Host species and environment drivers of ectoparasite community of rodents in a Mojave Desert wetlands

Abstract

Drivers of patterns of ectoparasitism in rodents in patchy Mojave Desert wetlands were investigated. A total of 1,571 ectoparasites in Mesostigmata, Trombidiformes, Siphonaptera and Ixodida were collected from 341 rodents (Microtus californicus scirpensis, Mus musculus, Reithrodontomys megalotis, Peromyscus eremicus, and Neotoma lepida) at eleven marshes. Trombiculids accounted for 82.5% of mites, followed by the mesostigmatid Ornithonyssus bacoti (17.5%), with chiggers predominating on voles and harvest mice. There were at least three genera of chiggers (Eutrombicula alfreddugesi, Euschoengastia sp. novel, and Blankaartia sp. novel). Fleas included Orchopeas leucopus (90.3% of all fleas) and O. sexdentatus (9.7%), and ticks were the novel endemic Ixodes mojavensis (82.1% of ticks) and Dermacentor similis (17.9%). On all hosts and at all marshes, coverage-based rarefaction sampling was over 96%, indicating coverage sufficient for analysis. Dissimilarities in ectoparasite community structure were driven mainly by chiggers, I. mojavensis and O. leucopus. Northern marshes were dominated by chiggers; central marshes by I. mojavensis; and southern marshes by O. leucopus. Primary determinants of ectoparasite community structure were host species, patch size, and parasite interspecific interactions. Host species richness and environmental factors such as patch distance and water and plant availability were not significantly associated with patterns of ectoparasitism. There were nine (60%) significant negative pairwise associations between ectoparasite taxa and no significant positive relationships. Ixodes mojavensis had the highest number of negative associations (with five other species), followed by chiggers and O. bacoti with two negative associations each. The study area is among the most arid in North America and supports numerous rare and endemic species in increasingly isolated wetland habitat patches; knowledge of ectoparasite ecology in this region identifies potential ectoparasite vectors, and provides information needed to design and implement programs to manage vector-borne diseases for purposes of wildlife conservation.

Repeated Cross-Sectional Survey of Ectoparasites in Sheep from Central Tunisia: Does Low Prevalence Indicate Good Hygiene or Resistance to Ectoparasites?

“…This trend in tick abundance compared to other ectoparasites is similar to those reported from Ethiopia, Iran and Iraq, where ticks were the main collected ectoparasites (31.8, 90 and 46.7%, respectively) [ 50 , 53 , 56 ]. The ectoparasite community assemblage is influenced by biotic and abiotic factors, which means that there are host-related factors (host species, gender, age, breed and immune system) and environment-related factors (temperature, humidity and human disturbance) [ 57 ]. In addition, several studies focused on interactions between different ectoparasites co-infesting an animal [ 58 , 59 ].…”

Host sweet host: Rodent communities support similar ectoparasite diversity regardless of anthropogenic disturbance

“…No generalisations have emerged from studies that have examined how attributes of different rodent species, such as sex, age, and body size, influence ectoparasite diversity (de Mendonça et al., 2020; Kiffner et al., 2011; Krasnov et al., 2005; López‐Pérez et al., 2022; Medvedev et al., 2020; Moravvej et al., 2016; Obiegala et al., 2021; Surkova et al., 2018). For body size, most studies show a positive association with ectoparasite load (Butler et al., 2020; Froeschke et al., 2013), while others found no relationship (Maaz et al., 2018; Shuai et al., 2022).…”

Effects of Season, Habitat, and Host Characteristics on Ectoparasites of Wild Rodents in a Mosaic Rural Landscape

“…These have both a direct effect, important especially for parasite taxa spending most of their time off-host (e.g., ticks), and an indirect effect, mediated by the response-in terms of density, physiological status, behaviour, etc.-of their hosts to the environment. Different parasite taxa may have different preferences for the characteristics of the host and environment [5,6], resulting in contrasting patterns of prevalence and mean abundance, while also shaping the spatiotemporal dynamics of parasite assemblages at the landscape level.…”