Oviposition site selection and avoidance of additional mating by females of the dragonfly,Cordulia aenea amurensis Selys (Corduliidae)

Summary Females of an odonate species in which oviposition sites overlap with mating sites may adopt one or more of the following strategies when they lay eggs except when they ‘trade’ mating for access to suitable oviposition sites or for services (guarding, etc.) provided by males: (1) ovipositing at hidden places; (2) ovipositing at a time when males are neither patrolling nor watching; (3) indicating non-receptivity by a behavioral display. The density of ovipositing females of the dragonfly,Cordulia aenea amurensis Selys which was studied between 1970 and 1983 at a pond (H?rai-numa, Sapporo, Hokkaido) had a high negative correlation with the distance from ‘entrance’ (a part of shore at which the arrival of most adults seems to have occurred). On the other hand, oviposition was rarely observed at a sector being distant from entrance in spite of the inference that larval survivorship was probably high at this sector. Most females oviposited among emergent vegetation in which approach of males to them was difficult, and they scarcely traveled across the open water in search of oviposition sites. Therefore, most females of the population studied were considered to adopt the first strategy. The second and third strategy were not adopted by the population studied. Finally, the influences of some environmental factors and traits possessed by a species on the adoption of these tactics or on the execution of the ‘trades’ were discussed. Ecological studies ofCordulia aenea amurensis Selys, VII. This work was supported in part by a Grant-in-Aid for Special Project Research on Biological Aspects of Optimal Strategy and Social Structure from the Japan Ministry of Education, Science and Culture.     

A life table ofMogannia iwasakii (Homoptera: Cicadiidae) in sugarcane field of Okinawa

Summary A preliminary life table of the sugarcane cicada,Mogannia iwasakii, which became a pest of sugarcane in Okinawa recently, was presented based on the results of field survey. Mortality rates during egg and later nymphal stages were low but a remarkable reduction of the number of individuals in a cohort took place at the 1st nymphal instar, mainly due to predation by ants. Ants also killed the cicada during and just after the final ecdysis and birds concentrated their feeding on adults. Prenatal mortality of adults was, however, low in the infested area, suggesting the ‘escape’ of cicadas from the pressure of predators. This espace is considered to be a factor responsible to the maintainance of outbreak for a long time. Increase in the acreage of ratton canes and wide-use of organochlorine insecticides during the 1960’s were assumed to be the factors responsible to the initial increase of this species.     

Tables for the analysis of selective predation experiments

Summary This paper discusses the analysis of selective predation experiments with two types of prey when the prey are not replaced after they have been removed by the predators. In an earlier paper (Manly et al., 1972) consideration was given to situations where the replication of experiments allows the estimation of standard errors from the experimental results; in the present paper a table of standard errors is given for a large range of experiments and replication is therefore no longer necessary. The standard errors were calculated on an electronic computer by solving the exact equations given in the earlier paper. The suggested method of analysis is illustrated using some data where the prey were red and yellow artificial ‘maggots’ and the predators were garden birds.     

Component analysis and modelling of the movement process: Analysis of simple tracks

Summary The construction of a general model of animal movement using the ‘experimental components' approach ofC. S. Holling is proposed. The process of ‘movement’ is interpreted very generally as any displacement of the whole organism in space. The rationale for modelling such processes rests upon the idea that there is a basic “canonical” pattern of movement characteristic of a species moving in a homogeneous environment, which pattern is overlaid by the various directional stimuli present in more usual heterogeneous environments. The ‘canonical movement model’ is a necessary first step in construction of more realistic representations. We suggest it can be made using six components viz. the initial heading of the animal, the mean and variance of the angular displacements made by the animal as it moves, the mean and variance of the speed of the animal, and a term for the continuity of the movement. We have measured all these components in the field for the two-dimensional movement of the inter-tidal snail,Polinices incei and these results are presented here. Difficulties inherent in the measure ment of angular displacement in particular are discussed and means of resolving them proposed. The shortcomings involved in the measurements and techniques for their more detailed representation and the next steps in the proposed modelling sequence are discussed.     

Biology ofHyphantria cuneaDrury (Lepidoptera: arctiidae) in Japan. V. Preliminary life tables and mortality data in urban areas

Summary Studies on the population dynamics of the fall webworm,Hyphantria cunea have been carried out at three survey stations and along selected roads in the urban area of Tokyo since 1966. Twelve survivorship curves obtained during two years and 8 life tables show that the mortality rate in early developmental stages of the fall webworm is remarkably low as compared with that of other lepidopterous defoliaters and the mortality rate in later developmental stages is compensatory high. The low mortality rate in early stages is considered to be due to the protective role of the nest-web and the lack of egg and larval parasites. All but one parasitic species emerge from prepupae and pupae. Spiders living in the nest-web of the fall webworm play an important role in reducing the number of young larvae. Direct observations and caging experiments showed that relatively high mortality during later larval stages is mainly due to predation by birds (in the first generation) and wasps (in the second generation). The generation mortality in the survey stations always exceeded the level where the population is kept at the steady state, and the outbreak of this moth is considered to be continued by the immigration of adults from large trees growing in gardens on which the larvae can escape from predation pressure. Contributions from JIBP-PT No. 51. A part of this study was supported by the special project research, ‘Studies on the dynamic status of biosphere’, sponsored by the Ministry of Education.     

Well-Being is a Process of Becoming: Respondent-Led Research With Organic Farmers in Madagascar

Malagasy ‘players’—farmers, middle men, organic organisations and policy makers—see in export-orientated organic agriculture a way for Madagascar to build upon its historic export strengths: spices, essential oils, medicinal plants and tropical fruits. They point to the de facto organic status of most farming in the country and view organic production strategies as a means for Malagasy farmers to differentiate their produce in the highly competitive world market (Ramboatiana and Randriamanantena 2000; Randriamanantena 1998; Vallée 2000). However, producing for the export market poses significant challenges for Malagasy farmers. Despite its apparent ‘fit’ with existing farming practice, ‘true’ certified organic practice does not necessarily offer a means towards achieving a Malagasy farmer-defined ‘good life’. Smallholders can be disempowered through their incorporation into wider systemic relationships whose more powerful actors—such as buyers and consumers—and their ‘rules’ about what ‘organic’ is, for example, are necessarily unfamiliar. Yet farmers are very interested in the significant opportunities for much-needed cash that organic farming offers. This paper argues that strengthening farmer agency, and thus their presence as actors in international food chains, can be partially achieved if farmers are involved in devising the rules for organic and social certification. I set out eight principles that I have developed which seem important when trying to capture and measure ‘quality of life’ for the purposes of social certification. My theoretical and empirical work, detailed here, is set within a methodological discussion on how to best ensure that research is ‘respondent-led’. Respondent-led research is, I argue, critical for ensuring that an understanding of the components of ‘quality of life’, and their operationalisation as standards and indicators, is truly meaningful to the target group.

Individual and institutional determinants of multidimensional poverty: A European comparison

In this article we evaluate to what extent between-country differences in the probability of being ‘multidimensional’ poor can be explained by a range of ‘domain-specific’ indicators of welfare regime arrangements. To this end, a so-called micro-macro model is estimated, testing the ‘independent’ effect of institutions, as opposed to alternative explanations such as between-country differences in population composition and economic affluence. Although we conclude that institutional arrangements do influence the risk of multidimensional poverty in the expected direction, we also find that bringing the ‘economy’ back into the analyses has a non-trivial impact. Our results point at several avenues for further discussion and research. First, although the more elaborate welfare regimes generally do a better job in preventing poverty, the level of transfers is not always ‘proportional’ to the general standard of living in these countries. Second, we only find partial confirmation for the often cited ‘negative’ impact of labour market flexibility and the related equality-jobs trade-off. While stricter employment regulations do reduce the poverty risk (be it only after controlling for economic affluence), flexibility in terms of the availability of fixed-term labour seems to be preferable to unemployment, even if at the individual level, labour market flexibility increases the likelihood of being poor quite severely.

The evolutionary significance of wing dimorphism in carabid beetles (Coleoptera: Carabidae)

A review of data on the background of wing dimorphism in carabid beetles (Coleoptera: Carabidae) and especially of the closely relatedCalathus cinctus andC. melanocephalus is given. In bothCalathus species wing dimorphism is inherited in a simple Mendelian fashion with the brachypterous condition dominant, but inC. melanocephalus the expression of the long winged genotype is under environmental control as well. The development of long winged phenotypes in the latter species is favoured by relatively favourable environmental conditions, such as high temperatures and a high food-supply. The higher fecundity of the larger and heavier long winged females of both species may compensate for losses of long winged phenotypes by flight activities. The evolutionary significance of both types of inheritance is discussed in relation to dispersal. The ‘fixed type’ as found inC. cinctus is considered an opportunistic short term ‘between sites strategy’, whereas the ‘dynamic type’ ofC. melanocephalus represents a flexible long term ‘within sites strategy’.     

The Capability Approach and Fuzzy Poverty Measures: An Application to the South African Context

One way of making the capability approach (CA) operational uses fuzzy poverty measures. In this paper, we present a new approach to applying these measures in the South African context using responses to a questionnaire on ‘The Essentials of Life’ in conjunction with a methodology for dealing with the vagueness of poverty. Our results suggest very low cut-offs for people or households to classify as definitely poor for some social indicators. These cut-offs are far lower than those Klasen used in his application of the CA. The attempt to apply the CA using Cheli and Lemmi’s ‘totally fuzzy and relative’ poverty measure in conjunction with our approach to specifying cut-offs can lead to incoherence. This measure can, nonetheless, be useful when social indicators have a ‘relativist component’. While the Cerioli and Zani measure does not lead to such incoherence, it also has a serious weakness.     

The ‘What’, ‘Why’ and ‘How’ of Employee Well-Being: A New Model

This paper examines the ‘what’, ‘why’ and ‘how’ of employee well-being. Beginning with the ‘what’ of well-being, the construct of mental health was explored with the aim of building a model of employee well-being. It was proposed that employee well-being consists of three core components: (1) subjective well-being; (2) workplace well-being and (3) psychological well-being. Following this, the ‘why’ of employee well-being was investigated; that is, why employee well-being should be an important matter for organisations. It was argued that employee well-being is an important precursor to organisational well-being, as indicated by its links to employee turnover and performance. The next section was concerned with the ‘how’ of employee well-being; that is, how well-being can be reliably enhanced. Drawing on two models of strengths and a practice model of psychological assessment, it was asserted that strength-based development can reliably enhance employee well-being. A solid framework for understanding and measuring employee well-being is offered in the hope that it will foster a more integrated approach to assessing and optimising employee well-being.