Sexual selection for bright females prevails under light pollution

The functions of sexually selected traits are particularly sensitive to changes in the environment because the traits have evolved to in-crease mating success u...     

Field effects of faecal residues from ivermectin slow‐release boluses on the attractiveness of cattle dung to dung beetles

A 2‐year study was performed in two sites in southern France to assess the effect of ivermectin residues on the attractiveness of cattle dung to colonizing insects. Insect captures were compared between pitfall traps baited with dung from untreated cattle and dung from cattle that had been treated with a slow‐release (SR) bolus of ivermectin. Cattle dung was collected at different times after treatment (4, 14, 42, 70 and 98 days). Excretion showed a plateau, with levels ranging between 0.688 µg and 1.123 µg ivermectin per gram of wet dung. Faecal residues affected insect captures at both sites. Effects were independent of the time dung was collected after treatment, except for one result subsequent to a severe drought during the baiting period. Ivermectin‐contaminated dung showed a significant attractive effect, with increased captures regardless of the guild to which beetles belonged. This study demonstrates the attractiveness of ivermectin residues over a long period after the treatment of animals. It draws attention to the danger of widespread use of this endectocide‐based SR bolus, which is attributable to the preferential attraction of insects to treated dung, which potentially puts at risk the survival of their offspring.     

Trade-offs between flower number and investment to a flower in selfing and outcrossing varieties of Impatiens hypophylla (Balsaminaceae)

Floral resource allocation was compared on a whole-plant basis between two varieties of Impatiens hypophylla that differ in flower size. There were significant negative correlations between flower number and investments to a flower at both the within-population and between-variety levels. In individual flowers, var. hypophylla with larger flowers invested significantly more resources to male and pollinator-attractive functions, whereas investments to female function did not differ between the varieties. In experimental populations placed in the field, pollinators preferred the larger flowers of var. hypophylla even within the same habitat of var. microhypophylla, which has smaller flowers. There was a significant lack of observed heterozygosity only in var. microhypophylla. Thus, the outcrossing variety had more attractive but fewer flowers, while the selfing variety had less attractive but more abundant flowers.     

Evolution of heterospecific attraction: using other species as cues in habitat selection

We analyzed the ecological conditions that may favor a habitat selection process in which later arriving individuals (colonists) use the presence of earlier established species (residents) as a cue to profitable breeding sites (heterospecific attraction). In our model, colonists assessing potential breeding patches could select between high-quality source and low-quality sink patches. A proportion of the source patches were occupied by residents. Colonists could either directly sample the relative quality of the patches (termed samplers) or, alternatively, they could also use residents as a cue of patch quality (cue-users). Cue-users gained benefit from lowered costs when assessing occupied source patches. The cue-using strategy is an efficient way to choose the best possible patch not only when interspecific competition is intense, but also when benefits from social aggregation exceed the effects of competition. High relative cost of sampling empty patches increases the fitness of the cue-using strategy relative to samplers. The strongest attraction to heterospecifics was predicted when the benefit from aggregating with residents exceeded the effects of competition, and approximately half of the landscape consisted of occupied, high-quality source patches.     

The attraction of silk: base of group cohesion and collective behavior in social spiders

Social spiders differ from social insects by the production and the use of silk to build irregular webs. This silk prevents dispersion of the individuals and ensures the group cohesion during swarming and collective displacements, playing a part similar to tracks of pheromones in ants. A social spider Anelosimus eximius is attracted by conspecific silk and does not show any discrimination relative to its origin, excluding any group closure. The quantity of silk and the state of satiety of the individual modulate this attraction, and might explain how the spider society adapts the size of the web to its nutritional needs.     

Comparative Phenomenology of Ataques de Nervios,Panic Attacks,and Panic Disorder

This article examines a clinicalsample of 66 Dominican and Puerto Ricansubjects who reported ataques de nerviosand also psychiatric disorder, and disentanglesthe phenomenological experiences of ataquede nervios, panic attacks, and panic disorder. In-depth cultural interviews assessed thesymptomatic phenomenology of ataqueepisodes from the local perspective as well asin terms of key panic features, such asrecurrence, rapid peaking of symptoms, and lackof provocation. Independent diagnosticassessments of panic attacks and disorder werealso used to establish the phenomenologicaloverlap between ataque and panic. Ourfindings indicate that 36 percent ofataques de nervios fulfill criteria for panicattacks and between 17 percent and 33 percentfor panic disorder, depending on the overlapmethod used. The main features distinguishingataques that fulfill panic criteria fromataques that do not include whether theepisodes were provoked by an upsetting event inthe person's life and the rapidity of crescendoof the actual attack. A key finding is thatataques often share individualphenomenological features with panic episodes,but that these features usually do not ``runtogether' during the ataque experience.This confirms previous findings thatataque is a more inclusive construct thanpanic disorder. The importance of thesefindings for the clinical diagnosis andtreatment of persons with ataques isdiscussed.     

Reducing Meloidogyne incognita Injury to Cucumber in a Tomato-Cucumber Double-Cropping System

The effects of a root-knot nematode-resistant tomato cultivar and application of the nematicide ethoprop on root-knot nematode injury to cucumber were compared in a tomato-cucumber double-cropping system. A root-knot nematode-resistant tomato cultivar, Celebrity, and a susceptible cultivar, Heatwave, were grown in rotation with cucumber in 1995 and 1996. Celebrity suppressed populations of Meloidogyne incognita in the soil and resulted in a low root-gall rating on the subsequent cucumber crop. Nematode population densities were significantly lower at the termination of the cucumber crop in plots following Celebrity than in plots following Heatwave. Premium and marketable yields of cucumbers were higher in plots following Celebrity than in plots following Heatwave. Application of ethoprop through drip irrigation at 4.6 kg a.i./ha reduced root galling on the cucumber crop but had no effect on the nematode population density in the soil at crop termination. Ethoprop did not affect cucumber yield. These results indicate that planting a resistant tomato cultivar in a tomato-cucumber double-cropping system is more effective than applying ethoprop for managing M. incognita.     

Similarities and Varieties: A Brief Sketch on the Reception of Darwinism and Sociobiology in Japan

This paper discusses the reception of Darwinian evolutionary theory and sociobiology in Japan. Darwinism was introduced into Japan in the late 19th century and Japanese people readily accepted the concept of evolution because, lacking Christianity, there was no religious opposition. However, the theory of evolution was treated as a kind of social scientific tool, i.e., social Spencerism and eugenics. Although evolutionary biology was developed during the late 19th and the early 20th century, orthodox Darwinian theory was neglected for a long time. In the mid 1980s, sociobiology was introduced but it was ignored and criticized by a large part of the ecologist-evolutionist community in Japan. This hostile attitude was due to the absence of Darwinism among these scientists. Compared with the reception of sociobiology in English-speaking countries, there were both similarities and differences in Japan.     

Effects of European colonization on indigenous ecosystems: post-settlement changes in tree stand structures in Eucalyptus–Callitris woodlands in central New South Wales, Australia

Aim There has been considerable debate about pre‐settlement stand structures in temperate woodlands in south‐eastern Australia. Traditional histories assumed massive tree losses across the region, whereas a number of recent histories propose that woodlands were originally open and trees regenerated densely after settlement. To reconcile these conflicting models, we gathered quantitative data on pre‐settlement stand structures in Eucalyptus–Callitris woodlands in central New South Wales Australia, including: (1) tree density, composition, basal area and canopy cover at the time of European settlement; and (2) post‐settlement changes in these attributes. Location Woodlands dominated by Eucalyptus species and Callitris glaucophylla, which originally occupied approximately 100,000 km² in central New South Wales, Australia. Methods We recorded all evidence of pre‐settlement trees, including stumps, stags and veteran trees, from 39 relatively undisturbed 1‐ha stands within 16 State Forests evenly distributed across the region. Current trees were recorded in a nested 900 m² quadrat at each site. Allometric relationships were used to estimate girth over bark at breast height, tree basal area, and crown diameter from the girth of cut stumps. A post‐settlement disturbance index was developed to assess correlations between post‐settlement disturbance and attributes of pre‐settlement stands. Results The densities of all large trees (> 60 cm girth over bark at breast height) were significantly greater in current stands than at the time of European settlement (198 vs. 39 trees ha^?1). Pre‐settlement and current stands did not differ in basal area. However, the proportional representation of Eucalyptus and Callitris changed completely. At the time of settlement, stands were dominated by Eucalyptus (78% of basal area), whereas current stands are dominated by Callitris (74%). On average, Eucalyptus afforded 83% of crown cover at the time of settlement. Moreover, the estimated density, basal area and crown cover of Eucalyptus at the time of settlement were significantly negatively correlated with post‐settlement disturbance, which suggests that these results underestimate pre‐settlement Eucalyptus representation in the most disturbed stands. Main conclusions These results incorporate elements of traditional and recent vegetation histories. Since European settlement, State Forests have been transformed from Eucalyptus to Callitris dominance as a result of the widespread clearance of pre‐settlement Eucalyptus and dense post‐settlement recruitment of Callitris. Tree densities did increase greatly after European settlement, but most stands were much denser at the time of settlement than recent histories suggest. The original degree of dominance by Eucalyptus was unexpected, and has been consistently underestimated in the past. This study has greatly refined our understanding of post‐settlement changes in woodland stand structures, and will strengthen the foundation for management policies that incorporate historical benchmarks of landscape vegetation changes.