Epifaunistic arthropod parasites of the four-striped mouse, Rhabdomys pumilio, in the Western Cape Province, South Africa

Flea, lice, mite, and tick species associated with 510 Rhabdomys pumilio were collected at 9 localities in the Western Cape Province, South Africa. The aims of the study were first to quantify the species richness, prevalence, and relative mean intensity of infestation of epifaunistic arthropod species associated with R. pumilio, and second to determine temporal variations in the mean abundance of the parasitic arthropods. Each mouse was examined under a stereoscopic microscope and its parasites were removed, identified, and quantified. The epifaunal population was made up of more than 25,000 individuals and included 8 flea, 1 sucking louse, 11 mite, and 13 ixodid tick species. Female-biased sex ratios were noted for 9 (30%) of the ectoparasite species. Three undescribed mite and 1 undescribed tick species were recovered, and new locality records for 2 flea, the louse, and 2 mite species were documented. A phoretic host association between a nonparasitic mite species, Psylloglyphus uilenbergi kivuensis, and 3 flea species, Chiastopsylla rossi, Hypsophthalmus temporis, and Listropsylla agrippinae, was recorded. The mean abundance of the parasitic mite and insect species were higher during the cold wet season, whereas ticks were more numerous during the warm dry months. The large number of ectoparasite species on R. pumilio, a locally abundant and regionally widespread species, is of medical and veterinary importance particularly in relation to the transmission of pathogens such as Anaplasma marginale, Babesia caballi, and Babesia canis to domestic animals; Rickettsia conori; Yersinia pestis; and the viral disease Crimean-Congo hemorrhagic fever to humans.     

Parasitic and phoretic arthropods of sylvatic and commensal white-footed mice (Peromyscus leucopus) in central Tennessee, with notes on Lyme disease

Sixteen species of parasitic or phoretic arthropods were collected from 56 white-footed mice, Peromyscus leucopus, live-trapped in central Tennessee from April through November 1987. Arthropod infestation was compared for mice taken from sylvatic (woodland) versus commensal (household) habitats. Three species were recorded from hosts in both habitats: the sucking louse Hoplopleura hesperomydis, the flea Epitedia wenmanni, and the laelapid mite Androlaelaps casalis. Twelve of the 13 remaining arthropod species were taken only from mice trapped in woodland whereas the phoretic glycyphagid mite Glycyphagus hypudaei was collected only from commensal mice. Arthropod faunas on commensal hosts clearly were impoverished. The 12 additional arthropod species recorded from the woodland mice consisted of 1 nidicolous beetle, Leptinus orientamericanus; 1 bot, Cuterebra fontinella; 3 fleas, Ctenophthalmus pseudagyrtes, Orchopeas leucopus and Peromyscopsylla scotti; 1 tick, Dermacentor variabilis; 2 mesostigmatid mites, Androlaelaps fahrenholzi and Ornithonyssus bacoti; 3 chiggers, Comatacarus americanus, Euschoengastia peromysci, and Leptotrombidium peromysci; and 1 undescribed pygmephorid mite of the genus Pygmephorus. Two nymphal and 100 larval D. variabilis were examined for spirochetes and found to be uninfected.     

Parasitic and phoretic arthropods of the elephant-eared and the Santa Cruz kangaroo rats

The parasitic and phoretic arthropods of the elephant-eared kangaroo rat (Dipodomys elephantinus) and Santa Cruz kangaroo rat (D. venustus) are reported; most of these represent new host records. Thirteen of 14 (93%) of D. elephantinus and 11 of 12 (92%) of D. venustus had 11 and nine arthropod species, respectively. Larval and nymphal stages of the tick Dermacentor occidentalis were the most prevalent parasite (77%) on D. elephantinus whereas the mesostigmatid mite Androlaelaps fahrenholzi was the most prevalent (56%) on D. venustus. The arthropod fauna of these two closely related rodents were similar with seven of the 14 arthropod species occurring on both host species. Two species of the host specific listrophorid mite of the genus Geomylichus were found on both hosts.     

New insect host records for mites of the family Microdispidae (Acari: Heterostigmatina), with description of a new species of the genus Paramicrodispus

The mite Paramicrodispus scarabidophilus Hajiqanbar and Rahiminejad sp. nov. (Acari: Prostigmata: Microdispidae) is described and illustrated based on phoretic females recovered from Oryctes nasicornis L. (Col.: Scarabaeidae) hosts, which were collected from forests in northern Iran. It is the first record of the genus Paramicrodispus for the mite fauna of Iran. We also found Paramicrodispus crenulatus (Savulkina, 1978) associated with Lucanus ibericus Motschulsky (Col.: Lucanidae), the first report of association between beetles of the family Lucanidae and the mite family Microdispidae. Moreover, for the first time we report an association between beetles of the family Scarabaeidae and Paramicrodispus mites.     

Phoretic association betweenMacrocheles muscaedomesticae (Acari: Macrochelidae) and flies inhabiting poultry manure in Peninsular Malaysia

The phoretic association betweenMacrocheles muscaedomesticae and flies that inhabited poultry manure in a poultry farm in Sungai Buloh, Selangor, Malaysia was studied. The effects of temperature, relative humidity and fly abundance on phoretic rates also were in vestigated.The most abundant fly species found wasMusca domestica; Musca sorbens, Chrysomyia megacephala andOphyra chalcogaster were present in relatively large numbers.Representatives of ten families of mites were found on collectedMu. domestica. The most common mite wasMa. muscaedomesticae (Macrochelidae), found on all four species of flies mentioned above. The highest infestation (2.0%) occurred onO. chalcogaster butMu. domestica had the highest average number infested (5.7).The ventral part of the housefly's abdomen was the most common site of mite attachment. Usually only one mite was found attached per fly.The highest phoretic rate recorded was 64.4Ma. muscaedomesticae per 1000Mu. domestica. There was no correlation between phoretic rates andMa. muscaedomesticae abundance, nor was relative humidity a factor. However, a positive correlation was recorded in this host species between phoretic rates and temperature.This paper forms part of the Ph. D. thesis of the author submitted to the Universiti Sains Malaysia, Malaysia, in March 1988.     

The associations of phoretic mites (Acarina: Chelicerata) with sand-hoppers (Amphipoda: Crustacea) on the South Wales coast

Mites of the genera Halolaelaps and Phaulodinychus (Gamasida), together with Histiostoma (Acaridida) (Acarina: Chelicerata), occur amongst tidal debris strandlines on the sandy shores of the South Wales coast. Phoretic deuteronymphs of all three mites are dispersed between strandlines via talitrid amphipods (Talitridae: Amphipoda: Crustacea) which provide two principal advantages over the insect hosts used by most other phoretic Acarina. First, amphipods migrate between strandlines throughout the year allowing continual phoretic mite dispersal, and second, even juvenile Talitridae are sufficiently large to transport several mites. The highly aggregated populations of all three mites are distributed independently of amphipod age, sex and species, suggesting that host selection is primarily influenced by other factors. The most likely factors are those related to host behaviour and, in particular, monthly/diurnal quiescence when the mites encounter, and are boarded by, the desiccation-sensitive phoretic mites. The discrete site selection exhibited by each mite species is at least partly influenced by attachment mechanisms.     

Occurrence of Poecilochirus austroasiaticus (Acari: Parasitidae) in forensic autopsies and its application on postmortem interval estimation

Despite the fact that mites were used at the dawn of forensic entomology to elucidate the postmortem interval, their use in current cases remains quite low for procedural reasons such as inadequate taxonomic knowledge. A special interest is focused on the phoretic stages of some mite species, because the phoront-host specificity allows us to deduce in many occasions the presence of the carrier (usually Diptera or Coleoptera) although it has not been seen in the sampling performed in situ or in the autopsy room. In this article, we describe two cases where Poecilochirus austroasiaticus Vitzthum (Acari: Parasitidae) was sampled in the autopsy room. In the first case, we could sample the host, Thanatophilus ruficornis (Küster) (Coleoptera: Silphidae), which was still carrying phoretic stages of the mite on the body. That attachment allowed, by observing starvation/feeding periods as a function of the digestive tract filling, the establishment of chronological cycles of phoretic behavior, showing maximum peaks of phoronts during arrival and departure from the corpse and the lowest values in the phase of host feeding. From the sarcosaprophagous fauna, we were able to determine in this case a minimum postmortem interval of 10 days. In the second case, we found no Silphidae at the place where the corpse was found or at the autopsy, but a postmortem interval of 13 days could be established by the high specificity of this interspecific relationship and the departure from the corpse of this family of Coleoptera.     

Phoretic mites associated with animal and human decomposition

Phoretic mites are likely the most abundant arthropods found on carcases and corpses. They outnumber their scavenger carriers in both number and diversity. Many phoretic mites travel on scavenger insects and are highly specific; they will arrive on a particular species of host and no other. Because of this, they may be useful as trace indicators of their carriers even when their carriers are absent. Phoretic mites can be valuable markers of time. They are usually found in a specialised transitional transport or dispersal stage, often moulting and transforming to adults shortly after arrival on a carcase or corpse. Many are characterised by faster development and generation cycles than their carriers. Humans are normally unaware, but we too carry mites; they are skin mites that are present in our clothes. More than 212 phoretic mite species associated with carcases have been reported in the literature. Among these, mites belonging to the Mesostigmata form the dominant group, represented by 127 species with 25 phoretic mite species belonging to the family Parasitidae and 48 to the Macrochelidae. Most of these mesostigmatids are associated with particular species of flies or carrion beetles, though some are associated with small mammals arriving during the early stages of decomposition. During dry decay, members of the Astigmata are more frequently found; 52 species are phoretic on scavengers, and the majority of these travel on late-arriving scavengers such as hide beetles, skin beetles and moths. Several species of carrion beetles can visit a corpse simultaneously, and each may carry 1–10 species of phoretic mites. An informative diversity of phoretic mites may be found on a decaying carcass at any given time. The composition of the phoretic mite assemblage on a carcass might provide valuable information about the conditions of and time elapsed since death.     

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44-49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 μm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers.     

Importance of phoresy in the transmission of Acarina

Dispersal capacity plays a central role in the radiation of animals, facilitating the exploitation of habitats variously distributed in space or in time or both. Many living species are unable to leave a host, crawl around, and find a new host, so they must rely on external factors to be transmitted. Biotical factors may be important in passive transport and the process, by means of which an animal is passively transported by a selected carrier of different species, is known as "phoresy". Phoresy is a phenomenon in which one animal (the phoretic) seeks out and attaches to an animal of another species, with which it does not share any phase of the life cycle, for dispersal, during which time the phoretic animal becomes quiescent, stopping feeding and development. Activity starts again beginning with detachment, induced by stimuli originating from its carrier or the microhabitat. The adaptive traits of phoresy may be categorized as follow: host surface, quiescence, recognition of signals to abandon the carrier and, if needed, synchronization with the host life cycle. Phoresy is exploited by many Arthropods. In Acarina, there are basically four main types of phoresy. First, there is a type in which adult females are the only forms becoming phoretic and attachment is by means of chelicerae, palpal hooks and ambulacral claws, which grasp a seta or a fold of the integument of carrier-host. The second type is represented by mites, in which deutonymphs are phoretic; there is generally no cheliceral or sucker attachment in this group, mites instead hanging on by their ambulacral claws. The third type is similar to the second in that deutonymphs are phoretic; however, in this case, attachment to the host is by means of an anal pedicel formed by a substance, extruded through the anus, which hardens upon coming in contact with air and literally glues the mite to its host. In the fourth type there is a very highly modified deutonymph stage, called hypope, which only occurs at certain times, presumably when environmental conditions are no longer appropriate for the mite. Hypope is simplified morphologically, may have many sucker-like discs or claspers for efficient attachment, and is much more resistant to desiccation than are other stages of the life cycle.     

Age and reproductive status of adult Varroa mites affect grooming success of honey bees

This study evaluated for the first time the grooming response of honey bees to Varroa mites of different ages and reproductive statuses in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four classes of mites: gravid, phoretic foundresses, phoretic daughters and a combination of gravid and phoretic foundress mites. Each cage received 20 mites belonging to one of these classes. Our results showed that, 1?day after mite inoculation, phoretic daughter mites were the most prone to grooming by honey bees with an average mite drop of 49.8?±?2.6?%. The lowest mite drop was recorded for bees inoculated with phoretic foundresses (30.3?±?3.6?%) but was comparable to bees inoculated with gravid mites (31.8?±?3.8?%) and the combination of gravid and phoretic foundress mites (34.2?±?3.2?%). No differences among mite types were detected during the second and third days of observation. Regardless of mite type, the highest mite drop was recorded on the first day (35?±?2.1?%) compared to the drop for any subsequent day (<10?%). Because of the great reproductive potential of daughter mites, their inclusion in assessments of grooming behaviour may increase our insight into the importance of grooming in mite resistance.     

Bark and ambrosia beetles (Curculionidae: Scolytinae), their phoretic mites (Acari) and associated Geosmithia species (Ascomycota: Hypocreales) from Virgilia trees in South Africa

Bark and ambrosia beetles are ecologically and economically important phloeophagous insects that often have complex symbiotic relationships with fungi and mites. These systems are greatly understudied in Africa. In the present study we identified bark and ambrosia beetles, their phoretic mites and their main fungal associates from native Virgilia trees in the Cape Floristic Region (CFR) of South Africa. In addition, we tested the ability of mites to feed on the associated fungi. Four species of scolytine beetles were collected from various Virgilia hosts and from across the CFR. All were consistently associated with various Geosmithia species, fungi known from phloeophagous beetles in many parts of the world, but not yet reported as Scolytinae associates in South Africa. Four beetle species, a single mite species and five Geosmithia species were recovered. The beetles, Hapalogenius fuscipennis, Cryphalini sp. 1, and Scolytoplatypus fasciatus were associated with a single species of Elattoma phoretic mite that commonly carried spores of Geosmithia species. Liparthrum sp. 1 did not carry phoretic mites. Similar to European studies, Geosmithia associates of beetles from Virgilia were constant over extended geographic ranges, and species that share the same host plant individual had similar Geosmithia communities. Phoretic mites were unable to feed on their Geosmithia associates, but were observed to feed on bark beetle larvae within tunnels. This study forms the first African-centred base for ongoing global studies on the associations between arthropods and Geosmithia species. It strengthens hypotheses that the association between Scolytinae beetles and dry-spored Geosmithia species may be more ubiquitous than commonly recognised.     

Hygrobates salamandrarum sp. nov. (Acari, Hydrachnidia, Hygrobatidae) from China: the First Record of a Freshwater Mite Parasitizing Newts (Amphibia, Urodela)

Females of a new water mite species of the genus Hygrobates (Acari, Hydrachnidia, Hygrobatidae) were found to parasitize Pachytriton labiatus (Unterstein, 1930) (Amphibia, Salamandridae), a newt species from S China. Obviously, their particularly modified mouthparts are an adaptation for penetrating the amphibian skin. These data provide the first record of an adult water mite parasitizing a vertebrate host.     

Influence of spatio-temporal resource availability on mushroom mite diversity

Although biodiversity in nature is of fundamental importance because it improves the sustainability of ecosystems, communities of microscopic organisms are generally excluded from conservation targets for biodiversity. Here, I hypothesize that mushroom mite species richness is correlated with both spatial (i.e., mushroom size) and temporal (i.e., longevity of fruiting bodies) resource availability. I collected fruiting bodies in an old-growth forest over 4 years to collect mites and insects inhabiting the mushrooms. Mites were collected from 47 % of the fruiting bodies and approximately 60 % of the mite species were collected only once. Mite species richness was significantly correlated with the availability of long-lasting fruiting bodies. For example, bracket fungi contained more mite species than ephemeral fruiting bodies. Insect presence was also correlated with mushroom mite richness, probably as phoretic hosts and food resources for predacious mites. On the other hand, mushroom size seemed to be less important; small fruiting bodies sometimes harbored several mite species. Although mite species richness was correlated with mushroom species richness, mushroom specificity by mites was not clear except for a preference for long-lasting fruiting bodies. Therefore, I suggest that a constant supply of coarse woody debris is crucial for maintaining preferred resources for mushroom mites (e.g., bracket fungi) and their associated insects (mycophilous and possibly saproxylic insects).     

Migratory songbirds disperse ticks across Canada, and first isolation of the Lyme disease spirochete, Borrelia burgdorferi, from the avian tick, Ixodes auritulus

During a 3-yr comprehensive study, 196 ixodid ticks (9 species) were collected from 89 passerine birds (32 species) from 25 localities across Canada to determine the distribution of avian-associated tick species and endogenous Lyme disease spirochetes, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt, and Brenner. We report the following first records of tick parasitism on avian hosts: the rabbit-associated tick, Ixodes dentatus Marx, from Manitoba and Ontario; the mouse tick, Ixodes muris Bishopp and Smith, from British Columbia; and the blacklegged tick, Ixodes scapularis Say, from New Brunswick. Moreover, we provide the first record of the Neotropical tick, Amblyomma humerale Koch (1 nymph), in Canada and its parasitism of any bird. This tick was compared morphologically with nymphs of other Neotropical Amblyomma spp., and genetically, using a 344-bp fragment of the 12S rDNA sequence of 41 New World Amblyomma species. The first collections of the western blacklegged tick, Ixodes pacificus Cooley and Kohls, from passerine species in Alberta and British Columbia, are also reported. Notably, we further report the first isolation of B. burgdorferi from the bird tick, Ixodes auritulus Neumann, collected from an American robin, Turdus migratorius L., on Vancouver Island. Furthermore, B. burgdorferi-positive I. auritulus larvae were collected from a reservoir-competent fox sparrow, Passerella iliaca (Merrem). Our findings indicate that ground-dwelling passerines, in particular, are parasitized by certain ixodid ticks and play an important role across Canada in the wide dispersal of B. burgdorferi-infected ticks and increased risk of Lyme disease exposure.     

Review. When to leave the brood chamber? Routes of dispersal in mites associated with burying beetles

Most nests of brood-caring insects are colonized by a rich community of mite species. Since these nests are ephemeral and scattered in space, phoresy is the principal mode of dispersal in mites specializing on insect nests. Often the mites will arrive on the nest-founding insect, reproduce in the nest and their offspring will disperse on the insect's offspring. A literature review shows that mites reproducing in the underground brood chambers of burying beetles use alternative routes for dispersal. For example, the phoretic instars of Poecilochirus spp. (Mesostigmata: Parasitidae) disperse early by attaching to the parent beetles. Outside the brood chamber, the mites switch host at carcasses and pheromone-emitting male beetles, where juvenile and mature burying beetles of several species congregate. Because they preferably switch to beetles that are reproductively active and use all species of burying beetles within their ranges, they have a good chance of arriving in a new brood chamber. Other mite associates of burying beetles (Alliphis necrophilus and Uropodina) disperse from the brood chamber on the beetle offspring. We suggest that these mites forgo the possible time gain of dispersing early on the parent beetles because their mode of attachment precludes host switching. Their phoretic instars, once attached, have to stay on their host and so only dispersing on the beetle offspring guarantees that they are present on reproducing burying beetles of the next season. The mites associated with burying beetles providean example of multiple solutions to one life history problem – how to find a new brood chamber for reproduction. Mites that have mobile phoretic instars disperse on the parent beetles and try to arrive in the next brood chamber by host switching. They are independent of the generation cycle of a single host and several generations of mites per host generation are possible. Mites that are constrained by their mode of attachment disperse on the beetle offspring and wait until their host becomes mature and reproduces. By doing this they synchronize their generation time with the generation time of their host species. Exp Appl Acarol 22: 621–631 © 1998 Kluwer Academic Publishers     

Dynamic associations between <Emphasis Type="Italic">Ips sexdentatus</Emphasis> (Coleoptera: Scolytinae) and its phoretic mites in a <Emphasis Type="Italic">Pinus pinaster</Emphasis> forest in northwest Spain

The relationship between the pine bark beetle Ips sexdentatus and its phoretic mites in a Pinus pinaster forest in northwest Spain was studied during 2014. Four species of mites were collected, three of them from the body of the beetle—Histiostoma ovalis, Dendrolaelaps quadrisetus and Trichouropoda polytricha—the fourth, Cercoleipus coelonotus, was collected from the sediments. The main aims of this study were to explore (1) mite diversity and related parameters, (2) the location on the body of the (male and female) beetle, as well as mite assemblages, and (3) the seasonal dynamic association between mite species and the beetle. Results indicated that the diversity oscillated around 0.71 through the study period and the most dominant, frequent and abundant mite was H. ovalis. Histiostoma ovalis was found attached to almost all parts of the body (mainly on the elytral declivity and ventral thorax), whereas D. quadrisetus was exclusively found under the elytra, and T. polytricha displayed affinity towards the elytral declivity as well as the ventral thorax. None of the mite species displayed any preference for the sex of the beetle and the most frequent mite assemblage was H. ovalis, T. polytricha and D. quadrisetus all together. Maximum abundance of each phoretic mite species was related with each of the flight peaks of the beetle that would indicate that these mite species use phoresy as a primary method of transport for colonizing new food sources.     

Host Selection by the Herbivorous Mite Polyphagotarsonemus latus (Acari: Tarsonemidae)

This study examined the host-selection ability of the broad mite Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae). To make long-distance-shifts from one host plant patch to another, broad mites largely depend on phoretic association with whiteflies. However, the host plants of whiteflies and broad mites are not necessarily the same. We determined the host-preference and acceptance of free-moving and phoretic broad mites using two behavioral bioassays. We used a choice test to monitor host selection by free-moving mites. In the case of phoretic mites, we compared their rate of detachment from the phoretic vector Bemisia tabaci placed on leaves taken from various host plants. The suitability of the plant was further determined by monitoring mite’s fecundity and its offspring development. We compared the mites’ responses to young and old cucumber (Cucumis sativus cv. ‘Kfir’) leaves (3rd and 8–9th leaf from the apex, respectively), and two tomato (Solanum lycopersicum cvs. ‘M82’ and ‘Moneymaker’). Free-moving mites of all stages and both sexes preferred young cucumber leaves to old cucumber leaves and preferred young cucumber rather than young tomato leaves, demonstrating for the first time that broad mites are able to choose their host actively. As for phoretic mated females, although eventually most of the mites abandoned the phoretic vector, the rate of detachment from the whitefly vector was host dependent and correlated with the mites’ fitness on the particular host. In general, host preference of phoretic female mites resembled that of the free-moving female. Cues used by mites for host selection remain to be explored.