Pinworm Species Research Articles

Co-structure analysis and genetic associations reveal insights into pinworms (Trypanoxyuris) and primates (Alouatta palliata) microevolutionary dynamics

BackgroundIn parasitism arm race processes and red queen dynamics between host and parasites reciprocally mold many aspects of their genetics and evolution. We performed a parallel assessment of population genetics and demography of two species of pinworms with different degrees of host specificity (Trypanoxyuris multilabiatus, species-specific; and T. minutus, genus-specific) and their host, the mantled howler monkey (Alouatta palliata), based on mitochondrial DNA sequences and microsatellite loci (these only for the host). Given that pinworms and primates have a close co-evolutionary history, covariation in several genetic aspects of their populations is expected.ResultsMitochondrial DNA revealed two genetic clusters (West and East) in both pinworm species and howler monkeys, although population structure and genetic differentiation were stronger in the host, while genetic diversity was higher in pinworms than howler populations. Co-divergence tests showed no congruence between host and parasite phylogenies; nonetheless, a significant correlation was found between both pinworms and A. palliata genetic pairwise distances suggesting that the parasites’ gene flow is mediated by the host dispersal. Moreover, the parasite most infective and the host most susceptible haplotypes were also the most frequent, whereas the less divergent haplotypes tended to be either more infective (for pinworms) or more susceptible (for howlers). Finally, a positive correlation was found between pairwise p-distance of host haplotypes and that of their associated pinworm haplotypes.ConclusionThe genetic configuration of pinworm populations appears to be molded by their own demography and life history traits in conjunction with the biology and evolutionary history of their hosts, including host genetic variation, social interactions, dispersal and biogeography. Similarity in patterns of genetic structure, differentiation and diversity is higher between howler monkeys and T. multilabiatus in comparison with T. minutus, highlighting the role of host-specificity in coevolving processes. Trypanoxyuris minutus exhibits genetic specificity towards the most frequent host haplotype as well as geographic specificity. Results suggest signals of potential local adaptation in pinworms and further support the notion of correlated evolution between pinworms and their primate hosts.

Prevalence of <i>Blatticola blattae</i> (Thelastomatidae) in German cockroaches <i>Blattella germanica</i> in Japan

A survey for nematode infection in German cockroaches captured in restaurants in various areas of Japan as well as the laboratory-bred colony was carried out. The nematodes were then identified morphologically and molecularly. Of the 320 German cockroaches collected at 79 restaurants in 26 prefectures in Japan, 66.6% (213/320) were found to be parasitized by a single species of pinworm in the hindgut. The mean number of pinworms per cockroach was less than 1.6. Of the three laboratory-bred lines of cockroaches examined, 2 lines (NIID and NK) were found to be infected with a single species of nematode. The prevalence was 93.0% (40/43) and 84.8% (39/46), respectively. The other laboratory line (WAT) was found to be free of the nematode infection. The nematode detected in this study was identified as Blatticola blattae. This is the first report of B. blattae infection in German cockroaches in Japan. Our study showed that B. blattae is distributed all over Japan together with its host Blattella germanica. An experimental infection with B. blattae in nematode-free cockroach by contaminating the rearing environment with infected-cockroach feces showed that once the environment of the cockroach is contaminated with B. blattae eggs, the pinworm infection could spread easily.

Complex and Diverse Drivers of Parasite Loads in a Cosmopolitan Insect

The goal of parasite epidemiologists is to understand the factors that determine host infection levels. Potential infection determinants exist at many scales, including spatial and temporal environmental variation, among-host differences, and interactions between symbionts infecting the same host. All of these factors can impact levels of parasitism, but frequently only a subset is considered in any host-parasite system. We examined several potential determinants of pinworm infection in wild Australian cockroaches (Periplaneta australasiae) from multiple biological scales: (1) habitat; (2) season; (3) cockroach body size, developmental stage, and sex; and (4) interactions between 2 pinworm species (Leidynema appendiculata and Thelastoma sp.). Over 1 yr, we collected 239 cockroaches from 2 separate rooms in an Illinois greenhouse. We used generalized linear mixed-effects models (GLMMs) to evaluate simultaneously the influence of these factors on pinworm abundance, and nearly all had significant effects. Overall, the abundance of L. appendiculata was greater than Thelastoma sp., but the relative abundance of the 2 species was reversed in each room (i.e., a taxon × habitat effect). Abundance varied over 4 trapping seasons and increased with cockroach size. Adult cockroaches had more pinworms than nymphs, and there was also a significant taxon × stage effect: adult cockroaches had fewer pinworms than expected for their larger size, and this reduction was greater in Thelastoma sp. than in L. appendiculata. Cockroach sex had no effect on infection. Although females had more worms than males, this difference could be explained by the larger size of females. Finally, after controlling for all other potential determinants of infection, we found a strong negative association between Thelastoma sp. and L. appendiculata; cockroaches tended to be infected with either 1 pinworm species or the other. Our work underscores the importance of measuring potential determinants of infection from as many scales as possible. Such approaches are necessary to unravel the complexities of host-parasite interactions.

A pinworm's tale: The evolutionary history of Lemuricola (Protenterobius) nycticebi.

Lemuricola (Protenterobius) nycticebi is the only pinworm species known to infect strepsirrhine primates outside Africa, and the only pinworm species yet described in slow lorises. Here, we provided a detailed morphological comparison of female and male worms, and a first description of fourth-stage larvae collected from free-living slow lorises (Nycticebus menagensis) in Sabah, Malaysian Borneo. Using mitochondrial and nuclear markers, we also reconstructed the species' phylogenetic relationship with other pinworms infecting primates. Both morphological and molecular results indicated a distinct association between L. (P.) nycticebi and its host. However, while taxonomy identified this species as a member of the Lemuricola clade and grouped pinworms infecting lemurs and slow lorises together, phylogenetic reconstruction split them, placing L. (P.) nycticebi within the Enterobius clade. Our results suggest that L. (P.) nycticebi may represent a different taxon altogether, and that it is more closely related to pinworm species infecting Old World primates outside Madagascar. Pongobius pongoi (Foitová et al., 2008) n. comb. is also proposed.

Description of Enterobius (Colobenterobius) emodensis sp. n. (Nematoda: Oxyuridae) collected from Central Himalayan langur, Semnopithecus schistaceus, in Uttarakhand, India.

A new pinworm species, Enterobius (Colobenterobius) emodensis sp. n. (Nematoda: Oxyuridae) is described from the Central Himalayan langur, Semnopithecus schistaceus, in Mandal Valley, Chamoli District, Uttarakhand, India, based on mature and immature adults and fourth-stage larvae. This species closely resembles Enterobius (Colobenterobius) zakiri parasitic in Tarai langur, Semnopithecus hector, recorded from Uttarakhand and Uttar Pradesh, India, but is readily distinguished by having a shorter esophagus and a shorter spicule. It is surmised that this pinworm has co-speciated with the host langur. The new species is also characterized in that the posterior 1/3 of the esophageal corpus is much darker. Phylogenetic analysis based on the sequences of partial Cox1 gene of mtDNA suggested a basal position of diversification of Colobenterobius from the Enterobius lineage.

Lack of genetic structure in pinworm populations from New World primates in forest fragments

Microevolutionary processes in parasites are driven by factors related to parasite biology, host abundance and dispersal, and environmental conditions. Here, we test the prediction that isolation of host populations results in reduced genetic diversity and high differentiation among parasite populations. We conducted a population genetic analysis of two pinworms, Trypanoxyuris minutus and Trypanoxyuris atelis, commonly found parasitizing howler and spider monkeys in tropical rainforests across south-eastern Mexico, whose populations are currently isolated due to anthropogenic habitat loss and fragmentation. Mitochondrial DNA was employed to assess parasite genetic patterns, as well as to analyse their demography and population history. Both pinworm species showed high haplotype diversity but, unexpectedly, lower nucleotide diversity than that reported for other parasites. No genetic differentiation or population structure was detected in either pinworm species despite habitat loss, fragmentation and host isolation. Several scenarios are discussed that could help to explain the genetic panmixia found in both pinworm species, including higher than expected primate inter-fragment dispersal movements, and passive dispersal facilitating gene flow between parasite populations. The results suggest that large population sizes of parasites could be helping them to cope with the isolation and fragmentation of populations, delaying the effects of genetic drift. The present study highlights the complexity of the drivers that intervene in the evolutionary processes of parasites. Detailed genetic studies are needed, both in host and parasite populations, to assess the effects that habitat perturbation and environmental changes could have on the evolutionary dynamics of pinworms and primates.

A study on the occurrence of pinworms in the hindgut of Periplaneta americana.

American cockroach, Periplaneta americana harbours pinworms in their gut. In the present study, 88 host cockroaches were dissected and the number of adult females of each pinworm species was recorded from Barasat, North 24 Parganas, West Bengal. Three species of Oxyurid nematodes were found: Hammerschmidtiella diesingi (Hammerschmidt, Helminthologische Beiträge. Isis (oken), Leipz 5:351-358, 1838), Leidynema appendiculatum (Leidy in Proc Acad Natl Sci Phila 5:100-102, 1850) and Thelastoma sp. (Leidy in Proc Nat Acad Sci Phila 4:30, 1849). At a time two nematode infections (double infection) were also found. H. diesingi and L. appendiculatum mixed infection being more common than H. diesingi and Thelastoma sp. infection. Ed the H. diesingi shown highest prevalence (40.90%) and abundance pattern (1.227). It was the dominant species in most cases. Lowest prevalence (7.95%) and abundance pattern (0.272) was found in Thelastoma sp. Thelastoma sp. has the highest mean density (3.428) followed by Hammerschmidtiella diesingi (3) and Leidynema appendiculatum (2.368). Three species were never found in the same host. This study suggests that host sex had no noticeable impact on the occurrence of pinworms.

Pinworm diversity in free-ranging howler monkeys (Alouatta spp.) in Mexico: Morphological and molecular evidence for two new Trypanoxyuris species (Nematoda: Oxyuridae)

Two new species of Trypanoxyuris are described from the intestine of free-ranging howler monkeys in Mexico, Trypanoxyuris multilabiatus n. sp. from the mantled howler Alouatta palliata, and Trypanoxyuris pigrae n. sp. from the black howler Alouatta pigra. An integrative taxonomic approach is followed, where conspicuous morphological traits and phylogenetic trees based on DNA sequences are used to test the validity of the two new species. The mitochondrial cytochrome oxidase subunit 1 gene, and the nuclear ribosomal 18S and 28S rRNA genes were used for evolutionary analyses, with the concatenated dataset of all three genes used for maximum likelihood and Bayesian phylogenetic analyses. The two new species of pinworms from howler monkeys were morphologically distinct and formed reciprocally monophyletic lineages in molecular phylogenetic trees. The three species from howler monkeys, T. multilabiatus n. sp., T. pigrae n. sp., and Trypanoxyuris minutus, formed a monophyletic group with high bootstrap and posterior probability support values. Phylogenetic patterns inferred from sequence data support the hypothesis of a close evolutionary association between these primate hosts and their pinworm parasites. The results suggest that the diversity of pinworm parasites from Neotropical primates might be underestimated.

Enterobius(Enterobius)shriverin. sp. (Nematoda: Oxyuridae: Enterobiinae) fromMacaca fascicularisRaffles, 1821 (Primates: Cercopithecidae: Cercopithecinae) and Three Other Cercopitheciid Primate Species: With Additional Information onEnterobius(Enterobius)macaciYen, 1973

ABSTRACT: Four cercopitheciid primate species at an academic institution research facility within the United States were found infected with an Enterobius species that was morphologically and genetically distinct from all currently known species of pinworms and is herein described as Enterobius shriveri n. sp. Phylogenetic analysis is provided for E. shriveri based on analysis of a partial 18S ribosomal RNA gene (rDNA) and a partial mitochondrial cytochrome c oxidase I (Cox1) gene. Three of the 15 infected hosts were also co-infected with Enterobius macaci Yen, 1973. Electron microscopy and light microscopy images of both male and female E. shriveri and E. macaci specimens are provided, as are additional morphologic and morphometric data for E. macaci, both of which indicate differences between Asiatic mainland and Japanese island isolate forms.

The complete mitochondrial genome of Oxyuris equi: Comparison with other closely related species and phylogenetic implications

The equine pinworm Oxyuris equi (Nematoda: Oxyuridomorpha) is the most common horse nematode, has a worldwide distribution, and causes major economic losses. In the present study, the complete O. equi mitochondrial (mt) genome was sequenced, and the mt genome structure and organization were compared with those of other closely related pinworm species, Enterobius vermicularis and Wellcomia siamensis. The O. equi mt genome is a 13,641-bp circular DNA molecule that encodes 36 genes (12 protein-coding genes, 22 tRNAs, and two rRNAs) and one non-coding region, which is slightly shorter than that of E. vermicularis and W. siamensis. The O. equi mt gene arrangement was consistent with that of GA13-type E. vermicularis but it differs from GA12-type W. siamensis. Phylogenetic analyses using concatenated amino acid sequences of the 12 protein-coding genes with three different computational algorithms (maximum parsimony, maximum likelihood, and Bayesian inference) revealed that there were two distinct clades in Chromadorea nematodes that reflected infraorder. Spiruromorpha formed one clade, whereas Rhabditomorpha, Ascaridomorpha, and Oxyuridomorpha formed another clade. O. equi, E. vermicularis, and W. siamensis represent distinct but closely related species, which indicated that Oxyuridomorpha is paraphyletic. Sequencing the O. equi mt genome provides novel genetic markers for studying the molecular epidemiology and population genetics of pinworms.

Morphology of the oxyurid nematodes Trypanoxyuris (T.) cacajao n. sp. and T. (T.) ucayalii n. sp. from the red uakari monkey Cacajao calvus ucayalii in the Peruvian Amazon.

Cacajao calvus ucayalii (Thomas, 1928) (Primates: Pitheciidae), a subspecies endemic to the Peruvian Amazon, occurs in patchy and sometimes isolated populations in north-eastern Peru and is in a vulnerable situation, mainly due to habitat loss and hunting. This rareness and remote distribution means that, until now, parasitical studies have been limited. Based on optical and scanning electron microscopy of specimens of both sexes, we report two new species of Trypanoxyuris pinworms occurring in the large intestine of the Peruvian red uakari, namely Trypanoxyuris (Trypanoxyuris) cacajao and Trypanoxyuris (Trypanoxyuris) ucayalii. Both species showed a distinct morphology of the lips and cephalic structure. Sexual dimorphism in the lateral alae was observed in both male and the female worms, with ventral ornamentation being shown in the oesophageal teeth. The finding of these new pinworm species highlights the possibility of discovering other species.

Distribution of Thelastomatoid Nematodes (Nematoda: Oxyurida) in Endemic and Introduced Cockroaches on the Galápagos Island Archipelago, Ecuador.

The thelastomatoid pinworm fauna (Nematoda: Oxyurida: Thelastomatoidea) was surveyed in 3 endemic species and 6 introduced species of cockroach hosts (Insecta: Blattaria) in the Galápagos Islands, Ecuador. A total of 658 host specimens were examined from preserved collections that had been collected between 1966 and 2003 from 7 islands in the archipelago. Eight species of pinworms were identified from these cockroach hosts, including the dominant species Cephalobellus ovumglutinosus and a Severianoia sp. as well as Leidynema appendiculata, Hammerschmidtiella diesingi, an unidentified Cephalobellus species resembling Cephalobellus magalhaesi, an unidentified Protrellus species closely resembling Protrellus shamimi, and an undescribed Blattophila sp. Five new host records are identified for C. ovumglutinosus including the endemic Galápagos cockroaches Chorisoneura carpenteri, Ischnoptera snodgrassii, and Ischnoptera santacruzensis. These endemics were also infected with an undescribed Blatticola sp. Other species recorded resemble known pinworms from other hosts around the world. Prevalence between islands and between host species was variable, but total prevalence for individual pinworm species was consistently low (<10%). A single host specimen examined was infected with more than 1 pinworm species; otherwise only a single species was observed in each infected host. At least 1 introduced pinworm species carried to the islands via invasive cockroach hosts was present in endemic host species, but several globally widespread introduced pinworm species were absent from endemic cockroaches. Santa Cruz was inhabited by the greatest number of pinworm species, likely due to a higher rate of invasive host introduction. This survey, the first from this region, showed that the distribution and transmission of pinworms in the Galápagos Islands is complex and may provide future models of invertebrate dispersal and speciation in an ecosystem already rich with examples of evolution.

Trypanoxyuris atelis and T. atelophora (Nematoda: Oxyuridae) in wild spider monkeys (Ateles geoffroyi) in tropical rain forest in Mexico: Morphological and molecular evidence

Two species of pinworms, Trypanoxyuris atelis and Trypanoxyuris atelophora were collected from the black-handed spider monkey (Ateles geoffroyi) in several localities across southeastern Mexico, representing the first record for both species in Mexican primates. Identification of pinworm species was based on morphological and molecular data. These pinworms are distinguished from other congeners, and from each other, by the buccal structure, the lateral alae, and the morphology of the oesophagus. Phylogenetic analyses based on sequences of the mitochondrial cytochrome c oxidase subunit 1 gene placed T. atelis as the sister species of Trypanoxyuris minutus, a parasite of the howler monkey Alouatta palliata, and T. atelophora as the sister species of T. microon, a parasite of the night monkey, Aotus azarae. These relationships were supported with high posterior probability values by Bayesian inference. Comparisons of additional pinworm taxa from Neotropical primates are needed to assess oxyurid diversity, and to better understand the evolutionary relationships among these nematodes and their primate hosts.

Discovery of a 240 million year old nematode parasite egg in a cynodont coprolite sheds light on the early origin of pinworms in vertebrates.

BackgroundWe report the discovery of a nematode parasite egg (Nemata: Oxyurida) from a coprolite closely associated with the remains of several species of Cynodontia, dated to 240 million years old. This finding is particularly significant because this is the oldest record of an oxyurid nematode yet discovered, and because the cynodonts are considered a stem-group of the mammals.MethodsWe extracted material from a fully mineralized coprolite by both scraping the surface, and removing fragments from its interior with clean dental instruments used a single time. A single drop of glycerol from a new vial was added as a clearing reagent. Each slide was sealed with wax and examined with an optical microscope at 100× to 400× magnification.ResultsFrom one coprolite, 550 slides were examined; from 275 of these slides, sediment was examined that was scraped from the surface of the coprolite, and from the other 275 slides, material was examined that was extracted from the interior of the coprolite. All microscopic structures encountered were photographed, measured, and identified when possible.ConclusionsFrom the coprolite examined, we discovered an egg representing a new species of pinworm that, based on the egg structure, clearly places it in the family Heteroxynematidae. Nematodes of the order Oxyurida have very constrained life-histories, occurring only in animals that are not strictly carnivorous and also ingest large amounts of plant material. This fact enabled us to determine which species of cynodont, from several collected at the site in Brazil, are most likely the depositors of the coprolite, and therefore were the putative host of the parasite.

Discovery of a 240 million year old nematode parasite egg in a cynodont coprolite sheds light on the early origin of nematode parasites in vertebrates

BackgroundWe report the discovery of a nematode parasite egg (Nemata: Oxyurida) from a coprolite closely associated with the remains of several species of Cynodontia, dated to 240 million years old. This finding is particularly significant because this is the oldest record of an oxyurid nematode yet discovered, and because the cynodonts are considered a stem-group of the mammals.MethodsWe extracted material from a fully mineralized coprolite by both scraping the surface, and removing fragments from its interior with clean dental instruments used a single time. A single drop of glycerol from a new vial was added as a clearing reagent. Each slide was sealed with wax and examined with an optical microscope at 100× to 400× magnification.ResultsFrom one coprolite, 550 slides were examined; from 275 of these slides, sediment was examined that was scraped from the surface of the coprolite, and from the other 275 slides, material was examined that was extracted from the interior of the coprolite. All microscopic structures encountered were photographed, measured, and identified when possible.ConclusionsFrom the coprolite examined, we discovered an egg representing a new species of pinworm that, based on the egg structure, clearly places it in the family Heteroxynematidae. Nematodes of the order Oxyurida have very constrained life-histories, occurring only in animals that are not strictly carnivorous and also ingest large amounts of plant material. This fact enabled us to determine which species of cynodont, from several collected at the site in Brazil, are most likely the depositors of the coprolite, and therefore were the putative host of the parasite.

Travassosinema dalei sp. n. (Thelastomatoidea; Nematoda) from the hind gut of an Australian scarabaeid larva

Travassosinema dalei sp. n. (Thelastomatidae, Oxyuromorpha, Rhabditida), a new species of pinworms, is described from the posterior gut of a scarabaeid larva collected at Mount Glorious, Queensland, Australia. Numerous males of T. dalei sp. n. were discovered together with females bearing cephalic umbraculum, a set of six cephalic wings, which is characteristic for the genus Travassosinema Rao, 1958. The conspecificity of males with females was proven by sequencing of the LSU rDNA D2D3 segment and observed mating of males and females. Description is illustrated by drawings and SEM images. Relationships between three genera of umbraculum-bearing nematodes are discussed.

Description of Lemuricola (Lemuricola) pongoi—male (Nematoda: Enterobiinae) parasitising orangutan Pongo abelii

The study presents the first description of male specimen (allotype) of the pinworm species Lemuricola (Lemuricola) pongoi, parasitising Sumatran orangutan (Pongo abelii) from Sumatra (Indonesia). The male specimen morphology presents all features fully corresponding with diagnose of the genus and subgenus Lemuricola. We are agreeing that Protenterobius is synonymous with Lemuricola because the length of tail appendix in males is not a sufficient feature for separation of the genera or subgenera. For L. (L.) pongoi male are characteristic features: body length (4,803 microm), total oesophagus length (530), tail length (235), tip of tail length (188) and spicule length (90).

Phylogenetic relationships of rodent pinworms (genus Syphacia) in Japan inferred from 28S rDNA sequences

The 28S rDNA from nine species of the genus Syphacia collected in Japan was sequenced, and the phylogenetic relationship was inferred from multiple sequence alignment of 28S rDNA by the MAFFT program. Phylogenetic tree indicates that S. petrusewiczi, which was the only species belonging to the subgenus Seuratoxyuris, has diverged earlier than other rodent pinworms examined and was distantly separated from the others genetically. It was revealed that S. agraria and S. vandenbrueli, whose subgeneric status has not been specified, belonged to the subgenus Syphacia together with other 6 species. Syphacia montana from Clethrionomys, Eothenomys and Microtus was very closely related to S. obvelata from Mus, and that S. frederici from Apodemus and S. vandenbrueli from Micromys were comparatively closely related to the former two species. The phylogenetic relationship among the three species of Syphacia found in Japanese Apodemus was inconsistent with the biogeography of host rodents. The co-evolutionary relationship between pinworm species and their host rodents may not be so strict and host switching has probably occurred frequently during the course of evolution.

Why Museums Matter: A Tale of Pinworms (Oxyuroidea: Heteroxynematidae) Among Pikas (Ochotona princeps and O. collaris) in the American West

Permanent and well-supported museum or natural history collections provide a solid foundation for the process of systematics research through creation of an empirical record which validates our understanding of the biosphere. We explore the role of museums in ongoing studies of the complex helminth fauna characteristic of pikas (Ochotona spp.) in the American west. These studies address the taxonomy for pinworms of the Labiostomatinae and the problems associated with the absence of adequate type series and vouchers and with misidentifications in original descriptions. We demonstrate that the types for Labiostomum (Labiostomum) coloradensis are identical to some specimens in the syntype series representing L. (Eugenuris) utahensis, although the published descriptions are in disagreement. Both are identical to L. (Eugenuris) talkeetnaeuris and, as a consequence, are reduced as junior synonyms. Only 2 species of large pinworms, namely L. (Labiostomum) rauschi and L. (Eugenuris) talkeetnaeuris, are widely distributed in Ochotona collaris and O. princeps. Although this serves to clarify the taxonomy for species in these genera, prior records remain confused, as representative voucher specimens from all major surveys in North America were never submitted to museum collections. We strongly suggest that type and voucher series should not be held in private or personal collections, where such are eventually lost, discarded, or destroyed through neglect due to inattention and the absence of curation. The potential to accumulate meaningful baselines for assessment of environmental change is jeopardized if materials from survey and inventory are not routinely submitted to museum collections. The capacity of museum repositories, as a focus for systematics, ecology, and evolutionary studies and for the development of resources for biodiversity informatics, continues to be undervalued and poorly utilized by a cadre of scientists who are dependant on accurate and definitive information that transcends specific disciplines.

Two remarkable pinworms (Nematoda: Enterobiinae) parasitizing orangutan (Pongo abelii) in the Sumatra (Indonesia) including Lemuricola (Protenterobius) pongoi n.sp.

Abstract Two species of pinworms (Enterobiinae) were collected from fresh faeces of semi-wild orangutans Pongo abelii Lesson living in northern Sumatra (Indonesia). The female of Enterobius (Enterobius) buckleyi Sandosham, 1950 is redescribed. Lemuricola (Protenterobius) pongoi n. sp. is described on the basis of females (no males are available) and distinguished from L. (P.) nycticebi (Baylis, 1928) by cephalic and mouth morphology (head and teeth superstructures), body (9.85–15.46 mm) and tail (2.34–2.95 mm) length, smaller eggs (48–56 x 22–28 μm), longer vulva distance from anterior extremity (2.05–3.09 mm) and other features. Characteristic is the total body length/oesophagus length ratio (1: 15.3–22.0). Both nematode species were studied using scanning electron microscopy for the first time.