Core and occasional species: A new way forward

Various methods have been used to divide communities into core species and occasional or satellite species. Some methods are somewhat arbitrary, and there is evidence that many communities are more multimodal than bimodal. They also tend to rely on having multiple years of data. A completely novel method is presented that not only has no requirement for long-term datasets but can divide communities into multiple groups. It is based on probability a species is present, calculated using Simpson's index and the sequential removal of species from the data. The sequential Simpson's index method was applied to species data from a grassland insect community. It was also applied to eleven other datasets that had been divided into core and occasional species in previously published studies. The new method was found not only to be consistent with previous core–occasional assessments but also able to identify multimodality in species abundance distributions. Although ideally used with a measure of persistence (frequency of occurrence) to rank species, community structure is consistently described even with only species abundance data. The method can be applied to short or long-term datasets and can help identify multimodality and provide valuable insight into how communities change in time or space

Hemiptera community and species responses to grassland sward islets

Sward islet is a term that has been used to describe a patch of longer vegetation in a pasture produced by a reduction in cattle grazing around their dung. They are known to affect the abundance and distribution of grassland arthropods. Hemiptera, like other groups, are found in higher densities within islets than the surrounding sward. Does this modify the community composition or is there just a density effect? Evidence from a paired (islets, non-islets) study at an Irish cattle-grazed site, would suggest that although a change in the density of species explains much of the patterns observed, some species respond to islets in different ways. Grassland Auchenorrhyncha were dominated by two genera, Javesella (mostly J. obscurella and to a lesser extent J. pellucida) and Macrosteles (mostly M. viridigriseus with some M. laevis and M. sexnotatus). The nymphs and to a lesser extent the adults, showed contrasting distribution patterns in relation to islets. Javesella were more common in the islets, whereas Macrosteles showed little difference between the two sub-habitats. Possible reasons for the difference in sub-habitat choice between these two Auchenorrhyncha taxa are discussed

The community ecology of Ribautodelphax imitans (RIBAUT, 1953) (Hemiptera: Delphacidae), a rare UK planthopper in a distinct grassland habitat

Ribautodelphax imitans Ribaut. (Hemiptera: Delphacidae) is a rare planthopper throughout its recorded range, and in the UK where it is afforded conservation priority status. Following the discovery of this species on a site in Cambridgeshire, UK in 2010 a study was designed to understand the population status of R. imitans and its place in the Auchenorrhyncha community structure. The species was found not to be rare within the community – in fact it was one of the most abundant delphacids on the site. However, the community was dominated by Javesella pellucida (Fab.). Although the reason for the general rarity of R. imitans on a national scale is still unclear, evidence from the community structure suggests that strong interspecies interactions between other species that it is phenologically synchronous with may be a factor

Can monophagous specialists mediate host plant choices in generalist planthoppers (Hemiptera: Delphacidae)?

A preference experiment was set up with two planthopper species (Hemiptera: Delphacidae) to test the influence of competition on host plant choice. The delphacid Javesella pellucida was chosen as a generalist and the rarer Ribautodelphax imitans as a monophagous specialist, which feeds on the grass, tall fescue Schedonorus arundinaceus. In the absence of the specialist, the generalist showed a marked preference for tall fescue. In some experiments, however, the introduction of the specialist resulted in a shift of preference to an alternative plant if the specialist was established prior to the introduction of the generalist. This experiment supports the hypothesis that specialist herbivores can potentially alter the host plant choices of generalists, which may lead to differing host plant use patterns in insect communities

Hemiptera records from Lake Spechtensee and from Southern Styria (Austria)

Hemiptera records gained in July 2015 in course of the 7th European Hemiptera Congress in Styria are presented. In total, 144 Auchenorrhyncha, 143 Heteroptera, 13 Psylloidea and 2 Aphididae species were collected. Ribautodelphax imitans (Delphacidae), Eurhadina saageri (Cicadellidae), Notonecta maculata (Notonectidae), Notonecta meridionalis (Notonectidae) and Polymerus cognatus (Miridae) are new records for Styria

The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015

What can I do for urban insect biodiversity? Applying lessons from ecological research

Introduction: In one sense, urban ecosystems might be thought of as unique in the range of challenges and opportunities for insects that they create. However, many of the ecological processes and anthropological effects they encapsulate can equally be found in other human dominated environments. So applying ecological lessons from both within and outside urban areas is important for insect conservation within our towns and cities. Methods: Here, I apply this principle by describing the entomological lessons relevant to urban insect conservation that I have learned from my work in both urban areas and agricultural systems. I will describe work on roundabouts and the importance of habitat management for insects. I will introduce you to some rare species in some urban green spaces. Results/Conclusion: I will show you what I have found in my studies of small-scale habitat heterogeneity, and consider how that might be applied to urban environments. I will finish by reflecting on the success, or otherwise, of my personal attempts to encourage insect biodiversity, and consider what I and we, as entomologists, need to be doing

A new species of the unusual leafhopper genus Phlogis Linnavuori (Hemiptera: Cicadellidae: Signoretiinae) from Uganda

Phlogis kibalensis sp. nov. from Kibale National Park, Uganda is described and illustrated. It differs from the other species of the genus known from Africa (P. mirabilis) in the shape of the aedeagus, in particular the shape of the sub-apical lateral processes, as well as in style shape and some aspects of colouration

Grassland Arthropod Species Richness in a Conventional Suckler Beef Production System and One Compatible with the Irish Agri-Environment Scheme (REPS)

Grassland management practices, such as grazing, strongly affects the biodiversity of grassland arthropods; increasing grazing intensity causes a general decline in species richness (Morris, 2000). One of the aims of the Rural Environment Protection Scheme (REPS) is to conserve and enhance biodiversity within Irish agricultural land (Feehan et al., 2002). In order to determine the effectiveness of this aspect of REPS, one must compare the relative biodiversity of grassland under REPS with that of conventionally managed grassland. Aiming to determine whether species richness was higher in REPS-compatible compared with a standard system of management, we measured the species richness of grassland arthropods within two contrasting grassland treatments within an experimental study of suckler beef production