bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marginal attack rate, k‐values and density dependence in the analysis of contemporaneous mortality factors
Authors: Elkinton J. S. , Buonaccorsi J. P. , Bellows T. S. , Van Driesche R. G. 
Published: October 2006

Summary
Procedures for calculating the marginal attack rates and associated k‐values from observed death rates are presented for contemporaneous predators or parasitoids that either do or do not discriminate against previously parasitized hosts.
The relationships among previous methods for quantifying contemporaneous mortalities are discussed.
Solutions to the problem of calculating marginal rates taken from human survival analysis are given under the assumption of proportional hazards. These calculations are easily extended to three or more contemporaneous sources of mortality.
The conditions under which proportional hazards can be expected are discussed.
These methods are compared to that of Varley et al., 1973 for assessment of density dependence among contemporaneous predators.
Life tables and population parameters of the green leafhopper, Nephotettix cincticeps (Uhler), in the southwestern district of Japan with special reference to the first generation on foxtail grass
Authors: Widiarta I Nyoman , Fujisaki Kenji , Nakasuji Fusao 
Published: October 2006

SummaryThe three year (1988–1990) life tables of Nephotettix cincticeps were constructed, and the daily survival rate and longevity of female adults were estimated by Hokyo and Kiritani's (1967) method for the overwintering and the first‐generations on the foxtail grass in Okayama, southwestern Japan. The life tables and the population parameter values estimated were compared with those in the other generations on rice. The FARMCOP suction sampler was employed to survey the population density.The durations of pre‐ovarial maturation of female adults of the 1st generation on foxtail grass and rice seedling were similar. Longevity of adults of the overwintering and the first generations which emerged on the wild host was longer than that of the other generations (2nd and 3rd generations) on the rice plants. Fecundity of females decreased successively as the generation proceeded and it became lowest in the final 3rd generation.Only about 3.5 percent of first‐instar nymphs of the 1st generation emerged as adults in the fallow field. The survival rate of nymphs on foxtail grass was always lower in comparison with that on rice plants. However, the survival rates of nymphs on foxtail grass and rice seedling were not significantly different from each other under laboratory conditions. In the fields, senescence of foxtail grass occurred in the midst of nymphal period of the 1st generation. The survival rate of nymphs on foxtail grass decreased with the increasing in the nymphal density. Abundance of spiders during the 1st generation was higher than that in the early stage of rice plants.
Anopheles culicifacies giles: Adult ecological parameters measured in rural punjab province, pakistan using capture‐mark‐release‐recapture and dissection methods, with comparative observations on An. stephensi liston and An. subpictus grassi
Authors: Reisen William K. , Mahmood Farida , Azra Khawar 
Published: October 2006

SummaryDispersal, immigration and emigration rates, horizontal and vertical survivorship and absolute population size were estimated for micropopulations of An. culicifacies, An. stephensi and An. subpictus at a series of cattle sheds in rural Punjab Province, Pakistan, during November 1979 and May 1980 using capture‐mark‐release‐recapture and dissection methods. Dispersal was temperature‐related, with populations more vagile during May. Mean dispersal distance per individual was low for all species. More than 70% of all recaptures were taken at the point of release and the longest detected flight was 1250 meters.Horizontal survivorship was greater during November and was always less than vertical survivorship calculated from dissection agegrading data. Survivorship during the nulliparous period was greater than survivorship throughout total life, indicating the survivorship curve may be slightly sigmoid. Daily population sizes of endemic and immigrating females and males were calculated usingBailey's (1952) modification of the Lincoln Index, with the daily captures adjusted for immigration which was highest in May. Daily additions to the indoor resting population exclusive of immigrants were estimated using the method ofManly andParr (1968). The relationship of the present findings to malaria transmission and genetic control were discussed.
Lifetime mating success of males in a natural population of the papilionid butterfly, Atrophaneura alcinous (Lepidoptera: Papilionidae)
Authors: Suzuki Nobuhiko , Matsumoto Kazuma 
Published: October 2006

SummaryLifetime mating success of males in a natural population of the papilionid butterfly, Atrophaneura alcinous, was investigated and causes of the variation were examined. The most successful males mated with 5 females, whereas about 73% of the males failed to mate. Body size of males was not correlated with their eclosion date, longevity and lifetime mating success. There was no trade‐off between mating success and longevity, and long‐lived males had a disproportionately high mating success. Although number of available females per male per day was not variable among males with different longevities, long‐lived males had higher mating efficiency. Time interval between matings by non‐virgin males was shorter than that from eclosion to the first mating. High lifetime mating success of long‐lived males was strongly related to their mating experience, not to their age per se.
Sectors of activity, topography, and parasitism in home areas of New Guinea coarse‐haired rats, and Trombiculidae (Acarina)
Authors: Mohr Carl O. 
Published: October 2006

SummaryHome areas of hosts are, in effect the gardens in which parasite populations grow. The parasites flourish in response to the kind and amount of host activity modified, of course, by the habitat, and become microcommunities supported by their host and its artifacts. When scatter diagrams of points at which hosts have been observed are divided by median major and minor axes, and when the resulting four quarters, designated A, B, C, D, corresponding to concentration of points in the quarters, the relative concentration usually is: A>B>C>D. The concentration of observed points also is generally greatest nearest the major axis and frequently, but not always, near the median center. Nests of hosts, hence nest‐parasites, appear generally to be near the center. For the host examined in detail here, the New Guinea coarse‐haired rat, most Leptotrombidium deliensis appear to have been acquired in the AB sector of the host's home areas but a greater diversity of chiggers is acquired in the CD sector. It is postulated that, if L. akamushi had been present, it would have occurred in the CD sector where, though the observed concentration of host activity was least, the mixed grassforb and shrub habitat would have been more suitable than in the AB sector. Gahrliepia pingue, C. ewingi, Schoengastia blestowei and S. schueffneri, appear also to be more abundant in the CD sector than in the AB sector. The chiggers themselves have home clusters, or lairs, and adjacent areas of activity (home areas) somewhat resembling those of the hosts.
Studies on interspecies competition between the azuki bean weevil, Callosobruchus chinensis, and the southern cowpea weevil, C. maculatus II. Competition under different environmental conditions
Authors: Fujii Koichi 
Published: October 2006

SummaryThe experimental studies was done on the interspecies competition between the azuki bean weevil, Callosobruchus chinensis, and the southern cowpea weevil, C. maculatus, under the different environmental conditions.
At 30°C, 70% R. H., the change of food replenishment interval had no influence upon the competition results, and the competition always ended in the extinction of C. maculatus. But there was a tendency for the period of co‐existence to be elongated as the interval of replenishment lengthened.
At 30°C, 70% R. H., there were no differences in the competition processes and results between the competition using the dry bean (water content about 11%) or the normal one (about 15%).
At 32°C, 64% R. H., the competition result was reversed from that at 30°C, 70% R. H. This is thought to be due to the differences of the developmental rates and the numbers of eggs oviposited between the two species at these conditions.
In some cases the competition result could be understood from the point of the phenomena of single species populations of both species, but in other cases, the results were in conflict with the expectation from those phenomena. To analyze the competition mechanism, it is necessary to investigate the interaction between species.
Evolution and physiological consequences of de‐alation in crickets
Authors: Tanaka Seiji 
Published: October 2006

AbstractWing shedding or de‐alation is a common phenomenon among crickets. Its significance and effects on other traits were examined based on the results from experiments using artifical or natural de‐alation. Artificial de‐alation at adult emergence induces rapid egg production and flight muscle histolysis in several species examined. However, natural de‐alation does not always shorten the pre‐ovipositional period because it does not occur immediately after adult emergence and because oviposition starts before de‐alation. In some cases, naturally de‐alated females produce more eggs than to intact females during early adult life, but peak ovipositing activity occurs before de‐alation. Therefore, retention of the hindwings does not suppress high ovipositing activity in such cases. It appears that de‐alation is a result rather than a causal factor in ending migration. Ovarian development and flight muscle histolysis, which can be stimulated by de‐alation, are controlled by the jevenile hormone, but the mechanism inducing de‐alation remains unknown. The possible factors leading to the evolution of de‐alation are discussed.
Inbreeding effects on competition in Tribolium
Authors: Craig David M. , Mertz David B. 
Published: October 2006

AbstractWhen replicate cultures of T. confusum and T. castaneum are husbanded together under identical treatment conditions, sometimes T. confusum eliminates T. castaneum, and other times, T. castaneum wins (i.e., competitive indeterminacy occurs). While several plausible explanations were advanced, the results of Mertz et al. (1976) implicated demographic stochasticity and not classical genetic founder effect as the predominant factor influencing the identity of the winning species. They also observed, however, that the size of the founding population had an influence on the competitive strength of T. castaneum. The present study shows that the decline in competitive strength that accompanied decreasing founder size in T. castaneum can be amply explained by simple inbreeding depression. The eggs of inbred adults showed an approximate 15% reduction in hatchability when compared to outbred adults. No evidence was found that the decrease in competitive strength was due either to prior history differences or reduced genetic heterogeneity of the founding adults.
Age distribution, sex ratio and mortality of the red fox Vulpes vulpes in Tochigi, central Japan: an estimation using a museum collection
Authors: Takeuchi Masahiko , Koganezawa Masaaki 
Published: October 2006

AbstractOne hundred and thirty carcasses of the red fox were collected in Tochigi Prefecture, by the Tochigi Prefectural Museum, from 1981 to 1991. The young/adult ratio of the sample was 1.60, which suggests that the hunting pressure has been relatively low in this area. Six percent of the animals were 5 years or older which compares to those taken in Hokkaido, but is higher than those in Europe and North America. The sex ratio for all specimens had a tendency towards male bias (0.587), but this bias was higher for the adult (0.605) than for the young (0.576). Among young (0 year‐old) foxes, more individuals were killed on roads than by trapping or shooting (P<0.02, chisquare test). This mortality pattern was caused by high mortality of young males (P<0.02). The proportions of adults killed by the three mortality factors were similar, though only one of the 14 foxes older than 4 years old was shot, probably due to age‐linked activity patterns. Most road‐kills of young foxes occurred in May when juveniles began exploiting and in November when sub‐adults began dispersal. The ratios of road‐kills for the whole sample and for adults alone were 42% and 34%, respectively. These high rates of road‐kills suggest that the mortality pattern in Tochigi has been affected by factors characteristic of urban environments.
Comparison of life tables between the solitary eumenid wasp Anterhynchium flavomarginatum and the subsocial eumenid wasp Orancistrocerus drewseni to evaluate the adaptive significance of maternal care
Authors: Itino Takao 
Published: October 2006

SummaryI compared life tables between the solitary eumenid wasp Anterhynchium flavomarginatumSmith and the subsocial eumenid wasp Orancistrocerus drewseniSaussure in Kyoto, Japan, during 1980–1983. The subsocial eumenid is parthenogenetic in this study area. There were 9 identified mortality factors in the solitary eumenid and 7 in the subsocial eumenid, 6 of which were common to the two eumenids. The important differences of mortality between the two eumenids were seen in the egg, larval, and prepupal stages. In the egg stage, mortality by the phorid fly Megaselia sp. was much lower in the subsocial eumenid (1.4%) than in the solitary eumenid (15.0%) likely because of the matenal care of the subsocial eumenid (progressive provisioning and other related behavior), which reduced predation pressure. In the larval stage, mortality by the miltogrammine fly Amobia distorta was also lower in the subsocial eumenid (8.1%) than in the solitary eumenid (23.8%) also probably because of the maternal care of the subsocial eumenid. A comparison of mortality in the two eumenids between the stable, long continuing natural nest sites and the additional temporal ones showed that the phorid fly remained near its birth place and parasitized stable nest sites. The miltogrammine fly followed returning eumenid wasps and parasitized those nest sites that have a high host density. In the prepupal stage, mortality by endogenous death was higher in the subsocial eumenid than in the solitary eumenid. Mortality due to the rhipiphorid beetle was also higher in the subsocial eumenid probably due to more frequent flower‐visits by the subsocial eumenid.The defense mechanism of the subsocial eumenid was discussed in relation to the evolution of subsociality.
Niche modification and stability of competitive systems. II. Persistence of interspecific competitive systems with parasitoid wasps
Authors: Shimada Masakazu 
Published: October 2006

SummaryEffects of niche shift in ecological time scale on the population dynamics of competing species were studied in the experimental populations of two parasitoid wasp species, Anisopteromalus calandrae and Heterospilus prosopidis (both are solitary parasites), on a host, the azuki bean weevil, Callosobruchus chinensis. Four resource conditions were set up with combination of kind of bean (azuki or black eye), and host distribution (uniform or clumped). In each resource condition, four developmental stages of hosts were provided as a resource spectrum for parasitoid wasps.Population dynamics of the two wasp populations were investigated in each resource condition in Multi‐Generation Competitive Systems (MGCS), in which fresh hosts of four developmental stages were periodically introduced and were parasitized competitively by the two wasp species. Competitive coexistence of both wasps occurred in the azuki‐clumped condition, where the peaks of the resource utilization curves separated in the two species; pupae in A. calandrae and the early or late fourth instar in H. prosopidis, A. calandrae was eliminated in the azuki‐uniform condition and H. prosopidis went extinct in two black eye conditions irrespective of host distributions. The degrees of overlap of the resource utilization patterns of the two wasp species during population dynamics were not significantly different among resource conditions irrespective of the results of coexistence or extinction. Even in the azuki‐clumped condition, however, extinction of A. calandrae was observed when resource partitioning could not be realized with only the late fourth instar larvae available to wasps. Further analytical experiments showed that parasitizing ability of A. calandrae increased with host density per bean with azuki beans, but A. calandrae could express higher parasitizing ability with black eye beans than H. prosopidis irrespective of host density per bean.The flexibility in parasitizing ability by A. calandrae for various host stages under different resource conditions was thought to be the major factor in determining the competitive coexistence or the extinction of either species under different resource conditions. The present experiments also suggested that different second‐best host stages between competitors could be a major contributing factor to competitive coexistence.
Group predatory behavior by the assassin bug Agriosphodrus dohrniSignoret (Hemiptera: Reduviidae)
Authors: Inoue Hiroshi 
Published: October 2006

SummaryNymphs of Agriosphodrus dohrniSignoret (Reduviidae) have a strong gregariousness and show group predatory behavior. This study was conducted to clarify adaptive significance of group predation of this species, including laboratory observations and 6‐year field surveys.In the laboratory, observations on both solitary and group attacking against armyworms were made at varying prey size classes to compare the capture success rate by solitary predators with that by groups. The efficiency in capturing the prey was significantly higher in group attacking at any prey size class compared.Data obtained from the field surveys indicated the tnedency for searching nymphs to feed in group and to increase the number of predators feeding per prey item with increasing prey size. Average sizes of prey captured were also larger in group feeding throughout the nymphal stage. In particular, it was remarkable that, when prey were “creeping” types, the upper size limit of prey eaten was dramatically increased.
Population dynamics of the japanese clouded apollo Parnassius glacialisbutler (Lepidoptera: Papilionidae). I. changes in population size and related population parameters for three successive generations
Authors: Matsumoto Kazuma 
Published: October 2006

Summary
Population dynamics of a univoltine butterfly Parnassius glacialis (Lepidoptera: Papilionidae) was studied with mark‐recapture methods for three successive generations in a hilly region in Kanazawa City, Ishikawa Prefecture, Japan in 1981–1983.
Jolly (1965) andSeber's (1973) method was applied to the mark‐recapture data to estimate population parameters (daily survival rate, longevity, population size, sex ratio, etc.).
Sampling ratios were at least 50% and 30% for males and females, respectively.
Mean daily survival rate for males ranged 0.81–0.86 and that for females 0.80–0.84. Mean longevity was about 4–7 days for the males and about 5 days for the females. Spiders killed more males than females. Maximum longevity for an individual recorded during the study was 31 days for males and 18 days for females.
Emergence of the butterflies was later and less synchronous in 1981 than in 1982 and 1983. This was thought to be due to later extinction of heavier snow in 1981 than in the other years.
The population remained relatively stable for the three successive generations, with estimated total numbers of 914, 1277, and 869.
Estimated sex ratio (% females) was 30–40% at emergence
On the nature of errors involved in estimating stage‐specific survival rates by Southwood's method for a population with overlapping stages
Authors: Sawyer A. J. , Haynes D. L. 
Published: October 2006

SummaryThis paper has examined the effect of within‐stage mortality on the estimation of stage‐specific survival rates bySouthwood's (1978, p. 358) method. As pointed out bySouthwood, both the severity and timing of mortality affect the mean duration of a life stage, and consequently the estimate of the number of individuals entering that stage. Knowledge of the form of the survivorship curve permits correction of the estimate under certain circumstances. The use ofSouthwood's method with two overlapping stages having different rates and patterns of mortality leads to complex errors in the estimation of survival for the first stage. The nature of these errors is examined analytically and via a simulation model.Southwood's method is fairly robust, with moderate differences in mortality rates leading to acceptable errors in estimating survival for the first stage. When both the rate and pattern of mortality in both life stages are the same, then the survival estimate is made without error. Precise estimates of stage‐specific survival will not usually be possible withSouthwood's method because of the errors introduced by the very parameters being measured. Direct measurement of mortality rates and survivorship patterns (seeSouthwood, 1978, p. 309) is strongly advised, at least in preliminary work.
A model for analyzing insect stage‐frequency data when mortality varies with time
Authors: Bellows T. S. , Ortiz M. , Owens J. C. , Huddleston E. W. 
Published: October 2006

SummaryA model is developed for the analysis of insect stage‐frequency data which may be applied to populations with age‐dependent mortality. The analysis of stage‐frequency data is divided into two steps. In the first step, the number of different mortality rates and their values are estimated. The second step provides estimates of developmental rates and variances for each developmental stage and in addition provides estimates of the number of recruits to each stage. The model may be used both in analysis and prediction of insect stage frequencies. Hence, in addition to estimating developmental and mortality rates from stage‐frequency data, it may also be used as a simulation model for an insect population. The model is applied to two populations of Hemileuca oliviaeCockerell, a lepidopterous pest of New Mexico grasslands. The model identifies, in the two populations, different mortality rates that are related to plant productivity.
Population dynamics of a migrant skipper butterfly Parnara guttata (Lepidoptera: Hesperiidae) II. Survival rates of immature stages in paddy fields
Authors: Nakasuji Fusao 
Published: October 2006

SummarySurvival rates and mortality factors of a migrant skipper Parnara guttata were censused in paddy fields in 4 localities of central and western Japan during 1975–1980, and 10 life tables were developed for 3 generations. Mortality rates of eggs, older larvae and pupae were high but those of younger larvae were very low. The high mortality rate was caused by parasitoids. Ten primary and 6 secondary parasitoids were recorded. Out of three egg parasitoids, Telenomus sp. was predominant. Larval parasitoids, Apanteles baoris and Pediobus mitsukurii which are specific to genus Parnara were predominant in wet land habitat, i.e. paddy land. On the other hand, tachinid flies which have a wide host range and a high searching ability were predominant in dry land habitats. Mortalities of eggs and pupae contribute more to the change in the total mortality of immature stages than those of other stages. egg parasitoids which are the major mortality factor of eggs acted density‐dependently but larval and pupal parasitoids did not do so. The total mortality of immature stages occurred more or less density‐dependently. Larval density on rice plants scarecely affected the survival rate of larvae.