bluuebunny/crossref_metadata_2025_split huggingface dataset:
Models for mating disruption by means of pheromone for insect pest control
Authors: Barclay Hugh J. , Judd Gary J. R. 
Published: November 2006

AbstractModels are presented to investigate the population dynamic behavior of a pest population with the release of pheromone for mating disruption. Three mechanisms of mating disruption are considered: (i) confusion of males, (ii) competition with female pheromone trails yielding false trail following, (iii) emigration of males prior to mating. In addition, several refinements to confusion are considered. Confusion and emigration of males were found to be very similar both quantitatively and dynamically; also, a combination of both mechanisms was very little more efficient than either one separately. False trail following is difficult to compare with the other two, since competition with wild females is involved and thus the total population size enters the equations. Density dependence of the action of pheromones results in some cases in which mating disruption cannot control the pest population. Similarly, aggregation of the pest population decreases the efficiency of the method unless the pheromone action is density independent. Delayed mating of females makes control easier, and may constitute one mechanism for mating disruption.
Spatial pattern analysis of the incidence of aster yellows disease in lettuce
Authors: Madden L. V. , Nault L. R. , Murral D. J. , Apelt M. R. 
Published: November 2006

AbstractThe 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 ofpbetween 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.
Population studies based on relative abundance of five different life history stages of Ayu, Plecoglossus altivelis (Pisces, Plecoglossidae), in Lake Biwa
Authors: Miura Taizo 
Published: November 2006

Summary
Comparison of relative abundance of each two successive life history stages was made for studying population dynamics of ayu, Plecoglossus altivelis, in Lake Biwa.
Number of eggs spawned is proportional primarily to the size of biomass of spawner population although spawning success plainly depends on presence or absence of heavy rain in the spawning period.
Although density of fry tends to be proportional to that of egg, yearly fluctuation of the fry mortality may be caused by changes in density of food organisms but is not in compensatory way.
From the fry stage to the juvenile one the rate of mortality and/or of growth seem to fluctuate in compensatory way which is supposed to be related to a shortage of food.
Yearly fluctuation of mortality of adult stage is caused by an artificial factor as changes of fishing intensity.
Necessity of studying actual events at each stage of the life history process separately in relation with environmental conditions is discussed through the result of the present analysis.
Interspecific competition between two species of Trichogrammatidae III The analytical study on the competition
Authors: Sasaba Takafumi 
Published: November 2006

SummaryThe 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 than T. japonicum at a lower density of the parent wasps. (2) The parasitic efficiency of T. minutum was high as compared with T. japonicum. (3)T. japonicum was consistently superior to T. minutum in the interspecific competition at larval stage.
Population behaviour of the southern green stink bug, Nezara viridula, with special reference to the developmental stages of early‐planted paddy
Authors: Kiritani Keizi , Hokyo Nobuhiko , Iwao Syun'iti 
Published: November 2006

SummaryPopulation behaviour of adults and 5th‐instar nymphs of Nezara 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 byIwaoet 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.
Application of a marking‐and‐recapture method for the analysis of larval‐adult populations of an insect, Nezara viridula (Hemiptera: Pentatomidae)
Authors: Iwao Syun'iti , Kiritani Keizi , Kokyo Nobuhiko 
Published: November 2006

SummaryDifficulty 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 (Leslieet al., 1953) has been devised to analyze the capture‐recapture data of the 5th‐instar larvae and adults of Nezara 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.
Preliminary studies for the population estimation of the cryptomeria red mite, Oligonychus hondoensis
Authors: Kobayashi Fujio , Murai Minoru 
Published: November 2006

SummaryThis is the second paper dealing with techniques necessary to the population estimation of the Cryptomeria red mite feeding on a coniferous Cryptomeria tree, with the final object of determining the absolute population. Results are as follows:
The population can be defined as the whole of mites existing on branches with foliage younger than two years old, because more than 95% of individuals are always there.
Optimal sampling unit varies according to mite population. Unless a fixed unit is necessary, seasonal placement of units is recommended.
Since significant variance is associated with crown levels, representative sampling from each level is designed. These calculation should be based on the data transformed to logarithms, as the relation between mean and variance suggests that the population data are of contagious distribution.
A trial to calculate the total length of branches for each age, which is needed for the conversion to absolute population, is described.
Experimental studies on the distribution of the aphid counts
Authors: Shiyomi Masae , Nakamura Kazuo 
Published: November 2006

SummaryThe present paper dealt with the sequential changes of the distribution pattern of apterous females aphid populations, that were artificially settled at the beginning on the experimental barley ‘field'. The aphids were settled at random or even with a fixed denisty per plant. For five or six days after the settling, the number of individuals followed the negative binomial distributions in all cases while the parameters k and p were varying. The estimated values of k were rather small for the first one week after the settling, which may suggest that the number of moving aphids between plants was relatively small and the degree of concentration expressing the intrinsic increase was high. After that, as the number of individuals increased, the number of moving aphids between plants would be considered to be increased. It was found that with the lapse of time the degree of concentration decreased or k became larger.The distribution of aphids per blade in a plant was also described briefly.
Natural mortality at different population densities of a pine shoot moth, Evetria cristata
Authors: Kanamitsu Keiji 
Published: November 2006

SummaryA field population of Evetria 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 of E. 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 and Pediobius 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.
Studies on interspecies competition between the azuki bean weevil and the southern cowpea weevil
Authors: Fujii Koichi 
Published: November 2006

SummaryExperimental studies was made on the interspecies competition between the azuki bean weevil, Callosobruchus chinensis and the southern cowpea weevil, C. macultatus. And the following results were obtained.
The reverse result of competition between the two species observed under the air‐tight condition and the air‐free one. That is, the population of the azuki bean weevils destroyedby that of the southern cowpea weevils under the former condition and vice versa under the latter. It is thought that such a reversal is due to the difference of sensibility of each species to the air‐tight condition.
Under the air‐free condition, change of the time interval of food‐supplying had no effect on the result of competition within the limits of this experiment. The population of the southern cowpea weevils was always destroyed by that of the azuki bean weevils. But there was a certain degree of correlation between the duration of co‐existence and the interval of food‐supplying.
From the results, it is possible to say that by changing the degree of air‐tightness, or the time interval of food‐supplying, the co‐existence period and the final result of competition can be changed.
The different mechanism of competition between two species in the present experiment from the experiments ofUtida (1952) andYoshida (1957) were discussed.
A difference in the mechanism of interspecies competition and intraspecies competition was expected from the level of total population numbers of two species and the individual weight of C. chinensis.
A comparative analysis on the distribution of nymphal populations of some leaf‐ and planthoppers on rice plant
Authors: Kuno Eizi 
Published: November 2006

SummaryThe frequency distribution of the number of nymphs per hill of rice plant were analyzed for three species of rice leaf‐ and planthoppers, Nilaparvata lugens, Delphacodes striatella and Nephotettix cincticeps, based on the sampling data obtained during their last generations in the paddy field.For every species concerned, individual distributions were proved to be contagious and to fit well to the negative binomial distribution. Further, it was found that the value of negative binomial parameter k is so stable for same species that a single value of k is applicable for a series of counts with different means, whereas that k differs remarkably among different species: if the reciprocal of the weighted estimate of common k which is an adequate index measuring degree of contagiousness of the distribution, is compared among different species, it is higher in the order of Nilaparvata, Delphacodes and Nephotettix.The ecological and practical implication of constancy and heterogeneity within and among species was discussed respectively as to the value of parameter k.
On a method for estimating the rate of population interchange between two areas
Authors: Iwao Syun'iti 
Published: November 2006

SummaryA method for estimating the rate of population interchange between two areas is described in this paper. It is applicable to the case where the sampling ratios and the survival factors of the populations on two areas are different from each other. From the marking‐and‐recapture data taken at three successive occasions, we can obtain the estimates of emigration factors, total survival factors over two areas and the ratio of surviving migrants to the total survivors over the two areas, for each of two populations initially living on different areas.
Observations on populations of the horseshoe crab Limulus (=Xiphosura) polyphemus
Authors: Sokoloff Alexander 
Published: November 2006

Summary
Marked populations of Limulus (=Xiphosura) polyphemus reveal that in Cold Spring Harbor, New York, they consisted of 10,000–18,000 adults in 1957 and 1961. The sex ratio in 1957 was about 4 males: 1 female. Pairs may remain attached for as long as 9 days. An undisturbed female may lay as many as 12,000 eggs in one nest.
The Cold Spring Harbor populations appear to be rather sedentary: none of the 1,000 animals marked on the north edge of the sandspit in 1961 were detected in the outer harbor either at Laurel Hollow Beach or the peninsula adjacent to the Cold Spring Harbor Yacht Club 500–800 meters from the tagging site (see Fig. 1), nor were they found in the small beach adjacent to the Biological Laboratory in the inner harbor. Similarly, none of the 300 animals marked at this last site were found at the north edge of the sandspit.
The phenotype of the compound eye varies from black to pigmentless. Samples observed in Cold Spring Harbor and in the Marine Biological Laboratory, Woods Hole, Massachusetts (separated by Long Island Sound and a distance of 150 miles) differ in the frequency of the various phenotypes scored, but the mode of inheritance of eye color remains obscure.
The available evidence indicates Limulus has considerable phenotypic variation in regard to body size, eye color, and other characters believed to be inherited, with the result that demes or physiological races are created. It is argued that the belief that this organism is stable and has not changed since the Triassic 200 million years ago has foundation only in regard to the pattern of the body of Limulus, but not in regard to its genotype. Limulus does not seem to be different from other organisms for which considerable genetic evidence is available, and thus the statement that DNA is fairly stable and has remained so for 200 million years is open to question.
A marking‐and‐recapture analysis of the adult population of a phytophagous lady‐beetle, Epilachna sparsa orientalis
Authors: Iwao Syun'iti , Machida Akisato 
Published: November 2006

SummaryA marking‐and‐recapture study of a population of overwintered adults of Epilachna 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 of E. sparsa orientalis and E. vigintioctomaculata.
Local distribution of two swallows of genus Hirundo, and breeding success of H. rustica
Authors: Mizuta Kuniyasu 
Published: November 2006

SummaryThe distribution of nests of the swallows was investigated in 1957, 1962 and 1963 at Koriyama, Nara Prefecture. Roughly speaking, the nest of Hirundo rustica was located in the urban areas, and that of H. daurica in the rural areas. This subdivision of the habitat seems to be due to the traditional system more or less depending on some interactions between them. The trend of the decrease in the nest number has not been found out from the 3‐year studies.The observation on the breeding success of H. rustica was done in 1963, and it was estimated that 869 youngs in total fledged out from the study area.
Damped oscillation of population density at equilibrium
Authors: Utida Syunro 
Published: November 2006

SummaryIt has been theoretically assumed that the population density at the equilibrium oscillates with damping from generation to generation. In the adult population of the southern cowpea weevil, Callosobruchus maculatus, it was exemplified. But, it was not so clear in the adult population of the azuki bean weevil, C. chinensis as seen in that of C. maculatus. This difference seems to be due to the scramble type of competition that occurs in larval stage in C. maculatus, instead of in the egg stage as C. chinensis. Comparing with the oscillation from generation to generation obtained in the present experiment to that of Lucilia population found byNicholson, the oscillation in Lucilia population is composed of the cycle in a generation and the descending phase of each cycle of it is not regulated density‐dependently. The present result seems to be more appropriate for the demonstration of the theory of self‐adjustment of population.
Quantitative evaluation of predation by spiders on the green rice leafhopper, Nephotettix cincticeps Uhler, by a sight‐count method
Authors: Kiritani Keizi , Kawahara Sachio , Sasaba Takafumi , Nakasuji Fusao 
Published: November 2006

SummaryA sight‐count method for evaluation of predation by spiders on the green rice leafhopper, Nephotettix cincticeps was proposed and its applicability was tested under natural conditions.The number (n) of leafhoppers preyed on by spiders per rice hill per day was estimated by the formula:
urn:x-wiley:14383896:pope0187:equation:pope0187-math-0001
where F is the frequency of predation observed per hill:P is given by dividing the time spent feeding on prey by 24 hours; and C refers to the total amount of feeding activity expressed in terms of the activity during the standard time interval. The total number (N) of prey attacked during the specified period can be given as follows:
urn:x-wiley:14383896:pope0187:equation:pope0187-math-0002
With this method, the role of paddy‐inhabiting spiders, Lycosa pseudoannulata, Oedothorax insecticeps, Tetragnatha spp, and Enoplognatha japonica, as predator of N. cincticeps was evaluated with reference to life tables of the prey.The advantages and limitation of the sight‐count method were discussed as compared with other methods so far proposed.
A study of natural populations of the celery leaf‐miner Philophylla heraclei L. (Diptera, Tephritidae)
Authors: Leroi B. 
Published: November 2006

SummaryThe study of the population dynamics of the celery leaf‐miner, Philophylla heraclei, must take into account the fact that the host‐plant is not present permanently and that it develops between the two annual generations of the insect. This development affects in particular the quality and quantity of the leaves fed upon by the mining larvae. It is possible to know the numerical change of the populations from one annual generation to the next (bivoltine insect) and from one year to the next by counting the populations in the various larval instars, responsible for the injury caused to celery.An accurate method of counting of larval numbers, taking into account their change parallel with that of the host‐plant, is described in this text. It makes it possible to know with accuracy the duration and importance of the infestations in relation to external factors and to factors inherent to the host‐plant itself. Certain traits of larval behaviour, particularly the transfer of a larva from its original mine to a secondary mine as a result of food shortage can thus be established and estimated quantitatively.
Sampling error as a misleading artifact in “key factor analysis”
Authors: Kuno Eizi 
Published: November 2006

SummaryThe influences of sampling error in key factor analysis are investigated statistically. The error involved in the data distorts the results in various misleading ways. In the course of detecting key factors by correlation analysis, the distortion arises in the following two ways: (1) the contributions made by the first and the last components of population trend index (log I or K) to the total variation are overrated as compared with the others; and (2) spurious negative correlation arises between successive two components. The risk of misinterpretation due to such disturbance is usually increased further if the error is concentrated on any particular developmental stages. In the tests to detect density‐dependence by using regression analysis, the error consistently acts as if it were a density‐dependent factor: under the effect of sampling error, the slope b for the regression of log Ni+1 on log Ni, for example, is expected to become<1 even where there is no density‐dependent factor at all. A set of formulas are derived which may serve to check and correct these misleading distortions caused by the error. It is also shown that such undesirable influences can be avoided, at least to a considerable extent, if appropriate sampling plans are adopted for the study. The validity of key factor analysis is discussed in reference to this and some related problems.