Thermal change alters the outcome of behavioural interactions between antagonistic partners

1. Concerns about climate change often trigger the question whether physiological and behavioural responses of species will enable them to persist. However, species do not exist alone and are largely dependent on interactions with others within communities. 2. In the present study, a mechanistic approach is used to test the hypothesis that inter‐specific differences in metabolic response to unpredictable short‐term thermal changes can change the outcome of host–parasitoid behavioural interactions. 3. The effect of a drop or a rise of 5 °C on resting metabolic rates (RMR) of the main aphid pest of cereal crops in Western Europe, the host Sitobion avenae Fabricius and its main natural enemy, the parasitoid Aphidius rhopalosiphi De Stefani‐Perez was measured. Also, defence and attack behaviours were measured for host and parasitoid separately as well as in interaction, since behavioural strategies of both species largely determine parasitism success. 4. The results showed that, when no change in temperature occurred, parasitoids had the highest oviposition rate. However, only with a rise of temperature behavioural interactions were disrupted: the parasitoid attack rate decreased whereas the aphid defence rate increased. This alteration in behaviour was associated with a stronger thermal response of RMR in hosts than in parasitoids, suggesting that species‐specific thermal responses of RMR could give valuable information on changes in the outcome of species interactions under warm spells but not under cold ones. 5. It was shown that relatively modest thermal changes with non‐lethal effects can have profound consequences for interacting co‐evolved species which may affect ecosystem services, such as biological control of pest populations.     

Eutrophication and macroalgal blooms in temperate and tropical coastal waters: nutrient enrichment experiments with Ulva spp.

Receiving coastal waters and estuaries are among the most nutrient‐enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast‐growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth‐limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low‐ to high‐nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high δ¹⁵N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.     

The demography of coarse wood in north temperate lakes

1. Exchange of material across habitat boundaries is a key process in riparian zones. The movement of coarse wood from lakeshore forests to the littoral zone, where it provides habitat for aquatic organisms, is not well understood. In 2003, we resampled coarse wood within the littoral zone of four lakes in Northern Wisconsin (U.S.A.), that had originally been surveyed in 1996, to quantify the spatial arrangement of littoral coarse wood and estimate input, loss and movement rates.
2. All four lakes had a clumped pattern of littoral coarse wood, and the locations of clusters were similar in both census years. Littoral coarse wood was more abundant than expected on moderate to steep slopes, on southern shorelines, and in areas with sparse residential development.
3. All four lakes had a net accumulation of coarse wood; rates of wood input ranged from 0.5 to 1.9 logs km⁻¹ year⁻¹, i.e. there was more wood in 2003 than 1996. Movement rates of tagged logs varied 14-fold among lakes, with a maximum in one lake of 42% of logs recovered in 2003 more than 20 m from their 1996 location. Median distance moved ranged from 22 to 323 m among the four lakes.
4. Areas of persistently high wood density may be keystone habitats whose presence enables the persistence of populations of certain aquatic organisms. Conservation of locations with high wood density may be important to maintain target densities of coarse wood of lakes with human development.     

From Secrets of Life to the Life of Secrets: Tracing Genetic Knowledge as Genealogical Ethics in Biomedical Britain

I argue that the facts of a 'genealogical ethics' are built up over time as local moralities of information disclosure and non-disclosure. In the context of predictive genetic testing technologies, family members must discriminate between genetic information that they think is 'good' to know or make known, and knowledge that they think is 'bad' to tell and share with others. But attempts to deal with the kinship implications of genetic foreknowledge frequently entail unresolved processes of moral decision-making, both within and across the generations. Seen as embodied experiences of moral reckoning, these genealogical knowledge dilemmas also implicate a myriad of interests and divergent claims beyond the life of any one person. This article considers why a specifically anthropological formulation of 'genealogical ethics' challenges the conceptual premiss of individual autonomy underpinning the 'right to know' debates of mainstream Western bioethics.     

Systematics and biogeography of the genus Actenodia (Coleoptera: Meloidae: Mylabrini)

Abstract.  The genus Actenodia Laporte de Castelnau (Meloidae: Mylabrini) is revised. It includes 18 species distributed in the Mediterranean and Saharo-Arabian regions, and in eastern and southern Africa; A. carpanetoi sp.n. from Mozambique is described. The bionomics of the genus is summarized, according to a collection of records on phenology, elevation, habitat preference and host plants. A classification of the genus is proposed after a morphological cladistic analysis: one Afrotropical lineage clearly emerged with three distinct groups of species, whereas other taxa, all Palaearctic except A. mirabilis , remained unresolved. The analysis of the nuclear internal transcribed spacer 2 rDNA sequences of some Palaearctic and Afrotropical species supports the distinction of the Afrotropical lineage. The first instar larvae of two species, A. chrysomelina from southern Africa and A. denticulata from Arabia, are described for the first time and compared with two other Palaearctic species described previously; inferences from larval morphology are discussed. The adult morphology of all species is described briefly and illustrated, and a key to the species is provided, as well as locality data. Three new synonymies are proposed: A. extera Dvořák, 1993 syn.n. = A. septempunctata Baudi di Selve, 1878; A. sexpunctata Pic, 1948 syn.n . = A. curtula Fähraeus, 1870 ; A. unimaculata lanzai Kaszab, 1973 syn.n . = A. unimaculata Pic, 1908. The biogeography of the genus is discussed within the framework of a more general analysis of the disjunct distribution models.