Caswell Munyai

• PhD
• Senior Lecturer at University of KwaZulu-Natal

Aquatic ecosystems face a growing threat from pollution by heavy metals, nutrients and organic contaminants from anthropogenic stressors such as rapid urban, industrial and mining development and agriculture. Phytoremediation, the use of macrophytes to remove pollutants, offers a promising alternative and this review aims to explore the potential a...

There is mounting evidence that invasive alien species (IAS) have adverse effects on plant health and the global economy, posing a significant threat to biodiversity and ecosystem functioning. Identifying and assessing emerging IAS, such as plant pathogens, is a proactive approach that might assist in prioritising potential pathogen threats before...

The Soutpansberg Mountain (SM) range in the northern part of the Limpopo Province within the Vhembe Biosphere Reserve, is a refuge for high diversity of organisms due to its geological history and location. As part of the South African National Survey of Arachnida (SANSA), the spider diversity of the Soutpansberg Mountain was determined over 27 yea...

Spiders are the dominant representative of the top predator guild in many terrestrial ecosystems, but their diversity and distribution in forests in South Africa are still understudied. This study aimed to determine ground‐dwelling spider diversity, composition and distribution patterns in both sand forest and savanna (and their ecotone) using pitf...

Savannas cover almost a third of terrestrial Earth, but their exceptional biodiversity values are often underappreciated. Large tracts of temperate savanna have disappeared, while tropical savanna has been earmarked for agriculture. Contemporary threats include agriculture, altered disturbance regimes, resource extraction, inappropriate fire regime...

A tribute to Prof. Stefan Foord, arachnologist, who died tragically at the age of 52 years.

Background: Active and passive arthropod sampling techniques have their specific limitations. Pitfall trapping is a commonly used passive sampling method, and bush beating, aerial hand collection above the knee, aerial hand collection below the knee cryptic and non-cryptic are widely used active sampling techniques. Objective and method: Pitfall tr...

Invasive alien pests have caused a considerable negative impact on socio-economic growth and development in the South African agricultural sector. An effective strategy called horizon scanning has recently gained momentum in assessing the preparedness level for prospective changes or threats by invasive alien pests. The study was conducted to ident...

Ecological disturbance is fundamental for grassland management and the maintenance of its biodiversity. Fire and grazing are the primary habitat disturbances influencing the structure and composition of grassland ecosystems, both acting to remove grass biomass. Little is known about the effects of such grass biomass removal on grassland ants, an ec...

Taxonomy has played an important role in biodiversity assessments. It provides an understanding of biodiversity components, data that are essential for making decisions on conservation and sustainable use and is also a foundation for phylogenetic studies. Although this field of study has played an important role in identifying and describing biodiv...

Gall-inducing insects are a classic example of how insects can impact the morphology and physiology of their host plants by forming galls which act as nutrient sinks. An 8-months laboratory study was conducted to determine the impact of the galls induced by Polymorphomyia basilica oviposition and or the subsequent larval feedingon the growth and re...

Anoplolepis gracilipes is an invasive species that is a major threat to native ecosystems worldwide. It has been listed as one of the top 100 worst invasive species in the world and is well known for its negative impact on native arthropods and some vertebrates. This study aimed to confirm the presence or absence of A. gracilipes in some major Sout...

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 ca...

The international trade of plants and their products, such as fresh fruits, can facilitate the introduction and spread of foreign pests and diseases. We examined South Africa’s import of stone fruits (Prunus spp.) as a pathway for introducing Monilinia fructicola (G. Wint.) Honey and document recommended phytosanitary measures to deal with the risk...

Agricultural intensification with the continuous use of pesticides and intensive tillage contributes to the loss and extinction of invertebrates. Over 40% of insect species may become extinct in the next few decades. The extinction of a single insect species has the potential to have severe consequences for food production. As a result, epigeic pre...

Understanding where biodiversity is and how it is distributed is crucial to conserving vulnerable and dynamic ecosystems. Although natural forests support greater diversity and are vital for the conservation of organisms, recent studies have argued that monoculture plantations can be used as an alternative habitat for forest species. We investigate...

Biodiversity patterns along elevational gradients are generally characterised by monotonic decreases or mid-elevational peaks in species richness, while elevational zones may be characterised by distinct assemblages, or higher zones may be subsets of lowland assemblages. Elevational gradients in diversity have been less studied in the Afrotropical...

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 an...

Edible insects may be a sustainable source of protein and some other nutrients, especially for low economic status communities. The current study determined the influence of insect type, geographic location and cooking method on the nutritional composition of insects. The investigation would contribute to maximal derivation of the nutritional benef...

International agricultural trade is a pathway by which pests and diseases can be transported and introduced to new areas. We examined South Africa's import of kiwifruit (Actinidia spp.) as a pathway for the introduction of mites in the genus Brevipalpus (Acari: Tenuipalpidae). Kiwifruit is imported as fresh fruit and propagation material from vario...

Pyrrolizidine alkaloids (PAs) are amino alcohols, often esterified with mono- or dicarboxylic acids, found in several plant families, including the Asteraceae. Pyrrolizidine alkaloids are used for plant defence against generalist invertebrate herbivores. However, specialist herbivores that are able to sequester PAs from the host plant species deriv...

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, veget...

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 be...

Habitat structure is a key determinant of variation in biodiversity. The effects of increased vertical and horizontal vegetation structure can result in marked shifts in animal communities. This is particularly true for ants in response to woody thickening, with predicted negative impacts on ant diversity. We used pitfall traps to study the respons...

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 o...

South African National Parks (SANParks) is implementing rehabilitation projects in parks where acquired lands have degrees of degradation. Such parks need to have empirical data to determine the degree of degradation and the success of the projects. We sampled epigeal ants at degraded and control sites in Mountain Zebra and Mokala National Parks to...

The tephritid Cecidochares connexa has been used to good effect as a biological control agent on the Asian/West African biotype of the invasive alien shrub Chromolaena odorata, but does not develop well on the different, southern African C. odorata biotype. A stem-galling tephritid fly, Polymorphomyia basilica, from the northern Caribbean islands,...

A 9-month laboratory study was carried out to determine the impact of herbivory by a moth with shoot-boring larvae, Dichrorampha odorata Brown and Zachariades (Lepidoptera: Tortricidae) on growth and reproductive ability of its host plant, Chromolaena odorata (L.) King and Robinson (Asteraceae), a major invasive alien plant species in southern Afri...

Ants are sensitive to habitat change and may be affected by disturbances, such as alien plant invasion. Alien plant invasion is associated with negative effects on the functioning of ecosystems and may have adverse impacts on biodiversity. The aim of this study was to determine the diversity of ground‐dwelling ants in Tanglewood and Giba Gorge Rese...

As the need to better understand the ecology of hotspots of endemism intensifies, the insurance hypothesis is drawing increasing attention from policy-makers and scenario-planners. The hypothesis states that biodiversity increases ecosystem stability. When species numbers fluctuate, there is potential for further perturbation, loss of function and...

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 is likely to change. Both effects have implications...

Predators play a disproportionately positive role in ensuring integrity of food webs, influencing ecological processes and services upon which humans rely. Predators tend to be amongst the first species to be affected by anthropogenic disturbance, however. Spiders impact invertebrate population dynamics and stabilise food webs in natural and agricu...

The relationship between levels of dominance and species richness is highly contentious, especially in ant communities. The dominance‐impoverishment rule states that high levels of dominance only occur in species‐poor communities, but there appear to be many cases of high levels of dominance in highly diverse communities. The extent to which domina...

Human-dominated landscapes comprise the bulk of the world’s terrestrial surface and Africa is predicted to experience the largest relative increase over the next century. A multi-scale approach is required to identify processes that maintain diversity in these landscapes. Here we identify scales at which animal diversity responds by partitioning re...

List of bat species, families and foraging groups recorded from manual identifications of a random subset of four sites (two nights each) per village, and the codes given to species-groups defined for subsequent automated identification with minimal overlap in call parameters using scans and filters in Analook v. 4.1t, 2015 (Titley Electronics, www...

Proportion of total richness contributed by alpha and beta components for all seven taxa based on individual- and sample-based partitioning respectively. (DOCX)

Response of animal communities to three land use types: Croplands, settlements, and rangelands in a rural landscape using two response variables, (a) abundance and (b) richness. All values were standardized for comparison to represent standard deviations from the mean. Whiskers represent the range, boxes the first and third quartiles, dark lines th...

R-script and associated R output of PERMANOVA analyses for acoustically-obtained (SM2 bat detectors, Wildlife Acoustics) abundance data for 13 species-groups of bats using Bray-Curtis distance. Analyses were conducted in R using the “vegan”, “car” and “MASS” packages. Species group codes and foraging associations (open-air, clutter and clutter-edge...

Africa’s savannas are undergoing rapid conversion from rangelands into villages and croplands. Despite limited research, and evidence of deleterious effects to biodiversity, international organisations have earmarked this system for cropland. Invertebrates, and ants in particular, are sensitive indicators of habitat fragmentation, and contribute to...

Landuse change and ant assemblages, diversity, and functional groups

What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of mo...

Dichrorampha odorata (Lepidoptera: Tortricidae) is a moth from Jamaica whose larvae bore into, and kill, the shoot tips of the invasive alien plant, Chromolaena odorata (L.) King and Robinson (Asteraceae). This study reports aspects of the biology of D. odorata, and also determined the host specificity (larval and adult no-choice trials) of the mot...

In recent years the focus in ecology has shifted from species to a greater emphasis on functional traits. In tandem with this shift, a number of trait databases have been developed covering a range of taxa. Here, we introduce the GlobalAnts database. Globally, ants are dominant, diverse and provide a range of ecosystem functions. The database repre...

Aim In ectotherms, the colour of an individual's cuticle may have important thermoregulatory and protective consequences. In cool environments, ectotherms should be darker, to maximize heat gain, and larger, to minimize heat loss. Dark colours should also predominate under high UV‐B conditions because melanin offers protection. We test these predic...

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 distur...

The distribution, abundance and sensitivity of invertebrates to habitat change are largely unknown. Long-term monitoring of ecological gradients with standardised and comparable protocols can form the basis of a better understanding. Altitudinal gradients are particularly relevant within this context. Here we provide a check list and baseline data...

Factors that drive species richness over space and time are still poorly understood and are often context specific. Identifying these drivers for ant diversity has become particularly relevant within the context of contemporary global change events. We report on a long-term biannual (wet and dry seasons), standardized sampling of epigeal ants over...

Mountains are biodiversity hotspots and provide spatially compressed versions of regional and continental variation. They might be the most cost effective way to measure the environmental associations of regional biotic communities and their response to global climate change. We investigated spatial variation in epigeal ant diversity along a north–...