Deconstructing intercontinental invasion pathway hypotheses of the Mediterranean fruit fly (Ceratitis capitata) using a Bayesian inference approach: are port interceptions and quarantine protocols successfully preventing new invasions?

Aim Knowledge of how effective interceptions and quarantine measures are in preventing new biological invasions is of paramount importance for maintaining ecosystem function in a rapidly changing world. Here, we determine current macrogeographic population structure and routes of invasion of the Mediterranean fruit fly (Ceratitis capitata) using genetic approaches and reconstruct and test invasion pathway hypotheses in a Bayesian framework. Location Africa, Australia, Greece, Guatemala and Madeira. Methods We sampled 323 C. capitata individuals from 14 locations worldwide and genotyped all individuals for 11 polymorphic microsatellite markers. We calculated measures of genetic diversity and determined population structure. Moreover, we reconstructed and tested eighteen invasion pathway scenarios in a Bayesian framework using ABC modelling. Results We show a decrease in genetic diversity outside the native range (Africa) into the introduced range (Australia, Greece, Guatemala and Madeira). The most likely invasion pathway scenario closely matched the historical records, with an initial colonization of Europe from Africa and a secondary colonization of Australia from Europe. Moreover, we show an introduction from Greece to the Americas and, finally, a back introduction into South Africa from Europe. Main conclusions Given the lack of new introductions into colonized (non-African) locations despite increasing trade, and apart from the initial invasion and establishment of the species outside of Africa, we conclude that quarantine and interception measures have been largely successful to date

Pathways to achieve universal household access to modern energy by 2030

A lack of access to modern energy impacts health and welfare and impedes development for billions of people. Growing concern about these impacts has mobilized the international community to set new targets for universal modern energy access. However, analyses exploring pathways to achieve these targets and quantifying the potential costs and benefits are limited. Here, we use two modelling frameworks to analyse investments and consequences of achieving total rural electrification and universal access to clean-combusting cooking fuels and stoves by 2030. Our analysis indicates that these targets can be achieved with additional investment of US$(2005)65-86 billion per year until 2030 combined with dedicated policies. Only a combination of policies that lowers costs for modern cooking fuels and stoves, along with more rapid electrification, can enable the realization of these goals. Our results demonstrate the critical importance of accounting for varying demands and affordability across heterogeneous household groups in both analysis and policy setting. While the investments required are significant, improved access to modern cooking fuels alone can avert between 0.6 and 1.8 million premature deaths annually in 2030 and enhance wellbeing substantially

What do near-term observations tell us about long-term developments in greenhouse gas emissions? A letter

Long-term scenarios developed by integrated assessment models are used in climate research to provide an indication of plausible long-term emissions of greenhouse gases and other radiatively active substances based on developments in the global energy system, land-use and the emissions associated with these systems The phenomena that determine these long-term developments (several decades or even centuries) are very different than those that operate on a shorter time-scales (a few years) Nevertheless, in the literature, we still often find direct comparisons between short-term observations and long-term developments that do not take into account the differing dynamics over these time scales In this letter, we discuss some of the differences between the factors that operate in the short term and those that operate in the long term We use long-term historical emissions trends to show that short-term observations are very poor indicators of long-term future emissions developments Based on this, we conclude that the performance of long-term scenarios should be evaluated against the appropriate, corresponding long-term variables and trends The research community may facilitate this by developing appropriate data sets and protocols that can be used to test the performance of long-term scenarios and the models that produce the

A comprehensive view on climate change: coupling of Earth system and integrated assessment models

There are several reasons to strengthen the cooperation between the integrated assessment (IA) and earth system (ES) modeling teams in order to better understand the joint development of environmental and human systems. This cooperation can take many different forms, ranging from information exchange between research communities to fully coupled modeling approaches. Here, we discuss the strengths and weaknesses of different approaches and try to establish some guidelines for their applicability, based mainly on the type of interaction between the model components (including the role of feedback), possibilities for simplification and the importance of uncertainty. We also discuss several important areas of joint IA–ES research, such as land use/land cover dynamics and the interaction between climate change and air pollution, and indicate the type of collaboration that seems to be most appropriate in each case. We find that full coupling of IA–ES models might not always be the most desirable form of cooperation, since in some cases the direct feedbacks between IA and ES may be too weak or subject to considerable process or scenario uncertainty. However, when local processes are important, it could be important to consider full integration. By encouraging cooperation between the IA and ES communities in the future more consistent insights can be developed

DNA barcoding and the documentation of alien species establishment on sub-Antarctic Marion Island

Invasive alien species constitute a substantial conservation challenge in the terrestrial sub-Antarctic. Management plans, for many of the islands in the region, call for the prevention, early detection, and management of such alien species. However, such management may be confounded by difficulties of identification of immatures, especially of holometabolous insects. Here we show how a DNA barcoding approach has helped to overcome such a problem associated with the likely establishment of an alien moth species on Marion Island. The discovery of unidentifiable immatures of a noctuid moth species, 5 km from the research station, suggested that a new moth species had colonized the island. Efforts to identify the larvae by conventional means or by rearing to the adult stage failed. However, sequencing of 617 bp of the mitochondrial cytochrome oxidase subunit I gene, and comparison of the sequence data with sequences on GENBANK and the barcoding of life database enabled us to identify the species as Agrotis ipsilon (Hufnagel), a species of which adults had previously been found regularly at the research station. Discovery of immatures of this species, some distance from the research station, suggests that a population may have established. It is recommended that steps to be taken to eradicate the species from Marion Island. © 2008 Springer-Verlag.Articl

Model projections for household energy use in developing countries

The residential sector plays an important role in the energy system of developing countries. In this paper we introduce a bottom up simulation model for household energy use. The model describes energy demand for several end-use functions based on a set of physical drivers, such as floor space and heating degree days. The model also recognizes different population groups: i.e. urban and rural households, each distinguishing five income quintiles. The model is applied to analyze possible future developments of residential energy use in five developing world regions: India, China, South East Asia, South Africa and Brazil. We find that in each of these regions cooking is currently the main end-use function, but that other functions, such as space heating, cooling and appliances become more important. At the same time, energy consumption slowly shifts towards modern fuels. The model also shows that climate policy can reduce residential energy emissions, but could also slow down the energy transition away from traditional fuels in low income classes

A molecular identification approach for five species of mealybug (Hemiptera: Pseudococcidae) on citrus fruit exported from South Africa

Within South Africa, millions of rands in revenue are generated annually from the export of fruit produce. Citrus fruits are exported mostly to the U.S.A., South Korea and China. These countries have strict biosecurity laws in place which prohibit the import of specific problem insects, including several species of mealybug (Hemiptera: Pseudococcidae). Although the adult females for most species of mealybug are routinely identified through morphological keys, eggs and nymphs (crawlers) are more problematic. As such, export consignments are regularly refused based on the presence of unidentifiable mealybug nymphs or eggs. The aim of this paper is to report an easy, user-friendly molecular laboratory technique to accurately identify mealybug eggs and crawlers to species level. We amplified and sequenced a 749 bp portion of the mitochondrial DNA cytochrome oxidase subunit one (COI) gene. Phylogenetic trees indicated that the five species included here (Planococcus citri (Risso), Paracoccus burnerae (Brain), Pseudococcus longispinus (Targioni-Tozzetti), Ps. calceolariae (Maskell) and Ps. viburni (Signoret)) are reciprocally monophyletic and follow the 10× rule where sequence divergences separating species are an order of magnitude larger than divergences within species. As such, DNA can be extracted from eggs, crawlers or adults; analysed and compared with reference data, and unequivocally assigned to one of the five species.Articl