Comparing Deliveries of Sterile Codling Moth (Lepidoptera: Tortricidae) by Two Types of Unmanned Aerial Systems and from the Ground.

New Zealand apple exports must meet strict phytosanitary measures to eliminate codling moth (Cydia pomonella Linnaeus) (Lepidoptera: Tortricidae) larval infestation. This study was part of a program attempting the localized eradication of codling moth within an isolated cluster of seven orchards (391 ha). A conventional management program of insecticide sprays and pheromone mating disruption was supplemented with weekly releases of sterile moths for 1-6 yr. Our objective was to compare the recapture rate of sterile moths following their release by four methods, and the efficiency of each system. The methods were the following: a fixed-wing unmanned plane flying ~40-45 m high at 70 km/h, an unmanned hexacopter travelling 20 m high at 25 km/h, and manually from the ground via bicycles or motor vehicles. The different release methods were used in different years or weeks. Sterile male moths were recaptured in grids of pheromone traps positioned throughout each orchard. The highest recapture rate followed delivery by hexacopter, then bicycle, vehicle, and plane. There was a 17-fold difference in catches between releases by hexacopter and plane, and sixfold between vehicle and plane in the same season. Bicycle delivery had a 3.5-fold higher recapture rate than the plane in different years. The wind-borne horizontal drift of moths was investigated as a possible explanation for the disparity of recaptures between the two aircraft delivery systems. The methods in ascending order of time per hectare for delivery were the following: plane and vehicle, hexacopter, then bicycle. The advantages and disadvantages of each moth delivery method are discussed.

Combined Effects of Mating Disruption, Insecticides, and the Sterile Insect Technique on Cydia pomonella in New Zealand.

Codling moth was introduced into New Zealand, and remains a critical pest for the apple industry. Apples exported to some markets require strict phytosanitary measures to eliminate the risk of larval infestation. Mating disruption and insecticide applications are the principal means of suppression in New Zealand. We tested the potential for the sterile insect technique (SIT) to supplement these measures to achieve local eradication or suppression of this pest. SIT was trialed in an isolated group of six integrated fruit production (IFP) orchards and one organic orchard (total 391 ha), using sterilized insects imported from Canada, with release by unmanned aerial vehicle and from the ground. Eradication was not achieved across the region, but a very high level of codling moth suppression was achieved at individual orchards after the introduction of sterile moths in combination with mating disruption and larvicides. After six years of releases, catches of wild codling moths at three IFP orchards (224 ha) were 90-99% lower than in 2013-2014, the year before releases began. Catches at three other IFP orchards (129 ha) decreased by 67-97% from the year before releases began (2015-2016), from lower initial levels. At a certified organic orchard with a higher initial population under only organic larvicides and mating disruption, by 2019-2020, there was an 81% reduction in wild moths capture from 2016-2017, the year before releases began.

Author Correction: Radiative recombination of confined electrons at the MgZnO/ZnO heterojunction interface.

A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

Radiative recombination of confined electrons at the MgZnO/ZnO heterojunction interface.

We investigate the optical signature of the interface in a single MgZnO/ZnO heterojunction, which exhibits two orders of magnitude lower resistivity and 10 times higher electron mobility compared with the MgZnO/Al2O3 film grown under the same conditions. These impressive transport properties are attributed to increased mobility of electrons at the MgZnO/ZnO heterojunction interface. Depth-resolved cathodoluminescence and photoluminescence studies reveal a 3.2 eV H-band optical emission from the heterointerface, which exhibits excitonic properties and a localization energy of 19.6 meV. The emission is attributed to band-bending due to the polarization discontinuity at the interface, which leads to formation of a triangular quantum well and localized excitons by electrostatic coupling.

Nanoselective area growth of defect-free thick indium-rich InGaN nanostructures on sacrificial ZnO templates.

Nanoselective area growth (NSAG) by metal organic vapor phase epitaxy of high-quality InGaN nanopyramids on GaN-coated ZnO/c-sapphire is reported. Nanopyramids grown on epitaxial low-temperature GaN-on-ZnO are uniform and appear to be single crystalline, as well as free of dislocations and V-pits. They are also indium-rich (with homogeneous 22% indium incorporation) and relatively thick (100 nm). These properties make them comparable to nanostructures grown on GaN and AlN/Si templates, in terms of crystallinity, quality, morphology, chemical composition and thickness. Moreover, the ability to selectively etch away the ZnO allows for the potential lift-off and transfer of the InGaN/GaN nanopyramids onto alternative substrates, e.g. cheaper and/or flexible. This technology offers an attractive alternative to NSAG on AlN/Si as a platform for the fabrication of high quality, thick and indium-rich InGaN monocrystals suitable for cheap, flexible and tunable light-emitting diodes.

Fifteen into Three Does Go: Morphology, Genetics and Genitalia Confirm Taxonomic Inflation of New Zealand Beetles (Chrysomelidae: Eucolaspis).

Eucolaspis Sharp 1886 is a New Zealand native leaf beetle genus (Coleoptera: Chrysomelidae: Eumolpinae) with poorly described species and a complex taxonomy. Many economically important fruit crops are severely damaged by these beetles. Uncertain species taxonomy of Eucolaspis is leaving any biological research, as well as pest management, tenuous. We used morphometrics, mitochondrial DNA and male genitalia to study phylogenetic and geographic diversity of Eucolaspis in New Zealand. Freshly collected beetles from several locations across their distribution range, as well as identified voucher specimens from major museum collections were examined to test the current classification. We also considered phylogenetic relationships among New Zealand and global Eumolpinae (Coleoptera: Chyrosomelidae). We demonstrate that most of the morphological information used previously to define New Zealand Eucolaspis species is insufficient. At the same time, we show that a combination of morphological and genetic evidence supports the existence of just 3 mainland Eucolaspis lineages (putative species), and not 5 or 15, as previously reported. In addition, there may be another closely related lineage (putative species) on an offshore location (Three Kings Islands, NZ). The cladistic structure among the lineages, conferred through mitochondrial DNA data, was well supported by differences in male genitalia. We found that only a single species (lineage) infests fruit orchards in Hawke's Bay region of New Zealand. Species-host plant associations vary among different regions.

Poverty, health and satellite-derived vegetation indices: their inter-spatial relationship in West Africa.

BACKGROUND: Previous analyses have shown the individual correlations between poverty, health and satellite-derived vegetation indices such as the normalized difference vegetation index (NDVI). However, generally these analyses did not explore the statistical interconnections between poverty, health outcomes and NDVI. METHODS: In this research aspatial methods (principal component analysis) and spatial models (variography, factorial kriging and cokriging) were applied to investigate the correlations and spatial relationships between intensity of poverty, health (expressed as child mortality and undernutrition), and NDVI for a large area of West Africa. RESULTS: This research showed that the intensity of poverty (and hence child mortality and nutrition) varies inversely with NDVI. From the spatial point-of-view, similarities in the spatial variation of intensity of poverty and NDVI were found. CONCLUSIONS: These results highlight the utility of satellite-based metrics for poverty models including health and ecological components and, in general for large scale analysis, estimation and optimisation of multidimensional poverty metrics. However, it also stresses the need for further studies on the causes of the association between NDVI, health and poverty. Once these relationships are confirmed and better understood, the presence of this ecological component in poverty metrics has the potential to facilitate the analysis of the impacts of climate change on the rural populations afflicted by poverty and child mortality.

Dengue: recent past and future threats.

This article explores four key questions about statistical models developed to describe the recent past and future of vector-borne diseases, with special emphasis on dengue: (1) How many variables should be used to make predictions about the future of vector-borne diseases? (2) Is the spatial resolution of a climate dataset an important determinant of model accuracy? (3) Does inclusion of the future distributions of vectors affect predictions of the futures of the diseases they transmit? (4) Which are the key predictor variables involved in determining the distributions of vector-borne diseases in the present and future? Examples are given of dengue models using one, five or 10 meteorological variables and at spatial resolutions of from one-sixth to two degrees. Model accuracy is improved with a greater number of descriptor variables, but is surprisingly unaffected by the spatial resolution of the data. Dengue models with a reduced set of climate variables derived from the HadCM3 global circulation model predictions for the 1980s are improved when risk maps for dengue's two main vectors (Aedes aegypti and Aedes albopictus) are also included as predictor variables; disease and vector models are projected into the future using the global circulation model predictions for the 2020s, 2040s and 2080s. The Garthwaite-Koch corr-max transformation is presented as a novel way of showing the relative contribution of each of the input predictor variables to the map predictions.

A Bayesian geostatistical Moran Curve model for estimating net changes of tsetse populations in Zambia.

For the first time a Bayesian geostatistical version of the Moran Curve, a logarithmic form of the Ricker stock recruitment curve, is proposed that is able to give an estimate of net change in population demographic rates considering components such as fertility and density dependent and density independent mortalities. The method is applied to spatio-temporally referenced count data of tsetse flies obtained from fly-rounds. The model is a linear regression with three components: population rate of change estimated from the Moran curve, an explicit spatio-temporal covariance, and the observation error optimised within a Bayesian framework. The model was applied to the three main climate seasons of Zambia (rainy--January to April, cold-dry--May to August, and hot-dry--September to December) taking into account land surface temperature and (seasonally changing) cattle distribution. The model shows a maximum positive net change during the hot-dry season and a minimum between the rainy and cold-dry seasons. Density independent losses are correlated positively with day-time land surface temperature and negatively with night-time land surface temperature and cattle distribution. The inclusion of density dependent mortality increases considerably the goodness of fit of the model. Cross validation with an independent dataset taken from the same area resulted in a very accurate estimate of tsetse catches. In general, the overall framework provides an important tool for vector control and eradication by identifying vector population concentrations and local vector demographic rates. It can also be applied to the case of sustainable harvesting of natural populations.

Using global maps to predict the risk of dengue in Europe.

This article attempts to quantify the risk to Europe of dengue, following the arrival and spread there of one of dengue's vector species Aedes (Stegomyia) albopictus. A global risk map for dengue is presented, based on a global database of the occurrence of this disease, derived from electronic literature searches. Remotely sensed satellite data (from NASA's MODIS series), interpolated meteorological data, predicted distribution maps of dengue's two main vector species, Aedes aegypti and Aedes albopictus, a digital elevation surface and human population density data were all used as potential predictor variables in a non-linear discriminant analysis modelling framework. One hundred bootstrap models were produced by randomly sub-sampling three different training sets for dengue fever, severe dengue (i.e. dengue haemorrhagic fever, DHF) and all-dengue, and output predictions were averaged to produce a single global risk map for each type of dengue. This paper concentrates on the all-dengue models. Key predictor variables were various thermal data layers, including both day- and night-time Land Surface Temperature, human population density, and a variety of rainfall variables. The relative importance of each may be shown visually using rainbow files and quantitatively using a ranking system. Vegetation Index variables (a common proxy for humidity or saturation deficit) were rarely chosen in the models. The kappa index of agreement indicated an excellent (dengue haemorrhagic fever, Cohen's kappa=0.79 ± 0.028, AUC=0.96 ± 0.007) or good fit of the top ten models in each series to the data (Cohen's kappa=0.73 ± 0.018, AUC=0.94 ± 0.007 for dengue fever and 0.74 ± 0.017, AUC=0.95 ± 0.005 for all dengue). The global risk map predicts widespread dengue risk in SE Asia and India, in Central America and parts of coastal South America, but in relatively few regions of Africa. In many cases these are less extensive predictions than those of other published dengue risk maps and arise because of the key importance of high human population density for the all-dengue risk maps produced here. Three published dengue risk maps are compared using the Fleiss kappa index, and are shown to have only fair agreement globally (Fleiss kappa=0.377). Regionally the maps show greater (but still only moderate) agreement in SE Asia (Fleiss kappa=0.566), fair agreement in the Americas (Fleiss kappa=0.325) and only slight agreement in Africa (Fleiss kappa=0.095). The global dengue risk maps show that very few areas of rural Europe are presently suitable for dengue, but several major cities appear to be at some degree of risk, probably due to a combination of thermal conditions and high human population density, the top two variables in many models. Mahalanobis distance images were produced of Europe and the southern United States showing the distance in environmental rather than geographical space of each site from any site where dengue currently occurs. Parts of Europe are quite similar in Mahalanobis distance terms to parts of the southern United States, where dengue occurred in the recent past and which remain environmentally suitable for it. High standards of living rather than a changed environmental suitability keep dengue out of the USA. The threat of dengue to Europe at present is considered to be low but sufficiently uncertain to warrant monitoring in those areas of greatest predicted environmental suitability, especially in northern Italy and parts of Austria, Slovenia and Croatia, Bosnia and Herzegovina, Serbia and Montenegro, Albania, Greece, south-eastern France, Germany and Switzerland, and in smaller regions elsewhere.

The influence of the wind in the Schmallenberg virus outbreak in Europe.

A model previously developed for the wind-borne spread by midges of bluetongue virus in NW Europe in 2006 is here modified and applied to the spread of Schmallenberg virus in 2011. The model estimates that pregnant animals were infected 113 days before producing malformed young, the commonest symptom of reported infection, and explains the spatial and temporal pattern of infection in 70% of the 3,487 affected farms, most of which were infected by midges arriving through downwind movement (62% of explained infections), or a mixture of downwind and random movements (38% of explained infections), during the period of day (1600-2100 h, i.e. dusk) when these insects are known to be most active. The main difference with Bluetongue is the higher rate of spread of SBV, which has important implications for disease control.

Statistical models for spatially explicit biological data.

Existing algorithms for predicting species' distributions sit on a continuum between purely statistical and purely biological approaches. Most of the existing algorithms are aspatial because they do not consider the spatial context, the occurrence of the species or conditions conducive to the species' existence, in neighbouring areas. The geostatistical techniques of kriging and cokriging are presented in an attempt to encourage biologists more frequently to consider them. Unlike deterministic spatial techniques they provide estimates of prediction errors. The assumptions and applications of common geostatistical techniques are presented with worked examples drawn from a dataset of the bluetongue outbreak in northwest Europe in 2006. Emphasis is placed on the importance and interpretation of weights in geostatistical calculations. Covarying environmental data may be used to improve predictions of species' distributions, but only if their sampling frequency is greater than that of the species' or disease data. Cokriging techniques are unable to determine the biological significance or importance of such environmental data, because they are not designed to do so.

A new algorithm quantifies the roles of wind and midge flight activity in the bluetongue epizootic in northwest Europe.

The 2006 bluetongue (BT) outbreak in northwestern Europe had devastating effects on cattle and sheep in that intensively farmed area. The role of wind in disease spread, through its effect on Culicoides dispersal, is still uncertain, and remains unquantified. We examine here the relationship between farm-level infection dates and wind speed and direction within the framework of a novel model involving both mechanistic and stochastic steps. We consider wind as both a carrier of host semio-chemicals, to which midges might respond by upwind flight, and as a transporter of the midges themselves, in a more or less downwind direction. For completeness, we also consider midge movement independent of wind and various combinations of upwind, downwind and random movements. Using stochastic simulation, we are able to explain infection onset at 94 per cent of the 2025 affected farms. We conclude that 54 per cent of outbreaks occurred through (presumably midge) movement of infections over distances of no more than 5 km, 92 per cent over distances of no more than 31 km and only 2 per cent over any greater distances. The modal value for all infections combined is less than 1 km. Our analysis suggests that previous claims for a higher frequency of long-distance infections are unfounded. We suggest that many apparent long-distance infections resulted from sequences of shorter-range infections; a 'stepping stone' effect. Our analysis also found that downwind movement (the only sort so far considered in explanations of BT epidemics) is responsible for only 39 per cent of all infections, and highlights the effective contribution to disease spread of upwind midge movement, which accounted for 38 per cent of all infections. The importance of midge flight speed is also investigated. Within the same model framework, lower midge active flight speed (of 0.13 rather than 0.5 m s(-1)) reduced virtually to zero the role of upwind movement, mainly because modelled wind speeds in the area concerned were usually greater than such flight speed. Our analysis, therefore, highlights the need to improve our knowledge of midge flight speed in field situations, which is still very poorly understood. Finally, the model returned an intrinsic incubation period of 8 days, in accordance with the values reported in the literature. We argue that better understanding of the movement of infected insect vectors is an important ingredient in the management of future outbreaks of BT in Europe, and other devastating vector-borne diseases elsewhere.

The arrival, establishment and spread of exotic diseases: patterns and predictions.

The impact of human activities on the principles and processes governing the arrival, establishment and spread of exotic pathogens is illustrated by vector-borne diseases such as malaria, dengue, chikungunya, West Nile, bluetongue and Crimean-Congo haemorrhagic fevers. Competent vectors, which are commonly already present in the areas, provide opportunities for infection by exotic pathogens that are introduced by travel and trade. At the same time, the correct combination of environmental conditions (both abiotic and biotic) makes many far-flung parts of the world latently and predictably, but differentially, permissive to persistent transmission cycles. Socioeconomic factors and nutritional status determine human exposure to disease and resistance to infection, respectively, so that disease incidence can vary independently of biological cycles.

Cis-regulatory analysis of the sea urchin pigment cell gene polyketide synthase.

The Strongylocentrotus purpuratus polyketide synthase gene (SpPks) encodes an enzyme required for the biosynthesis of the larval pigment echinochrome. SpPks is expressed exclusively in pigment cells and their precursors starting at blastula stage. The 7th-9th cleavage Delta-Notch signaling, required for pigment cell development, positively regulates SpPks. In previous studies, the transcription factors glial cell missing (SpGcm), SpGatae and kruppel-like (SpKrl/z13) have been shown to positively regulate SpPks. To uncover the structure of the Gene Regulatory Network (GRN) regulating the specification and differentiation processes of pigment cells, we experimentally analyzed the putative SpPks cis-regulatory region. We established that the -1.5kb region is sufficient to recapitulate the correct spatial and temporal expression of SpPks. Predicted DNA-binding sites for SpGcm, SpGataE and SpKrl are located within this region. The mutagenesis of these DNA-binding sites indicated that SpGcm, SpGataE and SpKrl are direct positive regulators of SpPks. These results demonstrate that the sea urchin GRN for pigment cell development is quite shallow, which is typical of type I embryo development.

Using satellite images of environmental changes to predict infectious disease outbreaks.

Recent events clearly illustrate a continued vulnerability of large populations to infectious diseases, which is related to our changing human-constructed and natural environments. A single person with multidrug-resistant tuberculosis in 2007 provided a wake-up call to the United States and global public health infrastructure, as the health professionals and the public realized that today's ease of airline travel can potentially expose hundreds of persons to an untreatable disease associated with an infectious agent. Ease of travel, population increase, population displacement, pollution, agricultural activity, changing socioeconomic structures, and international conflicts worldwide have each contributed to infectious disease events. Today, however, nothing is larger in scale, has more potential for long-term effects, and is more uncertain than the effects of climate change on infectious disease outbreaks, epidemics, and pandemics. We discuss advances in our ability to predict these events and, in particular, the critical role that satellite imaging could play in mounting an effective response.

Global data for ecology and epidemiology: a novel algorithm for temporal Fourier processing MODIS data.

BACKGROUND: Remotely-sensed environmental data from earth-orbiting satellites are increasingly used to model the distribution and abundance of both plant and animal species, especially those of economic or conservation importance. Time series of data from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensors on-board NASA's Terra and Aqua satellites offer the potential to capture environmental thermal and vegetation seasonality, through temporal Fourier analysis, more accurately than was previously possible using the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor data. MODIS data are composited over 8- or 16-day time intervals that pose unique problems for temporal Fourier analysis. Applying standard techniques to MODIS data can introduce errors of up to 30% in the estimation of the amplitudes and phases of the Fourier harmonics. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel spline-based algorithm that overcomes the processing problems of composited MODIS data. The algorithm is tested on artificial data generated using randomly selected values of both amplitudes and phases, and provides an accurate estimate of the input variables under all conditions. The algorithm was then applied to produce layers that capture the seasonality in MODIS data for the period from 2001 to 2005. CONCLUSIONS/SIGNIFICANCE: Global temporal Fourier processed images of 1 km MODIS data for Middle Infrared Reflectance, day- and night-time Land Surface Temperature (LST), Normalised Difference Vegetation Index (NDVI), and Enhanced Vegetation Index (EVI) are presented for ecological and epidemiological applications. The finer spatial and temporal resolution, combined with the greater geolocational and spectral accuracy of the MODIS instruments, compared with previous multi-temporal data sets, mean that these data may be used with greater confidence in species' distribution modelling.

Estimating the malaria risk of African mosquito movement by air travel.

BACKGROUND: The expansion of global travel has resulted in the importation of African Anopheles mosquitoes, giving rise to cases of local malaria transmission. Here, cases of 'airport malaria' are used to quantify, using a combination of global climate and air traffic volume, where and when are the greatest risks of a Plasmodium falciparum-carrying mosquito being importated by air. This prioritises areas at risk of further airport malaria and possible importation or reemergence of the disease. METHODS: Monthly data on climate at the World's major airports were combined with air traffic information and African malaria seasonality maps to identify, month-by-month, those existing and future air routes at greatest risk of African malaria-carrying mosquito importation and temporary establishment. RESULTS: The location and timing of recorded airport malaria cases proved predictable using a combination of climate and air traffic data. Extending the analysis beyond the current air network architecture enabled identification of the airports and months with greatest climatic similarity to P. falciparum endemic regions of Africa within their principal transmission seasons, and therefore at risk should new aviation routes become operational. CONCLUSION: With the growth of long haul air travel from Africa, the identification of the seasonality and routes of mosquito importation is important in guiding effective aircraft disinsection and vector control. The recent and continued addition of air routes from Africa to more climatically similar regions than Europe will increase movement risks. The approach outlined here is capable of identifying when and where these risks are greatest.

Global traffic and disease vector dispersal.

The expansion of global air travel and seaborne trade overcomes geographic barriers to insect disease vectors, enabling them to move great distances in short periods of time. Here we apply a coupled human-environment framework to describe the historical spread of Aedes albopictus, a competent mosquito vector of 22 arboviruses in the laboratory. We contrast this dispersal with the relatively unchanged distribution of Anopheles gambiae and examine possible future movements of this malaria vector. We use a comprehensive database of international ship and aircraft traffic movements, combined with climatic information, to remap the global transportation network in terms of disease vector suitability and accessibility. The expansion of the range of Ae. albopictus proved to be surprisingly predictable using this combination of climate and traffic data. Traffic volumes were more than twice as high on shipping routes running from the historical distribution of Ae. albopictus to ports where it has established in comparison with routes to climatically similar ports where it has yet to invade. In contrast, An. gambiae has rarely spread from Africa, which we suggest is partly due to the low volume of sea traffic from the continent and, until very recently, a European destination for most flights.

Climate change and the recent emergence of bluetongue in Europe.

Bluetongue, a devastating disease of ruminants, has historically made only brief, sporadic incursions into the fringes of Europe. However, since 1998, six strains of bluetongue virus have spread across 12 countries and 800 km further north in Europe than has previously been reported. We suggest that this spread has been driven by recent changes in European climate that have allowed increased virus persistence during winter, the northward expansion of Culicoides imicola, the main bluetongue virus vector, and, beyond this vector's range, transmission by indigenous European Culicoides species - thereby expanding the risk of transmission over larger geographical regions. Understanding this sequence of events may help us predict the emergence of other vector-borne pathogens.