Mammal ectoparasites are a fundamental, although often underappreciated, component of global biodiversity. They influence host population dynamics, community structure, and evolutionary processes, and play key roles in human and other animal health as vectors of bacteria, viruses, and protozoa. For example, ticks, fleas, lice, and mites—the principal groups of mammal ectoparasites—have complex life cycles and intimate ecological relationships with their hosts. This makes them sensitive indicators of climate and environmental change and central players in the emergence and re-emergence of vector-borne diseases. In the Global South, a range of geopolitical, economic, and environmental factors converge to increase both the urgency and complexity of studying mammal ectoparasites. Although these regions encompass diverse climates, including tropical and subtropical zones, many areas experience ecological conditions that support high vector diversity. Additionally, historical and current changes in land use, driven by global economic pressures and development models, have transformed natural landscapes worldwide. In the Global South, these transformations often intersect with high levels of interaction among wildlife, domestic animals, and humans, collectively shaping the dynamics of ectoparasite ecology. In combination with climate change, which is altering the distribution and seasonality of ectoparasites, these conditions make research in the Global South not only locally relevant but also critical for anticipating global scenarios. Thus, understanding these complex biological systems is not only a scientific challenge, but also a shared ethical responsibility of the global scientific community. Historically, research on mammal ectoparasites focused primarily on taxonomic and faunistic approaches aimed at describing regional diversity and ectoparasite–host associations. Over recent decades, however, the field has expanded dramatically. New molecular tools, phylogenetic analyses, ecological models, and spatial approaches integrating climatic and environmental data now allow scientists to address broader questions about ectoparasite distribution, host–ectoparasite coevolution, and pathogen transmission in the context of global climate change. The growing use of georeferenced databases, GIS analyses, ecological niche modelling, biogeography, and environmental genomics is transforming our understanding of ectoparasite biodiversity and ecology. These methodological advances are particularly valuable against the backdrop of rapidly changing natural ecosystems. Climate change, habitat fragmentation, and land-use change are redefining the geographic ranges of ectoparasites and their hosts, thereby increasing opportunities for transmission among wildlife, livestock, and humans. In addition, globalisation, with its increased interconnectedness means that ectoparasite-associated risks transcend local borders. Addressing these challenges requires integrative, interdisciplinary, and equitable approaches that consider ecological, epidemiological, and social dimensions. This Special Issue ‘Mammalian ectoparasite threats and management under a changing climate in the Global South’ is comprised of 20 articles spread over five issues of Medical and Veterinary Entomology, including one review, 17 original articles and two short communications. This Special Issue brings together contributions from researchers working primarily in the Global South, a region where ecological complexity, biodiversity, and socio-economic vulnerability are uniquely intertwined. In recent years, growing attention has been given to the scientific impact of parachute science in this field, which has highlighted the need for research to be led and shaped by those working within their own regions. In this context, scientists from the Global South continue to produce research of exceptional rigour, innovation, and relevance. Their studies not only expand our understanding of ectoparasite–host–environment dynamics but also provide critical insights for managing zoonotic and vector-borne diseases on our changing planet. The studies compiled in this Special Issue address these subjects from different perspectives. It is anticipated that climate change will lead to an expansion of the geographic ranges of ectoparasites, thus resulting in an increase in the transmission of vector-borne diseases. Consequently, there is a necessity for a more profound comprehension of the trophic dynamics between ectoparasites and their hosts. In this Special Issue, Mortier et al. (2025) emphasise the significance of comprehending how the life histories of ectoparasite species affect the preservation of isotopic host signals, and they analyse the utilisation of stable isotope analyses of ectoparasites to infer host dietary niches and preferences. It was found that different species of ectoparasites represented their hosts' isotopic signatures in distinct ways, and concluded that isotopic approaches to parasitology could have potential applications in understanding ectoparasite–host dynamics and improving vector-borne disease transmission models. In the field of ecological modelling, the utilisation of ecological niche models and species distribution models is regarded as being of paramount importance for the investigation of species distributions across a range of spatial and temporal scales. In their review in this Special Issue, Valdez-Espinoza et al. (2025) provided an overview of the state of the art in the utilisation of these concepts and tools in the study of tick species on a global scale. The utilisation of ecological models in the study of ticks and tick-borne pathogens has yielded valuable insights into their spatial epidemiology. The review also identified several gaps and presented new opportunities for improvement in this area. Host–ectoparasite associations in this current context of a changing climate highlights how shifting environmental conditions influence ectoparasite dynamics, host interactions, and the structure of ectoparasite communities, with direct implications for transmission risk in the Global South. In this Special Issue, López Berrizbeitia et al. (2025) modelled favourability-based relationships between rodents and their flea assemblages across South America. Their results showed that climate was the main factor influencing the distributions of fleas and hosts. López Berrizbeitia and Hamidi (2025) applied quantitative approaches to identify patterns of distributional congruence in rodent ectoparasites in Iran. These authors emphasise the significance of endemic zones in the management of reservoirs and vectors, as well as in conservation efforts. Ospina-Pérez et al. (2025) projected current and future distributions of a tick species under different climate-change scenarios across the Colombian Caribbean and Andean regions and other Neotropical ecoregions. These models suggest that tick distribution presents high climatic suitability and a possible expansion of the species distribution in areas currently not recorded in the Neotropics. The propagation of various ectoparasites may increase the likelihood of vector-borne disease transmission, thereby influencing the emergence and transmission dynamics of diseases. This phenomenon underscores the escalating public health and animal welfare hazards posed by vector-borne diseases in the Global South, which are compounded by ongoing environmental and climatic shifts. In this Special Issue, Espinoza-Carniglia et al. (2026) confirmed the presence of vector-borne bacteria in fleas of cricetid rodents near Gran La Plata, Argentina, a densely populated area. Ruiz et al. (2025) studied the presence of ectoparasite vectors and Rickettsia species in opossums within a rural landscape of the Pampas region, Argentina. The authors confirmed this mammalian species is a potential nexus between wild and domestic epidemiological cycles of ectoparasites and emerging pathogens, playing a key role in the transmission and maintenance of ectoparasites and ectoparasite-borne bacteria within these ecosystems. In regions experiencing deforestation, increased interactions between wild and domestic hosts have been shown to heighten the risk of zoonotic disease transmission (Urdapilleta et al., 2025). These authors analysed the prevalence and distribution of Bartonella species, as well as their phylogenetic relationships, in companion animals, wildlife and their associated fleas in different landscapes of the Atlantic Forest ecoregion of Argentina. This study is crucial to understanding transmission dynamics and to address the challenges posed by fleas as infection amplifiers and spillover phenomena. Ospina-Sánchez et al. (2025) provided metataxonomic profiles of bacterial and parasitic communities in ticks (Amblyomma spp.) collected from wildlife in Colombia. This study highlights the high microbial diversity, focusing on the dominance of tick-borne genera with potential risks for zoonotic and veterinary diseases (such as Francisella and Rickettsia). Acosta et al. (2025) proposed that road ecology studies should be considered a potential source of information for the investigation of ectoparasites and their associated bacteria. The presence of road-killed animals may offer significant opportunities to understand the occurrence, diversity and distribution of organisms, as well as to monitor wildlife disease without the need to capture sacrifice animals. The results of this study improve our understanding of the biodiversity of Patagonian fleas and flea-borne bacteria in a previously unknown ecosystem. Co-invasion, defined as the simultaneous introduction of hosts and ectoparasites, is of considerable ecological and epidemiological concern. This event has the capacity to modify existing ectoparasite–host dynamics in the invaded environment through the simultaneous introduction of new ectoparasite species (co-introduction) and/or acquisition of ectoparasites from the recipient community (the invasive species acquires ectoparasites from its new range), with the potential to affect native fauna, domestic species, and humans. In this Special Issue, Lizama-Schmeisser et al. (2025) evaluated the phenomenon of co-invasion of fleas from invasive rats in native rodents of Chile. This study underscores the capacity of rats to contract fleas from native rodents, signifying considerable public health ramifications, as it may enable the transmission of pathogens across diverse habitats where these rats are present. Taxonomic research is imperative for resolving species boundaries and host specificity. In this Special Issue, Shather and Kalef (2026) described the morphological and genetic characterisation of ticks from sheep in northern Baghdad, Iraq; Lobos-Ovalle et al. (2025) analysed the diversity of parasitic flies associated with bats in three ecoregions from Chile, and Gomez-Puerta and Jara (2026) presented the description of sarcoptic mange mites from a South American coati in Peru. The influence of ectoparasites on their hosts is contingent on factors such as host size, behaviour, population density, and location. Furthermore, the impact of parasitism extends beyond the individual, regulating host populations and altering ecological dynamics such as trophic interactions, food web structure, and biodiversity. In this Special Issue, Attir et al. (2026) investigated the prevalence, species composition and infestation levels of ectoparasites in dromedaries from different camel herds across northern Algeria's Sahara Desert, and assessed the effects of camel age and sex on ectoparasite loads and infestation patterns regarding the host's affected body region, while Gomez-Puerta et al. (2026) stated that the high prevalence of lice in alpacas from Peru could be a significant concern for the health of alpacas and the welfare of the newborn and young alpacas (crias) in the region. Figueroa et al. (2026) analysed the association between environmental variables and host density with the louse incidence and abundance of sucking lice that parasitise rodents in northern Chile. This study demonstrated that seasonal environmental variation did not impact all lice species equally, emphasising the need for further research into the ecological and biological drivers of these dynamics. Urdapilleta et al. (2026) emphasised the impact of environmental, biological, and socioeconomic factors on flea infestation. The challenges associated with public health and biodiversity conservation were analysed under several different scenarios. Santos et al. (2025) studied the relationship between five genera of haemoparasites found in the South American coati, using a modularity network metric and a general linear model to investigate the influence of biotic and abiotic variables and haemoparasite infections on the functional roles of coati individuals. Lopes et al. (2026) stated that under current warming trends and longer dry seasons in the Brazilian Cerrado, increases in temperature may enhance botfly (Metacuterebra infulata) fecundity and accelerate pupal development, potentially increasing transmission, ectoparasite-induced anaemia in hosts, and the risk of shifts in host–ectoparasite distributions under climate change. The findings of all these articles underscore the complex interplay between host behaviour, environmental factors, and ectoparasite ecology in urban environments, offering insights into the management of urban wildlife diseases. Collectively, these investigations examine host–ectoparasite relationships and the natural history of diverse mammalian systems, providing morphological and molecular descriptions, temporal dynamics of parasitism, and network-level perspectives. Together, these elements help elucidate the ecological processes driving ectoparasite community structure and transmission risk. Although the Global South bears a high burden of ectoparasite-borne diseases, it also suffers from a chronic lack of financial resources and limited surveillance capacity. The papers in this Special Issue demonstrate that scientific excellence is not solely determined by research funding, but also by strong academic training, collaborative peer networks, and the perseverance and resilience of historically underserved communities. An additional challenge is the limited international dissemination of scientific knowledge from low- and middle-income countries, as high publication and open-access fees restrict visibility and perpetuate unequal geographic representation in the literature. In this context, as Global South research teams produce high-quality science, they may require more intentional support to achieve equitable visibility. Although Medical and Veterinary Entomology is published under a hybrid model (i.e., both subscription and open access publishing options are available) so the possibility of publishing without cost to the authors exists, papers published under the subscription model are not open access so will have reduced visibility. The creation of this Special Issue with its associated publicity as well as a temporary period when it is freely available for everyone to read, is a significant step toward scientific equity. By removing economic barriers, the journal is helping to create a more inclusive and accessible platform for sharing essential research on the biology and ecology of mammalian ectoparasites, which impact global health, conservation, and vector management. As editors of this Special Issue, and as members of this scientific community, we are proud to highlight the commitment, creativity, and resilience of researchers working in the Global South. We hope this Special Issue stimulates new collaborations, strengthens ties between regions and disciplines, and inspires a new generation of researchers committed to a more just and equitable science. María Soledad Leonardi: Conceptualization; writing – original draft; writing – review and editing. Juliana P. Sánchez: Writing – original draft; writing – review and editing; conceptualization. Maureen Laroche: Writing – review and editing. Emma N. I. Weeks: Writing – review and editing. The authors declare no conflicts of interest.
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