bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of the individual number entering each development stage in an insect population
Authors: Kobayashi Shiro 
Published: October 2006

SummaryA method for estimating the number entering each development stage from data obtained by regular sampling through one generation of an insect population was described. This method is consisted of the following two procedures: The provisional estimates are calculated on the assumption that each stage has a common mortality in a sampling interval. Then these estimates are corrected on another assumption that the mortality is different in each stage but constant during a stage.The result of testing its validity with two laboratory populations of the common cabbage butterfly, Pieris rapae crucivora, showed the availability of the present method.
Dynamics of distribution in animal communities: Theory and analysis
Authors: Tokeshi Mutsunori 
Published: October 2006

SummaryTheoretical and analytical problems of the dynamics of distribution and abundance in animal communities were examined. In many communities, species with low abundance and of limited spatial occurrence (i.e., rare species) typically form a conspicuous peak when a frequency distribution of the number of species is constructed with respect to the proportion of sites occupied within an area of distribution. Models of distribution dynamics, including a new model proposed here, were compared with a range of animal community data using a new procedure to assess single‐ and bi‐modal patterns in frequency distributions of spatial occurrence. Data reveal that single‐modality with an excess of rare species occurs more frequently than bimodality. Even when bimodality is detected, the mode representing wide‐spread species is in the majority of cases smaller than that for rare species. Thus, a new model in which the rate of local extinctions is assumed to be negatively related to patch occupancy (or population abundance) is in better agreement with observed data than earlier models. Some problems of analysis, in particular model assumptions and testing, are discussed.
Management sampling for larvae of the colorado potato beetle
Authors: Binns M. R. , Mailloux G. , Bostanian N. J. 
Published: October 2006

SummaryUntreated plot of ‘Kennebec’ and ‘Superior’ potatoes were sampled for Colorado potato beetle (CPB) at L'Assomption, Quebec, in 1982, 1986 and 1987. Numbers of CPB larvae per stalk were counted on 74 occasions for sample sizes ranging from 50 to 200 stalks. Regression techniques were used to estimate the relationship between mean and cumulative proportion of stalks infected. These were used to set up binomial sequential probability ratio test (SPRT) sampling plans for pest management decision making with tally numbers (or tally thresholds, cutoff numbers) equal to 0,1,…10. A binomial scheme defined by tally number equal to 4 is proposed for general use, and corresponding plans are given, with estimated operating characteristic and average sample number curves.
Model analysis of the effect of environmental fluctuation on the species replacement pattern of pelagic fishes under interspecific competition
Authors: Matsuda Hiroyuki , Wada Tokio , Takeuchi Yasuhiro , Matsumiya Yoshiharu 
Published: October 2006

SummaryThere are two factors affecting long‐term fluctuation of planktotrophic pelagic fish: environmental fluctuation and interspecific competition. Long‐term catch data of planktotrophic pelagic fishes in Japan suggest that the chub mackerel (species B) was replaced by the sardine (A), A was replaced by the anchovy, Pacific saury and horse mackerel (Group C), and species in group C were replaced by species B. If species A defeats B, B defeats C, and C defeats A in interspecific competitive ability, then the abundance of these three groups fluctuate forever and dominate in the same order. We call this cyclic advantage hypothesis for species replacement. In this model, environmental fluctuation affects the species replacement as a trigger. Environmental fluctuation does not determine the next dominant species but greatly affects when the next replacement occurs.
Persistence of females that produce only female progeny in lepidoptera
Authors: Ishihara Michio 
Published: October 2006

SummaryIn Lepidoptera females that produce only female progeny, can be found in wild populations of at least 11 species. The genetic variation is passed on to each generation of female offspring. If genetically abnormal females produce more female offspring than normal females do and mating is random, then populations containing these abnormal females will have a biased population sex ratio. Unmated females will increase due to the scarcity of males and so the population as a unit will die out. Several possible biological explanations for the persistence of the genetic variation have been proposed. But experiments and observations have not verified those hypotheses. Simulations of Heuch's model (1978), however, have shown that the variation persists if the population is distributed, in patches and there is dispersal among patches, even when insects disperse at random. Abnormal females tend to persist at both low and high migration rates, but the probability of persistence is higher at high migration rates. It has been suggested that abnormal females in a population are an adaptation, but the results of this investigation show that this explanation, may not be plausible.
Shift in life‐history strategy from reproduction to defense with colony age in the galling aphid Hemipodaphis persimilis producing defensive first‐instar larvae
Authors: Akimoto S. 
Published: October 2006

SummaryColony defense in some aphids is performed by sterile soldiers but in others by monomorphic larvae of a specific instar stage. This paper, focusing on a galling aphid Hemipodaphis persimilis with monomorphic defensive first instars, examined the mechanism by which the proportion of defenders is regulated in the colonies. Demographic analyses showed that the ratios of first instars (defenders) were kept constantly high (58% on average) from mid June to late September. High proportions of first instars could be explained by consistently high birth rates (birth rate hypothesis) or by a prolonged duration of the first instar stage (instar span hypothesis).With the progress of colony age, the mature‐embryo content of apterous adults, used as an index of the birth rate, decreased and the proportions of advanced instars increased. These results did not support the birth rate hypothesis. By contrast, calculation of a newly proposed index, the molting rate, showed that the duration of the first‐instar stage was short in incipient galls but became longer with colony age. The duration of other instar stages was always kept short. These results corroborate the instar span hypothesis and suggest that the prolongation of the first‐instar stage is an adaptive mechanism by which the defender ratio is kept high in mature colonies where the birth rate is declining. The frequency of aggressive behavior in first instars increased from incipient to mature galls. Seasonal changes in the instar span and aggressiveness of first instars suggest that in H. persimilis colonies there is a strategic shift from the reproductive to defensive phase with colony age.
A measure of sexual selection for interspecific comparisons of species with diversified mating systems and different mortality schedules
Authors: Nishida Takayoshi 
Published: October 2006

SummaryBased on variances in components of lifetime reproductive success (LRS), a new index of the intensity of sexual selection was proposed mainly useful for interspecific comparisons. The index was defined as the male to female ratio of the standardized variance in mating efficiency during mating period. The index can to a large extent exclude the effect from natural selection which commonly act on both sexes in mating period and also from mortality in pre‐reproductive period. This empirical measure has some defects in the strict sense (i.e., dichotomy of natural and sexual selection), however, it enables interspecific comparisons of the intensity of sexual selection among different taxonomic groups of animals with various mating systems and mortality schedules.
New regression formula to estimate the whole population for recapture‐addicted small mammals
Authors: Tanaka Ryo , Kanamori Masaomi 
Published: October 2006

SummaryWe have devised a census formula of curvilinear regression suitable for capture‐recapture data of recapture‐addicted populations of the Japanese field vole (Microtus montebelli) obtained under a grid‐plan with single‐catch traps in order to estimate the whole population. The equation is founded on the assumption that the trappable population on the initial day is increased in way of an exponential curve until it reaches to the whole during one trapping period. The effect of trap‐preoccupation by marked and multiple collisions is considered in the formula. As a result of its application to field data of the vole, it has turned out that the equation is required for the data gained under the trapping plan with trap spacing 10m, but not for those under the plan with spacing 5m, to estimate the whole. A convenient method of analysis of the formula is offered here, but we have been yet unable to introduce assymptotic variance of estimates.
Sex ratios in laboratory and field populations of the old field mouse, Peromyscus polionotus
Authors: Smith Michael H. 
Published: October 2006

SummaryMales outnumbered females as juveniles but not as adults among mice captured by hand in their burrows. The higher production of male offspring together with their higher mortality rate resulted in a 1∶1 sex ratio for the adult mice. Despite the equal abundance of each sex, more males than females were caught in traps. Males must have a higher chance of encountering a trap and/or of entering a trap after finding it.
The estimation of population density of the green rice leafhopper, Nephotettix cinticeps Uhler, in spring field by the capture recapture method
Authors: Nakamura Kazuo , Itô Yosiaki , Miyashita Kazuyoshi , Takai Akira 
Published: October 2006

SummaryThe population parameters of green rice leafhopper, Nephotettix cincticeps in hibernated generation was estimated by the capture‐recapture method on the gramineous weeds of resting paddy field from late in April to mid‐May, 1962–1965.The difficulty of applying the capture‐recapture method to this insect is caused from the low density and the low activity of the leafhopper, so that it is necessary to make the suitable plan of capture‐recapture series and to construct the special method to detect the population parameters.The number of adults differed greatly among the years and among the plots in the same year. But, in general, the density was relatively high late in April, and decreased rapidly in May. The number of males was higher than that of females late in April, but decreased rapidly to become lower in May.The sampling efficiency with sweep‐net depends upon the many factors, such as weather and floristic conditions; especially the atmospheric temperature and the force of wind are considered to affect greatly to the efficiency. In general, low temperature and strong wind are the cause of low sampling efficiency.
Estimation of the stage‐specific survival rate in the insect population with overlapping stages
Authors: Kiritani Keizi , Nakasuji Fusao 
Published: October 2006

SummaryAn application ofHokyo andKiritani's method (1967) was attempted to estimate the stage specific survival rates of the population with overlapping stages. This method can be written as follows assuming a constant daily survival rate (K) throughout the life:
urn:x-wiley:14383896:pope0143:equation:pope0143-math-0001
where, and F refer respectively to the total incidence of ith instar nymphs and that of individuals after ith instar inclusive, and αi refers to the developmental period of ith instar.Application of this model to caged and natural populations of the southern green stink bug, Nezara viridula, was made to test its validity. The estimates of the initial number of successive stages obtained from the present method were compared with those fromRichards andWaloff's method (1954) for the caged populations of 1st, 2nd and 3rd generations. The superiority of the present method to theRichards andWaloff's in estimating adult numbers was shown in all the generations examined. When different daily survival rates are involved in the course of population decrease, application of the revised method proposed byHokyo andKiritani (1967), gives much reliable estimate as compared with one before correction.The present method is useful in constructing life table of such species as scale insects which complete their life cycle within a defined space, but their successive stages overlap considerably.
A statistical model of the reproduction of aphids
Authors: Shiyomi Masae 
Published: October 2006

Summary
The logistic function has been generally used to describe the reproductive process of a “population” of animal. However, this model can not give us any information about the reproductive process of “individuals” in the population. In this study a statistical model on the basis of the reproduction of individuals of barley aphid is presented to find the proportion of the mature individuals, the heterogeneity in reproductive ability of the aphids, etc.
The model is constructed as follows:
The probability that j insects are found on a plant at time t0 is represented as Q(j).
The probability that h individuals of j have reproductive ability, say, mature individuals, in the period t0 to t1 is represented as B(h/j)=jChwh(1−w)j−h, where w is the proportion of mature individuals.
In a population with a homogeneous reproductive ability, the probability that each parent lays i offspring in the period t0 to t1 is represented as P(i/m)=e−mmi/i!, where m is mean. And, in a population, m changes according to the gamma distribution. Hence the probability that a parent lays i offspring between t0 and t1 is represented as , where p and k are parameters of negative binomial distribution. The probability that h parents on a plant lays s offspring is represented as .
From the assumptions mentioned above, the probability that s offspring are to be found at time t1 on a plant with the original j individuals at time t0 is represented byurn:x-wiley:14383896:pope0167:equation:pope0167-math-0003
The experimental populations were demonstrated to fit well to the model.
Population dynamics of the chestnut gall‐wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) IV. Further analysis of the distribution of eggs and young larvae in buds using the truncated negative binomial series
Authors: Itô Yosiaki 
Published: October 2006

SummaryDistribution pattern of eggs and the first instar larvae of the chestnut gall‐wasp, Dryocosmus kuriphilus, per bud of the chestnut tree was re‐examined using the truncatedPoisson and the truncated negative binomial series. The results are as follows:
About sixty percent of the distribution are approximated by the truncated negative binomial and another thirty percent by the truncatedPoisson. When the distribution has been approximated by the truncated negative binomial, the show scattered values, some of which are near thePoisson, but the mean value of is about 4 both in eggs and in the first instar larvae.
The number of buds which have not been infested by gall‐wasps is resulted from various factors as follows: (a) Buds formed after the laying activity of gall‐wasps has ceased; (b) Old and shrunk buds which were avoided in laying; (c) Buds in which eggs have died by the time of sampling; and (d) Buds escaping ovipositions by chance. Most of the gall‐wasp‐free buds located in the middle part of the shoot are accounted for the zero‐class expected by the negative binomial series.
Brass (1958) moment method for estimating parameters of the truncated negative binomial give good precision within the range of from 1 to 10 and of from 1 to 6.
It is concluded that the truncated distributions used are useful for the purpose of analysis of the distribution pattern of the chestnut gall‐wasp.
Why is there so much genetic variation for wing dimorphism?
Authors: Roff Derek A. 
Published: October 2006

AbstractWing dimorphism appears in general to be determined either by a single locus, 2 allele system in which brachyptery is dominant, or by the additive action of numerous loci. In the latter case studies indicate that the heritability is typically quite large. It is generally postulated that wing dimorphism is under strong selection: why then is genetic variation not eroded? In this paper I consider three possible explanations. First, genetic variation may not be exposed to selection because environmental heterogeneity effectively makes heritability zero. Because wing dimorphisms are known to evolve it seems unlikely that this is the primary factor. Second, directional selection on a threshold trait may push the population almost to monomorphism but erodes genetic variance at a very slow rate. This mechanism cannot preserve variation but makes it possible for other factors to more easily maintain variability. Finally, I demonstrate that in a heterogeneous environment spatio‐temporal variation in fitness will itself maintain a genetic polymorphism for wing dimorphism.
Wing dimorphism and the migratory syndrome: Correlated traits for migratory tendency in wing dimorphic insects
Authors: Fairbairn Daphne J. 
Published: October 2006

AbstractThe hypothesis that the morphological, physiological, and behavioral traits comprising the migratory syndrome in insects are genetically correlated through pleiotropic effects of genes controlling the titre of a common hormonal determinant is explored. Evidence that juvenile hormone (JH) influences the component traits of the migratory syndrome is presented, and thus JH is assumed to be the underlying, common determinant. However, readers are cautioned that this does not imply that JH is solely responsible for these traits, nor is this necessary for the arguments presented. For wing dimorphic taxa, the “correlated traits hypothesis” predicts covariance within wing morphs between JH titre and the proportion winged. Four simple genetic models for wing‐morph determination are considered: single‐locus with short‐winged (SW) dominant; single‐locus with long‐winged (LW) dominant; polygenic, fixed threshold, shifting distribution; and polygenic, shifting threshold, fixed distribution. In each case, wing morphology is assumed to be a threshold trait with the liability being JH titre at some critical stage of development. All models predict covariation between %LW and the mean JH titre of at least one of the wing morphs, but the form and direction of the relationship depends critically on the genetic model used. The results suggest that we should expect the traits associated with the migratory syndrome, and hence the trade‐offs associated with the evolution of wing dimorphism, to be correlated with proportion winged and, in this sense, to be frequency‐dependent.
Body mass changes in Trimeresurus flavoviridis (Viperidae) on Okinawa Island, Japan
Authors: Nishimura Masahiko , Kamura Takao 
Published: October 2006

AbstractBody masses of wild‐caught habu, Trimeresurus flavoviridis, were measured with known error range. Habu larger than mature female size had steeper slope in length‐mass regression than smaller individuals. Females outweighed males in most snout‐ventlength classes and in early summer. Gravid females outweighed non‐gravid ones by about 20% on the average, but the body mass ranges of the two groups overlapped. Through the body mass change in mature females, the proportion of gravid females was estimated to be about 0.5.
Spatio‐temporal variation of natural and sexual selection in breeding populations of the coreid bug, Colpula lativentris (Heteroptera: Coreidae)
Authors: Nishida Takayoshi 
Published: October 2006

AbstractSpatio‐temporal variations of lifetime reproductive succes (LRS) of both male and female individuals of a coreid bug Colpula lativentris were measured and analyzed using the multiple regression method of Arnold and Wade (1984a, b). The standardized variance of LRS was larger in males than that in females as males often to secure mates for a long period whereas females could easily find mates and oviposit simply dependent on ovarial maturation. LRS was partitioned into 4 consecutive fitness components: (1) reproductive lifespan, (2) copulating efficiency, (3) guarding efficiency (for males) or oviposition efficiency (for females), and (4) number of eggs per clutch. In males copulating efficiency was the largest determining factor of LRS, whereas in females reproductive lifespan was the most important factor. Such tendencies were stable on both a yearly and local basis. Patterns of relative contribution of natural selection (reproductive lifespan and number of eggs per clutch) and sexual selection (copulating efficiency and guarding or oviposition efficiency) to LRS were clearly different between males and females. This sexual difference is, at least to some extent, thought to be brought about by sexual selection among males for mating opportunity, though no physical fight was observed among males. Directional selection on body length was found only in relation to the clutch size of females because large females tended to lay larger clutches. No significant directional selection was found in other fitness components.
Seasonal host alternation by the andromeda lace bug, Stephanitis takeyai (Heteroptera: Tingidae) between its two main host‐plant species
Authors: Tsukada Morio 
Published: October 2006

AbstractI studied the seasonal occurrence of the andromeda lace bug, Stephanitis takeyai, on its two main host‐plant species. In a secondary forest in Kyoto, this bug altered its hosts seasonally, i.e., from an evergreen shrub, Pieris japonica, in winter to a deciduous shrub, Lyonia elliptica, in summer. In contrast, in Nara park where few L. elliptica were available, the bug exploited only P. japonica. Thus, seasonal host alternation by this bug is not obligate. A comparison of adult longevity and fecundity on the two host‐plant species demonstrated the higher quality of L. elliptica as a food resource. Corresponding to this difference in host quality, there was a dramatic difference in the seasonal population growth in the two study sites. In Nara, the population size at the beginning of the 2nd generation was almost the same as in the overwintered generation, whereas in Kyoto the population size in the 2nd generation was approximately one hundred times as large as in the overwintered generation. Thus seasonal host alternation is adaptive for the bug. In a previous study, I reported that overwintering as eggs in living leaves of their hosts is likely to be common among all the related species of this bug. Thus, this trait can be considered to be a phylogenetic constraint to the group. I speculate that host alternation by this bug has been derived because it is more adaptive from autoecy on an evergreen plant, similar to the pattern currently found in Nara, and that this bug can not only exploit deciduous host due to a phylogenetic constraint.