Are aliens threatening European aquatic coastal ecosystems?

Inshore waters of European coasts have accumulated a high share of non-indigenous species, where a changeable palaeoenvironment has caused low diversity in indigenous biota. Also strongly transformed modern coastal ecosystems seem to assimilate whatever species have been introduced and tolerate the physical regime. Adding non-native species does not have any directional predetermined effects on recipient coastal ecosystems. The status of being a non-native rather refers to a position in evolutionary history than qualify as an ecological category with distinct and consistent properties. Effects of invaders vary between habitats and with the phase of invasion and also with shifting ambient conditions. Although aliens accelerate change in European coastal biota, we found no evidence that they generally impair biodiversity and ecosystem functioning. More often, invaders expand ecosystem functioning by adding new ecological traits, intensifying existing ones and increasing functional redundancy.     

Are Honeydew/Sap-feeding Butterflies (Lepidoptera: Rhopalocera) Affected by Particulate Air-pollution?

Air-pollution has frequently been suggested as a cause of the decline of some butterfly species: a suggestion based mainly on lowered species richness close to industrial areas in Europe. There have been frequent calls, in vain, for research on the direct effect of air-pollution on Lepidoptera, recent research being confined to the indirect role via climate change.Based on studies of the species loss and natural recolonisation of Epping Forest (a large woodland area close to London, UK) I suggest that those species feeding as adults on sugar-rich fluids direct from the surface of trees or leaves (i.e. aphid honeydew on leaves or sap-runs on tree-trunks) were affected by particulate air-pollution.Species loss was high during the period of maximum smoke emissions. Since 1950 five species have recolonised naturally, of which four are honeydew feeders. It is possible that high levels of particulate air-pollution caused the extinction of butterflies feeding on honeydew from polluted leaves. Predictions are made which will allow this hypothesis to be tested.     

Are populations of European earwigs,Forficula auricularia,density dependent?

Biocontrol using naturally occurring predators is often limited by population parameters of those predators. Earwigs, Forficula auricularia L. (Dermaptera: Forficulidae), are important predators in fruit orchards. They are capable of suppressing outbreaks of pest species, such as pear psyllid and various apple aphid species. Earwigs therefore play an important role in integrated pest management in fruit orchards and are essential in organic top fruit cultures. However, earwig populations are very unstable, showing large between-year variation in densities, which limits their practical use. Extensive knowledge of regulating processes of populations is therefore crucial for efficient orchard management. A 2-year phenological study in several apple and pear orchards in Belgium showed a significant displacement of third instars during the second brood in relation to the presence of adults. We also observed a yearly population crash at the time of moulting into adults. This population decrease was correlated with earwig numbers at peak density. The crash occurred at lower earwig densities in apple orchards than in pear orchards. Six possible regulating mechanisms for this density-dependent decrease are discussed: (1) migration, (2) pesticides or orchard management, (3) starvation, (4) pathogens, (5) parasites and parasitoids, and (6) predation or cannibalism. If we can identify these regulating processes, specific management activities could be developed to prevent the population crash, hereby increasing population densities in the orchards.     

Does Extensive Grazing Benefit Butterflies in Coastal Dunes?

Grazing at low stocking rates has become a common management practice in nature restoration projects in the Netherlands. However, detailed knowledge of grazing impact is often poor, in particular for invertebrates. This study addressed the impact of extensive grazing on butterflies. Butterflies are critical indicators of habitat quality for many plant and animal species. We compared monitoring data from 1992 to 1996 for calcareous coastal dune areas in the Netherlands with different management: 11 grazed areas, 7 ungrazed areas and 4 areas managed by annual cutting. Grazing typically concerned year‐round grazing by cattle and/or ponies, at low stocking rates (0.05–0.26 head ha^?1 yr^?1). Butterfly abundance was related to species composition and structure of the vegetation. Changes in butterfly abundance were positive in grazed and ungrazed areas compared to cut areas. Species richness was not affected by management, but individual species differed in their response. Species from open grassland benefited most from grazing, particularly Issoria lathonia (Queen of Spain Fritillary) and Lycaena phlaeas (Small Copper). No clear negative effects of grazing were observed, but species occurrence was not always positively related to the environmental characteristics associated with grazing. In the long run, even lower stocking rates might prove more beneficial to the butterfly community as a whole. Four of the more frequently observed species, I. lathonia, Hipparchia semele (Grayling), Pyrgus malvae (Grizzled Skipper) and Aricia agestis (Brown Argus), are listed as threatened to susceptible in the Netherlands. All were apparently favored by grazing. It is concluded that extensive grazing has good potential to enhance butterfly diversity in restoration projects.     

Application of European biomonitoring techniques in China: Are they a useful tool?

This paper focuses on the application of various biomonitoring techniques in China. We report a study in the Pearl River Basin (Guangzhou) based on the application of diatom indices as well as a study on the waterways in Wuhan based on evaluation of toxicity (using phytotoxicity, Daphnia magna and Microtox™ tests) and the Extended Biotic Index (EBI). Regarding the diatom indices, acceptable results were obtained based on comparison of the chemical water quality level and the European and Japanese indices, despite a lack of taxonomic information. The toxicity tests applied to the Wuhan waterways (Yangtze and Han Rivers) produced interesting results and can be considered to represent a useful tool for water pollution control in this area. Application of the EBI in Wuhan produced results that were contradictory to the toxicological analyses, as there were no indications of toxicity, whereas EBI indicated poor water quality. It can be concluded that in principle, certain European biological indicators can be considered to represent feasible tools to be applied in China. However, further studies will have to be carried out to develop bioindices based on Chinese data sets. The use of bioindices based on macroinvertebrates is limited to less polluted and smaller rivers with a lithic river substratum, whereas diatom indices are also applicable under extreme conditions (e.g., under high pollution loads or in large river streams with sandy riverbed sediments through installing artificial substrates).     

Butterflies of the Cambrian benthos? Shield position in bradoriid arthropods

Mode of preservation and method of recovery strongly influences our understanding of the life habits of extinct organisms. Bradoriid arthropods were abundant, and diverse members of early Cambrian ecosystems and most life reconstructions display these animals with the two shields of the carapace open in a ‘butterfly’ configuration. This favoured reconstruction is largely based on the abundance of ‘crack‐out’ specimens preserved in this position (e.g. Kunmingella from the early Cambrian of China). In contrast, large collections of acid processed bradoriids from the Arrowie Basin of South Australia (Cambrian Stage 3) are preserved with a narrow gape at the ventral margin or completely closed with the carapace folded along the dorsal midline. The relative abundance of conjoined, closed (or partially closed) specimens from the lower Cambrian Hawker Group succession suggests that at least some bradoriid taxa were capable of withdrawing appendages and tightly closing the shields, challenging the common view that the majority of bradoriids usually held their carapaces open in a ‘butterfly’ configuration during life. New data show that layers of the bradoriid carapace are continuous through the dorsal fold with no evidence for complex articulating structures as in ostracod hinges. The relatively pliable, sclerotized or lightly mineralized calcium phosphate composition of the carapace and the simple, flexible dorsal fold facilitated opening and closing of the shields. Despite not being closely related, ostracods share close biomechanical and ecological similarities with bradoriids. The evolution of more complex articulating hinge structures – together with well‐developed musculature – in ostracods during the Early Ordovician, may have provided more efficient means for shield articulation and movement, thus promoting the ecological success of ostracods throughout the Phanerozoic.     

Are species sets?

I construe the question ‘Are species sets?’ as a question about whether species can be conceived of as sets, as the term ‘set’ is understood by contemporary logicians. The question is distinct from the question ‘Are species classes?’: The conception of classes invoked by Hull and others differs from the logician's conception of a set. I argue that species can be conceived of as sets, insofar as one could identify a set with any given species and that identification would satisfy three desiderata: the set would be a set of organisms, the identification would be apposite, and the identification would permit the formulation of statements about species in set-theoretic terms. One cannot, however, identify a species with any given set. Understanding the claim that species are sets in this way enables one to understand better the dispute between some who accept the claim (e.g., Kitcher 1984, 1987) and some who apparently reject it (e.g., Mayr 1987).     

Are kea prosocial?

Prosocial behaviour is widespread in humans, but evidence for its occurrence in other species is mixed. We presented a parrot species, the kea (Nestor notabilis) with a series of experiments to test whether they exhibit prosocial tendencies. Across the first round of testing, in our first condition, two of the four kea acted prosocially, as they preferred to choose a prosocial token which rewarded both themselves and a partner, rather than a token that rewarded only themselves. Three of the four kea then showed a preference for the prosocial token in a second condition where they alternated taking turns with a partner. However, no kea showed a decrease in the third yoked control condition in which the experimenter replicated the token choice made by the partner in the previous alternating trials. This yoked condition was used to dissociate truly reciprocal behaviour, whereby the actor made choices based on their partner's choices, from a response to the amount of rewards conferred to the partner. Finally, three of the four kea continued to choose the prosocial token in the fourth asocial control condition where no partner was present. However, in round two of testing, one kea changed its token choices to a similar pattern to that expected if kea are prosocial, in that it preferred the prosocial token in the initial condition, showed a trend for the prosocial token when turns were alternated, but chose at chance in the yoked and asocial conditions. This study therefore found no evidence of spontaneous reciprocity in kea but further testing is required before we can conclude that kea are not capable of prosocial behaviour at all.     

Are mAbs different?

Apart from the nifty science behind their development, are monoclonal antibodies (mAbs) different than other new technologies? As highlighted by Cohen and Wilson in their interesting new paper, mAbs are distinctive from most traditional pharmaceuticals in some ways: their relatively high prices; their high costs of development; their mode of administration; the fact that, unlike many other drugs, they offer disease modification not simply symptomatic relief; the frequency of supplemental indications and off-label use – much of it recognized in drug compendia and reimbursable; and the lack of a clear pathway for their generic substitution.