The material here described was obtained from the large intestine of a Humboldt's Woolly Monkey (Lagothrix humboldtii) which died at the Zoological Gardens, London, about a month after it had been received there. In addition to the Enterobius infection there was a severe infection with Ascaris lumbricoides, involving both liver and small intestine. A single specimen of Necator was present, and along with the Enterobius were two immature female worms of doubtful identity, which are also described in this paper.

During the past decade, golden jackal populations have substantially increased, yet little is known of their potential for transmitting parasites within animal and human hosts. In the present study, between 2005 and 2010, 447 jackals from six localities in Serbia were examined for intestinal parasites. Two species of trematodes (Alaria alata, Pseudamphistomum truncatum), three nematodes (Toxocara canis, Ancylostoma caninum, Gongylonema sp.), and seven cestodes (Taenia pisiformis, Taenia hydatigena, Multiceps multiceps, Multiceps serialis, Mesocestoides lineatus, Mesocestoides litteratus, Dipylidium caninum) were identified. Pseudamphistomum truncatum and M. serialis species were recorded for the first time. The overall prevalence of parasitic infection was 10.3%. No significant differences were found in the prevalence of infection between males and females (P>0.817), between localities (P>0.502), or with regard to annual cycles (P>0.502). In the infected jackal population, 65% harboured multiple infections and one individual was a host to five different types of parasite species, the highest number of parasites we recorded in a single host. These findings indicate that although the prevalence of gastrointestinal helminths in the jackal population in Serbia is significantly lower than expected from earlier studies, further monitoring is required given the jackal's rapid population increase.

Further investigations on the occurrence of Anguillulina dipsaci on onion seed are presented. It is shown by the examination of 2,000 seeds individually that the parasite is usually located on the seed in the region of the hilum. A given seed may have as many as 4·7 worms or only 1 worm attached to it.

A method of seed fumigation with methyl bromide is described whereby the parasites attached to seeds are killed but the seed is unharmed. By the use of a test-bottle technique it has been found that a minimum dosage of 600, i.e. a concentration-time product of 600 involving an exposure to the fumigant of 18 to 24 hours at 24°C. is necessary for the destruction of the parasites attached to the seeds and in such flower-part débris as may be mixed with it.

The fumigant has no harmful effect on the vitality of the seed at dosages sufficient to destroy the parasite nor at much higher dosages. There is thus a wide upper margin of safety in its use. Two practical methods for the fumigation of large quantities of seed are described.

The probable origin of seed-borne infection from lightly infected parent bulbs is discussed. It is shown that at the present time seedborne infection is fairly widespread and has been found to occur on at least 9 different varieties of onion seed as distributed by seed merchants. Recommendations as to control are made which it is suggested would go far to reduce the incidence of the disease in this country.

Chromosome set and rDNA sequences of the larval digenean Cercariaeum crassum were analysed in order to clarify its systematic position and possible adult form. Parasites were obtained from the sphaeriid bivalve Pisidium amnicum, collected in Lithuanian and Finnish rivers. The karyotype is shown to consist of five pairs (2n = 10) of large, up to 14 μm, chromosomes. Complement, composed of a low diploid number of exclusively bi-armed elements, presumably arose through Robertsonian fusions of acrocentric chromosomes. Consistent with a Robertsonian-derived karyotype, one or two small, metacentric, mitotically stable B chromosomes were detected in the cells of parthenitae isolated from some host individuals. A phylogenetic analysis using rDNA internal transcribed spacer 2 (ITS2) and 28S sequences corroborates the allocation of C. crassum to the family Allocreadiidae. In neighbour-joining and maximum parsimony phylogenetic trees C. crassum clusters into one clade with Allocreadium spp., and is the closest sister group in relation to A. isoporum; the level of rDNA sequence divergence between them (2.67% for ITS2 and 1.16% for 28S) is consistent with the level expected for intrageneric variation. The present study adds significant information to a database for establishing species-specific characters for confident characterization of different developmental stages of allocreadiid species, clarification of their life cycles and evaluation of intra- and interspecific variability.

Infectivity of Himasthla elongata cercariae to mussels, their second intermediate hosts, and resistance by these hosts to infection were assessed on the basis of the cercariae's ability to encyst in mussel haemolymph in vitro. A series of experimental in vivo infections of mussels with batches of cercariae, each batch released from a different single infected mollusc and referred to as a clone (due to their shared genotype), demonstrated that the results of the in vitro tests corresponded to the actual indices of infectivity/susceptibility of the parasites and their hosts. Most cercarial clones had high infectivity, with a few clones having very high or, at the other extreme, very low infectivity. A similar pattern was revealed in mussel resistance to cercarial infection. Most of the molluscs tested were moderately susceptible to cercarial infection, but at each extreme a small fraction (less than 10%) displayed very high or very low susceptibility. It was shown that there were no totally compatible or totally incompatible ‘cercaria clone/mussel’ combinations. Results obtained are compared with the data on intra-population variability using the characters parasite infectivity/host compatibility for trematode/mollusc–first intermediate host associations. Results are made relevant to actual infection levels in mussel settlements at the White Sea.

Congenially athymic nude mice (BALB/c-nu/nu) and BALB/c-nu/+ were infected with 500 embryonated Toxocara canis eggs. Six weeks later they were reinfected with the same number of eggs. The liver and other organs were examined for numbers of 2nd-stage larvae at 2,4, and 6 weeks after reinfection. Far more larvae were trapped in the liver after reinfection than after the primary infection but fewer were found in the livers of BALB/c-nu/nu than in BALB/c-nu/+ mice.

The development of the microfilariae of Litomosoides carinii from the ova, has been studied by phase-contrast microscopy, and recorded with photomicrographs. All stages in the development were obtained by puncturing the uteri of adult female worms at intervals along their lengths, transferring the larvae which emerged onto agar coated slides and allowing the weight of a coverglass to flatten them sufficiently for detailed examination.

The head and the tail end of the larva were differentiated at a fairly early stage and about the same time a hook-like structure appeared on the head. Subsequently a body cavity was formed within the larva which was associated with the appearance of highly refractile subcuticular cells. Later this cavity became filled with different types of cells.

Throughout its development the larva was enclosed within a membrane which was later stretched by the movement of the larva to form the sheath of the microfilaria. All the microfilariae from the adult female worms, from the pleural fluid, and from the peripheral blood of the large number of infected cotton rats examined, were seen by phase-contrast microscopy to have sheaths.

The morphology of the tegument of four microphallid metacercariae from the stage of invasive cercariae to their maturation as encysted metacercariae inside their crustacean second intermediate hosts is described. The tegument of the metacercariae developed surface lamellae and projections which, along with coated vesicles in the surface syncytium, indicated that the tegument had an absorptive function. The disappearance of secretory granules from the tegument at the same time as the appearance of the first cyst wall suggested that the tegument had a role in primary cyst production. Following this, the metacercariae continued to grow and seemingly retained their absorptive ability. The tegument was also involved in the transport of material into the perimetacercarial lumen prior to its eventual inclusion in the developing inner cyst layers. It appeared that this material originated in tegumental cells located amongst the parenchymal cells beneath the tegumental syncytial layer. On completion of the secondary cyst layers there was a gradual degeneration of structures associated with absorption and a progressive accumulation of dense discoid granules traceable to underlying tegumental cells. All four microphallid species (Maritrema arenaria, M. subdolum, Levinseniella brachysoma and Microphallus claviformis) demonstrated the same developmental pattern but the period spent in each stage differed depending on the time spent migrating to encystment sites. The pattern of tegumental development described is thought to be applicable to all microphallid metacercariae and possibly to other metacercariae which undergo growth and development in their second intermediate hosts.

The structure of the cuticle of third and fourth stage larvae and of adult Brugia pahangi (Nematoda: Filarioidea) was studied by light microscopy and by transmission and scanning electron microscopy. The cuticle of these worms was basically typical of the class Nematoda and consisted of cortical, matrix, and basal layers. Finely spaced annulation grooves were present and their function is discussed.

Descriptions of the cuticular ultrastructure of filarial nematodes are meagre. Studies on the cuticle of adult worms are limited to those of Kagei (1960, 1963) on Setaria cervi and Litomosoides carinii and of McLaren and Hockley (personal communication) who examined L. carinii and Dipetalonema vitea

A new Heterorhabditis species of entomopathogenic nematode was isolated from soil of the Atacama Desert in Chile. The new species is characterized by morphometrics of the infective juvenile (IJ) with length (L) = 611 (578–666) μm, head to excretory pore length (EP) = 115 (101–126) μm, tail = 69 (62–79) μm long, (EP/tail) × 100 (E%) = 165 (149–182) and L/maximum body diameter (ratio a) = 28 (25–31). The male has spicules 45 (40–49) μm long, gubernaculum 20 (17–22) μm long and (spicule length/anal body diameter) × 100 (SW%) = 205 (179–249). The hermaphroditic adult has shallow cuticular folds immediately anterior and posterior to the vulva, a slight post-anal swelling and a finely rounded tail terminus. Morphologically, H. atacamensis n. sp. resembles H. safricana, H. marelatus, H. downesi and H. amazonensis, but can be distinguished by characters of adult and IJ stages. In particular, for adult males, H. atacamensis n. sp. differs from H. amazonensis by the number and orientation of the genital papillae and from H. downesi by the position of the excretory pore; by the shape of the female tail terminus from H. downesi and by the position of the IJ hemizonid from H. marelatus. Heterorhabditis atacamensis n. sp. is further characterized by internal transcribed spacer (ITS) and D2D3 rDNA sequences, the closest species, H. safricana, being separated by 13 bp across 730 bp of the ITS (incorporating ITS1 (partial sequence), 5.8S (complete sequence), ITS2 (complete sequence)) and 5 bp across 592 bp of the partial 28S (incorporating D2D3) sequence. The morphological and molecular data confirm that H. atacamensis n. sp. is a valid species.

A comparative study has been made of certain species of Diphyllobothrium which are primarily parasites of birds, but which have been obtained from man and other hosts, both naturally and experimentally. As a result of this work it appears that only two valid species are known in birds, namely: Diphyllobothrium dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825). These species differ markedly from each other in certain morphological features and there appears to be a noticeable difference in their host-adaptation, inasmuch as D. ditremum occurs only in birds belonging to the families Phalacrocoracidae, Ardeidae, Colymbidae and Anatidae, while D. dendriticum occurs naturally in birds belonging to the Laridae and other families, and experimentally also in mammals.

Several kinds of data were collected from worms belonging to the genus Proteocephalus, living in the intestines of Pygosteus pungitius and Gasterosteus aculeatus.

a. Morphological data. When we compare the morphological characteristics of worms from the two hosts we find small differences in those characteristics commonly used in the descriptions of species of the genus Proteocephalus. Regularly differences of the same magnitude are used to separate species.

b. Experimental infections show that a high degree of host specificity exists in worms from the two hosts. It is impossible to cultivate worms originally coming from one host species in the intestine of the other. These experimental infections were carried out either by feeding intermediate hosts carrying plerocercoids to fishes free of infection, or by collecting worms from the intestine of one fish and introducing them into the intestine of another fish.

Experimental infections of alien hosts failed whereas infections of the proper host, carried out as controls, always were successful.

c. Mixed populations of Gasterosteus and Pygosteus living in a small closed canal system gave additional data indicating the existence of a high degree of host specificity. Throughout the year Gasterosteus showed no infection at all whereas Pygosteus was “normally” infested.

d. Monthly dissections of Pygosteus showed that in Proteocephalus living in this fish species no seasonal cycle exists similar to that found by Hopkins in Proteocephalus from Gasterosteus. The stages of development of Proteocephalus collected during the dissections of Gasterosteus correspond with Hopkins' seasonal cycle.

e. As a result of these observations it is proposed to consider the worms from Pygosteus as belonging to a distinct species. Since Dujardin was the first to describe worms belonging to the genus Proteocephalus and living in the intestine of Pygosteus as Proteocephalus ambiguus (Dujardin, 1845) this obviously ought to be the name of the species involved. The use of the name P. filicollis (Rudolphi, 1802) is restricted to material from Gasterosteus.

Data presented in this study highlight the potential of allozyme electrophoresis in providing unequivocal genetic evidence for the identification of life cycle stages, particularly where species have complex life cycles. Adults of the nematode Echinocephalus overstreeti parasitize the elasmobranch Heterodontus portusjacksoni. The putative larval form which is morphologically dissimilar is found in two species of marine molluscs, Chlamys bifrons and Pecten albus. Electrophoretic analysis indicated that the adult and larval forms shared alleles at all of the 34 enzyme loci established. Furthermore, there were no fixed allelic differences between larval forms from different mollusc species.

In the serodiagnosis of alveolar echinococcosis, the detection of specific reactions against not only protein but also carbohydrate antigen is useful and both antigens supplement each other. Though recombinant protein antigens have recently advanced, the preparation of carbohydrate antigen still depends on extraction from crude antigens. In the latter case, it is not conventional to obtain carbohydrate antigen as a single component for examination and research. Therefore, chemically synthesized carbohydrate antigens were prepared for serodiagnosis by the enzyme-linked immunosorbent assay (ELISA). Four antigens with the structure of glycosphingolipids from Echinococcus multilocularis were examined and one antigen, Galβ1-6(Fucα1-3)Galβ1-6Galβ1-ceramide, was found to show significant serodiagnostic potential in differentiating alveolar from cystic echinococcosis.

Release of Echinostoma caproni cercariae and Schistosoma mansoni from experimentally infected Biomphalaria glabrata snails maintained under different laboratory conditions was studied. Infected snails were isolated individually for 1 h in Stender dishes containing 5 ml of artificial spring water and the number of cercariae released during this time was recorded. Of numerous conditions tested, the addition of lettuce, the use of water conditioned by B. glabrata snails and a temperature of 35°C significantly increased the release of E. caproni cercariae. A significant increase in cercarial release of S. mansoni was seen only in cultures fed lettuce. A temperature of 12°C caused a significant decrease in cercarial release of both E. caproni and S. mansoni. Increased snail activity associated with feeding behaviour was probably responsible for the enhanced cercarial sheds observed in this study.

The main goals of this study were to compare the richness of parasitic trematodes in amphibians with diverse habits (terrestrial, fossorial, semi-aquatic and arboreal), and to evaluate whether the composition of the trematode community is determined by ecological relationships. Specimens were collected between April 2001 and December 2006 from a common area (30 ha) in Corrientes Province, Argentina. Trematodes of amphibians in this area comprised a total of 19 species, and were dominated by common species. Larval trematodes presented highest species richness, with the metacercaria of Bursotrema tetracotyloides being dominant in the majority (7/9, 78%) of the parasite communities. Adults of the trematode Catadiscus inopinatus were dominant in the majority (6/9, 67%) of amphibians. The amphibians Leptodactylus latinasus, Leptodactylus bufonius and Scinax nasicus presented a high diversity of trematodes, whereas Leptodactylus chaquensis had the lowest diversity even though it presented with the highest species richness. The patterns of similarity among amphibian species showed groups linking with their habitats. Leptodactilid amphibians, with a generalist diet and an active foraging strategy showed highest infection rates with adult trematodes. The mean richness of trematode species related to host's habitat preferences was higher in semi-aquatic amphibians. Results suggest that semi-aquatic amphibians, present in both aquatic and terrestrial environments, present a greater diversity of parasites as they have a higher rate of exposure to a wider range of prey species and, hence, to diverse infective states. The trematode composition is related to the diets and mobility of the host, and habitat.

Thirty-one faecal samples were collected from red deer in the northern area of Varese, in the Italian region of Lombardy, between August and October 2008. The animals had either been hunted or accidently killed. Examination for internal parasites showed a prevalence of 45.2% for Elaphostrongylus cervi larvae and species identification was confirmed by polymerase chain reaction (PCR). Ninety-seven faecal samples were also collected from two goat flocks grazing in the same area between December 2007 and May 2008. These showed a prevalence of 74.7% for lungworms. Furthermore, the central nervous systems from five goats and one sheep from this area with a history of neurologically related lameness were examined. Histopathology confirmed E. cervi cerebro- spinal nematodiasis in five cases out of six. This study demonstrates E. cervi transmission from wild to domestic ruminants when the animals graze in the same area, and the possible occurrence of clinical disease in infected goats and sheep associated with high prevalence in deer.

Border Leicester X Suffolk sheep infected with a strain of S. mattheei maintained in hamsters do not develop the same pathological changes as Romney Marsh sheep infected with the same strain of parasite before hamster passage. To determine the cause of this reduced pathogenicity, five Romney Marsh sheep were each infected with 10 000 cercariae of the hamster-passaged parasite and five with 10 000 cercariae of a S. mattheei strain from Onderstepoort, South Africa, passaged exclusively through sheep.

Striking pathological and parasitological differences were found between the two strains. Infection with the “sheep” strain was lethal, whereas infection with the “hamster” strain produced little evidence of clinical disease. By 13 weeks post-infection the mean body weight of the sheep infected with the sheep strain had declined by 15% compared with both the uninfected controls and the sheep infected with the hamster strain, and the mean PCV was lowered to 20% in the sheep strain infected animals. Egg production began at seven weeks with the sheep strain, faecal counts rising to more than 300 e.p.g., whereas only two of the sheep infected with the hamster strain passed eggs in the faeces (at nine weeks) and the maximum egg count was 50 e.p.g. Twice as many adult worms of the sheep strain were recovered, and, although the number of eggs found in the tissues “per worm pair” was not significantly different, overall egg production was higher for the sheep strain; also more of the sheep strain eggs were deposited in the intestines. Similar parasite differences were seen in a supplementary study in mice and it seemed that “attenuation” of the parasite had occurred, presumably due to its maintenance in hamsters. Histopathological observations and faecal egg counts both indicated an inability of hamster strain eggs to penetrate the intestinal lumen; this was probably important in reducing the pathogenicity of the hamster strain.

Recently, in the Journal of Helminthology (May 2013), Dao et al. reported that Opisthorchis viverrini-like flukes were found in the bile duct of domestic ducks in Vietnam. They stated that this is the first record of Opisthorchis sp. in birds in Vietnam. However, three Opisthorchis species – O. cheelis, O. longissimus and O. parageminus – in birds in Vietnam were described by Le in 2000. Amongst these, O. parageminus was first reported, by Oshmarin in 1970, as a new Opisthorchis species found in domestic ducks (Anas platyrhynchos) in Vietnam. Morphologially O. viverrini-like flukes described by Dao et al. are much more similar to O. parageminus than to O. viverrini. The phylogenetic trees of internal transcribed spacer 2 (ITS2) and cytochrome oxidase 1 (CO1) gene sequences also showed that the O. viverrini-like liver flukes from domestic ducks were closer to O. lobatus than to O. viverrini. Therefore, O. viverrini-like liver flukes reported by Dao et al. (2013) are most likely to be O. parageminus.