Redescription of species of Gongylonema Molin, 1857 (Nematoda: Spiruroidea: Gongylonematidae) parasitic in some Australian vertebrate hosts and description of three new species.

Gongylonematid nematodes (Nematoda: Gongylonematidae) parasitic in some Australian vertebrates are described from the monotypic genus Gongylonema (Gongylonema) (Molin, 1857). Three previously incompletely described species from a megapod and murid rodents are re-described from limited material. Three additional species are described from murid rodents and macropodid, potoroid and phalangerid marsupials. A key to species is provided.

Two new genera and species of Nippostrongylinae (Nematoda: Heligmonellidae) parasites of two murine rodents (Muridae): from the Moluccas, Indonesia and Papua New Guinea with a comment on a pentastomatid.

Bisastrongylus multiovorum gen. nov., sp. nov. (Nematoda: Heligmonellidae: Nippostrongylinae) is described from a murid, Melomys obiensis, from the Moluccas, Indonesia. The new genus differs from all other Nippostrongylinae genera in having a synlophe of 12 unequal ridges with a type A carene, the dorsal ridge 1 being larger than the ventral ridge 1'. Pentastomid larvae, an acanthocephalan, Plagiorhynchus sp., and the nematodes Rictularia sp., a spirurid and the nippostrongylin Soricstrongylus obreensis gen. nov., sp. nov. were collected from the murid Pseudohydromys murinus from Central Province, Papua New Guinea. The new genus is distinguished by a combination of characters including a synlophe of 11-13 ridges at mid body, left ventral ridges larger and a sub frontal axis of orientation. The assemblage of P. murinus is discussed and a re-evaluation of nippostrongylin Odilia sp., previously reported from P. murinus indicates that the specimens were likely a Parasabanema sp.

Occurrence of Hymenolepis diminuta: a potential helminth of zoonotic importance in murid rodents / Ocorrência de Hymenolepis diminuta: um helminto potencial de importância zoonótica em roedores murídeos

The study reveals the prevalence of a potential rodent-borne zoonotic helminth species, Hymenolepis diminuta in commensal rodents caught from irrigated and rain-fed areas of Swat, Pakistan. Three hundred and fifty rodents (269 rats and 81 mice) trapped during vegetative, flowering/fruiting and mature/harvesting stages of crops were studied from 2011-2013. Hymenolepisdiminuta eggs were identified on the basis of their shape, size, colour and markings on the surface of the egg shell and three pairs of embryonic hook-lets. Overall prevalence of H. diminuta was 3.14% (n=11/350). The highest prevalence 3.49% (n=5/143) of H. diminuta was noted at harvesting stages of the crops whereas the lowest 2.59% (n=2/77) during vegetative stage. Infection was higher in males 3.25% (n=7/215) than females 2.96% (n=4/135). Adult rodents were highly infected while no sub-adult was found infected. Infection was higher in mice 3.70% (3/81) than rats 2.69% (8/269) while no significance (p=1.0000:0.1250 to 32.00 CI). Rats and mice appears to show the most suitable reservoirs by hosting H. diminuta a zoonotic helminth. The presence of these rodents in all possible habitats can act as a main channel of transferring parasites through various habitats and can pose a hazard to humans in the area.

O estudo revela a prevalência de uma espécie potencial de helmintos zoonóticos transmitidos por roedores, Hymenolepis diminuta, em roedores comensais capturados em áreas irrigadas e alimentadas pela chuva de Swat, Paquistão. Trezentos e cinquenta roedores (269 ratos e 81 camundongos) presos durante os estágios vegetativo, floração/frutificação e maturidade/colheita das safras foram estudados de 2011-2013. Ovos de Hymenolepisdiminuta foram identificados com base em sua forma, tamanho, cor e marcações na superfície da casca do ovo e três pares de anzóis embrionários. A prevalência geral de H. diminuta foi de 3,14% (n = 11/350). A maior prevalência 3,49% (n = 5/143) de H. diminuta foi observada na fase de colheita das lavouras, enquanto a menor 2,59% (n = 2/77) durante a fase vegetativa. A infecção foi maior nos homens 3,25% (n = 7/215) do que nas mulheres 2,96% (n = 4/135). Roedores adultos foram altamente infectados, enquanto nenhum subadulto foi encontrado infectado. A infecção foi maior em camundongos 3,70% (3/81) do que em ratos 2,69% (8/269), embora sem significância (p = 1,0000: 0,1250 a 32,00 CI). Ratos e camundongos parecem mostrar os reservatórios mais adequados hospedando H. diminuta um helmintos zoonótico. A presença desses roedores em todos os habitats possíveis pode atuar como um canal principal de transferência de parasitas através de vários habitats e pode representar um perigo para os humanos na área.

Response of small mammal and tick communities to a catastrophic wildfire and implications for tick-borne pathogens.

Through their potentially devastating impacts on the environment, wildfires may impact pathogen, vector, and host interactions, leading to changing risks of vector-borne disease in humans and other animals. Despite established risks for tick-borne disease and increasing frequency and severity of wildfires in the United States, impacts of wildfire on ticks and tick-borne pathogens are understudied. In 2015, the large Wragg fire extensively burned a long-term field site at Stebbins Cold Canyon University of California Reserve (CC). We characterized the tick, reservoir host and pathogen community over a two-year period after the burn, comparing our findings to pre-fire data and to data from Quail Ridge Reserve (QR), a nearby unburned site. After the fire, there were 5.5 times more rodent, primarily Peromyscus spp., captures at CC than QR (compared to 3.5 times more pre-fire). There were significantly fewer dusky-footed woodrats (Neotoma fuscipes) at both sites post-fire, likely due to drought but not fire. Pre-fire tick infestation prevalence on rodents was comparable across sites (12.5% at CC and 9.9% at QR) and remained low at CC post-fire (13.7%) but was significantly higher at QR (48.0%), suggesting that ticks or their habitat were destroyed during the burn. Normalized difference vegetation indices documented a 16-fold loss of vegetation post- compared to pre-fire at CC; loss of vegetation and direct impacts on fauna are likely the main drivers of the post-fire differences in ticks we saw at CC. These data contribute to our understanding of tick-associated disease risks in our increasingly disturbed landscapes.

Zoonotic Helminthiases in Rodents (Bandicota indica, Bandicota savilei, and Leopoldamys edwardsi) from Vientiane Capital, Lao PDR.

Zoonotic helminths of three rodent species, Bandicota indiaca, Bandicota savilei, and Leopoldamys edwardsi, were investigated in Vientiane capital, Lao PDR. A total of 310 rodents were infected with 11 species of helminth parasites. There were 168 (54.2%) of 310 rodents infected with zoonotic helminths. From our results, there are six recorded zoonotic helminth species, and the highest prevalence was exhibited by Raillietina sp. (30.7%), followed by Hymenolepis diminuta (17.7%), Hymenolepis nana (2.6%), Echinostoma ilocanum (1.9%), Echinostoma malayanum (1.3%), and Angiostrongylus cantonensis (1%). This is the first study of zoonotic helminths in L. edwardsi and the first report of H. diminuta, H. nana, E. ilocanum, and E. malayanum in Bandicota indica and B. savilei, and the first demonstration of A. cantonenensis in B. indica in Lao PDR. From our results, these three rodents are potentially important reservoir hosts of zoonotic helminths. Thus, effective control programs should be considered for implementation to prevent the transmission of these zoonoses in this area.

Native and Introduced Trypanosome Parasites in Endemic and Introduced Murine Rodents of Sulawesi.

The Indonesian island of Sulawesi is a globally significant biodiversity hotspot with substantial undescribed biota, particularly blood-borne parasites of endemic wildlife. Documenting the blood parasites of Sulawesi's murine rodents is the first fundamental step towards the discovery of pathogens likely to be of concern for the health and conservation of Sulawesi's endemic murines. We screened liver samples from 441 specimens belonging to 20 different species of murine rodents from 2 mountain ranges on Sulawesi, using polymerase chin reaction (PCR) primers targeting the conserved 18S rDNA region across the protozoan class Kinetoplastea. We detected infections in 156 specimens (10 host species) with a mean prevalence of 35.4% (95% confidence interval [CI] = 30.9-39.8%). Sequences from these samples identified 4 infections to the genus Parabodo, 1 to Blechomonas, and the remaining 151 to the genus Trypanosoma. Within Trypanosoma, we recovered 17 haplotypes nested within the Trypanosoma theileri clade infecting 117 specimens (8 host species) and 4 haplotypes nested within the Trypanosoma lewisi clade infecting 34 specimens (6 host species). Haplotypes within the T. theileri clade were related to regional Indo-Australian endemic trypanosomes, displayed geographic structuring but with evidence of long-term connectivity between mountains, and had substantial phylogenetic diversity. These results suggest T. theileri clade parasites are native to Sulawesi. Conversely, T. lewisi clade haplotypes were recovered from both endemic and introduced rodents, demonstrated complete geographic separation between clades, and had low genetic diversity. These results suggest that the T. lewisi clade parasites invaded Sulawesi recently and likely in 2 separate invasion events. Our results provide the first records of metakinetoplastids in Sulawesi's rodents and highlight the need for more extensive sampling for pathogens in this biodiversity hotspot.

Common occurrence of divergent Cryptosporidium species and Cryptosporidium parvum subtypes in farmed bamboo rats (Rhizomys sinensis).

BACKGROUND: Bamboo rats are widely farmed in southern China for meat, but their potential in transmitting pathogens to humans and other farm animals remains unclear. METHODS: To understand the transmission of Cryptosporidium spp. in these animals, 709 fecal samples were collected in this study from Chinese bamboo rats (Rhizomys sinensis) on nine farms in Jiangxi, Guangxi and Hainan provinces, China. They were analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. Cryptosporidium parvum, C. parvum-like and C. ubiquitum-like genotypes identified were subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) gene. RESULTS: Altogether, Cryptosporidium spp. were detected in 209 (29.5%) samples. The detection rate in samples from animals under two months of age (70.0%,105/150) was significantly higher than in samples from animals above 2 months (18.6%, 104/559; χ2 = 150.27, df = 1, P < 0.0001). Four Cryptosporidium species/genotypes were identified: C. parvum (n = 78); C. occultus (n = 1); a new genotype that is genetically related to C. ubiquitum (n = 85); and another new genotype that is genetically related to C. parvum (n = 44). Among them, C. parvum (27,610 ± 71,911 oocysts/gram of feces) and the C. parvum-like genotype (38,679 ± 82,811 oocysts/gram of feces) had higher oocyst shedding intensity than the C. ubiquitum-like genotype (2470 ± 7017 oocysts/gram of feces) and the C. occultus (1012 oocysts/gram of feces). The C. parvum identified belonged to three subtypes in two rare subtype families, including IIpA9 (n = 43), IIpA6 (n = 6) and IIoA15G1 (n = 9), while the C. parvum-like and C. ubiquitum-like genotypes generated very divergent gp60 sequences. CONCLUSIONS: Results of the present study suggest that bamboo rats on the study farms were infected with diverse Cryptosporidium species and divergent C. parvum subtypes, which probably had originated from their native habitats. As similar C. parvum subtypes have been recently detected in humans and farmed macaques, attentions should be paid to the potential role of these new farm animals in the transmission of zoonotic pathogens.

Digenean parasites of Sigmodontinae rodents from Argentina: a list of species, new host, and geographical records.

INTRODUCTION: Among Argentinean rodents, only one species of Muridae and seven of Cricetidae were reported as digenean hosts. Despite the available data, the taxonomic diversity of the Digenea from rodents has been little explored. An update on digeneans of Sigmodontinae rodents (Cricetidae-Muroidea) in Cuenca del Plata is provided. New host and geographical data are recorded and taxonomic and ecological data are summarized. METHODS: Rodents were collected from 11 localities in the region Cuenca del Plata, Argentina. Moreover, other unidentified specimens from four localities, deposited in the Colección de Helmintología del Museo de La Plata, were studied. Prevalence, mean intensity, and mean abundance are provided. RESULTS: Eight species of digeneans belonging to four families were identified. Twelve new geographical records for five provinces of Argentina are presented. In addition, six new host-parasite associations are reported. The information is presented in a taxonomic list for each digenean species: site of infection, host records, locality records, and comments. CONCLUSIONS: It becomes interesting to explore the diets and habits of each rodent species to understand the dispersal and transmission ability of each group of digeneans. This survey constitutes an update on digeneans of Sigmodontinae rodents in Cuenca del Plata, Argentina.

The Competition Between Immatures of Ixodes ricinus and Dermacentor reticulatus (Ixodida: Ixodidae) Ticks for Rodent Hosts.

The numbers of Ixodes ricinus (L.) and Dermacentor reticulatus (Fabricius) larvae and nymphs attached to small mammals are influenced by interspecific competition. The present study analyses data collected over several years in two study areas: Kosewo Górne (Mazurian District, N Poland; between July 1997 and July 2009) and Bialowieza Primeval Forest (E Poland; in July 2007). In total, 975 ticks were collected from striped field mice (Apodemus agrarius), yellow-necked mice (A. flavicollis), bank voles (Myodes glareolus), and root voles (Microtus oeconomus). In total, of the 203 investigated rodents, 137 were infested with ticks and 39 demonstrated mixed infection. The numbers of the two tick species found on Apodemus mice were significantly negatively correlated with those on root voles; similarly, although bank voles were significantly more frequently infested by I. ricinus than by D. reticulatus, the reverse was observed in root voles. In addition, among the voles, each tick species was found in different locations on the host body, which could also result from competitive interactions; furthermore, competitive release regarding microhabitat selection was observed on hosts infested with one tick species. This competition may be driven by the limited area of host body available for foraging by ticks, i.e., safe areas of high vascularization covered by thin skin. However, the mechanisms of such competition require further investigation.

Redescription of Subulura (Murisubulura) andersoni (Cobbold, 1876) (Nematoda: Subuluridae) from Bunomys spp. (Rodentia: Muridae) of Sulawesi, Indonesia, with special reference to S. (M.) suzukii and other related species in the adjacent areas.

Subulura (Murisubulura) andersoni (Cobbold, 1876) (Nematoda: Subuluridae) is redescribed in detail using light and scanning electron microscopy based on materials collected from Bunomys chrysocomus and Bunomys andrewsi (Rodentia: Muridae) of Sulawesi, Indonesia, to provide basic reference data for identification. Comparison was made among congeners from adjacent areas, especially Subulura (Murisubulura) suzukii Yagi and Kamiya, 1981 of Japan. Because morphological differences distinguishing S. (M.) andersoni from S. (M.) suzukii and S. (M.) sipiroki were only the thickness of female tail and length of male tail, respectively, further study using DNA sequence analysis is necessary to prove their distinctness.

A new species of sucking louse Hoplopleura villosissima n. sp. (Psocodea: Phthiraptera: Hoplopleuridae) and a new host record of the spiny rat louse Polyplax spinulosa Burmeister, 1839 (Psocodea: Phthiraptera: Polyplacidae) from the long-haired rat Rattus villosissimus Waite (Rodentia: Muridae) in Australia.

BACKGROUND: The sucking louse fauna of endemic Australian rodents has been under-studied for decades. Sixty-five species of native rodents have been recorded in Australia. However, only 11 species of lice have been reported from 11 species of endemic Australian rodents. RESULTS: We describe a new species of sucking louse, Hoplopleura villosissima Wang (Psocodea: Phthiraptera: Hoplopleuridae), and report a new host record of the spiny rat louse, Polyplax spinulosa Burmeister, 1839 (Psocodea: Phthiraptera: Polyplacidae), from the long-haired rat, Rattus villosissimus Waite (Rodentia: Muridae), which is endemic to Australia. CONCLUSIONS: This study is the first record of sucking louse from R. villosissimus and the first record of a species of Polyplax Enderlein, 1904 from an endemic Australian rodent. This study brings the total number of sucking louse species in endemic Australian rodents from 11 to 13. Previously, only the introduced brown rat, Rattus norvegicus Berkenhout and the black rat, Rattus rattus Linnaeus were recorded as the hosts of P. spinulosa in Australia. Because R. villosissimus overlaps with R. rattus in distribution but not with R. norvegicus, we propose that P. spinulosa transferred to R. villosissimus from R. rattus.

Morphological asymmetry and habitat quality: using fleas and their rodent hosts as a novel experimental system.

Morphological asymmetry is widely used to measure developmental instability and higher levels of asymmetry often correlate with decreased mating success, increased inbreeding, increased stress and decreased habitat quality. We studied asymmetry and relationships between asymmetry and host identity in two flea species, host generalist Xenopsylla ramesis and host specialist Parapulex chephrenis, and asked: (1) what the level of asymmetry was in their femurs and tibiae; (2) which type of asymmetry predominates; and (3) whether fleas that fed on host species distantly related to their principal host species produced offspring that exhibited greater asymmetry compared with offspring of fleas that fed on their principal host species. We found fluctuating asymmetry in femurs and tibiae of X. ramesis and in the tibiae of P. chephrenis as well as significantly left-handed directional asymmetry in the femurs of P. chephrenis Host species identity significantly impacted asymmetry in leg segments of P. chephrenis but not in those of X. ramesis Offspring asymmetry increased when mother fleas fed on a host that was distantly related to the principal host. Fleas parasitizing multiple host species might compensate for developmental instability when utilizing a novel host species; therefore, host-switching events in host-specific parasites could be constrained by the relatedness between a novel and a principal host species.

Myocoptid mites (Acariformes: Myocoptidae) of the fauna of the former USSR.

Mites of the family Myocoptidae (Acariformes: Sarcoptoidea) of the former USSR are revised based on the collection of the Zoological Institute RAS (St. Petersburg, Russia). Seventeen described species are recorded. Four species are described as new for science: Trichoecius dubininae sp. nov. from Lasiopodomys gregalis (Pallas) (Rodentia: Cricetidae) from Russia (Chelyabinsk Prov., type locality), Kazakhstan and Kirghizia, T. lemmus sp. nov. from Lemmus sibiricus (Kerr) (Rodentia: Cricetidae) from Russia (Taymyr peninsula), T. meriones sp. nov. from Meriones meridianus (Pallas) (Rodentia: Muridae) from Turkmenia, and Myocoptes meriones sp. nov. from Meriones tamariscinus (type host) from Kirghizia (type locality) and Meriones libycus (Lichtenstein) from Tajikistan. In addition, the presence of 7 more species in the fauna of the former USSR is considered highly probable. Myocoptids of the former USSR represent all 6 genera currently recognized in the family. Keys to species, their hosts and localities are provided and all data are summarized in tabular format. A new name Apocalyptoides nom. nov. is proposed for the preoccupied generic name Apocalypsis Bochkov, 2010 not Butler (1876).

A review of Gongylonema spp. (Nematoda: Gongylonematidae) in North American rodents with description of a new species from the cotton rat, Sigmodon hispidus (Mammalia: Cricetidae).

Gongylonema archboldi n. sp. (Nematoda: Gongylonematidae) is described from tunnels in the gastric mucosa of the stomach of the cotton rat (Sigmodon hispidus) from Highlands County, Florida, U.S.A. Measurements are also given for specimens from cotton mice (Peromyscus gossypinus), oldfield mice (Peromyscus polionotus), Florida mice (Podomys floridanus), and golden mice (Ochrotomys nuttalli) from the same locality. Additional specimens were collected from the cotton rat and the rice rat (Oryzomys palustris) from Berry Island, San Patricio County, Texas. The new species is differentiated from congeners by a combination of the following characters: length of the left spicule, length and shape of the gubernaculum, distribution of cuticular bosses, length of esophagus, and distance of the vulva from the posterior end. The status of the genus Gongylonema in North American rodents is reviewed.

Musserellus gen. nov., and Five New Species of Fleas (Siphonaptera: Stivaliidae) From Murid Rodents in Sulawesi and West Papua, Indonesia.

A new stivaliid flea genus, Musserellus, and five new species are described. The new genus is compared with its closest morphological relatives, the genera Rectidigitus Holland and Metastivalius Holland. Musserellus vanpeeneni sp. nov., Musserellus wattsi sp. nov., Musserellus whitei sp. nov., and Musserellus marshalli sp. nov. are described from endemic murid rodents in Sulawesi, Indonesia, while Musserellus dunneti sp. nov. is described from Rattus rattus in West Papua, Indonesia. Host associations and the biogeographical relevance of the faunal connection between Sulawesi and New Guinea shown by Musserellus are briefly discussed.

Geographical Distribution and Seasonal Indices of Chigger Mites on Small Mammals Collected on the East Coast of the Republic of Korea.

The geographical distributions and relative population densities of scrub typhus vector mites collected from small mammals were determined for 5 locations on the east coast of the Republic of Korea. Collection sites included Goseong, Gangneung, and Hoengseong in Gangwon province and Uljin and Yeongdeok in Gyeongbuk province. A total of 275 small mammals including members of Rodentia (rodents) and Soricomorpha (shrews, such as Crocidura lasiura ) belonging to 4 genera and 4 species were captured in the field from 2012 to 2013. Apodemus agrarius was collected most frequently (220, 80%), followed by C. lasiura (25, 9.1%), Mus musculus (15, 5.5%), and Myodes regulus (15, 5.5%). A total of 23,436 larval chigger mites (Family Trombiculidae) belonging to 3 genera and 8 species (Leptotrombidium pallidum, Leptotrombidium scutellare, Leptotrombidium palpale, Leptotrombidium orientale, Leptotrombidium zetum, Neotrombicula tamiyai, Neotrombicula japonica, and Euschoengastica koreaensis) were collected from the small mammals. The predominant chigger species collected during the spring and fall seasons from A. agrarius were L. pallidum (57.6%), L. palpale (14.5%), and L. scutellare (7.9%). Leptotrombidium scutellare was collected only along the southeastern coast at Yeongdeok, Gyeongbuk province. The geographical distribution of scrub typhus vectors and reservoir hosts are important aspects of understanding the epidemiology of the disease as well as the potential impacts of climate change and health risks.

Taxonomic revision of the Nippostrongylinae (Nematoda, Heligmonellidae) parasites of Muridae from the Australasian region. The genus Odilia Durette-Desset, 1973.

The species of the genus Odilia Durette-Desset, 1973 (Heligmonellidae, Nippostrongylinae) are re-distributed among eight genera of which five are new. This classification is mainly based on certain characters of the synlophe not previously taken into account at the supraspecific level. These characters mainly include the presence or absence of a careen, the relative size of the ridges forming the careen, the development and position of ridge 1', the development of the left ridge and right ridge, and the distribution of the largest ridges. Eighteen of the 20 known species are rearranged in the following genera: Odilia sensu stricto Durette-Desset, 1973 with Odilia mackerrasae (Mawson, 1961) as type species, Chisholmia n. gen. with Chisholmia bainae (Beveridge & Durette-Desset, 1992) n. comb. as type species, Equilophos n. gen. with Equilophos polyrhabdote (Mawson, 1961) n. comb. as type species, Hasegawanema n. gen. with Hasegawanema mamasaense (Hasegawa, Miyata & Syafruddin, 1999) n. comb. as type species, Hughjonestrongylus Digiani & Durette-Desset, 2014 with Hughjonestrongylus ennisae (Smales & Heinrich, 2010) as type species, Lesleyella n. gen. with Lesleyella wauensis (Smales, 2010) n. comb. as type and sole species, Parasabanema szalayi Smales & Heinrich, 2010, and Sanduanensis n. gen. with Sanduanensis dividua (Smales, 2010) as type and sole species. Odilia uromyos Mawson, 1961 and Odilia carinatae Smales, 2008 are not included in the new classification. A key to the proposed genera is provided. The new generic arrangement follows a distribution more related to the biogeographical areas than to the host groups.

Syphacia (Syphacia) maxomyos sp. n. (Nematoda: Oxyuridae) from Maxomys spp. (Rodentia: Muridae) from Sulawesi and Sumatra, Indonesia.

The present report describes Syphacia (Syphacia) maxomyos sp. n. (Nematoda: Oxyuridae) from two species of spiny rats, Maxomys musschenbroekii from Sulawesi and M. whiteheadi from Sumatra. It is characterized by a cephalic plate extending laterally with dorsoventral constriction and stumpy eggs with an operculum rim reaching pole. It is readily distinguishable by the former feature from all of hitherto known representatives of this genus in Indonesia, but it resembles parasites in Murini and Hydromyni rodents in continental Asia and Sahul. This is the first Syphacia species distributed in both the Sunda Shelf and Sulawesi with the exception of Syphacia muris, a cosmopolitan pinworm found in rodents of the of genus Rattus. It is surmised that S. maxomyos is specific to Maxomys and that it was introduced to Sulawesi by dispersal of some Maxomys from the Sunda Shelf.

Ectoparasites of murids in peninsular Malaysia and their associated diseases.

A considerable number of rat-borne ectoparasite studies have been conducted since the early 1930s in the Malayan Peninsula (now known as peninsular Malaysia). The majority of studies were field surveys and collections of specimens across the region, and were conducted primarily to catalogue the ectoparasite host distribution and discover novel species. This has generated a signification amount of information, particularly on the diversity and host distribution; other aspects such as morphology, host distribution and medical significance have also been investigated. Amongst the four main groups (mites, fleas, ticks, lice), rat-borne mites have received the most attention with a particular emphasis on chiggers, due to their medical importance. More recent studies have examined the distribution of ectoparasites in rats from different habitat type simplicating a high prevalence of zoonotic species infesting rat populations. Despite being capable of transmitting dangerous pathogens to human, the health risks of rat-borne ectoparasites appear to be small with no serious outbreaks of diseases recorded. Although an extensive number of works have been published, there remain gaps in knowledge that need to be addressed, such as, the distribution of under studied ectoparasite groups (listrophorids and myobiids), determining factors influencing infestation, and understanding changes to the population distribution over time.

Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice.

A previously unrecognized species of hymenolepidid cestode attributable to Hymenolepis is described based on specimens in Peromyscus polionotus, oldfield mouse, from Georgia near the southeastern coast of continental North America. Specimens of Hymenolepis folkertsi n. sp. differ from those attributed to most other species in the genus by having testes arranged in a triangle and a scolex with a prominent rostrum-like protrusion. The newly recognized species is further distinguished by the relative position and length of the cirrus sac, shape of seminal receptacle, and relative size of external seminal vesicle and seminal receptacle. Hymenolepidid cestodes have sporadically been reported among the highly diverse assemblage of Peromyscus which includes 56 distinct species in the Nearctic. Although the host genus has a great temporal duration and is endemic to the Nearctic, current evidence suggests that tapeworm faunal diversity reflects relatively recent assembly through bouts of host switching among other cricetid, murid, and geomyid rodents in sympatry.