bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining pheromone‐baited and food‐baited traps for insect pest control: Effects of developmental period
Authors: Barclay Hugh J. , Haniotakis George E.
Published: October 2006

An age‐structured population dynamics model is presented that incorporates pheromone‐trapping and food‐trapping as control methods for an insect pest. The model yields the following results. Low rates of pest survivorship allow lower trapping rates for control. Species with long developmental periods are easier to control than those with shorter developmental periods (other factors being equal) due to lower net survival. The rates of pheromone trapping alone for effective control are usually very high. The combination of pheromone and food trapping allows control with much lower trapping rates than either method alone. Even small amounts of immigration of adult pests into the control area renders pheromone control ineffective, whereas food traps suppress both the immigrants and the resident population. Food‐ (or odor‐) baited traps which attract both males and females are only somewhat more efficient than those which attract females alone. The existence of density‐dependent population regulation assists the control program substantially, but this assistance declines as food trapping becomes a more important part of the control program. Larval competition strongly affects the required trapping rates for eradication; species in which all larvae exert strong competition are much easier to control than those in whic the younger larvae contribute little to the total competitive depression.
Effects of female body size and timing of nest foundation on the reproduction of the Japanese paper wasp, Polistes jadwigae Dalla Torre (Hymenoptera: Vespidae)
Authors: Tsuchida Koji
Published: October 2006

Females in hibernation site (FH) were significantly larger than foundresses (FO), suggesting that larger FH were less successful in founding their nest. Body size of FO did not correlate with two nest characters, i.e., the number of cells at pupal stage (CP) and the timing of nest foundation (DP). However, CP negatively correlated with DP in 2 of 3 studied years, suggesting that foundress who founded her nest earlier than others tended to construct larger number of cells irrespective of her body size.
Relationship between surplus energy and body weight in fish populations
Authors: Hiyama Yoshiaki , Kitahara Takeru
Published: October 2006

This paper theoretically analyses the relationship between surplus energy, which is available for either somatic growth or reproduction, and body weight. From the data of metabolism and growth of the biwamasu, Oncorhynchus rhodurus, obtained by Miura et al., a Bernoulli's differential equation is induced to represent the relationship between body weight and the sum of surplus energy and active metabolic rate. Solving this equation gives the amount of surplus energy, f(Wx), as follows:f(Wx) = (αWx1−γ+β1−γ)1/(1−γ)−Wx, in which α, β and γ are constants and Wx is body weight at age x. The function is applied to ten fish populations and consequently it is found to be useful for a wider age range and a wider variety of fishes than the conventional function.
Note on a method for analyzing stage‐frequency data
Authors: Manly Bryan F. J.
Published: October 2006

A new method for analyzing stage‐frequency data is proposed which is based on the estimation of rates of transition between one stage and the next highest stage in one unit of time, and a unit time survival rate that is assumed to be constant. Once these estimates are calculated it becomes possible to also estimate the mean durations of stages, stage‐specific survival rates, and numbers entering stages. An advantage of the method is that it can be applied with any distribution of entry times to stage 1, and any distribution of numbers in stages when sampling begins. Use of the method is illustrated on data from a copepod population in a Canadian lake.
Warning coloration in sawfly Athalia rosae larva and concealing coloration in butterfly Pieris rapae larva feeding on similar plants evolved through individual selection
Authors: Ohara Yoshitsugu , Nagasaka Koukichi , Ohsaki Naota
Published: October 2006

Green larvae of the butterfly Pieris rapae and black larvae of the sawfly Athalia rosae feed on green leaves of the same cruciferous plants. To demonstrate that P. rapae has concealing coloration and that A. rosae has warning coloration, the larvae of the two species were supplied to naive chicks Gallus gallus on white, green or black backgrounds. P. rapae larvae were palatable and their green body color acted as a concealing coloration. On the other hand, A. rosae larvae were unpalatable and their black body color acted as a warning coloration.

There is a general consensus that warning coloration is an altruistic character which needs victims, and thus can evolve through kin selection or green beard selection. However, black A. rosae larvae were seldom injured by chicks' attack, in particular, on the green background. Therefore, the warning coloration of A. rosae larvae can be a selfish character and hence can evolve through individual selection as well as concealing coloration of P. rapae.
Host plant conspicuousness and the distribution of eggs and larvae in the butterfly, Anthocharis scolymus (Lepidoptera: Pieridae)
Authors: Masumoto Toshiya , Nomakuchi Shintaro , Sawada Kouji
Published: October 2006

We investigated how the distribution pattern of eggs and larval on the host plant, Turritus glabra, was influenced by the oviposition behavior of the pierid butterfly Anthocharis scolymus. Females searched for the host plants visually and they frequently approached taller host plants with sparse surrounding vegetation. After encountering host plants, oviposition behavior of females was independent of host plant characteristics such as height, density, and type of surrounding vegetation. A female laid eggs singly on a host plants. Most females appeared to lay their eggs regardless of the presense of eggs on the host plant. Consequently egg and larva tended to be abundant on conspicuous host plants as measured by height or relative isolation from other plants. However, overcrowding of eggs on an individual host decreased the survival rate of larvae.
The plastic reproductive allocation of the cruciferous perennial Rorippa indica in response to different degrees of feeding damage
Authors: Yano Shuichi
Published: October 2006

The degree of feeding damage in the wild to the cruciferous perennial Rorippa indica (L.) Hieron ranged from 0% (not damaged) to 100% (heavily damaged). However, “not damaged” and “heavily damaged” individuals did not differ in the relative suitability of their intrinsic traits for P. rapae, which caused the heaviest damage on the plant. Therefore, the different degrees of feeding damage may be due to variability in the extrinsic traits of the plant, that is, it may be determined by the habitat conditions where individual plants exist. Furthermore, R. indica allocated more resource to seed production at the expense of the roots when it was experimentally subjected to heavy leaf damage. The result suggested that R. indica individuals may escape, by means of seed dispersal and seed dormancy, from unfavorable habitats where they are heavily damaged by herbivores.
Correlated effects of the response to conditioned medium in the flour beetle, Tribolium castaneum
Authors: Lavie Batia , Ritte Uzi
Published: October 2006

Dispersal rates were measured in lines selected for high and low response of egg production to conditioned media, and responsivness of egg production was measured in lines selected for high and low dispersal. A positive correlation was found between these two traits, each of which had previously been found to have a simple genetic basis. It is suggested that in Tribolium castaneum the sensitivity to environmental conditions is mediated through a Sensor gene, which can activate either response, according to circumstances.
Detection of, and sampling procedures for, the citrus blackfly in urban southern Florida
Authors: Dowell Robert V. , Cherry Ronald H.
Published: October 2006

The dispersion pattern of the citrus blackfly (CBF)Aleurocanthus woglumi Ashby on urban citrus trees was studied in southern Florida. There was no usable correlation (r2=0.41) between the % of older leaves infested with CBF versus that on the newest mature flush, but there was a strong correlation (r2=0.87) between the % of leaves in the newest mature flush infested with CBF and loge, where is the number of egg spirals of CBF/leaf on the same leaves. CBF egg spirals are distributed among the flushes in groups rather than singly and the flushes are not over‐dispersed. Visual surveys proved superior to sticky traps for the detection of CBF at low densities (<5% leaves infested) on citrus trees in an urban setting. A sampling procedure is described herein based upon visual surveys.
The influence of urine from asymptotic laboratory populations on sexual maturation in prairie deermice
Authors: Terman C. Richard , Bradley Eric L.
Published: October 2006

Male and female prairie deermice housed singly from weaning (21 days) until 40 days of age had urine from one of the following sources applied daily to their nostrils: sexually mature laboratory population males or females, and sexually mature breeder males or females from our laboratory colony. Other males and females were treated with water. Records were obtained of the weights of the tests, seminal vesicles and bacula of males and the ovaries and uteri of females at 40 days of age.

The major results of this study were as follow: Female urine from sexually mature and inhibited population or isolated mice stimulated the development of the male reproductive organs significantly more than water or male urine. Male urine applied to young males did not differentially affect the weights of their reproductive organs compared with water and thus showed no inhibition effects.

The reproductive organs of females treated with male urine did not differ significantly in weight from those of females treated with female urine. Females treated with water developed significantly larger uteri than those treated with urine from sexually mature population females (P≤0.02), inhibited population females (P<0.001) and inhibited population males (P<0.007).
Searching preference of the parasitoid, Anisopteromalus calandrae (Howard) for different stages of the host, Callosobruchus maculatus (F.) in the laboratory
Authors: Heong K. L.
Published: October 2006

The functional response parameters of the parasitoid, Anisopteromalus calandrae (Howard) to the third instar, the fourth instar and the pupae of Callosobruchus maculatus (F.) were estimated from the Random Parasitoid Equation. By modifying this equation for a two host situation and using the parameters estimated above, a no switch model could be obtained. This model was then used to test for switching. In the preference experiments where two stages of the host were presented to the female parasitoid, a definite preference for the fourth instar followed by the pupa and the third instar, respectively was shown. There was, however, no evidence of switching. There was also no evidence that the data fitted the no switch models which suggests that when the parasitoid is searching in an environment with two or more hosts, its searching behaviour is more complex.
Postembryonal growth and its variability of the three marine fishes with special reference to the mechanism of growth variation in fishes
Authors: Yamagishi Hiroshi
Published: October 2006

To study the relation of growth variation to the behaviour pattern, newly hatched Hemiramphus sajori, Chrysophrys major and Zebrias zebra were reared in 30 litter aquaria during one month, and body length was measured four times.

In Hemiramphus sajori coefficient of variation of body length (CV) first increased but showed a tendency to decrease with development of schooling behaviour.

In Chrysophrys major CV markedly increased and mode of the distribution curve of body length inclined towards the left side, associated with appearance of aggression and cannibalism.

In Zebrias zebra, when behaviour pattern changed from planktonic to demersal some of the small individuals nearly ceased growing. At that time CV of body length remarkably increased and the mode of the distribution curve of body length shifted towards the right side.

In all the species a positive correlation was seem between specific growth rate and initial body length soon after intensive feeding began. An negative correlation was observed in most of individuals of Hemiramphus sajori after the appearance of schooling behaviour. When a conspicuous increase in CV and skewness in distribution curve took place, a separate type of correlation was seen in large and small group in the population.

Based on above mentioned and other materials a general mechanism of growth variation in fishes was discussed.
A model of plant‐to‐plant movement of aphids: A new approach
Authors: Bryant Edwin H.
Published: October 2006

A stochastic model was applied to the changes in the distribution of aphids on plants in a field determined by their plant‐to‐plant movements.

The expected numbers of aphids on plants were calculated for the 5 days of an experiment reported byShiyomi (1967) and compared with observed frequencies at these times.
Differences in population parameters of two Tribolium castaneum strains in environments of different shapes
Authors: Wool David
Published: October 2006

Survival and duration of development of two Tribolium castaneum strains were not the same when reared in environments of different shapes under the same external conditions.

The bb strain survived better in jars than vials. The ++ strain survived better in vials than in jars of type 3.

Both strains (as well as their hybrid (+b)) developed faster in vials (type 1) than in shallow jars (type 2). Both strains developed faster in jars of type 3 than in vials, at the low density. At the high density, the strains reacted differently: ++ developed faster in vials, but bb developed faster in jars.

Cultures of “selected” strains followed the population trends they exhibited in the selection experiments from which they came.

In both densities and in all environments, mean individual weight of ++ adults was always higher then that of bb, suggesting that this character is, at least in part, genetically determined.

The differences in survival and developmental period in environments of different shapes may be due to microclimatic differences between environments and to changes produced in them by the developing immatures.
Settling‐site selection and survival of two scale insects, Ceroplastes rubens and C. ceriferus, on citrus trees
Authors: Itioka Takao , Inoue Tamiji
Published: October 2006

We studied settling‐site selection and the resulting survival of two sessile scale insects, Ceroplastes rubens and C. ceriferus, in the citrus tree, Citrus unshiu, in central Japan.

C. rubens preferred 0‐year‐old twigs most as a settling‐site; the density of nymphs settling on 0‐year‐old twigs was significantly higher than those on ≥1‐year‐old twigs, and few nymphs settled on ≥3‐year‐old twigs. The mean survival rates from settling until reproduction in the next year were significantly higher on more preferred twigs than on less preferred ones. In C. ceriferus, nymphs significantly preferred 1‐ and 2‐year‐old twigs to 0‐ and ≥3‐year‐old ones, and the mean survival rates on the more preferred 1‐ and 2‐year‐old twigs were significantly higher than those on less preferred ≥3‐year‐old twigs. However, the survival rate on less preferred 0‐year‐old twigs was slightly higher than those on 1‐ and 2‐year‐old ones. Thus, in both species of scale, it was the preferred twigs which were more profitable sites for survival after settling, except for less preferred 0‐year‐old twigs for C. ceriferus.

In both scale species, most mortality was due to growth cessation, which is believed to be related to the twig quality as a food source. Predators and parasitoids were minor mortality factors.

Both species showed constant survival rates until the density of settled nymphs exceeded double the “upper‐limit” density, whereupon they decreased drastically.

Nymphs of C. rubens settling on twigs of high scale density showed a spacing‐out distribution, those of C. ceriferus did not. In C. rubens, an increase in preference for originally less profitable twigs at the later stage of the settling season was observed, but not in C. ceriferus. Accordingly, individuals of C. rubens showed a stronger tendency to avoid conspecifics than did C. ceriferus.

Although nymphs of the two scales clearly preferred more profitable sites, their settling‐site selection did not agree with the predictions from the ideal free distribution theory (Fretwell and Lucas, 1970). The discrepancies were (1) frequent settling on less profitable sites at the early stage of the settling season, (2) insufficient utilization of the most profitable twigs, and (3) virtually 100% mortality on overcrowded twigs under conditions where unoccupied profitable twigs still remained. These discrepancies are thought due to the limited dispersal time of nymphs.
Crucial factors determining the spatio‐temporal distribution patterns of three Athalia sawflies feeding on common cruciferous plants
Authors: Nagasaka Koukichi
Published: October 2006

Three Athalia sawflies, A. japonica, A. rosae and A. infumata, feeding on cruciferous plants, coexist in Japan. However, it is not known what ecological strategies they use and what environmental factors are crucial to such strategies. I attempted to explain these questions by examining the relationship between the spatio‐temporal distribution patterns of three Athalia sawflies and their habitats in three districts (Lowland, Intermediate and Mountain).

The three sawflies have different spatio‐temporal distribution patterns, though they usually used common cruciferous plants. A. japonica was abundant in spring and autumn but disappeared during summer in all the districts. In the Lowland, populations of A. rosae and A. infumata, like that of A. japonica, crashed in summer. However A. rosae occurred mainly in summer in the Intermediate and Mountain. Although A. infumata occurred in the same seasons as A. rosae in all districts, population levels of A. infumata were always lower than those of A. rosae.

The crucial factors controlling their population patterns were the availability of host plants and temperature. Population crashes of A. rosae and A. infumata were due to food depletion, and those of A. japonica were due to heat stress. On the other hand, their population patterns may be interpreted as phenological synchronization with their original host plants, though they all existed on common cruciferous plants.

The three sawflies may have evolved different strategies to escape from unfavorable habitat conditions. Such strategies are speculated to be summer diapause in A. japonica, long distance migration in A. rosae, and local dispersal in A. infumata.
Worker brood survival in honeybees
Authors: Fukuda Hiromi , Sakagami Shôichi F.
Published: October 2006

The brood survival in honeybee workers was measured in order to obtain the data basic to the preparation of life tables. Under normal condition, that is, at the center of brood area, the survival is high. The survival/stage function runs 100.0 eggs, 94.2 unsealed brood (=feeding larvae), 86.4 sealed brood (=post‐feeding larvae and pupae) and 85.1 adults. The total duration of immature stages is 20 days in 87.1%, 21 days in 8.3% and 19 days or more than 22 days in the residual fraction of successfully emerging workers.

The survival remarkably decreases at peripheral areas within the hive. Various factors affecting the brood survival are discussed and the importance of a dense worker cover on the brood area is stressed in relation to the maintenance of thermal conditions optimal to the brood. The occurrence of one factor, which is not expected in solitary animals, the self‐control of population by egg eating, is pointed out.
The ingestion in wolf spiders I. Capacity of gut of Lycosa pseudoannulata
Authors: Nakamura Kazuo
Published: October 2006

An wolf spider, Lycosa pseudoannulata, collected from the field were reared in test tubes supplied with fruit flies as the food, and the number and weight of fruit flies killed per unit time and the weight of residuum of killed flies were recorded. When the cumulative number of flies killed by a spider was plotted against time after the beginning of food supply, the angle of the curve obtained decreased gradually until a constant value. In this time, it seems that the gut of spider had saturated with food and the increase rate of number of flies killed reflects the rate of food disappeared from gut by assimilation and egestion. The amount of ingestion was obtained by subtracting the weight of residuum and the gain of live weight of the spider from the weight of killed flies. After the gut has saturated, the amount of food remained in the gut is considered to be equal to the capacity of gut, which is an essential factor in the study of predation. The amount of food disappearance from gut was also estimated.

There was a linear relationship between the log body weight of spiders and the log capacity of gut. The linear relationship was also seen between the log total amount of ingestion and the log total amount of food disappeared from gut.
Intraspecies competition in a field population of Gregopimpla himalayensis (Hymenoptera: Ichneumonidae) parasitic on Malacosoma neustria testacea (Lepidoptera: Lasiocampidae)
Authors: Shiga Masakazu , Nakanishi Akinori
Published: October 2006

Intraspecies competition in a field population of Gregopimpla himalayensis (Hym.: Ichneumonidae) parasitic on the prepupae of Malacosoma neustria testacea (Lep.: Lasiocampidae) was investigated.

The parasite oviposits the sufficient number of progeny (5 individuals/0.1 g dry weight of host) to exhaust a single host in a single attack. However, at the intensity less than 22–26 individuals/0.1 g d.w. of host, all individuals can emerge, i.e. density‐dependent mortality does not occur. Within this range of intensity, survival of parasite larvae is guaranteed by diminution in body size and decreasing sex ratio. In contrast, total biomass of parasites showed a peak at 5 individuals/0.1 g d.w. of host at which a single host is exhausted.

Above the intensity of 22–26, extraordinary minute individuals appeared and they died before maturation.

If intraspecies competition play a role in regulation of G. himalayensis population in the field, the process is usually not through density‐dependent mortality but through decreasing reproductive rate caused by decrease in the sex ratio, adult longevity and fecundity.
Selection for divergent emigration rates in laboratory populations of Musca domestica
Authors: Collier Boyd
Published: October 2006

High and low emigration rates through a laboratory system were selected for in populations of house flies (Musca domestica L.). Emigration consisted of movement of flies from on plastic box to another by way of a connecting tube. Selection was carried out by first dividing a wild population of flies into two lines and then selecting for movement from the box in one line and against movement from the box in the other line. The selection experiment was performed twice. In both experiments a statistically significant difference between the two strains was obtained in three to four generations of selection. In the second experiment, after 5 genrations the mean number of high emigration rate flies emigrating in 1 hour was 4.37 times the mean number of low emigration rate flies and in 24 hours was 2.81 times the number of low emigration rate flies. The second experiment was terminated after 6 generations, but the first experiment was continued for 35 generations. In this case, divergence ceased in roughly 15 generations.

The possible relevance of the findings to laboratory population experiments in which spatial discontinuities are included is discussed.
Stability of environment and of insect populations
Authors: Wolda Henk , Spitzer Karel , Lepš Jan
Published: October 2006

The abundance of moths was monitored with light‐traps in two sites in southern Bohemia, České Budějovice for 22 years and in Černiš for 9 years. In these sites, that are vastly different in environmental stability and predictability, stability of insect populations was studied. The amplitude of fluctuations in abundance of the insect populations, as measured by the coefficient of variation (CV), varied a great deal between species so that there was a large overlap between the two sites. Nevertheless there was a highly significant tendency for species at Černiš, the more stable site, to have smaller values of CV, i.e., to be less fluctuating. Also in species co‐occurring in the two sites, the CV at Černiš tended to be smaller. Trends in abundance of individual species over time, both increases and decreases, were common in both sites and did not differ between habitats. Environmental stability begets insect population stability in terms of the amplitude of the fluctuations, but trends in time occur irrespective of stability of the habitat.
A ten‐year study of population dynamics of citrus pests in the pesticide‐reduced orchard
Authors: Itioka Takao , Inoue Tamiji , Ishida Norio
Published: October 2006

To determine the effectiveness of a pest management system that uses pesticides at a low level, we censused populations of seven insect pests and three plant diseases from 1980 to 1989 in a citrus orchard which was managed with a pesticide‐reduced and pesticide‐free protocols, in Wakayama Prefecture, Japan. In the orchard, we controlled the pests solely by spraying petroleum oil once a year from 1980 to 1985, by not spraying insecticide in 1986, and spraying only germicide in 1987. The arrowhead scale population remained much lower level at which citrus trees begin to wither when petroleum oil was sprayed, whereas it rapidly increased and began to wither trees during the years without spraying petroleum oil. The Indian wax scale population rapidly increased only during a 2‐year period and then declined. Although the infection level of the sooty mold was unusually high on the trees where the density of the scale was high, this pathogen did little damage to citrus trees. The population of the red wax scale gradually increased throughout the census period but did not reach the level at which citrus trees begin to be damaged. Other pests also caused negligible damages to citrus trees. The results indicated that the pesticide‐reduced pest management system which was proposed by Inoue and Ohgushi (1976, 1977) is valid for the prevention of the outbreak of the arrowhead scale, and that is has the sufficient control efficiency for the other pests in citrus orchards.
A mathematical model for the survivorship curve
Authors: Murai Minoru
Published: October 2006

A mathematical function describing the various kinds of survivorship curve is formulated with the useful parameter, environmental capacity. Three types of the survivorship curve illlustrated byDeevey can be obtained from changing the value of this function. When a cohort is large and the competition occurs in the scramble type, this function shows the third type ofDeevy's and this to the first type in the case of low density and the contest type of competition. But the second type would rather be obtained by the action of density independent agencies.
A method for estimating natural survival rate and mean fecundity of an adult insect population by dissecting the female reproductive organs
Authors: Hokyo Nobuhiko , Kiritani Keizi
Published: October 2006

Several problems were discussed in relation toMacDonald's method (MacDonald, 1957) for estimating the survival rate of a natural population of adults with varying survival rates and unstable age structure.

Random samplings with a fixed sampling ratio and an appropriate census interval is pre‐requisite during the occurrence of the adults.

At each sampling, female adults are dissected to know the ratio, pi, of nulliparous females in ith sample (i=0, 1, 2, 3, …,). The Σnipi/Σni gives an estimate of the ratio, Fα/F, of nulliparous females in the population where ni refers to the population size on ith census date. If a constant daily survival rate is assumed, the daily survival rate is estimated from equation (4′). When the survival rate is not constant over the period of adult occurrence, e. g. before and after the initiation of oviposition, the survival rate during pre‐ovipositional period is estimated by equation (4″).

Decision of an economic census interval to obtain a reliable estimate of the ratio, Fα/F, is depending on the form of emergence curve, particularly on its duration and the length of pre‐ovipositional period. If the normal distribution can be assumed for the emergence curve, an interval less than one third of the emergence period is recommended. Concerning with insects having a long pre‐ovipositional period, a census interval which exceeds one third of the emergence period still gives a good estimate of Fα/F.

The mean realized fecundity of some kind of insects can be estimated by equation (5′ or 5″) using the estimates obtained by the present method.
Productivity of high and low density populations of Japonaria laminata armigera (Diplopoda) in a warm‐temperate forest ecosystem
Authors: Saito Susumu
Published: October 2006

The productivity of the final larval and adult populations of a large sized diplopod, Japonaria laminata armigera were studied at a warm temperate ever‐green broad leaf forest in Chiba Japan. The population density was about 200/m2 in May 1962, and 7/m2 in May 1966, the former being about 30 times as much as the latter. A remarkable growth of animals was seen from June to November, and the growth pattern of individuals in both populations was very similar. The growth and mortality were calculated by the following formulae,
urn:x-wiley:14383896:pope0153:equation:pope0153-math-0001
where G is growth, M mortality, Nt number at the time t,Wt−1 mean body weight of animals at the time t−1, ΔN decrease in number during the period of time from t−1 to t, ΔW growth in mean body weight during the time from t−1 to t. The constant b in the formula R=aWb representing the relation between body weight and oxygen consumption of Japonaria laminata was determined at 0.81, and Q10 was estimated at about 2. The amounts of growth and assimilation were calculated. The pattern of dynamics in terms of productivity of the population in the two periods were very similar. But, the amounts of assimilation were computed at 57.8 kcal/m2/from May 1962 to April 1963, and 3.01 kcal from May 1966 to April 1967. The former is 20 times as much as the latter. The growth or ecological efficiencies for the populations were similar.
Extinction of the trochid gastropod,Umbonium (Suchium) moniliferum(Lamarck), and associated species on an intertidal sandflat
Authors: Tamaki Akio
Published: October 2006

On an intertidal sandflat in western Kyushu, Japan in 1979, the trochid gastropod,Umbonium (Suchium) moniliferum(Lamarck), and the thalassinidean ghost shrimp,Callianassa japonicaOrtmann, densely inhabited the lower and upper zones, respectvely.Callianassa japonicasubsequently expanded its distribution range considerably, having occupied almost the entire sandflat by 1983. Concurrently, theU. moniliferumpopulation gradually declined, becoming extinct in 1986. Furthermore, the populations of 9 species associated withU. moniliferum(predators, an ectoparasite, and subsequent inhabitants of emptyU. moniliferumshells) had disappeared by the end of 1992. The extinction processes ofU. moniliferumand the two other most numerically dominant species, the ectoparasitic gastropod,Odostomiasp., and the hermit crab,Diogenes nitidimanusTerao, were described in detail. It is believed that the bioturbation of sediments byC. japonicawas responsible for the extinctions, possible mechanisms involved being discussed. This is the first documented record of the extinction of a large part of a macrobenthic assemblage centering on a filter‐feedingUmboniumspecies which is characteristic of the benthic communities on many intertidal sandflats extending from Japanese to Southeast‐Asian waters.
Annual survival rate and age structure of habu, Trimeresurus flavoviridis (Viperidae), on Minna island, Japan: Estimation from removal trapping
Authors: Nishimura Masahiko , Katsuren Seiki
Published: October 2006

A population of a viperid snake, Trimeresurus flavoviridis, was studied over 10 years by removal trapping on a small subtropical island in Japan. The sex ratio of trapped individuals changed seasonally, but was not biased to either sex in the whole sample of 258 individuals. The age of each individual was estimated through the size structure and the age‐size relationship. The minimum number of individuals at the beginning of the study was estimated through accumulating older individuals trapped in the subsequent years. By assuming an annual natural survival rate in the course of this accumulation, an age structure was simulated which led to calculate a resulted natural survival rate. The assumed rate of 0.62 fitted best to the resulted one. The annual trapped proportion estimated on the simulated absolute number of individuals was higher in older individuals than in younger ones with the overall mean of 16%.
Cyclicity and synchrony of historical outbreaks of the beech caterpillar, Quadricalcarifera punctatella (Motschulsky) in Japan
Authors: Liebhold Andrew , Kamata Naoto , Jacob Thomas
Published: October 2006

Historical records of the incidence of defoliation caused by the beech caterpillar, Quadricalcarifera punctatella (Motschulsky) in northern Japanese prefectures from 1910–1993 were used to characterize the cyclicity and synchrony of outbreaks. Cyclicity and synchrony were quantified using standard Box‐Jenkins time series methods as well as spectral analysis and simple Markov models. Statistical analysis of these records indicated the presence of quasi‐periodic behavior with 8–11 yr between outbreaks. Outbreaks tended to occur synchronously among different prefectures, though the onset of outbreaks was typically lagged. This study illustrates the use of specific statistical methods for characterizing cyclicity and synchrony from crude records of the presence/absence of outbreaks.
Phylogentic constraints, adaptive syndromes, and emergent properties: From individuals to population dynamics
Authors: Price Peter W.
Published: October 2006

The hypothesis is developed that there are causal linkages in evolved insect herbivore life histories and behaviors from phylogenetic constraints to adaptive syndromes to the emergent properties involving ecological interactions and population dynamics. Thus the argument is developed that the evolutionary biology of a species predetermines its current ecology.Phylogenetic Constraints refer to old characters in the phylogeny of a species and a group of species which set limits on the range of life history patterns and behaviors that can evolve. For example, a sawfly is commonly limited to oviposition in soft plant tissue, while plants are growing rapidly.Adaptive Syndromes are evolutionary responses to the phylogenetic constraints that minimize the limitations and maximize larval performance. Such syndromes commonly involve details of female ovipositional behavior and how individuals make choices for oviposition sites relative to plant quality variation which maximize larval survival. Syndromes also involve larval adaptations to the kinds of choices females make in oviposition. The evolutionary biology involved with phylogenetic constraints and adaptive syndromes commonly predetermines the ecological interactions of a species and its population dynamics. Therefore, these ecological interactions are calledEmergent Properties because they are natural consequences of evolved morphology, behavior, and physiology. They commonly strongly influence the three‐trophic‐level interactions among host plants, insect herbivores, and carnivores, and the relative forces of bottom‐up and top‐down influences in food webs. The arguments are supported using such examples as galling sawflies and other gallers, shoot‐boring moths and beetles, budworms, and forest Macrolepidoptera. The contrasts between outbreak or eruptive species and uncommon and rare species with latent population dynamics are emphasized.
Humid microenvironment prerequisite for the survival and growth of nymphs of the rice brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae)
Authors: Isichaikul Somchai , Fujimura Koichi , Ichikawa Toshihide
Published: October 2006

Nymphs of Nilaparvata 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 of N. lugens in rice fields was discussed on the basis of the results.
An introduction experiment of an herbivorous lady beetle: Characteristics of the adult population
Authors: Sawada Hiroichi , Ohgushi Takayuki
Published: October 2006

In May 1971, 45 adults of an herbivorous lady beetle Epilachna niponica (Coleoptera: Coccinellidae) from Asiu Experimental Forest were introduced into a botanical garden of Kyoto University, where is 10 km south of the southern limits of its distribution with being 3–5°C warmer than the original site. The introduced population of the lady beetle was thus investigated from 1975 to 1981. Mark‐release‐recapture experiments were applied to individual adult beetles, to estimate population size and daily survival rate. Overwintering adults emerged from hibernation around early April, reaching peak numbers in late April to early May, then gradually declined to late June. No adults remained at the end of June. Adult survival was maintained at a high level to early May, and declined consistently until late in the reproductive season. New adults began to emerge in late June and quickly reached a peak in early July; thereafter they decreased in number and had entered hibernation by late October. In spite of seasonally deteriorating food resources and heat stress in summer, new adults showed moderately high survival during the inimical period. New adults which emerged later in the season tended to be smaller in body size than those that emerged early. The proportion of females in the new adult population gradually increased throughout the pre‐hibernating period, suggesting that male‐biased mortality occurred during this period. When compared to the source population, the introduced population had a higher rate of population growth. Coupled with the improved population growth, heavy leaf damage during the larval period suggested that intensive intraspecific competition was most likely to occur among larvae in the introduced population.
Habitat stability and the larval mosquito community in treeholes and other containers on a temperate Island
Authors: Sota T. , Mogi M. , Hayamizu E.
Published: October 2006

The temporal fluctuation of water levels and the presence of mosquito larvae were investigated for four types of small container habitats (treeholes, bamboo stumps, cemetery stone vases, and cemetery stone vessels) on Kabeshima Island in Kyushu, southwestern Japan. The probability that containers held water was positively correlated with the quantity of the preceding rainfall and with the depth and volume of the containers. It was estimated that dehydration occurred more regularly in autumn and winter than in summer. The probability that mosquito larvae were present in each type of container was positively correlated with habitat stability in terms of the probability of the existence of standing water and the coefficient of variation of the water level. Twelve species of mosquito larvae, including two rare predators, were found. Species composition differed between the different types of container. Although 4 to 10 species used each type of container, the median number of species per container was two for treeholes and bamboo stumps, and one for the others. The dominant species was Tripteroides bambusa in treeholes and bamboo stumps, Aedes albopictus in stone vases, and A. japonicus in stone vessels. The larval mosquito community, which lacked major predators, possessed the following features that may facilitate the coexistence of many species: (1) niche segregation amongst species in terms of their selection of container types; (2) an aggregated distribution of the individual species among containers of the same type; (3) high intraspecific mean crowding (and hence probably intense intraspecific competition) in the dominant species in each type of container; (4) independent species associations within the same type of container; and (5) low interspecific mean crowding (and hence probably not intense interspecific competition) between species in the same type of container.
Seasonal life cycle and autogeny in the mosquitoAedes togoiin northern Kyushu, Japan, with experimental analysis of the effects of temperature, photoperiod and food on life‐history traits
Authors: Sota Teiji , Mogi Motoyoshi
Published: October 2006

We studied seasonal changes in the larval population structure, adult size, and autogeny (egg production without a bloodmeal) of the mosquitoAedes togoion the seacoast of northern Kyushu, Japan. The effects of temperature, photoperiod and food conditions on larval development, adult size and autogeny were studied in the laboratory.Aedes togoioverwintered in both the egg and larval stages and was multivoltine. Adult size was greater in spring and autumn and smaller in summer. Autogeny occurred in spring and autumn but not in summer. Autogenous females were larger than anautogenous females, and larger autogenous females produced more eggs. Laboratory experiments showed that autogeny was promoted under low temperature and short‐day conditions which corresponded with spring/autumn conditions in the field. Experimental food limitation in the larval stage greatly reduced adult size and autogenous egg production. In the field, large inter‐pool variations in adult size and autogeny rate probably resulted from variations in nutrient and crowding conditions. Seasonal autogeny ofAedes togoiwas discussed in terms of life‐history strategy under fluctuating environmental conditions where relative advantages of autogenous and anautogenous reproduction alternate seasonally.
Genetic estimations for body size characters, development period and development rate in a coccinelid beetle, Harmonia axyridis
Authors: Ueno Hideki
Published: October 2006

Heritabilities and genetic correlations for body size characters and development period in a coccinellid beetle, Harmonia axyridis were estimated by a sib‐analysis experiment. Positive genetic correlations were detected between size characters and development rate. If this is upheld in the field, genetic variation would be eliminated, as the loci affecting the characters are supposed to be fixed. However, the results indicated moderate heritabilities for all characters. Possible explanations for the results are discussed.
A multiple regression method for analysing stage‐frequency data
Authors: Manly Bryan F. J.
Published: October 2006

A linear regression method that allows survival rates to vary from stage to stage is described for the analysis of stage‐frequency data. It has advantages over previously suggested methods since the calculations are not iterative, and it is not necessary to have independent estimates of stage durations, numbers entering stages, or the rate of entry to stage 1. Simulation is proposed to determine standard errors for estimates of population parameters, and to assess the goodness of fit of models.
Factors affecting body size variation within a population of an herbivorous lady beetle, Henosepilachna niponica (Lewis)
Authors: Ohgushi Takayuki
Published: October 2006

Size variation in newly‐emerged adults was examined in two different local populations of an herbivorous lady beetle, Henosepilachna niponica, for 1976–80. Mean adult size of both sexes changed rather synchronously in the two populations over 5 years. Body size of adult beetles apparently decreased with increasing leaf damage of the plants on which they developed. Adult beetles which emerged late in the season, associated with increasing food deterioration, were smaller than those which emerged early. Ecological consequences of adult size variation is discussed in terms of oviposition site selection.
Female size and age‐specific fecundity in the small white butterfly, Pieris rapae crucivora Boisduval (Lepidoptera: Pieridae)
Authors: Kimura Kazuhiko , Tsubaki Yoshitaka
Published: October 2006

Individual differences in several reproductive parameters of female Pieris rapae were investigated in a controlled laboratory condition. Lifetime and age‐specific fecundity showed considerable variability between individuals. Larger females began oviposition at an earlier age than smaller ones, and larger females were more fecund than smaller ones. Larger females laid a larger proportion of their eggs in the early stages of their reproductive lifetime, whilst smaller females laid the larger proportion of their eggs later in their reproductive lifetime. The significance of the variance in age‐specific fecundity associated with female size is discussed with respect to the seasonal change in size and habitat utilization of this species.
Evaluation of statistical precision and design of efficient sampling for the population estimation based on frequency of occurrence
Authors: Kuno Eizi
Published: October 2006

The binomial sampling to estimate population density of an organism based simply upon the frequency of its occurrence among sampled quadrats is a labour‐saving technique which is potentially useful for small animals like insects and has actually been applied occasionally to studies of their populations. The present study provides a theoretical basis for this convenient technique, which makes it statistically reliable and tolerable for consistent use in intensive as well as preliminary population censuses. Firs, the magnitude of sampling error in relation to sample size is formulated mathematically for the estimate to be obtained by this indirect method of census, using either of the two popular models relating frequency of occurrence (p) to mean density (m), i.e. the negative binomial model, p=1−(1+m/k)−k, and the empirical model, p=1−exp(−amb). Then, the equations to calculate sample size and census cost that are necessary to attain a given desired level of precision in the estimation are derived for both models. A notable feature of the relationship of necessary sample size (or census cost) to mean density in the frequency method, in constrast to that in the ordinary census, is that it shows a concave curve which tends to rise sharply not only towards lower but also towards higher levels of density. These theoretical results make it also possible to design sequential estimation procedures based on this convenient census technique, which may enable us with the least necessary cost to get a series of population estimates with the desired precision level. Examples are presented to explain how to apply these programs to acutal censuses in the field.