Conceptualizing world art studies: An introduction

This special issue aims to contribute to the conceptualization of World Art Studies. The first two articles offer evaluative views from art history, the third and fourth perspectives from anthropology, the fifth and sixth arguments for including neo-evolutionary and neurological studies in understanding world art as a universal human behavior.     

Life history strategies and psychopathology: the faster the life strategies,the more symptoms of psychopathology

There is little extant empirical literature examining the associations between life history strategies and symptoms of psychopathology. The current study (N = 138) investigated the associations between life history strategies, symptoms of psychopathology, aggression, incidence of self-harm behaviour, and attachment (perceived parental support) in sample drawn from the general population and community mental health service providers. The results from the study indicate those with a faster life strategy report greater levels of aggression and symptoms of psychopathology. Further, perceptions of poorer parental support were associated with a faster life history strategy. Implications for life history theory, conceptualising psychopathology, and future research directions are discussed.     

Pushing back frontiers: Towards a history of art in a global perspective

Traditionally, art history is a discipline focusing on the developments of Western art and architecture. It is time, however, to broaden our perspective. The world is changing, art is changing, somutatis mutandis is art history. This does not happen on its own accord. Art history needs rewriting and art historians have to do it. We need to take a critical look at our premises and points of departure, and we need to change the art historical curricula at universities and art schools. At Leiden University, the Netherlands, the Department of Art History has opted for a new orientation and decided to study the history of art from a global perspective. This means that students will meet with three lines of approach to the visual art and material culture from regions other than the West. Firstly, they are introduced to the art and material culture of Asian, African, and Amerindian civilizations by colleagues from those fields, which Leiden is so fortunate to have. The Faculty of Arts at Leiden University, houses a wide variety of language and culture studies of the world. The second approach focuses on interactions, mutual influences, and interculturalization processes in art and culture. And the third addresses methodical-theoretical reflection on art history in a global perspective. The aim here is to formulate a theoretical framework for the study of art worldwide, thereby pursuing ‘comparative art history’. In order to achieve these perspectives, exchanging ideas and concepts with anthropologists can be very productive.     

Life history traits of the tropical freshwater copepod Mesocyclops longisetus (Crustacea: Copepoda)

The life history traits of a tropical copepod population of Mesocyclops longisetus were measured in the laboratory under defined and controlled culture conditions. Egg duration times at 25 and 30 °C were 42.1 and 29.6 hours, respectively. Development times from nauplius I to adult females and males were 22.3 and 18.3 days, respectively. Body sizes (cephalothorax length) of adult females and males were 1.00 and 0.60 mm, respectively. Clutch size averaged 70.2 eggs. Comparison of these traits with those of its congeners reveals considerable life history variation in the genus Mesocyclops. Lipid analyses of early stage eggs showed that the percent composition of triglycerides to total lipid in M. longisetus (22%) is similar to that of Mesocyclops edax (17%) and daphniid cladocerans, but only half that of a marine calanoid copepod. We suggest that zooplankton may adapt to different resource environments by either adjusting their egg size or altering the proportion of lipid that is readily available for metabolic energy of embryos and nauplii. The diverse arrays of zooplankton life histories may be explained in part by adaptations in lipid metabolism in response to the level and predictability of resources.     

Life history,morphology and crossability of Chondrus ocellatus forma ocellatus and C. ocellatus forma crispoides (Gigartinales,Rhodophyta) from the north-western Pacific

The morphology, life histories and crossability in culture are described for the marine red algae Chondrus ocellatus Holmes forma ocellatus from Japan, China and Korea and C. ocellatus f. crispoides Mikami (Gigartinaceae, Rhodophyta) from Japan. In culture, all isolates of both formae showed a Polysiphonia-type life history typical of the family Gigartinaceae. Plants of C. ocellatus f. ocellatus from Korea and China and some strains from Japan formed gametangia under long-day conditions (LD) at 15°C; however, two other Japanese strains required short-day conditions (SD) at 15°C for gametogenesis, indicating a photoperiodic response. Plants of C. ocellatus f. crispoides did not require SD for gamete formation. In all strains, tetrasporophytes of both formae produced tetrasporangia under LD. Isolates of C. ocellatus f. ocellatus from Japan, China and Korea were found to be completely sexually compatible regardless of photoperiodic characteristics, and the responses to daylength shown by progeny of LD and SD strains suggested Mendelian inheritance of a daylength factor. Chondrus ocellatus f. ocellatus was sexually incompatible with C. nipponicus Yendo, a morphologically similar species from Japan, but C. ocellatus f. crispoides was partially interfertile with both C. ocellatus f. ocellatus and C. nipponicus, indicating that the three entities are closely related. In view of the apparently higher breeding compatibility between C. nipponicus and C. ocellatus f. crispoides, and the fact that these two entities are more similar morphologically and reproductively, it is proposed, provisionally, to refer C. ocellatus forma crispoides to C. nipponicus.     

Life history and population dynamics of the western mosquitofish: a comparison of natural and introduced populations

Life history and population dynamic patterns of Gambusia affinis in southeastern Louisiana varied spatially and temporally in 1990 and 1991, but were consistent with previous reports of this species in the southern regions of its natural range. Several differences exist among populations in different geographic regions within the United States, as reported in the literature, which do not follow a' native v . introduced' dichotomy: (1) brood size decreases and offspring size increases from north to south; (2) large overwintered females in northern areas produce more broods within a season than those in southern populations, while the reverse is true for young-of–year females; (3) minimum size at first reproduction follows a seasonal pattern within populations, but tends to be smaller in southern and larger in northern and Hawaiian populations; (4) synchronous reproduction early in the season is characteristic of northern populations, but does not occur in southern areas; and (5) mosquitofish reproduce year–round in Hawaii, while 'southern' populations within the continental U.S. cease reproduction during winter.     

Life history and demography of Psyllaephagus zdeneki (Hymenoptera: Encyrtidae), a potential candidate for biological control of olive psylla,Euphyllura pakistanica (Hemiptera: Psyllidae)

Life history and demographic parameters of Psyllaephagus zdeneki Noyes and Fallahzadeh (Hymenoptera: Encyrtidae) were studied on its host the olive psyllid, Euphyllura pakistanica Loginova (Hemiptera: Psyllidae). Experiments were conducted in a growth chamber at 20±1 °C, relative humidity of 60±5%, and a photoperiod of 16:8 (L: D) hours. Four different olive cultivars (Fishomi, Shenge, Oil and Yellow) were used to test possible host plant influence on parasitoid performance. The pre-imaginal developmental period of female P. zdeneki varied from 24.96 (on Fishomi) to 26.34 (on Shenge) days, and for males from 21.63 (on Fishomi) to 24.44 (on Yellow) days. Adult female longevity differed significantly among the four cultivars, ranging from 12.46 (on Fishomi) to 14.97 (on Shenge) days. For each cultivar, adult female longevity was significantly greater than male longevity. Life table parameters showed survival rates (l _x ) in newly emerged females were 84.61, 82.25, 85.71 and 78.12% on Fishomi, Yellow, Shenge and Oil, respectively. Female egg deposition was highest on Yellow (138.4 eggs per female) and lowest on Fishomi (116.3 eggs per female). The highest and lowest intrinsic rate of increase were 0.28 (on Shenge) and 0.24 (on Oil), respectively. The mean generation time ranged from 14.6 (on Shenge) to 16.7 (on Oil) days. These results are discussed with respect to the potential impact P. zdeneki as a natural enemy of E. pakistanica, the most important pest of olive in the Fars province of Iran, as well as the influence of olive cultivar on parasitoid life table parameters.     

Life history and production of Agapetus quadratus (Trichoptera: Glossosomatidae) in a temporary, spring-fed stream

1. The life history and trophic basis of production of the caddisfly grazer Agapetus quadratus were studied in the torrent Gorg Blau, a spring‐fed stream on the island of Majorca that dries annually during summer. 2. Quantitative random samples were taken every 2–3 weeks during an annual surficial flow period, from November 2000 to mid‐July 2001. Instars of field‐collected larvae were determined by measurements of head width and pronotum length, and the sex of all pupae was determined to study sexual dimorphism and sex ratio. 3. Stage‐frequency histograms suggested a trivoltine population, with an average cohort time of 4 months. Larval development was asynchronous, with continuous growth and overlapping generations. Recruitment peaks were identified in mid‐November, early March and late June, indicative of winter, spring and summer generations. On average, females were larger than males and the mean sex ratio was 2 : 3 (females : males). Population densities and biomasses derived from the field data were used to calculate production and turnover rate. 4. Annual production of A. quadratus in the torrent Gorg Blau (4.80 g dry mass m^?2 year^?1) was the highest ever reported for the genus, being comparable with that estimated for some insects with rapid development and multiple cohorts. 5. Estimates of production of A. quadratus were combined with foregut content analysis to estimate the fraction of total production derived from the principal food sources: algae and organic detritus. Algae supported a major proportion of the production of this grazer. 6. The low density of predators characteristic of many temporary streams, and the small amplitudes in discharge and temperature during most of the wet period that characterise the spring habitats might allow high levels of grazer production in this particular Mediterranean stream.     

Life history variability of a grazing stream insect (Liponeura cinerascens minor; Diptera: Blephariceridae)

SUMMARY 1. Fourteen populations of Liponeura cinerascens minor from different sites in the Swiss Alps were investigated. Our goals were to describe the life history of this blepharicerid species and to analyse how it was influenced by temperature and food availability. 2. Temperature regimes and periphyton density at the sampling sites varied considerably. Mean annual temperature ranged from 3.8 to 6.5 °C, with annual amplitudes (i.e. the difference between the mean of the coldest and the warmest month) between 3.7 and 12.0 °C. Averaged periphyton density, which was assessed semiquantitatively on a scale from 0 to 5, ranged from 1.1 to 3.3. 3. Larvae or pupae of L. c. minor were found between January and October. Presence of larvae or pupae at individual sites ranged from 100 to 224 days and appeared to be mainly a result of hatching patterns. Individual larval development required between 7 and 20 weeks. Our findings suggest that L. c. minor is univoltine and undergoes an extended (≥4 months) egg dormancy during late summer, autumn and winter. 4. Development of L. c. minor was observed from <1 to 15.8 °C, indicating it is a cold‐stenotherm. Its geographical distribution seems to be constrained by high summer temperatures. Within the tolerated temperature range (0–16 °C), however, temperature had no apparent effect on hatching, larval growth rate or pupal size. 5. Larval growth rate and size of pupae were significantly correlated with food availability. Completion of larval development required 300–400 degree‐days at sites where periphyton was readily available, but >800 degree‐days where periphyton availability was low. 6. No evidence for intraspecific food competition was found, whereas food competition by other blepharicerid species, mainly Hapalothrix lugubris, appeared to be a major reason for the observed food limitation. However, as L. c. minor is much more widespread than H. lugubris, food competition between these two species is likely to occur infrequently. We therefore contend that variations in the life history of L. c. minor are mainly a consequence of its thermal constraints.     

Life history evolution in cichlids 2: directional evolution of the trade-off between egg number and egg size

The negative relationship between offspring number and offspring size provides a classic example of the role of trade-offs in life history theory. However, the evolutionary transitions in egg size and clutch size that have produced this negative relationship are still largely unknown. Since body size may affect both of these traits, it would be helpful to understand how evolutionary changes in body size may have facilitated or constrained shifts in clutch and egg size. By using comparative methods with a database of life histories and a phylogeny of 222 genera of cichlid fishes, we investigated the order of evolutionary transitions in these traits in relation to each other. We found that the ancestral large-bodied cichlids first increased egg size, followed by a decrease in both body size and clutch size resulting in the common current combination of a small-bodied cichlid with a small clutch of large eggs. Furthermore, lineages that deviated from the negative relationship between clutch and egg size underwent different transitions in these traits according to their body size (large bodied genera have moved towards the large clutch/small egg end of the continuum and small bodied genera towards the small clutch/large egg end of the continuum) to reach the negative relationship between clutch size and egg size. Our results show that body size is highly important in shaping the negative relationship between clutch size and egg size.     

Life history of the Onopordum capitulum weevil Larinus latus (Coleoptera: Curculionidae)

The population structure and stage-specific survival of the capitulum weevil, Larinus latus, a potential control agent for weedy Onopordum thistles in Australia, was studied in its native range in Greece. Although fecundity of this univoltine insect was low (35.4 eggs/female), survival was relatively high, with 45% of eggs reaching adulthood when protected from predators and parasitoids, and 23% surviving when exposed to these natural enemies. Other mortality factors of importance for immature stages were a failure to establish, due largely to oviposition by females on inappropriate sites on the thistle capitula, and inter- and intraspecific competition for larval resources. Once emerged, adult losses due to overwintering mortality and net migration were estimated at a further 48%. Despite these losses there was a net doubling of the population at the study site between Onopordum flowering seasons. The data suggest that movement of adults occurs both within and between patches and that variability in population size relative to the resource base is low. Overall, L. latus may be considered a K-strategist which forms relatively stable populations over a fragmented habitat and which maintains its population integrity through a certain degree of annual redistribution. The implications of these data for the potential effectiveness of L. latus as a biological control agent of weedy Onopordum spp. are discussed.     

Life history evolution in cichlids 1: revisiting the evolution of life histories in relation to parental care

Empirical links between egg size and duration of parental care in fishes have generated a considerable amount of theory concerning life history evolution. However, to date, this link has not been investigated in relation to other important life-history traits such as clutch size and body size, or while controlling for shared ancestry between species. We provide the first phylogenetically based tests using a database with information on egg size, clutch size, body size and care duration in cichlid fishes (Cichlidae). Multiple regression analyses, based on independent contrasts on both the species and the genus level, showed that clutch size is the variable most closely related to duration of care. This pattern appeared to be driven by post-hatch care relationships. Our results show that, contrary to expectation, there is no positive link between egg size and care duration in Cichlidae. Instead, greater reproductive output through increased clutch size investment appears to have coevolved with greater care of offspring. We suggest that re-evaluation of the generality of current models of the evolution of egg size under parental care in fishes is needed.     

Life history traits variation in heterogeneous environment: The case of a freshwater snail resistance to pond drying

Ecologists and population geneticists have long suspected that the diversity of living organisms was connected to the structure of their environment. In heterogeneous environments, diversifying selection combined to restricted gene flow may indeed lead to locally adapted populations. The freshwater snail, Galba truncatula, is a good model to address this question because it is present in a heterogeneous environment composed of temporary and permanent waters. In order to test the selective importance of those environments, we proposed here to measure survival of lineages from both habitats during drought episodes. To this purpose, we experimentally submitted adults and juveniles individuals from both habitats to drought. We found a difference in desiccation resistance between temporary and permanents waters only for adults. Adults from temporary habitats were found more resistant to drought. This divergence in desiccation resistance seems to explain the unexpected life history traits differences between habitats observed.     

Life history of the tick parasitoid Ixodiphagus hookeri (Hymenoptera: Encyrtidae) in Kenya

We conducted laboratory and field experiments to elucidate the life history of Ixodiphagus hookeri, a parasitoid of the ixodid tick Amblyomma variegatum in Western Kenya. Ixodiphagus hookeri females oviposited in unfed host nymphs as well as engorged nymphs, but rarely in engorged larvae. While I. hookeri developed to adults in engorged nymphs, the eggs laid in unfed nymphs disappeared within 2 days after oviposition. As temperature increased, development time of I. hookeri from oviposition to adult emergence in engorged nymphs decreased from 46 days at 23 °C to 35 days at 28 °C, and their immature survival in engorged nymphs decreased from 67% at 23 °C to 22% at 28 °C. No parasitoid adult emerged from hosts at 30 °C. Individual hosts parasitized by single females produced 42–53 adult wasps, 73% of which were females. As a typical pro-ovigenic species, I. hookeri females had an average of 84 mature eggs at emergence and lived only for a few days. When laboratory-reared, unfed nymphs of A. variegatum were attached to cattle for 4–9 days in subsistence farmers’ fields in Western Kenya, 25% of the engorged nymphs and 4% of the unfed nymphs on cattle were parasitized by I. hookeri, demonstrating that I. hookeri females search for and oviposit in A. variegatum nymphs on cattle. Unlike other strains of I. hookeri that overwinter as eggs in unfed nymphs, I. hookeri could continuously reproduce throughout the year in Western Kenya.     

Life history ofAphis gossypii on cucumber: influence of temperature, host plant and parasitism

Life table data forAphis gossypii Glover (Homoptera: Aphididae), an important pest in glasshouse cucumber crops, were studied at 20, 25 and 30°C on two cucumber cultivars (Cucumis sativus L.) in controlled climate cabinets. The development time on the cucumber cv. ‘Sporu’ ranged from 4.8 days at 20°C to 3.2 days at 30°C. Immature mortality was approximately 20% and did not differ between temperatures. Most mortality occurred during the first instar. Reproduction periods did not differ among temperatures, but at 25 and 30°C more nymphs were produced (65.9 and 69.8 nymphs/♀, respectively) than at 20°C (59,9 nymphs/♀) because of a higher daily reproduction. Intrinsic rate of increase was greatest at 25°C (r _m =0.556 day⁻¹). At 20 and 30°C the intrinsic rate of increase was 0.426 and 0.510, respectively. On cv. ‘Aramon’, the development time ofA. gossypii was approximately 20% longer at all temperatures. Immature mortality did not differ between the two cultivars. The intrinsic rate of increase on cv. ‘Aramon’ was 15% smaller than on cv. ‘Sporu’. The use of cucumber cultivars partially resistant to aphids is discussed in relation to biological control of cotton aphid in glasshouses. Development time and immature mortality on leaves of the middle and upper leaf layer of glasshouse grown cucumber plants (cv. ‘Aramon’) were comparable to development in the controlled climate cabinets. On the lower leaves immature mortality was much higher (approximately 82%) than on leaves of the middle (24.0%) and upper leaf layer (24.5%). Reproduction was less on the lower leaf layer (45.9, 70.5 and 70.1 nymphs/♀ on leaves of the lower, middle and upper leaf layer, respectively). Aphids, successfully parasitized byAphidius colemani Viereck (Hymenoptera: Braconidae) only reproduced when they were parasitized after the third instar. Fecundity was 0.1 to 0.9 and 10.5 to 13.3 nymphs/♀ for aphids parasitized in the fourth instar or as adults, respectively. Reproduction of aphids that were stung but survived the attack was lower than for aphids not stung. Average longevity of these aphids was equal to the longevity of aphids not stung byA. colemani.