of the upper cage-group were 69.5–72.7%
in mean value, and all the nymphs in this group died within 3 days after their release although half of them stayed on the
rice plants within 6 h after their release. The role of relative humidity as a limiting factor on the range of the microhabitat
and the population density ofN. lugens in rice fields was discussed on the basis of the results. 相似文献
12.
Alex C. Michalos Heather Creech Christina McDonald P. Maurine Hatch Kahlke 《Social indicators research》2011,100(3):391-413
Celebrating the UN Decade of Education for Sustainable Development (2005–2014), this paper presents results of two exploratory
surveys taken in the province of Manitoba, Canada in January to March 2008. A random sample of 506 adults completed a mailed
out questionnaire designed to measure respondents’ knowledge, attitudes and behaviours concerning the basic themes of the
UN Decade. In the same period, a convenience sample of 294 students in grades 6–12 in four schools was surveyed based on a
simplified version of the same questionnaire. Using these two datasets, we constructed somewhat crude standardized tests and
showed that for students and adults, having attitudes favourable to ESD/SD is relatively more influential than age, levels
of education and knowledge for behaviours favourable to ESD/SD. The differences are that (1) gender was most influential for
the student samples, while favourable attitudes were most influential for the adult samples; and (2) while attitudes were
practically equally influential to knowledge (though numerically more influential) for the student sample, attitudes were
vastly more influential than education for the adult samples. 相似文献
13.
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
14.
Use of the regression of mean crowding on mean density for estimating sample size and the transformation of data for the analysis of variance 总被引:8,自引:0,他引:8
Summary An approximate method for estimating the sample size in simple random sampling and a systematic way of transformation of sample
data are derived by using the parameters α and β of the regression of mean crowding on mean density in the spatial distribution
per quadrat of animal populations (Iwao, 1968). If the values of α and β have been known for the species concerned, the sample size needed to attain a desired precision
can be estimated by simply knowing the approximate level of mean density of the population to be sampled. Also, an appropriate
variance stabilizing transformation of sample data can be obtained by the method given here without restrictions on the distribution
pattern of the frequency counts.
Contribution from the Entomological Laboratory, Kyoto University No. 418.
Contributions from JIBP-PT No. 52. Aided in part by a grant from the Ministry of Education for the special project research,
‘Studies on the dynamic status of biosphere’. 相似文献
15.
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
16.
I Nyoman Widiarta Yoshito Suzuki Hiroichi Sawada Fusao Nakasuji 《Researches on Population Ecology》1990,32(2):319-328
Summary The population dynamics ofNephotettix virescens, a vector of rice tungro virus disease was investigated in a synchronized transplanting area at Jatisari (1984–1986), West
Java and in a staggered transplanting area at Sidan (1986–1988), Bali, Indonesia. The FARMCOP suction sampler was employed
for population censuses ofN. virescens and its natural enemies. The population growth pattern was affected by transplanting pattern: In the staggered transplanting
area, the population density increased from the immigrant generation to the first generation, and sharply decrease thereafter,
while in the synchronized transplanting area the population density often reached the highest peak in the second generation.
The degree of contageousness in the spatial distribution ofN. virescens was negatively correlated with population density of the immigrant generation.
Contribution from Indonesia-Japan Joint Program on Food Crop Protection 相似文献
17.
L. V. Madden L. R. Nault D. J. Murral M. R. Apelt 《Researches on Population Ecology》1995,37(2):279-289
The degree of aggregation of lettuce plants infected by aster yellows phytoplasma (AYP) was investigated in 12 fields from
three experiments. Position of diseased and healthy plants was mapped in a 6–9×12-m section of each field; for most analyses,
fields were divided into 10-plant quadrats. Mean disease incidence (p) ranged from 0.01 to 0.30. The frequency of diseased plants was described by the beta-binomial distribution, with an index
of aggregation (θ) ranging from 0 to 0.17, positively correlated withp, and generally increasing over time within a field. Distance-class analysis revealed a core-cluster size of only a few plants.
However, spatial autocorrelations ofp between quadrats were not significant, indicating that the scale of spatial pattern was small, generally less than 10 plants.
An overall measure of aggregation was given by the slope parameter of the binary form of the power law, in which the log of
the calculated variance is regressed on the log of the theoretical variance for a binomial distribution. The slope was 1.18
and significantly different from 1. Results for this “simple-interest” disease are interpreted in relation to the persistent
transmission of AYP by its aster leafhopper vector. 相似文献
18.
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
19.
Yoshitaka Tsubaki Rowan E. Hooper Michael T. Siva-Jothy 《Researches on Population Ecology》1997,39(2):149-155
The damselflyMnais pruinosa costalis (Odonata: Calopterygidae) is unusual in that males are dimorphic, existing as clear-winged non-territorial ‘sneaks’ and orange-winged
territorial ‘fighters’. Here we report the results of population census data and behavioural observations in the field and
laboratory, and present estimates of emergence period, reproductive period, total lifespan, and reproductive success of each
morph. Clear-winged males are smaller and have lower daily reproductive success than orange-winged males, but live for longer
in the field and laboratory. We accounted for the difference in the ‘operational reproductive life’ of the two morphs and
estimated lifetime reproductive success: there was no difference between clear-winged and orange-winged males. We discuss
possible mechanisms for the maintenance of the two forms. 相似文献
20.
Hidenori Ubukata 《Researches on Population Ecology》1984,26(2):285-301
Summary Females of an odonate species in which oviposition sites overlap with mating sites may adopt one or more of the following
strategies when they lay eggs except when they ‘trade’ mating for access to suitable oviposition sites or for services (guarding,
etc.) provided by males: (1) ovipositing at hidden places; (2) ovipositing at a time when males are neither patrolling nor
watching; (3) indicating non-receptivity by a behavioral display. The density of ovipositing females of the dragonfly,Cordulia aenea amurensis
Selys which was studied between 1970 and 1983 at a pond (H?rai-numa, Sapporo, Hokkaido) had a high negative correlation with the
distance from ‘entrance’ (a part of shore at which the arrival of most adults seems to have occurred). On the other hand,
oviposition was rarely observed at a sector being distant from entrance in spite of the inference that larval survivorship
was probably high at this sector. Most females oviposited among emergent vegetation in which approach of males to them was
difficult, and they scarcely traveled across the open water in search of oviposition sites. Therefore, most females of the
population studied were considered to adopt the first strategy. The second and third strategy were not adopted by the population
studied. Finally, the influences of some environmental factors and traits possessed by a species on the adoption of these
tactics or on the execution of the ‘trades’ were discussed.
Ecological studies ofCordulia aenea amurensis
Selys, VII.
This work was supported in part by a Grant-in-Aid for Special Project Research on Biological Aspects of Optimal Strategy and
Social Structure from the Japan Ministry of Education, Science and Culture. 相似文献