Novel Rickettsia and host records for argasid ticks, including Alveonasus cooleyi, on wild mammals in Baja California, Mexico.

We conducted surveillance of mammals to investigate their associations with argasid ticks and tick-borne pathogens. During 2021, a total of 20 wild carnivores and 57 lagomorphs were sampled, and 39 argasid ticks belonging to two species were collected. All mammals and ticks were tested by molecular assays to detect Borrelia and Rickettsia infections. Nine ticks identified as Otobius megnini were collected from two coyotes (Canis latrans) and 30 Alveonasus cooleyi (McIvor 1941) were collected from six bobcats (Lynx rufus) and one rabbit (Sylvilagus auduboni). We detected Rickettsia spp. DNA in 21 of the 27 (77.8%) tested Av. cooleyi and none of the O. megnini. No ticks were PCR-positive for borreliae and all mammals were PCR-negative for both pathogen genera. Phylogenetic analysis based on gltA, htrA, and 16 S rRNA targets revealed that all rickettsiae from Av. cooleyi clustered with ancestral group rickettsiae, likely representing a novel species of possibly endosymbiotic Rickettsia. The significance of Av. cooleyi and the newly identified Rickettsia sp. to the health of wildlife is unknown, and further work is indicated to determine whether they may be relevant to public health or carnivore conservation.

Population genetic structure and demographic history of the lone star tick, Amblyomma americanum (Ixodida: Ixodidae): New evidence supporting old records.

Range expansions are a potential outcome of changes in habitat suitability, which commonly result as a consequence of climate change. Hypotheses on such changes in the geographic distribution of a certain species can be evaluated using population genetic structure and demography. In this study we explore the population genetic structure, genetic variability, demographic history of, and habitat suitability for Amblyomma americanum, a North American tick species that is a known vector of several pathogenic microorganisms. We used a double digestion restriction site-associated DNA sequencing technique (dd-RAD seq) and discovered 8,181 independent single nucleotide polymorphisms (SNPs) in 189 ticks from across the geographic range of the species. Genetic diversity was low, particularly when considering the broad geographic range of this species. The edge populations were less diverse than populations belonging to the historic range, possibly indicative of a range expansion, but this hypothesis was not statistically supported by a test based on genetic data. Nonetheless, moderate levels of population structure and substructure were detected between geographic regions. For New England, demographic and species distribution models support a scenario where A. americanum was present in more northern locations in the past, underwent a bottleneck, and subsequently recovered. These results are consistent with a hypothesis that this species is re-establishing in this area, rather than one focused on range expansion from the south. This hypothesis is consistent with old records describing the presence of A. americanum in the northeastern US in the early colonial period.

The biology of Megalolaelaps colossus (Acari: Dermanyssina).

Aspects of life history and host interactions of Megalolaelaps colossus were studied in a laboratory environment. These mites appear to require a host for survival, but hosts do not survive very long in a laboratory setting, leading to a modified rearing protocol relying on regular host replacement. Specific data on phenology and incidence are reported. Direct observations on feeding, mating, transmission, and interaction with other mites could not be obtained, but indirect observations allow some hypotheses in each of these areas.

Phylogeography of Ticks (Acari: Ixodida).

Improved understanding of tick phylogeny has allowed testing of some biogeographical patterns. On the basis of both literature data and a meta-analysis of available sequence data, there is strong support for a Gondwanan origin of Ixodidae, and probably Ixodida. A particularly strong pattern is observed for the genus Amblyomma, which appears to have originated in Antarctica/southern South America, with subsequent dispersal to Australia. The endemic Australian lineages of Ixodidae (no other continent has such a pattern) appear to result from separate dispersal events, probably from Antarctica. Minimum ages for a number of divergences are determined as part of an updated temporal framework for tick evolution. Alternative hypotheses for tick evolution, such as a very old Pangean group, a Northern hemisphere origin, or an Australian origin, fit less well with observed phylogeographic patterns.

Ectoparasites of Propithecus diadema (Primates: Indriidae) With Notes on Unusual Attachment Site Selection by Haemaphysalis lemuris (Parasitiformes: Ixodidae).

An examination of ectoparasite loads in two populations of wild diademed sifakas, Propithecus diadema Bennett, yielded seven species-four mite species, a louse, a hippoboscid fly, and a leech. Prevalence of the tick Haemaphysalis lemuris Hoogstraal, the mites Liponyssella madagascariensis (Hirst) and Lemuralges propithecus Bochkov et al., and the louse Trichophilopterus babakotophilus Stobbe was quite high, at least 20%. H. lemuris was the most common ectoparasite in one population, while completely absent in a second one. When present, the most common attachment site for H. lemuris males was in the nares of their hosts.

Lemuralges propithecus sp. n. (Acariformes: Psoroptidae), an ectoparasite of the diademed sifaka Propithecus diadema (Primates: Indriidae).

A new species of the genus Lemuralges Fain, 1963 (Acariformes: Psoroptidae: Makialginae) is described from the Malagasy lemur Propithecus diadema (Bennett) (Primates: Indriidae) based on all postembryonic instars. This new species differs from the only known species in this genus, Lemuralges intermedius Fain, 1963, by the following features: both sexes of L. propithecus sp. n. show a pair of medioventral projections of the subcapitulum (vs without projections in L. intermedius) and the propodonotal shield is slightly ornamented (vs unornamented); in males the hysteronotal shield is completely covered by longitudinal striae (vs median part without striae), setae c2 are 120-140 µm long (vs 200-210 µm long), and femur III has a short transverse furrow dorsally (vs a longitudinal furrow); in females, setae h2 are, at least, 2 times shorter than h3 (vs slightly longer, or subequal to, h3), tibia IV has a ventro-apical projection (vs without projection). Larvae and protonymphs of the new species show some unique developmental delays. Female and male tritonymphs differ by their external morphology.

Post-embryonic development in the mite suborder Opilioacarida, with notes on segmental homology in Parasitiformes (Arachnida).

In order to study homology among the major lineages of the mite (super)order Parasitiformes, developmental patterns in Opilioacarida are documented, emphasizing morphology of the earliest, post-embryonic instars. Developmental patterns are summarized for all external body structures, based on examination of material in four different genera. Development includes an egg, a 6-legged prelarva and larva, three 8-legged nymphal instars, and the adults, for the most complete ontogenetic sequence in Parasitiformes. The prelarva and larva appear to be non-feeding. Examination of cuticular structures over ontogeny allows development of an updated model for body segmentation and sensillar distribution patterns in Opilioacarida. This model includes a body made up of a well-developed ocular segment plus at most 17 additional segments. In the larvae and protonymphs each segment may carry up to six pairs of sensilla (setae or lyrifissures) arranged is distinct series (J, Z, S, Sv, Zv, Jv). The post-protonymphal instars add two more series (R and Rv) but no extra segments. This basic model is compatible with sensillar patterns in other Parasitiformes, leading to the hypothesis that all taxa in that (super)order may have the same segmental ground plan. The substantial segmental distortion implied in the model can be explained using a single process involving differential growth in the coxal regions of all appendage-bearing segments.

The role of the integument with respect to different modes of locomotion in the Nematalycidae (Endeostigmata).

Previous research on the locomotion of the Nematalycidae has only been undertaken on Gordialycus, which is by far the most elongated genus of the family. Gordialycus is dependent on an unusual form of peristalsis to move around. It was not known whether the genera of Nematalycidae with shorter bodies also used this mode of locomotion. Our videographic recordings of Osperalycus did not reveal peristalsis. Instead, this mite appears to move around the mineral regolith via the expansion and constriction of the metapodosomal and genital region, allowing greater versatility in the way that the annular regions contract and extend. This type of locomotion would enable relatively short bodied nematalycids to anchor themselves into secure positions before extending their anterior regions through tight spaces. Low-temperature scanning electron micrographs show that the short bodied genera have integumental features that appear to be associated with this mode of locomotion. Peristalsis is almost certainly a more derived form of locomotion that is an adaptation to the unusually long body form of Gordialycus.

Two new mite species of the subfamily Harpirhynchinae Dubinin, 1957 (Acariformes: Harpirhynchidae), parasites of the passerine birds (Aves: Passeriformes) in Australia and South Asia.

Two new mite species of the subfamily Harpirhynchinae Dubinin, 1957 (Acariformes: Harpirhynchidae) are described from passerine birds (Aves: Passeriformes): Harpirhynchoides artamus n. sp. from Artamus fuscus Vieillot (Artamidae) from an unknown locality in South Asia and Neharpyrhynchus domrowi n. sp. from three host species of the family Meliphagidae, Acanthorhynchus tenuirostris (Latham) (type-host) from Australia (New South Walles), Ptiloprora perstriata (De Vis) and Myzomela rosenbergii Schlegel from Papua New Guinea.

Redefinition of Cosmolaelaps Berlese (Acari: Laelapidae) and description of five new species from Brazil.

Cosmolaelaps Berlese, 1903 was originally described as a subgenus of Laelaps Koch. More recently, this group has been treated at the generic level or as a subgenus of Hypoaspis Canestrini, 1885. One of the objectives of the present paper is to provide a detailed characterisation of Cosmolaelaps, here considered at the generic level, a group that was poorly characterised in its original description as well as in subsequent publications. It is most closely related to Stratiolaelaps Berlese, from which it can usually be distinguished by the presence of extra paired and unpaired setae on the opisthonotal region of the dorsal shield, as well as by not having hypertrophied chelicerae or corniculi. A total of 108 species belong to Cosmolaelaps, including the new species described here. Five other species may also belong to this genus, but the available published information does not allow their conclusive placement. The Brazilian fauna of Hypoaspidinae is poorly known, but Cosmolaelaps seems to be well represented in Brazil. Thus, the second objective of this paper is to describe five new species of Cosmolaelaps from that country, namely C. barbatus sp. nov., C. busolii sp. nov., C. confinisetarum sp. nov., C. jaboticabalensis sp. nov. and C. oliveirai sp. nov.

Description of the second species of Cingulacarus Elsen (Acari, Mesostigmata, Diplogyniidae), and notes on the genus.

Cingulacarus Elsen is a monotypic genus of Trigynaspida based on C. gangeticus Elsen, collected from the scarabaeid beetle Scarabaeus gangeticus (Castelnau) (Col., Scarabaeidae) in the Democratic Republic of the Congo. Herein, a second species of the genus, C. kermanensis sp. nov. is described based on female and male specimens collected in southeastern Iran, in association with Oryctes elegans L. (Col., Scarabaeidae). The diagnosis of the genus Cingulacarus is revised, with a discussion of the impact on current generic keys for the family Diplogyniidae, and a proposal to eliminate the current subfamilial classification within that family.

The microbiota of Amblyomma americanum reflects known westward expansion.

Amblyomma americanum, a known vector of multiple tick-borne pathogens, has expanded its geographic distribution across the United States in the past decades. Tick microbiomes may play a role shaping their host's life history and vectorial capacity. Bacterial communities associated with A. americanum may reflect, or enable, geographic expansion and studying the microbiota will improve understanding of tick-borne disease ecology. We examined the microbiota structure of 189 adult ticks collected in four regions encompassing their historical and current geographic distribution. Both geographic region of origin and sex were significant predictors of alpha diversity. As in other tick models, within-sample diversity was low and uneven given the presence of dominant endosymbionts. Beta diversity analyses revealed that bacterial profiles of ticks of both sexes collected in the West were significantly different from those of the Historic range. Biomarkers were identified for all regions except the historical range. In addition, Bray-Curtis dissimilarities overall increased with distance between sites. Relative quantification of ecological processes showed that, for females and males, respectively, drift and dispersal limitation were the primary drivers of community assembly. Collectively, our findings highlight how microbiota structural variance discriminates the western-expanded populations of A. americanum ticks from the Historical range. Spatial autocorrelation, and particularly the detection of non-selective ecological processes, are indicative of geographic isolation. We also found that prevalence of Ehrlichia chaffeensis, E. ewingii, and Anaplasma phagocytophilum ranged from 3.40-5.11% and did not significantly differ by region. Rickettsia rickettsii was absent from our samples. Our conclusions demonstrate the value of synergistic analysis of biogeographic and microbial ecology data in investigating range expansion in A. americanum and potentially other tick vectors as well.

A revision of the genus Afroheterozercon (Acari: Heterozerconidae).

Six new species of Afroheterozercon, A. mahsbergi, A. sanghae, A. goodmani, A. gabonensis, A. tanzaniensis and A. madagascariensis, are described from a range of localities in sub-Saharan Africa, bringing the total number of described species in the genus to ten. These mites appear to be common on especially larger millipedes. Distribution data suggest locality, rather than host, specificity. A preliminary analysis of relationships provided relatively weak resolution and no evidence of geographically restricted lineages.

Genus-level revision of the Heterozerconoidea (Parasitiformes: Mesostigmata).

The genera of Heterozerconoidea are revised based on a species-level analysis of relationships in the group. The family Discozerconidae in its current state may be paraphyletic. Diagnoses for the genera are updated, and a catalog of all described species is provided. As part of this re-analysis two new genera, Amyzozercon and Ecuazercon, and four new species are described, and a key to the genera is provided. Possible evolutionary implications of the proposed set of relationships in terms of biogeography and the evolution of podospermy are discussed.

Catalogue of the free-living and arthropod-associated Laelapidae Canestrini (Acari: Mesostigmata), with revised generic concepts and a key to genera.

The cosmopolitan mite family Laelapidae includes both free-living predatory species and species associated with arthropods, mammals or birds. This work presents a list of free-living and arthropod-associated species of laelapids, with corresponding taxonomic information and references. It includes 1088 species (in addition to three subspecies) assigned to 73 genera, 61 new combinations and two new synonymies at the generic level. Laelaps (Apolaelaps) Silvestri is raised to the generic level. Many of the species described before about 1950 are poorly characterised and cannot be classified with confidence at the family or generic level. Hence, ten genera, one subgenus, 121 species (ca. 70% of which were reported as Hypoaspis Canestrini or Laelaps (Hypoaspis) Canestrini) and one subspecies, are considered incertae sedis, because of their inadequate morphological characterisation in the literature. Some of these may not even belong to the Laelapidae or to the groups of interest for this publication. A total of 89 species, 30 genera, one subgenus, one tribe and one subfamily previously associated with genera treated in this catalogue are now placed in other families or, less commonly, in laelapid genera not considered here because they are considered essentially vertebrate parasites (taxa excluded). Twenty-six other species (one cited as a "variety") are cited as nomina nuda. An illustrated key to the 73 genera included in the catalogue along with revised generic diagnoses are provided.

Integrative Taxonomy of Dermacentor variabilis (Ixodida: Ixodidae) with Description of a New Species, Dermacentor similis n. sp.

Dermacentor variabilis is the most widely distributed three-host tick in North America, and transmits a variety of pathogens. Within the United States, this species has a discontinuous distribution, widespread east of the Rocky Mountains and with a few populations west of the Rockies. Phylogenetic evidence based on individual markers or relatively small data sets has suggested that populations at both sides of this geographic barrier may correspond to two different species. In this study, we further explore this hypothesis using an integrative taxonomy framework. Both molecular (mitochondrial and nuclear markers) and morphological analyses of specimens collected from central-eastern and western states were performed to explore species delimitation in this taxon. Results from these analyses were consistent, and provide strong evidence that D. variabilis actually corresponds to two species. Herein, the western populations are described as a new species, Dermacentor similis n. sp. The usefulness of integrative taxonomy in the context of species delimitation is also discussed.

Review of the genus Sessiluncus (Acari: Mesostigmata: Ologamasidae), description of male and redescription of female of Sessiluncus aegypticus, and notes on some morphological characters of the genus.

The concept of the genus Sessiluncus G. Canestrini is reviewed, based on a review of the literature and examination of some described and undescribed species. An updated diagnosis of the genus is presented. Valid species of Sessiluncus and their most diagnostic morphological characters are listed. The male of S. aegypticus Nasr Afifi, 1986 is described for the first time based on specimens collected in Egypt, and the female is redescribed from specimens collected in Egypt and Iran. Sessiluncus oculatus Vitzthum, 1935 is reported from Panama, and supplementary information on S. hungaricus Karg, 1964 and S. oculatus is presented. The labrum, paralabrum and paralabral stylus of S. aegpticus are also described. The idiosomal adenotaxy and poroidotaxy of the genus are described and discussed.

Size, shape, and direction matters: Matching secondary genital structures in male and female mites using multiple microscopy techniques and 3D modeling.

Studies of female genital structures have generally lagged behind comparable studies of male genitalia, in part because of an assumption of a lower level of variability, but also because internal genitalia are much more difficult to study. Using multiple microscopy techniques, including video stereomicroscopy, fluorescence microscopy, low-temperature scanning electron microscopy (LT-SEM), and confocal laser scanning microscopy (CLSM) we examined whether the complex sperm transfer structures in males of Megalolaelaps colossus (Acari: Mesostigmata) are matched by similarly complex internal structures in the female. While both LT-SEM and CLSM are well suited for obtaining high-quality surface images, CLSM also proved to be a valuable technique for observing internal anatomical structures. The long and coiled sperm transfer organ on the chelicera of the males (spermatodactyl) largely matches an equally complex, but internal, spiral structure in the females in shape, size, and direction. This result strongly suggests some form of genital coevolution. A hypothesis of sexual conflict appears to provide the best fit for all available data (morphology and life history).

The first Nearctic record of the genus Neocheiridium (Pseudoscorpiones: Cheiridiidae), with description of Neocheiridium gullahorum sp. n.

BACKGROUND: The genus Neocheiridium Beier, 1932 currently contains seven Neotropical (including Caribbean) and two Afrotropical species, with no Nearctic records. NEW INFORMATION: An undescribed species of Neocheiridium from South Carolina was discovered in the Ohio State University Acarology Collection and is described as Neocheiridium gullahorum, n. sp. (based on specimens of both sexes). A key to known world species of Neocheiridium is proposed.

New Species of the Genus Periglischrus (Acari: Spinturnicidae) from Monophyllus Bats (Chiroptera: Phyllostomidae) in the West Indies, Including a Morphometric Analysis of Its Intraspecific Variation.

The discovery of a new species, Periglischrus empheresotrichus, was determined through a review of museum collections, as well as a field survey of ectoparasites of island bats. This new species parasitizes on two bat species of the genus Monophyllus Leach, the Greater Antillean Long-tongued bat Monophyllus redmani Leach and the Lesser Antillean Long-tongued bat Monophyllus plethodon Miller. The female, male, deuthonymphs, and protonymph are described and illustrated. P. empheresotrichus n. sp. has an insular distribution, we evaluated the morphological variation of the adult populations, and concluded that intra-specific variation is correlated both with host species and locality (island) in the West Indies.