The dispersal and distribution of polyphagous predatory Coleoptera in cereals

Observations were made on the phenology of the dispersal of polyphagous arthropod predators from their overwintering habitats in field boundaries into adjacent farmland in cereal fields in southern England from 1981 to 1984. Agonum dorsale, Bembidion lampros and Demetrias atricapillus dispersed from overwintering habitats into adjacent cereal crops by crawling. B. lampros was fully dispersed by early May and the other two species by late May. Tachyporus spp. were thought to disperse mainly by flight, T. hypnorum being fully dispersed by mid-May and T. chrysomelinus by late May. A small proportion of A. dorsale marked in field boundaries in April before dispersal began were later recaptured up to 200 m into adjacent crops later in the season. Areas of a crop, immediately adjacent to field boundaries in which high numbers of predators had overwintered, were found to have significantly (P<0.01) higher numbers of predators that disperse by walking (A. dorsale, B. lampros and D. atricapillus) moving through them towards the centres of fields. By mid-summer, the mid-crop density of D. atricapillus was correlated with its overwintering density in surrounding field boundaries the previous winter, but this was not so in the other species. Mid-crop, mid-summer densities of A. dorsale were significantly (P<0. 02) correlated with mean percentage weed cover in fields. The densities of the other species were not correlated with weed cover. Analysis of data collected over a 10-yr period on a Sussex study area in late June revealed that significantly more D. atricapillus were found in fields surrounded by hedgerows than fields surrounded by fence-post and wire boundaries.     

Vocal Signature in Wild Infant Chimpanzees

A large array of communication signals supports the fission/fusion social organization in chimpanzees, and among them the acoustic channel plays a large part because of their forest habitat. Adult vocalizations convey social and ecological information to their recipients allowing them to obtain cues about an ongoing event from calls only. In contrast to adult vocalizations, information encoded in infant calls had been hardly investigated. Studies mainly focused on vocal development. The present article aims at assessing the acoustic cues that support individual identity coding in infant chimpanzees. By analyzing recordings performed in the wild from seven 3‐year‐old infant chimpanzees, we showed that their calls support a well‐defined individual vocal signature relying on spectral cues. To assess the reliability of the signature across the calls of an individual, we defined two subsets of recordings on the basis of the characteristics of the frequency modulation (whimpers and screams) and showed that both call types present a reliable vocal signature. Early vocal signature may allow the mother and other individuals in the group to identify the infant caller when visual contact is broken. Chimpanzee mothers may have developed abilities to cope with changing vocal signatures while their infant, still vulnerable, gains in independence in close habitat. Am. J. Primatol. 75:324‐332, 2013. © 2012 Wiley Periodicals, Inc.     

Highly polytypic taxon complex: interspecific and intraspecific integrative taxonomic assessment of the widespread pollinator Bombus pascuorum Scopoli 1763 (Hymenoptera: Apidae)

The recent development of the integrative taxonomic approach in bumblebees has led to unexpected merging or splitting of several taxa. Here we investigate the taxonomic statuses of one of the most abundant, widespread and polytypic Palearctic bumblebees, Bombus pascuorum. The latest review of this species includes 24 subspecies. We used an integrative approach based on genetic markers and male chemical reproductive traits and compared our results with the former classifications. Our results show that all B. pascuorum taxa are conspecific and share the same male chemical reproductive traits. The genetic structure observed in one mitochondrial and two nuclear markers poorly reflects the current subspecific classification. Indeed, the concordance of population genetic differentiation, population geographic distribution, and population colour pattern similarity suggests a different meaningful prospective classification with four taxon complexes: (i) the B. pascuorum dusmeti group, including all taxa from the Iberian Peninsula and south‐west France; (ii) B. pascuorum rehbinderi; (iii) B. pascuorum siciliensis; and (iv) B. pascuorum floralis groups (including all other taxa studied here).     

Phylogeography of spiny mice (genus Acomys, Rodentia: Muridae) from the south-western margin of the Sahara with taxonomic implications

The present study aims to depict the overall pattern of Acomys history in south-western Sahara. We tested the specific predictions that: (1) several mitochondrial clades can be identified and that they coincide with the described species; (2) successive phases of desert expansion and contraction during the last 3 Myr have resulted in several phases of demographic expansion and population fragmentation in Acomys ; and (3) isolation-by-distance occurs. The extent of phylogeographic patterns and molecular genetic diversity (cytochrome b gene and D-loop) were addressed in a survey of 90 individuals of Acomys from 38 localities. Our phylogeographical analyses show a strong genetic structure within western Saharan Acomys , with several phylogroups displaying non-overlapping geographic distributions. Restricted gene flow with isolation-by-distance was recorded and a signal of population expansion was detected within several clades. We suggest that during arid or semi-arid paleoclimatic periods, when large sandy areas were present, Acomys was restricted to rocky massifs, whereas, in more humid periods, when savannah and/or steppe habitat prevailed, this species was able to disperse and to survive outside rocky areas because food resources were abundant. Based on a comprehensive sampling and the use of an integrative approach (i.e. combining cytogenetic, molecular and morphological data), we firmly propose that Acomys airensis should be considered as a junior synonym of Acomys chudeaui .  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 29–46.     

Determinants of the domiciliary density of Triatoma infestans, vector of Chagas disease

In two heavily infested rural villages of Santiago del Estero, Argentina, where no indoor-spraying with residual insecticides had ever been carried out by official control services, we studied the influence of roof and wall structure, domestic use of insecticide, family size and the number of domestic dogs, on the domiciliary density of Triatoma infestans (Klug). Bug density was significantly associated with (1) the interaction between insecticide use and type of roof, (2) the structure of indoor walls, (3) the number of dogs sharing sleeping areas of people (room-mate dogs), and (4) the number of people plus room-mate dogs, but not with just the number of people resident in the house. The interaction between insecticide use and a roof made of 'simbol', a locally available grass (Pennisetum sp.), also reflected a younger age structure of domestic bug populations. In infested houses, the density of bugs infected with Trypanosoma cruzi Chagas was significantly correlated with overall bug density. Our data suggest that the application of environmental management measures by the affected people, such as plastering of walls and modification of roofs, coupled with keeping dogs away from bedrooms and application of insecticides, should limit the domestic population density of T. infestans and thus reduce the transmission of T. cruzi to people.     

RISK AND MID‐LEVEL MORAL PRINCIPLES

We discuss ethical aspects of risk‐taking with special focus on principlism and mid‐level moral principles. A new distinction between the strength of an obligation and the degree to which it is valid is proposed. We then use this distinction for arguing that, in cases where mid‐level moral principles come into conflict, the moral status of the act under consideration may be indeterminate, in a sense rendered precise in the paper. We apply this thought to issues related to pandemic influenza vaccines. The main conclusion of the paper is that on a principlist approach some acts may be neither right nor wrong (or neither permissible nor impermissible), and we claim that this has important implications for how we ought to make decisions under risk.