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1.
Summary Interrelations among acarine, fungal, and environmental components of bulk grain ecosystems were determined by canonical correlation
analyses. Twenty-seven variables were measured monthly in samples collected from 2 identical grain bulks in a granary in Winnipeg
during the years 1959–67. The relationships between 9 kinds of arthropods and 6 environ mental variables, and between the
same arthropods and 12 kinds of actinomycetes and fungi were examined. The maximum canonical correlation between arthropods
and environmental factors was 0.35, and between arthropods and microorganisms was 0.28; both are highly significant (p<0.001). In the first analysis correlations of the variables with the canonical variates revealed that correlations of the
variables with the canonical variates revealed that sampling location, depth, and temperature are the primary environmental
antecedents involved, and the criterion is primarily composed of mitesTarsonemus spp.,Tydeus interruptus and the psocid,Lepinotus reticulatus. In the second analysis the fungiNigrospora sphaerica, Aspergillus spp., andCochliobolus sativus are involved with the mitesCheyletus eruditus andAcarus siro. Generally, the results of these analyses complement the findings of factor and regression analyses of the same data reported
earlier.
Contribution No. 337 from the Research Station, Canada Department of Agriculture, Winnipeg, Manitoba. 相似文献
2.
Kazuyuki Fujita 《Researches on Population Ecology》1983,25(2):387-399
Summary An acarine predator-prey system in a circular stepping-stone environment was described with a simulation model to elucidate
the factors responsible for persistence of the system. The main assumptions in this model are: (1) The prey are inevitably
eliminated in patches in which predators exist. (2) The density of prey declines and becomes extinct by plant defoliation
due to feeding by prey. In this regard this model is different from the models which mimickedHuffaker's (1958) experiments and assumed stable plant-prey relations.
Analyses showed that the critical factor in persistence of the predator-prey system was the plant-prey relations, at any combination
of other parameters involved in the model. The predator-prey system did not persist long under the unstable relationship of
prey and plant. Otherwise the system persisted longer especially when I used a larger number of patches, a larger amount of
plant in each patch, and long-distance-migrations of the prey. In particular, frequent emigration of the prey regardless of
plant conditions was most effective. 相似文献
3.
Summary Principal component analysis (PCA) was used to determine the effects of infestation of bulk stored wheat by multiple species
of insects at 30±2°C for 60 wk. Eight 204-liter drums containing wheat at 15.5% moisture content were used as three distinct
man-made ecosystems: (a) Control system (2 drums), insect-free; (b) RST system (3 drums), artificially infested withRhyzopertha dominica (F.),Sitophilus oryzae (L.), andTribolium castaneum (Herbst); and (c) COT system (3 drums), infested withCryptolestes ferrugineus (Stephens),Oryzaephilus surinamensis (L.), andTribolium castaneum. The variables measured tri-weekly within each system included carbon dioxide, oxygen, temperature, grain moisture, seed
damage, grain weight and volume, dust weight and volume, fat acidity values (FAV) of the wheat, seed germination, microflora
includingAlternaria alternata
(Fr.) Keissler,Aspergillus glaucus group,Aspergillus candidus
Link, and bacteria, insects and the miteTarsonemus granarius
Lindquist. PCA provided multivariate synopsis of the data quantifying several important relationships among the variables monitored.
Tri-weekly and cumulative 60-wk analyses of each system showed that high bacterial counts were associated with high FAV levels;Tarsonemus numbers were positively related toAspergillus; Alternaria and seed germination were negatively related to FAV, bacteria and grain damage; and that the number of insects was related
to the presence ofAspergillus and negatively related to the presence of bacteria. Seed germination andAlternaria infection often decrease rapidly presumably because of infection by fungi of theAspergillus glaucus group. The combined action ofR. dominica andAspergillus spp. enhanced seed damage and increased grain moisture content thus promoting bacterial growth which in turn inhibited insect
and mold growth. Fat acidity values increased with time unless seed damage and bacterial infection were extensive as in the
RST system.
Contribution No. 903, Agriculture Canada, Research Station, 195 Dafoe Road, Winnipeg, Manitoba, R3T 2M9. 相似文献
4.
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
5.
Summary Life tables for worker honeybees covering all life span, and those for adults, were prepared for three seasonal cohorts,June bees, July bees andwintering bees. Survivorship curves forJune andJuly bees show a convex type being exceptional for insects, with relatively high mortality at egg and feeding larval stages and at
later adult stage after most bees became potential foragers. Adult longevity greatly lengthens inWinteriing bees and survivorship curve drops approximately with the same rate. A remarkable similarity of survivorship curves for men and
honeybees was demonstrated, apparently due to highly developed social care in both. Some comments were given on mortality
factors. The importance of life tables for population researches was shown by applying our result to the population growth
curve made byBodenheimer, based upon the data byNolan. At the asymptote of the uncorrected curve, the ratio of total population estimated by uncorrected curve to that by corrected
curve reaches about 3∶2.
Contribution No. 821 from the Zoological Institute, Faculty of Science, Hokkaido University, Sapporo, Japan.
Contributions from JIBP-PT No. 45. This study was in part supportod by a grant in aid from the Ministry of Education for the
special project research, “Studies on the dynamic status of biosphere.”
Population and bioeconomic studies on the honeybee colonies. II.
We express our sincere thanks to Dr. YosiakiIt?, National Institute of Agricultural Sciences, Tokyo, for his kind stimulation and advices to the present work. 相似文献
6.
Summary Population dynamics ofHeliothis virescens (F.) andHeliothis zea (Boddie) (Lepidoptera: Noctuidae) eggs and larvae were studied for two years in a small plot of cotton,Gossypium hirsutum (L.). Due to morphological and ecological similarities, the pooledHeliothis population was considered for most of the analyses. Two generations ofHeliothis eggs and larvae were completed during each year. Stage recruitment was estimated for the eggs and larval instars 2–6, and
recruitment variances were estimated by a Monte Carlo method. A modified form of the Weibull distribution was developed and
used as a model to characterize survivorship curves for each of the fourHeliothis generations. A Type I survivorship curve (mortality rate increasing with age) was inferred for both Generation 1 (early season)
data sets, whereas a Type II survivorship curve (mortality rate constant and thus independent of age) was inferred for both
Generation 2 (late season) data sets. The shapes of the survivorship curves for the individualH. virescens andH. zea populations were inferred to be the same as those for the pooled populations. Analysis of the contributions of various factors
toHeliothis stage-specific mortality indicated that natural enemies (predators and parasites) and the availability of food for larvae
were responsible for between-generation differences in survivorship patterns. 相似文献
7.
Yin Yin May 《Researches on Population Ecology》1978,20(1):61-78
Summary The seasonal and annual fluctuations in a population of the delphacid,Stenocranus minutus (Fab.) onDactylis glomerata L. were studied from March 1968 to September 1970. The study involved the comparison of several sampling methods to estimate
the egg, nymphal and adult numbers and an investigation into causes of mortality within each stage. A population budget was
made for the years 1969 and 1970. 相似文献
8.
W. S. Fargo T. L. Wagner R. N. Coulson J. D. Cover T. McAudle T. D. Schowalter 《Researches on Population Ecology》1982,24(1):123-131
Summary Detailed investigation of the within-tree population system ofDendroctonus frontalis
Zimmermann has resulted in a large data base consisting of abundance estimates for various life stages. This data base was used to construct
histograms for transformed estimates and several life stage indices. Histograms were also constructed for transformed values
of adult residence time, brood development time, and several host-tree characteristics.
Probability and cumulative density functions of the Weibull distribution were fitted, in tandem, to the scaled frequencies
and interval means for each histogram. The inverse cumulative function is known, and with a uniform random number generator,
allows the selection of random deviates from each distribution.
This technique can be used for generating initial (starting) values inD. frontalis population models.
Texas Agricultural Experiment Station Paper No. TA 16628 相似文献
9.
Idrus Abbas Koji Nakamura Haruo Katakura Hiroyuki Sasaji 《Researches on Population Ecology》1988,30(1):43-56
Summary Geographical variation in the elytral spot patterns of a phytophagous ladybird,Epilachna vigintioctopunctata, was studied in the Province of Sumatera Barat, Indonesia. Populations ofE. vigintioctopunctata were divided into four major groups (I–IV) by the incidence of spot pattern variations. Group I, occurring in the coastal
plains and inland lowlands, and Group IV, confined to the highlands, were the extremes of the spot pattern variations, the
latter had many more non-persistent spots and confluences with larger body size and advanced melanism than the former. These
two groups were connected with each other via the intermediate groups. A positive relationship was detected between the elevations
of sample sites and the average number of non-persistent spots per elytron. Consequently, present results favor the view that
the two previously recognized forms ofE. vigintioctopunctata (formae A and B inKatakura et al., 1988) represent a complicated intraspecific variation rather than two distinct sibling species. Elytral spot pattern
variations were not different between the sexes or between the beetles collected from different kinds of host plants.
Contribution No. 30 of Sumatra Nature Study (Entomology).
Supported in part by grants from Japan Society for the Promotion Science for JSPS-DGHE Scientific Cooperation (1980, 1982)
and for the RONPAKU program (toI. Abbas, 1984) and Grants-in-Aid for Overseas Scientific survey from the Ministry of Education, Science and Culture of Japan (Nos.
56041027 and 58041030). 相似文献
10.
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
11.
Summary The functional response ofPseudogonatopus flavifemur E & H (Hym., Dryinidae) was investigated by offering hosts (brown planthopper) at densities ranging from 8 to 160 per cage.
The response curve was found to be sigmoid, i. e.Holling's (1959) Type III curve. In experiments involving 310 hosts per cage distributed unevenly in 5 densities (10, 20, 40, 80
and 160 per hill), and a different female parasite density each time (viz. 1, 2, 4, 8 or 16 per cage), the behavioral response
was described well by the “random predator equation” ofRoyama (1971) andRoger (1972), which is a convex exponential curve. The area of discovery (a) decreased with an increase in female parasite density (P), and the relationship was described by the equation: loga=−1.0099−0.3638 logP. There was an apparent increase in handling time per host as the number of female parasites increased. Superparasitism, a
rare phenomenon under natural conditions, was often observed in the laboratory. The potential ofP. flavifemur as a biocontrol agent of the brown planthopper is discussed. 相似文献
12.
B. F. J. Manly 《Researches on Population Ecology》1979,21(1):30-39
Summary Various aspects of a model for key factor analysis (Manly, 1977a) are discussed. Equations for estimating the parameters of the model are given. The jackknife method is suggested
for obtaining standard errors for estimators. The case of circular populations (where the adults in one generation produce
all the individuals alive at the start of the next, generation) is considered. A computer program is described.
Varley
et al.’s (1973) data on the winter moth is used for illustrative purposes. 相似文献
13.
Takafumi Sasaba 《Researches on Population Ecology》1966,8(2):102-106
Summary The experiment was carried out in order to analyze the results of interspecific competition which were mentioned in the previous
reports (Sasaba 1964, 1965). The following definite tendencies were obtained and an account was given with regard to the process of competition.
(1)T. minutum had a higher reproductive rate thanT. japonicum at a lower density of the parent wasps. (2) The parasitic efficiency ofT. minutum was high as compared withT. japonicum. (3)T. japonicum was consistently superior toT. minutum in the interspecific competition at larval stage.
Contribution from the Entomological Laboratory, College of Agriculture, Kyoto University, No. 384. 相似文献
14.
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
15.
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
16.
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
17.
Osamu Imura 《Researches on Population Ecology》1986,28(2):281-293
Summary The population fitness in terms of the intrinsic rate of increaser
m was measured in eight pure (homogenic) strains ofEphestia kühniella
Zeller with different larva color at an optimal temperature of 25°C, and in three strains at unfavorble temperatures of 15, 17,
28, and 30°C, to understand a mechanism of maintenance of a larval color variation found in wild populations. The survival
rate, hatchability, and gross rate of reproduction were poorly correlated with the fitness but the mean generation time and
net reproduction rate were correlated with the fitness significantly at 25°C. Intermediate color (pink) strain(s) grew faster,
initiated reproduction earlier and had shorter longevities than other strain(s) under the range of 15 and 28°C; the fitness
was highest in the intermediate larval color strains except at 30°C in which all strains had a negative rate of increase.
The results were discussed with reference to the relationship between the larval color and fitness along with a maintenance
mechanism of the variation. 相似文献
18.
Akio Takafuji 《Researches on Population Ecology》1986,28(1):91-101
Summary Two types of the citrus red mite,Panonychus citri (M.) occur in some pear orchards in the intermediate latitudal areas in Japan during a certain period of the year (Takafuji andMorimoto, 1983): one is a diapausing type (DP) and the other a non-diapausing type (C). These two types are incompatible: no adult females are produced from the crosses between them (Takafuji andFujimoto, 1985). In the present study, females of each type were doubly crossed, first with a male of the other type, and then with
a male of the same type, to examine the effectiveness of the second mating. In the females of the DP type, the second mating
with a male of the same type was almost totally ineffective. In contrast, for the females of the C type the effectiveness
of the second mating depended on the durations of the first and second matings: the famles produced female offspring only
when the duration of the first copulation with a male of the DP type was brief and the second copulation with a male of the
C type lasted relatively long. The results suggested that if the two types coexist, the intercrossing between them will favour
the C type over the DP type. 相似文献
19.
Summary In the absence of spider mites, tydeids (Pronematus anconai
Baker andPronematus ubiquitus [Mc Gregor]) may serve as alternate prey to maintain good numbers of the predatory mite,Metaseiulus occidentalis (Nesbitt) (Acarina, Phytoseiidae), late in the season. This late-season predator and alternate prey relationship is necessary to stabilize
Pacific mite populations and perpetuate balance in San Joaquin Valley vineyards.
Thriving laboratory colonies of tydeids were reared on a diet of windblown pollens, including cattail pollen (Typha sp., Typhaceae) and bottlebrush pollen (Melaleuca sp., Myrtaceae).M. occidentalis was successfully reared on a diet of tydeids and ovipositing predator females were obtained. In addition, pollen dusted on
grapevines significantly increased both tydeid and indirectlyM. occidentalis populations late in the season. These studies suggest that artificially disseminating cattail pollen or manipulating good
pollen producing flora in and around vineyards may be used to correct situations where Pacific mites have become serious pests.
This study was supported by grant No. GB-7322 toC. B. Hyffaker by the National Science Foundation. 相似文献
20.
B. F. J. Manly 《Researches on Population Ecology》1973,14(2):151-158
Summary An equation is given for the estimation of selective values from data obtained by mark-recapture experiments, assuming that
selective pressures remain constant while the experiments are carried out. The equation does not have an explicit solution
but can readily be solved using a trial-and-error method.
The use of the equation is illustrated on some data reported byKettlewell
et al. (1969) from an experiment involvingtypica andedda morphs of the mothAmathes glareosa. It is found that theedda morph apparently had a selective advantage of about 12% per day compared to thetypica morph and that this is significantly different from zero. Using another methodKettlewell concluded that the selective advantage of theedda morph was only 7% and that this was not statistically significant. 相似文献