Thermoregulatory traits combine with range shifts to alter the future of montane ant assemblages.

Predicting and understanding the biological response to future climate change is a pressing challenge for humanity. In the 21st century, many species will move into higher latitudes and higher elevations as the climate warms. In addition, the relative abundances of species within local assemblages are likely to change. Both effects have implications for how ecosystems function. Few biodiversity forecasts, however, take account of both shifting ranges and changing abundances. We provide a novel analysis predicting the potential changes to assemblage-level relative abundances in the 21st century. We use an established relationship linking ant abundance and their colour and size traits to temperature and UV-B to predict future abundance changes. We also predict future temperature driven range shifts and use these to alter the available species pool for our trait-mediated abundance predictions. We do this across three continents under a low greenhouse gas emissions scenario (RCP2.6) and a business-as-usual scenario (RCP8.5). Under RCP2.6, predicted changes to ant assemblages by 2100 are moderate. On average, species richness will increase by 26%, while species composition and relative abundance structure will be 26% and 30% different, respectively, compared with modern assemblages. Under RCP8.5, however, highland assemblages face almost a tripling of species richness and compositional and relative abundance changes of 66% and 77%. Critically, we predict that future assemblages could be reorganized in terms of which species are common and which are rare: future highland assemblages will not simply comprise upslope shifts of modern lowland assemblages. These forecasts reveal the potential for radical change to montane ant assemblages by the end of the 21st century if temperature increases continue. Our results highlight the importance of incorporating trait-environment relationships into future biodiversity predictions. Looking forward, the major challenge is to understand how ecosystem processes will respond to compositional and relative abundance changes.

Climate mediates the effects of disturbance on ant assemblage structure.

Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk.

Carabid Beetles (Coleoptera) as Indicators of Sustainability in Agroecosystems: A Systematic Review.

The sustainability of agroecosystems is at risk owing to continuous anthropogenic disturbance. As such, there is a need to evaluate indicator taxa that may be used to monitor the health of agricultural management systems. Carabid beetles are ubiquitous and functionally crucial in agroecosystems while at the same time are sensitive to the changes caused by management practices. Their quick response to anthropogenic disturbances has been proposed as a practical and realistic tool for monitoring the sustainability of agricultural practices. However, there is still disagreement about carabids as possible indicators of agroecosystem sustainability. We conducted a systematic review of the responses of carabid beetles to agricultural systems in different biogeographical areas. We examined whether these beetles could serve as potential indicators of agroecosystem sustainability. The ISI Web of Science, Google Scholar, and Scopus were used to search for papers published from 2000-2019. In total, we included 69 studies indicating the use of carabids to monitor the impact of management practices in agroecosystems. Most studies were conducted in European countries (n = 37), while Southern Africa and East Asia countries were significantly under-represented (n = 10). Carabid beetle response to agroecosystems varied between management practices, with biodiversity indices (n = 41: positive 60%, negative 19%, and neutral 19%) being the most measured response variable, followed by functional diversity (n = 28: positive 67%, negative 25%, and neutral 7%). Overall, our findings highlight the need for more research in underdeveloped countries, to investigate the potential of overlooked carabids and include response variables measuring functional diversity in assessing the sustainability of agricultural management. This will assist policy makers and land managers in making active and informed decisions about agroecological disturbances and management.

Potential decline in the distribution and food provisioning services of the mopane worm (Gonimbrasia belina) in southern Africa.

The mopane worm (Gonimbrasia belina) is an edible insect distributed across southern Africa. As a culturally important source of food, the mopane worm provides nutrition, livelihoods and improves wellbeing for rural communities across its range. However, this is strong evidence that insect populations are declining worldwide, and climate change is likely to cause many insect species to shift in their distributions. For these reasons, we aimed to model how the ecosystem service benefits of the mopane worm are likely to change in the coming decades. We modelled the distribution of the mopane worm under two contrasting climate change scenarios (RCPs 4.5 and 8.5). Moreover, given that the mopane worm shows strong interactions with other species, particularly trees, we incorporated biotic interactions in our models using a Bayesian network. Our models project significant contraction across the species' range, with up to 70% decline in habitat by the 2080s. Botswana and Zimbabwe are predicted to be the most severely impacted countries, with almost all habitat in Botswana and Zimbabwe modelled to be lost by the 2080s. Decline of mopane worm habitat would likely have negative implications for the health of people in rural communities due to loss of an important source of protein as well as household income provided by their harvest. Biogeographic shifts therefore have potential to exacerbate food insecurity, socio-economic inequalities, and gender imbalance (women are the main harvesters), with cascading effects that most negatively impact poor rural communities dependent on natural resources.

The Role of Edible Insects in Rural Livelihoods, and Identified Challenges in Vhembe District, Limpopo, South Africa.

Edible insects are an important natural commodity in rural areas that is used for household consumption and to generate income through trade. As a result, edible-insect trading is a profitable business that provides employment and improves the livelihoods of impoverished rural people. This study aimed at determining the socioeconomic benefits of and reasons for trading insects, and to assess if edible insects are included in economic development strategies in the Vhembe district of Limpopo province, South Africa. We conducted 72 questionnaire interviews targeting traders in 5 towns across the district. Five insect groups belonging to four insect orders are traded in informal markets of the district. Mopane worms (Gonimbrasia belina) were the most traded (42%) edible insects. Unemployment (45%) and the demand for edible insects (34%) were the major reasons for trading insects. Insect trading has numerous benefits; however, the provision of income (60%) and financial support (35%) were stated as the primary benefits. Despite several benefits associated with trading in insects, there are many challenges such as insect spoilage and a decline in the availability of edible insects in the wild. Edible insects play an important role in food security and the rural economy by generating employment opportunities for unemployed traders. Trading in insects is a traditional practice based on indigenous knowledge, which has persisted as an economic practice that improves rural livelihoods by reducing poverty and increases the human dignity of rural citizens. Only four governmental organisations in Limpopo included edible insects in economic development strategies. Trading insects is primarily an informal activity. The government could stimulate the activity and broaden and deepen the community benefits by providing infrastructure, access to harvest areas, financial support, and business training as part of a rural empowerment strategy to end hunger and poverty while creating employment opportunities in rural areas.

Repeated surveying over 6 years reveals that fine-scale habitat variables are key to tropical mountain ant assemblage composition and functional diversity.

High-altitude-adapted ectotherms can escape competition from dominant species by tolerating low temperatures at cooler elevations, but climate change is eroding such advantages. Studies evaluating broad-scale impacts of global change for high-altitude organisms often overlook the mitigating role of biotic factors. Yet, at fine spatial-scales, vegetation-associated microclimates provide refuges from climatic extremes. Using one of the largest standardised data sets collected to date, we tested how ant species composition and functional diversity (i.e., the range and value of species traits found within assemblages) respond to large-scale abiotic factors (altitude, aspect), and fine-scale factors (vegetation, soil structure) along an elevational gradient in tropical Africa. Altitude emerged as the principal factor explaining species composition. Analysis of nestedness and turnover components of beta diversity indicated that ant assemblages are specific to each elevation, so species are not filtered out but replaced with new species as elevation increases. Similarity of assemblages over time (assessed using beta decay) did not change significantly at low and mid elevations but declined at the highest elevations. Assemblages also differed between northern and southern mountain aspects, although at highest elevations, composition was restricted to a set of species found on both aspects. Functional diversity was not explained by large scale variables like elevation, but by factors associated with elevation that operate at fine scales (i.e., temperature and habitat structure). Our findings highlight the significance of fine-scale variables in predicting organisms' responses to changing temperature, offering management possibilities that might dilute climate change impacts, and caution when predicting assemblage responses using climate models, alone.

Indigenous Knowledge about Consumption of Edible Insects in South Africa.

Consumption of edible insects is an indigenous practice that has played an essential role in human nutrition across Africa. The traditional use of insects forms an important part of food culture in Africa, and insects are consumed either as a delicacy, emergency, or staple source of food. However, indigenous knowledge about insect consumption is being lost because recent generations have adopted western methods and paid less attention to traditional practices. We conducted 500 questionnaires in five local municipalities in Kwazulu-Natal (KZN), and 122 questionnaires in four local municipalities in Vhembe district in Limpopo, South Africa, to document indigenous knowledge about edible insects' consumption, collection, and preparation methods used in Limpopo and KZN. Eight insect species belonging to five insect orders were used as food in Limpopo and KZN, with mopane worms (94%) and termites (70%) being the most preferred species by respondents in Limpopo and KZN, respectively. Ninety-five percent of the respondents occasionally consumed insects in Limpopo, while only 28% did so in KZN. Nutritional benefits and tradition were the main reasons for consuming insects. Edible insects are a nutritious diet and play an important role in people's livelihoods in rural areas. However, there was a notable decline in entomophagy, particularly in KZN. The decline may be related to occidental acculturation, discomfort associated with eating insects, and declining insect availability. To promote entomophagy, the authorities should encourage people to include edible insects in their diets because of their nutritional value. In addition, edible insect flour should be incorporated in food products such as biscuits, bread, energy bars, cereal, and cookies to promote acceptability.

Nutritional Composition of Edible Insects Consumed in Africa: A Systematic Review.

Edible insects are an important protein rich natural resource that can contribute to resilient food security. Edible insects not only play an important role in traditional diets, but are also an excellent source of protein in traditional dishes in Africa. We systematically searched Web-of-Science and Google Scholar from year 2000-2019 for studies on the consumption of insects and their nutritional composition in Africa, resulting in 98 eligible papers, listing 212 edible insect species from eight orders. These insects were rich in protein, fats, and fibre. The highest protein content was reported for Lepidoptera (range: 20-80%). Coleoptera had the highest carbohydrate content (7-54%), while Lepidoptera had the highest fat content (10-50%). Considering the excellent source of nutrition, and potential socio-economic benefits, from edible insects, they can contribute strongly to improved food security, and rural development in developing countries. In addition, edible insects can be used as a sustainable food source to combat food shortages in the future, for example, providing resilience during times of drought or other climate stressors.