Risk of spread of the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) in Ghana.

The impact of invasive species on biodiversity, food security and economy is increasingly noticeable in various regions of the globe as a consequence of climate change. Yet, there is limited research on how climate change affects the distribution of the invasive Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera:Liviidae) in Ghana. Using maxnet package to fit the Maxent model in R software, we answered the following questions; (i) what are the main drivers for D. citri distribution, (ii) what are the D. citri-specific habitat requirements and (iii) how well do the risk maps fit with what we know to be correctly based on the available evidence?. We found that temperature seasonality (Bio04), mean temperature of warmest quarter (Bio10), precipitation of driest quarter (Bio17), moderate resolution imaging spectroradiometer land cover and precipitation seasonality (Bio15), were the most important drivers of D. citri distribution. The results follow the known distribution records of the pest with potential expansion of habitat suitability in the future. Because many invasive species, including D. citri, can adapt to the changing climates, our findings can serve as a guide for surveillance, tracking and prevention of D. citri spread in Ghana.

Seasonal variation and risks of potentially toxic elements in agricultural lowlands of central Cameroon.

Intensive urban agriculture is expanding in Cameroon, which increases the risks of environmental pollution, particularly in the lowlands. This study assessed the seasonal characteristics of some potentially toxic elements and their ecological risks during the dry and wet seasons in urban agricultural soils in four lowlands in Yaoundé. The area and seasonal variation of some potentially toxic elements (Cu, Pb, Zn, Cd, Cr, and Ni) were evaluated using mixed-effects modeling. The pollution status of these elements in the soil was evaluated and interpreted using parameters such as the single pollution (SPI) and Nemerow composite pollution (NCPI) indices. In addition, the effect of these metals in the environment was assessed using the potential ecological risk index (PERI). The distribution of all the studied elements showed an area effect, while a seasonal effect was only noticeable for Cu. The concentration of Cu, Pb, and Zn was higher than the recommended threshold values in one of the areas sampled, while Cr exceeded these threshold values in all areas during both seasons. Cr exhibited the highest SPI among all studied elements during the dry and wet seasons in all areas. Except for the NCPI in one area, where grade V (strong) soil pollution was recorded during the wet season, the soil from all the study areas exhibited a slight pollution level (grade III) with a mean NCPI between 1 and 2. The PERI value of all areas was below the reference values during both seasons, suggesting an overall low potential contamination risk of the soil biota. The results indicate that preventive action to limit the heavy metal contamination in the lowlands of Yaoundé needs to be taken, for instance, through the promotion of more sustainable use of agrochemicals like pesticides and mineral fertilizers.

School water, sanitation, and hygiene (WaSH) intervention to improve malnutrition, dehydration, health literacy, and handwashing: a cluster-randomised controlled trial in Metro Manila, Philippines.

BACKGROUND: The impacts of multicomponent school water, sanitation, and hygiene (WaSH) interventions on children's health are unclear. We conducted a cluster-randomized controlled trial to test the effects of a school WaSH intervention on children's malnutrition, dehydration, health literacy (HL), and handwashing (HW) in Metro Manila, Philippines. METHODS: The trial lasted from June 2017 to March 2018 and included children, in grades 5, 6, 7, and 10, from 15 schools. At baseline 756 children were enrolled. Seventy-eight children in two clusters were purposively assigned to the control group (CG); 13 clusters were randomly assigned to one of three intervention groups: low-intensity health education (LIHE; two schools, n = 116 children), medium-intensity health education (MIHE; seven schools, n = 356 children), and high-intensity health education (HIHE; four schools, n = 206 children). The intervention consisted of health education (HE), WaSH policy workshops, provision of hygiene supplies, and WaSH facilities repairs. Outcomes were: height-for-age and body mass index-for-age Z scores (HAZ, BAZ); stunting, undernutrition, overnutrition, dehydration prevalence; HL and HW scores. We used anthropometry to measure children's physical growth, urine test strips to measure dehydration, questionnaires to measure HL, and observation to measure HW practice. The same measurements were used during baseline and endline. We used multilevel mixed-effects logistic and linear regression models to assess intervention effects. RESULTS: None of the interventions reduced undernutrition prevalence or improved HAZ, BAZ, or overall HL scores. Low-intensity HE reduced stunting (adjusted odds ratio [aOR] 0.95; 95% CI 0.93 to 0.96), while low- (aOR 0.57; 95% CI 0.34 to 0.96) and high-intensity HE (aOR 0.63; 95% CI 0.42 to 0.93) reduced overnutrition. Medium- (adjusted incidence rate ratio [aIRR] 0.02; 95% CI 0.01 to 0.04) and high-intensity HE (aIRR 0.01; 95% CI 0.00 to 0.16) reduced severe dehydration. Medium- (aOR 3.18; 95% CI 1.34 to 7.55) and high-intensity HE (aOR 3.89; 95% CI 3.74 to 4.05) increased observed HW after using the toilet/urinal. CONCLUSION: Increasing the intensity of HE reduced prevalence of stunting, overnutrition, and severe dehydration and increased prevalence of observed HW. Data may be relevant for school WaSH interventions in the Global South. Interventions may have been more effective if adherence was higher, exposure to interventions longer, parents/caregivers were more involved, or household WaSH was addressed. TRIAL REGISTRATION NUMBER: DRKS00021623.

Orbiviruses in biting midges and mosquitoes from the Zambezi region, Namibia.

The genus Orbivirus includes a variety of pathogenic viruses that are transmitted by biting midges, mosquitoes and ticks. Some of the economically most relevant orbiviruses are endemic to Namibia, like the livestock-pathogenic Bluetongue and African horse sickness viruses. Here, we assessed the diversity of orbiviruses circulating in the Zambezi region of north-eastern Namibia. A total of 10 250 biting midges and 10 206 mosquitoes were collected and screened for orbivirus infections. We identified Palyam virus (PALV) in a pool of biting midges (Culicoides sp.) sampled in the Wuparo Conservancy and three strains of Corriparta virus (CORV) in Culex sp. mosquitoes sampled in Mudumu National Park and the Mashi Conservancy. This is, to our knowledge, the first detection of PALV and CORV in Namibia. Both viruses infect vertebrates but only PALV has been reported to cause disease. PALV can cause foetal malformations and abortions in ruminants. Furthermore, a novel orbivirus, related to Kammavanpettai virus from India and Umatilla virus from North America, was discovered in biting midges (Culicoides sp.) originating from Mudumu National Park and tentatively named Mudumu virus (MUMUV). Complete genomes of PALV, CORV and MUMUV were sequenced and genetically characterized. The Namibian CORV strain showed 24.3 % nucleotide divergence in its subcore shell gene to CORV strains from Australia, indicating that African CORV variants vary widely from their Australian relatives. CORV was isolated in cell culture and replicated to high titres in mosquito and duck cells. No growth was found in rodent and primate cells. The data presented here show that diverse orbiviruses are endemic to the Zambezi region. Further studies are needed to assess their effects on wildlife and livestock.

Emerging properties of malaria transmission and persistence in urban Accra, Ghana: evidence from a participatory system approach.

BACKGROUND: Several studies that aim to enhance the understanding of malaria transmission and persistence in urban settings failed to address its underlining complexity. This study aims at doing that by applying qualitative and participatory-based system analysis and mapping to elicit the system's emergent properties. METHODS: In two experts' workshops, the system was sketched and refined. This system was represented through a causal loop diagram, where the identification of leverage points was done using network analysis. RESULTS: 45 determinants interplaying through 56 linkages, and three subsystems: urbanization-related transmission, infection-prone behaviour and healthcare efficiency, and Plasmodium resistance were identified. Apart from the number of breeding sites and malaria-positive cases, other determinants such as drug prescription and the awareness of householders were identified by the network analysis as leverage points and emergent properties of the system of transmission and persistence of malaria. CONCLUSION: Based on the findings, the ongoing efforts to control malaria, such as the use of insecticide-treated bed nets and larvicide applications should continue, and new ones focusing on the public awareness and malaria literacy of city dwellers should be included. The participatory approach strengthened the legitimacy of the recommendations and the co-learning of participants.

Sand Fly-Associated Phlebovirus with Evidence of Neutralizing Antibodies in Humans, Kenya.

We describe a novel virus, designated Ntepes virus (NPV), isolated from sand flies in Kenya. NPV has the characteristic phlebovirus trisegmented genome architecture and is related to, but distinct from, Gabek Forest phlebovirus. Diverse cell cultures derived from wildlife, livestock, and humans were susceptible to NPV, with pronounced permissiveness in swine and rodent cells. NPV infection of newborn mice caused rapid and fatal illness. Permissiveness for NPV replication in sand fly cells, but not mosquito cells, suggests a vector-specific adaptation. Specific neutralizing antibodies were found in 13.9% (26/187) of human serum samples taken at the site of isolation of NPV as well as a disparate site in northeastern Kenya, suggesting a wide distribution. We identify a novel human-infecting arbovirus and highlight the importance of rural areas in tropical Africa for arbovirus surveillance as well as extending arbovirus surveillance to include hematophagous arthropods other than mosquitoes.

Maize Cropping Systems Mapping Using RapidEye Observations in Agro-Ecological Landscapes in Kenya.

Cropping systems information on explicit scales is an important but rarely available variable in many crops modeling routines and of utmost importance for understanding pests and disease propagation mechanisms in agro-ecological landscapes. In this study, high spatial and temporal resolution RapidEye bio-temporal data were utilized within a novel 2-step hierarchical random forest (RF) classification approach to map areas of mono- and mixed maize cropping systems. A small-scale maize farming site in Machakos County, Kenya was used as a study site. Within the study site, field data was collected during the satellite acquisition period on general land use/land cover (LULC) and the two cropping systems. Firstly, non-cropland areas were masked out from other land use/land cover using the LULC mapping result. Subsequently an optimized RF model was applied to the cropland layer to map the two cropping systems (2nd classification step). An overall accuracy of 93% was attained for the LULC classification, while the class accuracies (PA: producer's accuracy and UA: user's accuracy) for the two cropping systems were consistently above 85%. We concluded that explicit mapping of different cropping systems is feasible in complex and highly fragmented agro-ecological landscapes if high resolution and multi-temporal satellite data such as 5 m RapidEye data is employed. Further research is needed on the feasibility of using freely available 10-20 m Sentinel-2 data for wide-area assessment of cropping systems as an important variable in numerous crop productivity models.

Taxonomy, Ecology, and Management of Native and Exotic Fruit Fly Species in Africa.

Horticulture is one of the most important agricultural subsectors in Africa, providing income, creating employment opportunities, and enhancing food and nutritional security. However, tephritid fruit flies are responsible for both direct and indirect losses, with alien invasive species often having the most severe ecological and economic impact. In the past 20 years, systematic analysis of tephritids has provided comparative information on taxonomy, synonymy, and character-state differentiation. New molecular techniques are now available for identifying species, reconstructing phylogenies, and studying population genetic structures. Research on biology, host range and shifts, thermotolerance, and demography has provided useful information for developing predictive and ecological niche models to guide management methods. In recent years, the responses of various species to attractants have been documented. Several suppression methods, including the release of coevolved parasitoid species targeting invasives, have been promoted within the context of integrated pest management, leading to improvement in the quality and quantity of fruits and vegetables produced. However, there is still the need for wide-scale availability of these technologies to smallholder growers across Africa.

Identification of methyl farnesoate from the hemolymph of insects.

Methyl farnesoate, [methyl (2E,6E)-3,7,11-trimethyldodeca-2,6,10-trienoate (1)] has not been thought be present in the hemolymph of insects, although it is the immediate biosynthetic precursor of the circulating insect hormone juvenile hormone III (methyl (2E,6E)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate) (2). Compound 1 was identified from the hemolymph obtained from five orders of insects. Identification of 1 from the American bird grasshopper was facilitated using both electron impact and chemical-ionization GC-MS, GC-FTIR, and 2D NMR techniques. The identifications from other insects were made using GC-MS, and the amounts of all were quantified using LIM-CI-GC-MS. The ratios of 1 and 2 varied in these insects during different developmental stages. The present results underscore the need for further studies on methyl farnesoate (1) as a circulating hormone in insects.

Combining temperature-dependent life table data into Insect Life Cycle Model to forecast fall armyworm Spodoptera frugiperda (JE Smith) distribution in maize agro-ecological zones in Africa.

The fall armyworm (FAW), Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), an invasive agricultural pest, has significantly impacted crop yields across Africa. This study investigated the relationship between temperature and FAW life history traits, employing life cycle modeling at temperatures of 20, 25, 28, 30, and 32°C. The development time for eggs, larvae, and pupae varied from 0-3 days, 10-18 days, and 7-16 days, respectively. The optimal temperature range for immature stage survival and female fecundity was identified as 21-25°C, with the intrinsic rate of increase (rm) and gross reproductive rate (GRR) peaking at 25-28°C. Model validation confirmed the accuracy of these findings. The research further projected the Establishment Risk Index (ERI), Activity Index (AI), and Generation Index (GI) for FAW under current and future climates (2050 and 2070) using RCP 2.6 and RCP 8.5 scenarios. Results indicate that RCP 2.6 leads to a reduction in high-risk FAW areas, particularly in central Africa. Conversely, RCP 8.5 suggests an increase in areas conducive to FAW activity. These findings highlight the impact of climate policy on pest dynamics and the importance of incorporating climatic factors into pest management strategies. The study predicts a potential decrease in FAW prevalence in West Africa by 2070 under aggressive climate mitigation, providing a basis for future FAW management approaches.

Urbanization and malaria have a contextual relationship in endemic areas: A temporal and spatial study in Ghana.

In West Africa, malaria is one of the leading causes of disease-induced deaths. Existing studies indicate that as urbanization increases, there is corresponding decrease in malaria prevalence. However, in malaria-endemic areas, the prevalence in some rural areas is sometimes lower than in some peri-urban and urban areas. Therefore, the relationship between the degree of urbanization, the impact of living in urban areas, and the prevalence of malaria remains unclear. This study explores this association in Ghana, using epidemiological data at the district level (2015-2018) and data on health, hygiene, and education. We applied a multilevel model and time series decomposition to understand the epidemiological pattern of malaria in Ghana. Then we classified the districts of Ghana into rural, peri-urban, and urban areas using administratively defined urbanization, total built areas, and built intensity. We converted the prevalence time series into cross-sectional data for each district by extracting features from the data. To predict the determinant most impacting according to the degree of urbanization, we used a cluster-specific random forest. We find that prevalence is impacted by seasonality, but the trend of the seasonal signature is not noticeable in urban and peri-urban areas. While urban districts have a slightly lower prevalence, there are still pockets with higher rates within these regions. These areas of high prevalence are linked to proximity to water bodies and waterways, but the rise in these same variables is not associated with the increase of prevalence in peri-urban areas. The increase in nightlight reflectance in rural areas is associated with an increased prevalence. We conclude that urbanization is not the main factor driving the decline in malaria. However, the data indicate that understanding and managing malaria prevalence in urbanization will necessitate a focus on these contextual factors. Finally, we design an interactive tool, 'malDecision' that allows data-supported decision-making.

Changes in eating habits and lifestyle during the first year of the COVID-19 pandemic across metropolitan regions in Brazil and Germany: A survey-based cross-sectional study.

COVID-19 caused profound societal changes to cope rapidly with the new circumstances. The food market changed its quantity, quality, form, and frequency dynamics. Consequently, food-eating habits and lifestyles like physical exercise likely experienced changes. An online-based survey was conducted between June 2020 and January 2021 in the metropolitan regions of Rhine Ruhr Metropolis (RRM), Greater São Paulo (GSP), other metropolitan regions in São Paulo state (oMRSP), other Brazilian metropolitan regions (oBRMR), and the remaining urban areas in both countries (oUA), representing different contexts of Brazil and Germany. We assessed self-reported changes in physical activity level, diet quality, self-reported eating habits, and buying groceries during the first year of the pandemic. In Germany, indoor and outdoor activities increased for 34% of the respondents, while in Brazil, there was a decrease in physical activity for 50% of the participants. The Healthy Eating Index (HEI) scored higher among Brazilians (16.8) than Germans (15.2) on a 0-29 HEI scale. Increased awareness of healthy and sustainable eating habits was observed in GSP (0.7), oMRSP (0.63), oBRMR (0.7), and oUA (0.68) on a scale from no change (0) to change (1). In RRM, an increase in convenience foods was noticed (0.86). Participants reported discomfort with food purchasing due to hygiene measures and avoided going to the supermarket (0.7 on average in Brazil and 0.58 for females using the same 0-1 scale). Also, food supply at the grocery shops was reported to be often unavailable and in lower quantities. A real-time assessment of self-reported changes in eating habits and lifestyle during the lockdown in 2020 in different contexts is insightful for rethinking strategies to improve conditions in the post-COVID-19 era and prepare for future pandemics.

Shifts in malaria vector species composition and transmission dynamics along the Kenyan coast over the past 20 years.

BACKGROUND: Over the past 20 years, numerous studies have investigated the ecology and behaviour of malaria vectors and Plasmodium falciparum malaria transmission on the coast of Kenya. Substantial progress has been made to control vector populations and reduce high malaria prevalence and severe disease. The goal of this paper was to examine trends over the past 20 years in Anopheles species composition, density, blood-feeding behaviour, and P. falciparum sporozoite transmission along the coast of Kenya. METHODS: Using data collected from 1990 to 2010, vector density, species composition, blood-feeding patterns, and malaria transmission intensity was examined along the Kenyan coast. Mosquitoes were identified to species, based on morphological characteristics and DNA extracted from Anopheles gambiae for amplification. Using negative binomial generalized estimating equations, mosquito abundance over the period were modelled while adjusting for season. A multiple logistic regression model was used to analyse the sporozoite rates. RESULTS: Results show that in some areas along the Kenyan coast, Anopheles arabiensis and Anopheles merus have replaced An. gambiae sensu stricto (s.s.) and Anopheles funestus as the major mosquito species. Further, there has been a shift from human to animal feeding for both An. gambiae sensu lato (s.l.) (99% to 16%) and An. funestus (100% to 3%), and P. falciparum sporozoite rates have significantly declined over the last 20 years, with the lowest sporozoite rates being observed in 2007 (0.19%) and 2008 (0.34%). There has been, on average, a significant reduction in the abundance of An. gambiae s.l. over the years (IRR = 0.94, 95% CI 0.90-0.98), with the density standing at low levels of an average 0.006 mosquitoes/house in the year 2010. CONCLUSION: Reductions in the densities of the major malaria vectors and a shift from human to animal feeding have contributed to the decreased burden of malaria along the Kenyan coast. Vector species composition remains heterogeneous but in many areas An. arabiensis has replaced An. gambiae as the major malaria vector. This has important implications for malaria epidemiology and control given that this vector predominately rests and feeds on humans outdoors. Strategies for vector control need to continue focusing on tools for protecting residents inside houses but additionally employ outdoor control tools because these are essential for further reducing the levels of malaria transmission.

Understanding knowledge, attitude and perception of Rift Valley fever in Baringo South, Kenya: A cross-sectional study.

Rift Valley fever (RVF) is a mosquito-borne viral hemorrhagic disease that affects humans and livestock. In Kenya, the disease has spread to new areas like Baringo County, with a growing realization that the epidemiology of the virus may also include endemic transmission. Local knowledge of a disease in susceptible communities is a major driver of prevention and control efforts. A cross-sectional survey using a semi-structured questionnaire was conducted in five locations of Baringo South that had reported RVF cases during the last outbreak, to determine the knowledge, attitude and perception of the predominantly agro-pastoralist community to RVF. Knowledge of RVF clinical signs, transmission, risk factors and prevention all contributed to the total knowledge score. Additionally, the respondents' attitude was based on their awareness of the threat posed by RVF and preparedness to take appropriate measures in case of suspected infection. Out of the 300 respondents, 80% had heard about the disease, however, only 9.6% attained at least half of the total knowledge score on RVF. Nevertheless, 86% recognized the threat it posed and knew the appropriate action to take in suspected human and livestock cases (positive attitude). Factors significantly associated with a better knowledge of RVF included higher education level, being Maasai, higher socio-economic index, old age and history of RVF in household members and livestock. Being Maasai and a higher socio-economic index were significantly associated with a positive attitude. The low level of knowledge exhibited by the respondents could be due to progressive loss of interest and information associated with a prolonged inter-outbreak period. This calls for regular awareness campaigns. More emphasis should also be put on educating communities on the role played by the mosquito vector in the epidemiology of RVF. The most promising routes of disseminating this information are radio and community gatherings.

Perspective article: Food security in tropical Africa through climate-smart plant health management.

Each year, Africa loses half of its harvest to pests (insects, pathogens, nematodes, weeds). To offset these losses and improve food security, pest management needs to be revamped urgently. Based on a synthesis of all 58 pest management projects conducted by IITA in its 55-year history, we advocate here for the implementation of the five following key climate-smart interventions, which have been shown to increase yields and decreasing CO2 outputs compared to the current practices that are largely based on the use of synthetic pesticides: 1. Sanitation at the country's borders and at the field level is the most cost-efficient way to prevent pest damage and losses from exotic pests entering new territories. 2. Good soil management strengthens the crop plant and enhances the effectiveness of all other interventions. 3. Biological control is the quickest and in the long run most cost-effective way to control invading insect pests and weeds. 4. Resistant varieties are often the only way to control already established diseases and are a mainstay control method in combination with other practices. 5. Various bio-pesticides based on viruses, bacteria and fungi against insects have been commercialized or can be produced on-farm; they are to replace synthetic pesticides, which continue to have large negative impacts on the environment and human health. To apply these five practices, new decision-support and climate services tools should be used to empower low-literacy farmers to take timely decisions about pest control and to act as business partners. Meanwhile, all actors in the pest control community should account for their environmental costs, which up to now are born solely by the community, while profits from pesticide sales are pocketed privately. To successfully disseminate these practices across the continent, enhanced and harmonized policy support is required.

Indigenous communities' perceptions reveal threats and management options of wild edible plants in semiarid lands of northwestern Kenya.

BACKGROUND: Understanding how local communities perceive threats and management options of wild edible plants (WEPs) is essential in developing their conservation strategies and action plans. Due to their multiple use values, including nutrition, medicinal, construction, and cultural as well as biotic and abiotic pressures, WEPs are exposed to overexploitation, especially within arid and semiarid lands, and hence the need to manage and conserve them. We demonstrate how an understanding of indigenous communities' perceptions could be achieved through an integrated participatory approach involving focus group discussions (FGDs) and field plot surveys. METHODS: We conducted three FGDs between October 2020 and April 2021 within three community units in northwestern Kenya with different socioeconomic and environmental characteristics. We subsequently surveyed 240 field plots of size 1 ha each to assess threats facing WEPs within a 5 km buffer radius in every study community. We compared ranks of threats and management options across community units. RESULTS: Rankings of threats and management options differed across the three study communities. We obtained strong positive linear relationships between field and FGD rankings of threats facing WEPs. Climate change, overstocking, overharvesting, and invasive species were the highest-ranked threats. Mitigation of climate change, local knowledge preservation, selection, propagation, processing, and marketing of WEPs ranked high among possible management options irrespective of the socioeconomic and environmental characteristics of the community unit. CONCLUSIONS: Our approach emphasizes the relevance of leveraging indigenous communities' perceptions and conducting field plot surveys to assess threats and management options for WEPs. Evaluating the effectiveness and cost-benefit implications of implementing the highly ranked management options could help determine potentially suitable habitats of the WEPs for conservation and management purposes, especially for priority WEPs.

Place of Residence Is Associated with Dietary Intake and BMI-SDS in Children and Adolescents: Findings from the DONALD Cohort Study.

We aimed to determine whether place of residence in the German urban food environment is associated with habitual dietary intake (energy, macronutrients, and food groups) and body mass index (standard deviation score of BMI and BMI-SDS). Our hypothesis was that place of residence may explain some variation in dietary intake and nutritional outcomes. For the cross-sectional analyses of DONALD study data, we grouped participants according to their geocoded residence in the north or south of Dortmund. We applied robust multi-level mixed effects regression models using residence as a predictor and (1) BMI-SDS or (2) dietary data (daily intake of energy (kcal), macronutrients (energy percentage), or food groups (g/1000 kcal)) as the outcome. Models were adjusted for age, sex, and household socio-economic status. An analysis was carried out on 1267 anthropometric measurements collected annually from 360 participants aged 6-18 years (935 3-day weighed dietary records from 292 participants) between 2014 and 2019. In the fully adjusted models, residence in the south was associated with a lower BMI-SDS (ß = -0.42, p = 0.02), lower intake of sugar-sweetened beverages (ß = -47.00, p = 0.04), and higher intake of vegetables (ß = 11.13, p = 0.04). Findings suggest that the place of residence, beyond individuals' socio-economic statuses, may be a contributing factor to dietary quality.

MASSAI: Multi-agent system for simulating sustainable agricultural intensification of smallholder farms in Africa.

The research and development needed to achieve sustainability of African smallholder agricultural and natural systems has led to a wide array of theoretical frameworks for conceptualising socioecological processes and functions. However, there are few analytical tools for spatio-temporal empirical approaches to implement use cases, which is a prerequisite to understand the performance of smallholder farms in the real world. This study builds a multi-agent system (MAS) to operationalise the Sustainable Agricultural Intensification (SAI) theoretical framework (MASSAI). This is an essential tool for spatio-temporal simulation of farm productivity to evaluate sustainability trends into the future at fine scale of a managed plot. MASSAI evaluates dynamic nutrient transfer using smallholder nutrient monitoring functions which have been calibrated with parameters from Malawi and the region. It integrates two modules: the Environmental (EM) and Behavioural (BM) ones.•The EM assess dynamic natural nutrient inputs (sedimentation and atmospheric deposition) and outputs (leaching, erosion and gaseous loses) as a product of bioclimatic factors and land use activities.•An integrated BM assess the impact of farmer decisions which influence farm-level inputs (fertilizer, manure, biological N fixation) and outputs (crop yields and associated grain).•A use case of input subsidies, common in Africa, markedly influence fertilizer access and the impact of different policy scenarios on decision-making, crop productivity, and nutrient balance are simulated. This is of use for empirical analysis smallholder's sustainability trajectories given the pro-poor development policy support.

Modeling climate change impacts on potential global distribution of Tamarixia radiata Waterston (Hymenoptera: Eulophidae).

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an efficient vector of "Candidatus Liberibacter" species, the causative agents implicated in citrus greening or huanglongbing (HLB). HLB is the most devastating citrus disease and has killed millions of citrus trees worldwide. Classical biological control using Tamarixia radiata Waterston (Hymenoptera: Eulophidae) against ACP has been successful in some regions. Climatic conditions are critical in determining suitable areas for the geographical distribution of T. radiata. However, paucity of information on climate change impacts on the global spread of T. radiata restricts international efforts to manage ACP with T. radiata. We investigated the potential global distribution of T. radiata using 317 native and non-native occurrence records and 20 environmental data sets (with correlation coefficients (|r| > 0.7)). Using the Maximum Entropy model, these data were analyzed for two shared socioeconomic pathways (SSPs) and two time periods (2030s and 2050s). We showed that habitat suitability for T. radiata occurred in all continents except Antarctica. However, the highly suitable areas for T. radiata were found in parts of the Americas, Asia, Africa and Oceania. The climate suitable areas would increase until the 2050s. The predictions showed that mean temperature of coldest quarter and precipitation of warmest quarter were the most important environmental variables that influenced the distribution of T. radiata. The model reliably predicted habitat suitability for T. radiata, which can be adapted in classical biological control programs to effectively manage ACP in an environmentally friendly manner.