Redescription of the genus Turnicola Clay & Meinertzhagen, 1938 (Phthiraptera: Ischnocera) and its type species

The socio-economic relevance of emergent viruses has driven a considerable research effort aimed at understanding the process of emergence. Virus emergence depends on a range of factors intrinsic to the virus, such as genetic traits that determine its fitness in different hosts (i.e., evolutionary factors), or extrinsic factors related to ecology and epidemiology that ultimately result in the virus encountering and infecting a new host population (i.e., ecological factors). Therefore, mechanisms underlying emergence involve the evolution of virus host range, which has received considerable research attention in the past. However, until recently, the focus on factors intrinsic to the virus has been at the expense of understanding ecological factors that affect host-range evolution. Previous work has highlighted the importance of knowing the host range of viruses, to understand how host and virus ecology influences the epidemiology of the virus, and thus the risk of infection. Nevertheless, it is unusual to find literature from studies that have characterised the host range of a virus in a given ecosystem. At the spatial scale of the landscape, the influence that environmental heterogeneity has on host and virus diversity and on the large numbers of plant-virus interactions, requires minimising biases in the quantification and comparison of communities. New high-throughput sequencing (HTS) approaches in combination with computational tools developed for big-data, are now the gold standard for addressing landscape scale dynamics and the joint study of the ecological and evolutionary factors that underlie virus emergence. The goal of this thesis was to identify ecological factors that determine plant-virus interactions in the heterogeneous communities of an agricultural ecosystem. The ultimate ambition of determining the ecological factors that drive transmission dynamics and emergence at the landscape scale, exceeds the scope of a doctoral thesis. Nevertheless, the goal of the thesis sets the basis for reaching that ambitious target through fulfilling a series of objectives; the first steps towards understanding virus emergence. The first objective, to evaluate plant community variation of an agricultural ecosystem in central Spain, was performed by comparing four key habitats subject to increasing levels of human intervention. The loss of biodiversity in agricultural ecosystems is expected to change epidemiological dynamics of plant viruses. Therefore, variation in plant communities from each of four habitat types, Oakwood, Wasteland, Edge and Crop, was evaluated to investigate, in the second objective, plant community structure-function relationships with virus diversity. To this aim, the second objective was to characterise the virome of plant communities in the four habitats using a HTS approach, to examine the contribution of ecological factors in structuring single-stranded RNA (ssRNA) virus communities. The third objective focused on watermelon mosaic virus (WMV), a widespread large host range generalist virus, where HTS was combined with RT-PCR amplification and Sanger sequencing to assess the effect of the four habitats on host range, incidence, and genetic diversity. The results showed plant assemblages of each of the habitats clustered into discrete categories, with Crop and Edge the most similar, and Oakwood the most differentiated plant community. The diversity of the plant assemblages differed among the habitats, Crop with the lowest diversity and Wasteland with the highest. Plant diversity was affected by seasonality. Apart from Crop with an opposite trend, the plant diversity of each habitat decreased between spring and autumn. Of the 118 total plant species that were sequenced, 106 of them were validated as hosts of viruses. Edge had the highest host richness with 52 species, and Crop the lowest with 28 species. Oakwood and Wasteland had 45 and 41 host species respectively. The highest virus (operational taxonomic unit; OTU) richness was detected in Edge followed by Wasteland. Oakwood and Crop, which were polar opposites in the level of disturbance, supported less species than the other two habitats. The distribution of viruses among the habitats was associated strongly with host species abundance only within Edge, but in general, host use was not driven by the abundance of any given plant species. A large proportion (62 %) of the 90 OTUs detected had host ranges of less than five species, and a small proportion (19%) had host ranges of 20 or more species. The host range of a given virus differed significantly among the habitats, with Edge producing the highest realised mean host ranges. The effect of habitat and host ecology on plant viruses was also evident in the structuring of WMV incidence, genetic diversity, and host range. Although sensitivity in detection by HTS was greater than by RT-PCR, both host range estimates of 43 and 24 species respectively, showed WMV infected species occurring in each habitat. The incidence of WMV was higher in Crop compared to Edge and Wasteland, but equivocal to that in Oakwood. Incidence was correlated with host species relative abundance in Crop, but not in the other habitats, with no dependency between seasonality and habitat in structuring incidence. The genetic diversity of WMV was not significantly structured according to host species or habitat, but rather between Cucumis melo and wild host species. Both phylogenetic inferences and haplotype networks showed 4 main clades of WMV, each with mixed host associations, and with Oakwood supporting the only habitat-specific clade. Overall, habitat associations with the coat protein gene of WMV were stronger than host species associations, but both had an important role in differentiation between and within WMV populations. This thesis demonstrated that viral detection by HTS is robust to quantifying variation at higher levels of organisation among habitats. Differences in community composition associated with each habitat at any given time, resulted in a subset of possible biotic interactions within each of them, and contributed to structuring plant-virus and virus-virus interactions at the ecosystem scale. Ecological differentiation among habitats was shown in the distinctions between their plant and virus community compositions, and the responses viruses had to host plant ecology. For instance, Edge was conducive to infections by many viruses, and supported host species that were infected on average by more viruses with wider realised host ranges compared to the other habitats, which revealed important ecological features of a reservoir community. Ecological interactions were also partly contingent on seasonality and the level of disturbance. The infection by viruses of a large majority of the plant samples suggests the association of symbionts with most host species is frequent. Thus, ecological factors affect transmission between and within plant communities of agricultural ecosystems, and influence the processes of host range evolution and, hence virus emergence. ----------RESUMEN---------- La relevancia socioeconómica de los virus emergentes ha impulsado un esfuerzo considerable en la investigación destinada a comprender el proceso de emergencia. La emergencia de los virus depende de una serie de factores intrínsecos al virus, como los rasgos genéticos que determinan su adaptación a diferentes huéspedes (es decir, factores evolutivos), o factores extrínsecos relacionados con la ecología y la epidemiología que, en última instancia, hacen que el virus encuentre e infecte a una nueva población de huéspedes (es decir, factores ecológicos). Por lo tanto, los mecanismos que subyacen a la emergencia implican la evolución de la gama de huéspedes del virus, tema que ha recibido una considerable atención en el pasado. Sin embargo, hasta hace poco el énfasis en el estudio de los factores intrínsecos del virus ha sido en detrimento de la comprensión de los factores ecológicos que afectan a la evolución de la gama de huéspedes. Los trabajos publicados han puesto de relieve la importancia de conocer la gama de huéspedes de los virus para entender cómo la ecología del huésped y del virus influye en la epidemiología del virus y, por tanto, en el riesgo de infección. Sin embargo, hay pocos estudios que hayan caracterizado la gama de huéspedes de un virus en un ecosistema determinado. A escala espacial del paisaje, la influencia que la heterogeneidad ambiental ejerce sobre la diversidad de huéspedes y virus y sobre el gran número de interacciones planta-virus, exige minimizar los sesgos en la cuantificación y comparación de las comunidades. Los nuevos enfoques de secuenciación de alto rendimiento (HTS) en combinación con las herramientas computacionales desarrolladas para big-data, son las mejores herramientas para abordar la dinámica a escala del paisaje y el estudio conjunto de los factores ecológicos y evolutivos que subyacen a la emergencia viral. El objetivo de esta tesis es identificar los factores ecológicos que determinan las interacciones planta-virus en las comunidades heterogéneas de un ecosistema agrícola. Determinar los factores ecológicos que afectan a la dinámica de transmisión y la emergencia a escala del paisaje excede del alcance de una tesis doctoral. Sin embargo, el trabajo realizado en esta tesis sienta las bases para alcanzar esa ambiciosa meta mediante el cumplimiento de una serie de objetivos como primeros pasos hacia la comprensión de la emergencia de los virus. El primer objetivo ha sido evaluar la variación de la comunidad vegetal de un ecosistema agrícola del centro de España, y se llevó a cabo comparando cuatro hábitats clave sujetos a niveles crecientes de intervención humana. Se espera que la pérdida de biodiversidad en los ecosistemas agrícolas cambie la dinámica epidemiológica de los virus de plantas. Por lo tanto, se evaluó la variación de las comunidades vegetales de cada uno de los

Parasite populations associated with different host species can encounter a variety of isolating reproductive barriers, leading to each population independently accumulating genome‐wide genetic differences due to their host associations. This phenomenon is called host‐associated differentiation (HAD) and has been proposed as an indicator of early diversification among parasitic arthropods. Although many parasite–host case study systems have been tested for the genetic signature of HAD (e.g., FST≥0.15 between sympatric, host‐associated populations in the absence of allopatry), it is unknown which isolating reproductive barriers best predict the general occurrence of HAD. HAD development has been attributed to biological and ecological factors that either directly generate reproductive isolation between parasites living on different hosts, such as ‘immigrant inviability’ (i.e., lower fitness of immigrants in non‐native environments), or that promote the accumulation of host‐specific genetic adaptations, such as the gallmaking feeding mode. In fact, some of these factors are shared across multiple case studies, suggesting that the occurrence of HAD is generalizable and can be predicted based on the incidence of significant biological and ecological factors. By means of a discriminant function analysis (DFA), this research assessed 108 arthropod parasite–host case studies for ecological and biological factors significantly correlated with the occurrence of HAD and whether these factors could be used to distinguish the presence of HAD from its absence. The DFA demonstrated that case studies that developed HAD could be distinguished from case studies that did not develop HAD. The results of the DFA were corroborated by a ‘non‐iterative partial least squares’ (NIPALS) discriminant model and a nominal logistic regression. Case studies with HAD could be robustly separated from case studies without HAD based on the incidence of these predictive factors: immigrant inviability, gallmaking, endophagy, recent range invasions of either hosts or parasites, differential host phenology, and differential parasite morphology. These results were used in an infinite random forest analysis to generate a hierarchy of conditional probabilities that separated HAD presence from absence. The results provide researchers with a tool for reliably predicting which untested parasite–host system would likely develop HAD. Immigrant inviability, gallmaking, and their combination were strongly correlated with the presence of HAD, which indicated parasite–host systems with these traits were highly likely to develop HAD. Contrary to expectation, endophagous feeding was negatively correlated with HAD presence, which indicated phytophagous endophagous feeders (excepting gallmakers) were highly unlikely to develop HAD. Furthermore, parasitoids were shown to be just as likely to develop HAD as not. Unfortunately, potentially significant predictive factors (e.g., allochrony) were excluded from analysis because too few case studies have been specifically tested for these factors. Furthermore, this analysis was biased by the lack of ‘negative’ publication results and the overrepresentation of research laboratories that primarily study HAD. Future research should accumulate novel HAD case studies that specifically test for allochrony, differential microbial associations, and morphological differentiation.

Two new species of quill mites (Acariformes: Syringophilidae) associated with doves of the subfamily Treroninae (Columbiformes: Columbidae) from the Oceanian realm are described: Gunabopicobia masalaje sp. nov. from six avian host species, Ptilinopus iozonus Gray (type host) Ducula pistrinaria (Bonaparte), D. rosacea (Temminck), D. rufigaster (Quoy and Gaimard), D. spilorrhoa (Gray), D. luctuosa (Temminck), and Peristerophila lature sp. nov. also from six host species Ducula luctuosa (type host ), D. spilorrhoa, Ptilinopus jambu Gmelin, P. melanospilus Salvadori, P. porphyreus Temminck, P. regina Swainson. Additionally, Treron waalia (Meyer) is noted as a new host species for Meitingsunes columbicus Glowska and Skoracki, 2010.

Family Laelapidae is an ecologically diverse group that includes free-living species and parasites of vertebrates and invertebrates. At least seven genera in this family are associated with small mammals. In this study, ectoparasitic laelapid mites of rodents and shrews were investigated in Lithuania. In total, 2,274 small mammal specimens of 12 species were trapped and 6,089 laelapid mites were collected. The updated list of ectoparasitic mites in Lithuania included 21 mite species. Seven mite species were identified as highly specific for a host species or genus, one species was moderately specific, and four mite species were assigned to generalist parasites. All host species had one or two superdominant mite species. The prevalence and mean intensity varied significantly depending on host species and habitat. We analyzed the influence of the host (species, sex, age) and environmental factors (landscape morphology type, habitat, anthropogenic effect) on the abundance of the mite community and most numerous mite species, as well as the impact of the host community (Shannon's diversity index, species richness, host abundance) on mean abundance of the mite community. Only particular host species (Apodemus flavicollis, Microtus agrestis, and Microtus arvalis) and habitats (pastures, mixed forests) influenced the abundance of mites.

In addition to the presence of a suitable host and vector, the prevalence of haemosporidians is influenced by several important factors, including the environmental conditions of the habitat, which depend on broader geographic characteristics. The aim of this study is to perform a preliminarily assessment of the distribution of blood parasites in birds from the mountainous area of Zhongar Alatau NP and to find potential new sites for research on their ecology in Kazakhstan. The results of this research constitute the first report on the occurrence of blood parasites from this area. A total of 58 birds, from the order Passeriformes and one individual from the order Caprimulgiformes, were examined during the study. The overall prevalence of infections caused by haemosporidian parasites (Haemoproteus, Leucocytozoon) was 18.6%. Neither the genus Plasmodium nor the presence of trypanosomes and microfilariae was detected in the birds examined. Three birds (5.1% prevalence) were infected with parasites of the genus Haemoproteus, in all eleven positive birds the analyses showed the presence of parasites of the genus Leucocytozoon (18.6% prevalence). The presence of parasites genus Haemoproteus was detected only in birds that were also infected with Leucocytozoon parasites. More infections with parasites of the genus Leucocytozoon are predicted due to the higher altitude and ecological factors at the capture sites, which are more favourable for the development of vectors of this genus. The species Haemoproteus majoris was detected in the host Emberiza cioides and species Haemoproteus minutus in host Turdus merula. Other species of this genus in the hosts Cyanistes cyanus and Turdus atrogularis were not determined. The species Leucocytozoon fringilinarum was detected in the hosts Cyanistes cyanus and Parus major, Leucocytozoon dubreuili was detected in Turdus atrogularis and Turdus merula. In the other host species Aegithalos caudatus, Emberiza cioides and Periparus aterus, it was not possible to dermine the species of the genus Leucocytozoon.

Historically, symbiotic protists in termite hindguts have been considered to be the same species if they are morphologically similar, even if they are found in different host species. For example, the first-described hindgut and hypermastigote parabasalian, Trichonympha agilis (Leidy, 1877) has since been documented in six species of Reticulitermes, in addition to the original discovery in Reticulitermes flavipes. Here we revisit one of these, Reticulitermes virginicus, using molecular phylogenetic analysis from single-cell isolates and show that the Trichonympha in R. virginicus is distinct from isolates in the type host and describe this novel species as Trichonympha burlesquei n. sp. We also show the molecular diversity of Trichonympha from the type host R. flavipes is greater than supposed, itself probably representing more than one species. All of this is consistent with recent data suggesting a major underestimate of termite symbiont diversity.

Genetic evidence indicates that Progamotaenia macropodis Beveridge, 1976 (Cestoda: Anoplocephalidae), found in various macropodid host species, is a complex of cryptic species. However, the genetic data are incomplete, and no morphological re-appraisal of the species has been undertaken since its original description. Here, additional mitochondrial cytochrome c oxidase I sequence data have been added from the type host, Macropus giganteus, as well as other host species, and a morphological study of all available material undertaken. A new species, Progamotaenia mollicula sp. nov., is erected for specimens from the tammar wallaby, Notamacropus eugenii, which are smaller, and the testes in pre-mature and mature proglottids occur invariably in two lateral groups. Specimens from the remaining host species, Macropus fuliginosus, Notamacropus parryi, N. rufogriseus, Osphranter robustus, and Wallabia bicolor are highly variable with obvious differences in length and proglottid shape, but with no reliable internal morphological characters for separating the various genotypes. The study was limited by incomplete molecular data (N. rufogriseus) and the poor quality of some of the preserved material.

A new feather mite genus Bernierinyssus gen. n. (Analgoidea: Pteronyssidae), associated with endemic Malagasy warblers (Passeriformes: Bernieridae), is proposed based on morphological evidence and DNA sequence data. Within this genus, we detected six mite species, including five new species described here: Bernierinyssus angulatus sp. n. from Crossleyia xanthophrys, B. bernieriae sp. n. from Bernieria madagascariensis, B. bifenestratus sp. n. from Hartertula flavoviridis, B. randiae sp. n. from Randia pseudozosterops, B. xanthomixis sp. n. from Xanthomixis zosterops (type host) and X. cinereiceps, and B. oxylabis (Mironov and Wauthy 2005) comb. n. (transferred from Pteronyssoides Hull). Phylogenetic relationships of these mites were nearly perfectly congruent with those of their hosts, indicating that ancestral Bernierinyssus probably co-dispersed to Madagascar on the common ancestor of Malagasy warblers and then cospeciated with their hosts. Species of Bernierinyssus are well-delimited based on several lines of evidence: morphology (clear among-specific differences in discrete characters), host associations (one mite species per one host species, except for B. xanthomixis), genetic distances (large COX1 barcoding gap between among- and within-species K2P distances: 8.22¨C12.38% vs 0¨C2.9%, respectively), and molecular phylogenetics (all species are well-supported, monophyletic clades). Our study suggests that species of the genus Bernierinyssus have evolved slower than their avian hosts or co-associated feather lice. Despite the discordance in the mitochondrial DNA evolutionary rates, speciation events in mites largely corresponded to bird species divergences, resulting in a nearly perfect correlation between mite and bird species richness (Eichler's Rule). The mite B. xanthomixis was associated with two avian species, but still formed two distinct shallow lineages (COX1 distance: 1.65%) separated by the host species. The nearly strict host-specificity pattern found in Bernierinyssus contrasts with that of continental feather mites, which tend to be less host-specific and have nearly equal proportions of single-host vs multi-host species.

Parasites are a selective force that shape host community structure and dynamics, but host communities can also influence parasitism. Understanding the dual nature from host-parasite interactions can be facilitated by quantifying the variation in parasite prevalence among host species and then comparing that variation to other ecological factors that are known to also shape host communities. Avian haemosporidian parasites (e.g. Plasmodium and Haemoproteus) are abundant and widespread representing an excellent model for the study of host-parasite interactions. Several geographic and environmental factors have been suggested to determine prevalence of avian haemosporidians in bird communities. However, it remains unknown whether host and parasite traits, represented by phylogenetic distances among species and degree of specialization in host-parasite relationships, can influence infection status. The aims of this study were to analyze factors affecting infection status in a bird community and to test whether the degree of parasite specialization on their hosts is determined by host traits. Our statistical analyses suggest that infection status is mainly determined by the interaction between host species and parasite lineages where tolerance and/or susceptibility to parasites plays an essential role. Additionally, we found that although some of the parasite lineages infected a low number of bird individuals, the species they infected were distantly related and therefore the parasites themselves should not be considered typical host specialists. Infection status was higher for generalist than for specialist parasites in some, but not all, host species. These results suggest that detected prevalence in a species mainly results from the interaction between host immune defences and parasite exploitation strategies wherein the result of an association between particular parasite lineages and particular host species is idiosyncratic.

The degree to which parasites use hosts is fundamental to host-parasite coevolution studies, yet difficult to assess and interpret in an evolutionary manner. Previous assessments of parasitism in eugregarine-host systems suggest high degrees of host specificity to particular host stages and host species; however, rarely have the evolutionary constraints on host specificity been studied experimentally. A series of experimental infections were conducted to determine the extent of host stadium specificity (larval vs. adult stage) and host specificity among 6 tenebrionid host species and 5 eugregarine parasite species. Eugregarines from all host species infected both the larva and adult stages of the host, and each parasite taxa colonized several host species (Tribolium spp. and Palorus subdepressus). Parasite infection patterns were not congruent with host phylogeny, suggesting that host phylogeny is not a significant predictor of host-parasite interactions in this system. However, the 2 host stages produced significantly different numbers of parasite propagules, indicating that ecological factors may be important determinants of host specificity in this host-parasite system. While field infections reflect extant natural infection patterns of parasites, experimental infections can demonstrate potential host-parasite interactions, which aids in identifying factors that may be significant in shaping future host-parasite interactions.

BackgroundRelationships between floral biology and pollinator behavior are important to understanding species diversity of hemiparasitic Psittacanthus mistletoes (c. 120 species). We aimed to investigate trait divergence linked to pollinator attraction and reproductive isolation (RI) in two hummingbird-pollinated and bird-dispersed Psittacanthus species with range overlap.MethodsWe investigated the phylogenetic relationships, floral biology, pollinator assemblages, seed dispersers and host usage, and the breeding system and female reproductive success of two sympatric populations of P. calyculatus and P. auriculatus, and one allopatric population of P. calyculatus. Flowers in sympatry were also reciprocally pollinated to assess a post-mating component of RI.ResultsHummingbird assemblages differed between calyculatus populations, while allopatric plants of calyculatus opened more but smaller flowers with longer lifespans and produced less nectar than those in sympatry. Bayesian-based phylogenetic analysis indicated monophyly for calyculatus populations (i.e. both populations belong to the same species). In sympatry, calyculatus plants opened more and larger flowers with longer lifespans and produced same nectar volume than those of auriculatus; populations shared pollinators but seed dispersers and host usage differed between species. Nectar standing crops differed between sympatric populations, with lower visitation in calyculatus. Hand pollination experiments indicated a predominant outcrossing breeding system, with fruit set after interspecific pollination two times higher from calyculatus to auriculatus than in the opposite direction.ConclusionsGiven the low genetic differentiation between calyculatus populations, observed trait divergence could have resulted from changes regarding the local communities of pollinators and, therefore, expected divergence for peripheral, allopatric populations. Using RI estimates, there were fewer heterospecific matings than expected by chance in P. calyculatus (RI4A = 0.629) as compared to P. auriculatus (RI4A = 0.20). When considering other factors of ecological isolation that affect co-occurrence, the RI4C values indicate that isolation by hummingbird pollinators was less effective (0.20) than isolation by host tree species and seed dispersers (0.80 and 0.60, respectively), suggesting that host usage is the most important ecological isolation factor between the two species. Accordingly, the absolute and relative cumulative strength values indicated that the host tree species’ barrier is currently contributing the most to maintaining these species in sympatry.

Microbial symbionts form abundant and diverse components of marine sponge holobionts, yet the ecological and evolutionary factors that dictate their community structure are unresolved. Here, we characterized the bacterial symbiont communities of three sympatric host species in the genus Ircinia from the NW Mediterranean Sea, using electron microscopy and replicated 16S rRNA gene sequence clone libraries. All Ircinia host species harbored abundant and phylogenetically diverse symbiont consortia, comprised primarily of sequences related to other sponge-derived microorganisms. Community-level analyses of bacterial symbionts revealed host species-specific genetic differentiation and structuring of Ircinia-associated microbiota. Phylogenetic analyses of host sponges showed a close evolutionary relationship between Ircinia fasciculata and Ircinia variabilis, the two host species exhibiting more similar symbiont communities. In addition, several bacterial operational taxonomic units were shared between I.variabilis and Ircinia oros, the two host species inhabiting semi-sciophilous communities in more cryptic benthic habitats, and absent in I.fasciculata, which occurs in exposed, high-irradiance habitats. The generalist nature of individual symbionts and host-specific structure of entire communities suggest that: (1) a 'specific mix of generalists' framework applies to bacterial symbionts in Ircinia hosts and (2) factors specific to each host species contribute to the distinct symbiont mix observed in Ircinia hosts.

Syphacia venteli Travassos, Mem Inst Oswaldo Cruz 32:607-613, 1937 is redescribed on the basis of specimens recovered from the type host, Nectomys squamipes (Brants 1827), from Brazil and Argentina. Specimens determined by Quentin (Bull Mus Natl Hist Nat 2:909-925, 1969) as S. venteli from Melanomys caliginosus (Tomes 1860) in Colombia were re-studied and assigned to a new species. In both species, structures such as the shape of the cephalic plate, details and distribution of the submedian papillae and amphids, presence and absence of the lateral and cervical alae, and shape and structure of the accessory hook of the gubernaculum were studied with the light microscope and scanning electron microscope. The present survey is the first detailed study of the species S. venteli since the original description, and the first record of this species from Argentina. Moreover, the present study suggests that the validity of some host species of Syphacia should be questioned and that through of the study of deposited specimens, a more exact number of parasitized host species can be confirmed, contributing to a better understanding of host specificity in this genus.

We describe two new quill mite species of the genus Meitingsunes Glowska and Skoracki, 2010 (Acari: Prostigmata: Syringophilidae) parasitizing columbiform birds (Columbiformes: Columbidae): M. chalcophaps sp. nov. collected from the Emerald Dove, Chalcophaps indica (Linnaeus) and M. turacoenas sp. nov. from the White-faced Cuckoo Dove, Turacoena manadensis (Quoy and Gaimard) (type host) and the Black Cuckoo-Dove, Turacoena modesta (Temminck). All host species were collected in Indonesia. These represent two new genus-level host records for Meitingsunes. In addition, we summarize the diversity of Meitingsunes and present a key to species in this genus.

Pimeliaphilus hemidactyli sp. nov., a new species of the mite genus Pimeliaphilus Trägårdh (Acariformes: Pterygosomatidae), is described from four host species of Hemidactylus: H. murrayi Gleadow (type host), H. frenatus Duméril & Bibron, H. parvimaculatus Deraniyagala and H. leschenaultii Duméril & Bibron (Sauria: Gekkonidae) from India. P. hemidactyli sp. nov. is the most similar to P. sharifi Abdussalam, 1941 and P. insignis (Berlese, 1892); this species can be distinguished from P. sharifi by the presence of 11 dorsal setae on the idiosoma, the absence of leg setae v”GII, v”TrIII and the presence of v’TrIV, and from P. sharifi by the presence of 11 dorsal setae on idiosoma, 1 pair of genital setae and the absence of coxal setae 4c. The standard morphological description of the new species is supplemented with sequencing data for cytochrome c oxidase subunit I (COI) and nuclear ribosomal genes: 18S rDNA and hypervariable region D2 of nuclear 28S rRNA. The present study also addresses specialisation amongst Pimeliaphilus hemidactyli sp. nov. using two measures of host specificity: (1) the number of host species used by the mites species at the study area; and (2) a measure that considers the taxonomic distinctness of the hosts used by the mite, weighted for its prevalence in the different hosts. The results of this study indicate that this species is highly host specific (a stenoxenous species) and that, in the presence of coexisting gecko species, it prefers Murray’s House gecko (H. murrayi) as a host (prevalence of 41%). A historical review of the genus is presented and a key to the genus is constructed.