Owing to the comparatively little use made of the flesh of the goat in this country, the helminthic parasites of this host have been far less studied than those found in other domestic animals. In other countries, where the goat plays a far greater economic rôle, a large number of parasitic worms have been recorded.

The effect of exogenous steroid hormones on the egg output of Heligmosomoides polygyrus (Nematoda: Trichostrongylidae) was examined in vitro. Using worms raised in female mice, it was found that estradiol, testosterone, and cortisone each significantly decreased egg output. Although similar trends were found using H. polygyrus raised in male mice, none of the decreases found was significant. No significant differences were found with ecdysone or progesterone treatments using worms from female or male mice. Treatment of worms with cortisone did not significantly affect retention of eggs within the uterus of H. polygyrus. Titration of the effect of cortisone on egg output indicated that levels of reduction were significant for concentrations of 5·6 × 10−6 M to 5·6 × 10−3 M in worms from female mice and for concentrations of 5·6 × 10−8, × 10−7, × 10−5 and × 10−3 in worms from male mice. Radioisotope labelling experiments showed incorporation of 3H-corticosterone in the nucleus of intestinal cells of H. polygyrus suggesting that its effect on egg production may be via a modulatory effect on the intestinal cells.

A detailed redescription of Gazellostrongylus lerouxi and Paracooperia serrata was given from specimenscollected from antelopes in Kenya. It was felt that there was no justification for the synonymy of the genus Gazellostrongylus with Paracooperia. Gazellostrongylus was placed in the tribe Ostertagiea.

Aphelenchus ritzemabosi is known as a serious parasite of greenhouse plants such as chrysanthemums and gloxinias but the number of records of its attacks on plants grown out of doors is increasing. Disease due to it has been observed in the open on chrysanthemums and dahlias in this country and in the present paper a new out-of-door host is added to the list of plants attacked by it.

Isozyme patterns of six enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, hexokinase, malate dehydrogenase, 6-phosphate dehydrogenase and phosphoglucomutase were examined in electrophoresed homogenates of adult male worms of Schistosoma japonicum and S. mansoni. In general, enzyme patterns obtained from the parasite homogenates differed from that of host (mouse) blood and muscle, indicating that electrophoretic patterns from parasite extracts are most probably of parasite origin. Adult male and female S. mansoni worms yielded identical patterns. However, all six enzyme patterns showed distinct differences between S. japonicum and S. mansoni. These results suggest that S. japonicum is clearly distinguishable from S. mansoni at the molecular level.

A number of these specimens were available for study. They were collected from the stomach of Galago crassicaudatus agisymbanus (Coquerel) in Tanganyika Territory by Dr. W. H. R. Lumsden whom I wish to thank for the material.

These stout worms have a thick cuticle which is finely striated. The well-developed lateral lips are smooth, hemispherical, each possessing a large triangular external tooth and three smaller internal teeth. There are two prominent papillae towards the dorsal and ventral margins of each lip. The cervical cuticle forms a collar round the anterior end.

Methods are discussed for greatly increasing the cyst content of Helerodera-intested soil, so that very little soil need be “floated” to provide the number of cysts necessary to form a replicate in bioassay. Such a “float” contains very little debris and may be used directly, thus avoiding the laborious and time-consuming step of separating the cysts from the debris. An apparatus for quick recovery of the “float” is described.

The following note is based on a sample of Filariae collected by Dr. W. Stefanski (University of Warsaw) from the trachea of a Black Stork shot in the neighbourhood of Warsaw and generously placed by him at my disposal.

Dactylogyrid species (Monogenea) communities were studied in roach, Rutilus rutilus, collected from two localities in the basin of Morava river, Czech Republic, during the period from April to November 1997 and March to September 1998 to determine the effect of water temperature on parasite abundance, species richness and diversity. Dactylogyrid species were found to co-occur on the gills of roach with up to six species found on the same host individual. Nine dactylogyrid species were identified with the abundance of each reaching a very low level. Niche size was considered to increase with species abundance even when water temperature was high. There was a strong effect of water temperature on abundance of the common dactylogyrid species (D. crucifer, D. nanus, D. rutili and D. suecicus) as well as of the rare species D. rarissimus. The temporary occurrence of the rare species was found without any temperature effect. Water temperature did not affect the relationship between abundance and niche size. Niche size increased with abundance, even when the water temperature was high, which suggests that negative interspecific interactions are not important within dactylogyrid communities.

The aim of this study was to determine the role in contractions of postsynaptic nicotinic acetylcholine (nACh) and γ-aminobutyric acid (GABA) receptors, in the bag region of Ascaris suum muscle cells, as well as the role of synaptic receptors between interneurons and motor neurons in the dorsal and ventral nerve cord. We have measured the isometric contractions of isolated segments of A. suum, with or without the nerve cord (dorsal or ventral). Contractions were caused by increasing concentrations of ACh or by electrical field stimulation (EFS). Based on our results, the presence of the nerve cord is essential for the contractile effects of ACh. The EC50 value of ACh for innervated muscle strips was 10.88 μm. Unlike intact (innervated) preparations, there was no contraction of the muscle flaps when the nerve cord was mechanically removed. Furthermore, continuous EFS produced stable contractions of innervated muscle strips, but they are not sensitive to mecamylamine (100 μm). However, GABA (30 μm) significantly inhibited the EFS-induced contractions. EFS with the same characteristics did not cause muscle contractions of denervated muscle strips, but EFS with a wider pulse induced the increasing of tone and irregular contractions. These contractions were completely insensitive to the effect of GABA. The EC50 for ACh did not differ between the dorsal and ventral segments (9.83 μm and 9.45 μm), while GABA exhibited features of competitive and non-competitive antagonists, regardless of whether it acted on the dorsal or ventral segments of A. suum. It is obvious that drugs will be more effective if they act on both the synaptic and extrasynaptic nACh and GABA receptors.

Terrestrial arthropods host a variety of helminth parasites, yet quantifying the intensity of infection in these hosts post-mortem is challenging because carcasses may desiccate quickly. We recovered cysticercoids of Hymenolepis diminuta from desiccated flour beetle (Tribolium confusum) carcasses by modifying a published insect rehydration procedure. Without rehydration, carcasses dissected more than 1 day post-mortem had noticeable degradation of cysticercoids. Mild rehydration (soaking in water only for 2 days, or 0.5–10% KOH for 1 h followed by 1 day in water, or 0.5% KOH for 1 day) left carcasses tough and time-consuming to dissect, but all parasites could be recovered and were similar in body size to fresh cysticercoids. Moderate rehydration (5–10% KOH for 1 day) allowed all parasites to be recovered and facilitated dissection by partially dissolving internal organs of the beetle while causing little degradation of the cysticercoids. Harsh rehydration (5–10% KOH for 1 day followed by 5 days in water) not only dissolved internal beetle tissues but also severely damaged cysticercoids, such that parasite counts were unreliable. The degree of initial carcass desiccation had little effect on results following rehydration. However, regardless of treatment used, intact cercomers were rarely retained on rehydrated cysticercoids. Rehydration was less successful on early developmental stages of the parasite, which were recovered reliably only as they neared the cysticercoid stage. This method has utility for studies of parasite-induced mortality by permitting accurate and reliable parasite counts from dead, desiccated hosts.

A total of 180 individuals of Scardinius erythrophthalmus from Srebarna Lake, north-east Bulgaria, were examined for helminth parasites during spring, summer and autumn of 2005–2006 (30 specimens per season). Helminth parasites were recorded in 166 individuals (92.2%). Ten helminth species were found: trematodes – metacercariae of Posthodiplostomum cuticola, Diplostomumchromatophorum and D. spathaceum; monogeneans – Dactylogyrus difformis, D. difformoides and Diplozoon scardinii; cestodes – metacestodes of Paradilepis scolecina; nematodes – larvae of Spiroxys contortus and Rhabdochona denudata and adults of Schulmanela petruschewskii. Significant seasonal differences in the mean abundance were recorded for D. difformis, D. difformoides and D. scardinii. Significant seasonal differences in prevalence were recorded for P. cuticola, D. difformis, D. difformoides and D. scardinii. Dominant species in the component communities were P. cuticola, D. difformis and D. difformoides. The species composition of the component community essentially differs from that in the adjacent Danube River; a possible reason is the specific hydrobiological situation of the lake, characterized by a low density of benthic molluscs and crustaceans.

When many worms co-infect the same host, their average size is often reduced. This negative density-dependent growth is called the crowding effect. Crowding has been reported many times for worms in their intermediate hosts, but rarely have the fitness consequences of crowding been examined. This study tested whether larval crowding reduces establishment success in the next host for two parasites with complex life cycles, the nematode Camallanus lacustris and the cestode Schistocephalus solidus. Infected copepods, the first host, were fed to sticklebacks, the second host. Fish received a constant dose, but the infection intensity in copepods was varied (e.g. giving two singly infected copepods or one doubly infected copepod). Worms from higher-intensity infections did not have significantly reduced infection success in fish. However, crowded treatments had a disproportionate number of low and high infection rates, and although this trend was not significant, it hints at the possibility that multiple worms within a copepod are more likely to either all infect or all die when transmitted to the next host. These results indicate that a smaller larval size due to crowding need not reduce the establishment probability of a worm in the next host.

Seven species of acanthocephalans were identified for the first time in teleost fish from the Bizerte lagoon, Tunisia, including Neoechinorhynchus (Hebesoma) agilis (Rudolphi, 1819) Van Cleave, 1916; N. (Neoechinorhynchus) rutili Müller, 1780 (Neoechinorhynchidae); Acanthocephaloide propinquus (Dujardin, 1845) Meyer, 1932; A. incrassatus (Molin, 1858) Meyer, 1932 (Arhythmacanthidae); Longicollum pagrosomi Yamaguti, 1935 (Pomphorhynchidae); Rhadinorhynchus cadenati (Golvan et Houin, 1964) Golvan, 1969 (Rhadinorhynchidae); and Telosentis exiguus (von Linstow, 1901) Van Cleave, 1923 (Illiosentidae). Acanthocephaloide propinquus, N. (N.) rutili, L. pagrosomi and R. cadenati were restricted to the rectum and the posterior intestine, whereas the other species (A. incrassatus, T. exiguus and N. (H.) agilis) colonized two or three parts of the intestine. The most diverse acanthocephalan fauna was recorded in Lithognathus mormyrus, with three species; two species were reported from Trachurus trachurus; and a single species was recorded in Liza aurata and in Atherina boyeri. Neoechinorhynchus (N.) rutili, L. pagrosomi and R. cadenati attained the lowest prevalences of less than 6% and were considered as to be rare species. Acanthocephaloide incrassatus, A. propinquus, T. exiguus and N. (H.) agilis were satellite species. The diversity of the acanthocephalan fauna in the fish from the Bizerte lagoon is compared with previous studies from other localities. The report of A. incrassatus, A. propinquus and N. (N.) rutili in L. mormyrus presents new host records in Mediterranean waters.

This worm was very abundant in the rectum of a tortoise, Homopus femoralis, from the Bloemfontein area, Orange Free State, South Africa. It was found together with several other oxyurids the description of which will form the subject of a later paper. Although the Probstmayria far exceeded the other oxyurids in number, male specimens of this genus were extremely rare for only one male was found after a prolonged search during the course of which many hundreds of females were encountered. In order that no specimens should be lost the entire alimentary canal together with its contents was submerged in hot 70% alcohol after scraping the mucosa.

Two males and one female Aphelenchoides were taken from the rootlets of radish, Raphanus sativus, in December, 1967, in the suburbs of Lucknow (India). They are described as new and are named Aphelenchoides franklini n.sp.

Factors which influence the establishment of tetrathyridia of Mesocestoides corti in mice following inoculation per os were examined. Only a proportion of the tetrathyridia penetrate the gut wall and gain access to the peritoneal cavity and liver, and most of these penetrate through the wall of the small intestine. It appears that tetrathyridia must attach to the intestinal mucosa and commence penetration immediately or they pass into the large intestine and are voided. Establishment was not influenced by strain, sex or age of host. However, the temperature at which tetrathyridia were maintained before inoculation did influence their ability to penetrate the intestinal wall. Additionally it appears that tetrathyridia have to undergo a morphological change before or during, this penetration phase.

The rediae of Fasciola hepatica were counted according to generation in adult and juvenile Lymnaea truncatula following single infection with Fasciola hepatica, double infection with F. hepatica and then Muellerius capillaris, or double infection with M. capillaris and F. hepatica. The rediae found in double infections were essentially first generation and an early cohort from the second generation. The following differences were observed in adult snails which underwent double infection when compared to corresponding single infections: i) dependent rediae were almost completely absent; ii) degenerating independent rediae were found in identical or decreased numbers; iii) living independent rediae of the first generation were decreased in number, while those of the second generation had variable decreased numbers. The results were similar in juvenile snails with double infections, except that the numbers of degenerating independent rediae were higher than those found in corresponding single infections and the numbers of rediae of the second generation were increased. The order of exposure in double infections had no influence on the number and maturation of fasciolid rediae.

Six families belonging to the Paramphistomoidea superfamily have been reported in South America, with only Zonocotylidae and Balanorchiidae being endemic. The Zonocotylidae was initially classified as Aspidogastrea and then as a paramphistomoid. This family comprises a single genus, Zononocotyle, with two species. It is primarily characterized by having an attachment organ with transverse ridges and a single testis. The placement of Zonocotylidae within Paramphistomoidea is controversial, as some researchers speculate that this genus is the most primitive member of the superfamily, while others consider it an aberrant form. The main objectives of our study were to provide the first sequences of Zonocotylidae and elucidate its phylogenetic position. We amplified the 28S gene from two parasites from Cyphocharax sp. from Punta Lara, Buenos Aires. Newly generated sequences were used to infer the phylogenetic relationships with other Paramphistomoidea species using a Bayesian approach. Zonocotylidae were clustered with Dadayiinae and Kalitrematinae (Cladorchiidae) species found in freshwater fishes from South America. Genetic analyses revealed that they formed a well-supported clade with cladorchiids in freshwater hosts from South America. However, the occurrence of genera of Cladorchiidae in North America, Middle America, Asia, and Australia suggested its polyphyletic nature and may indicate the need for the erection of new families. Other Paramphistomoidea families may also require further revision. The addition of new sequences to phylogenetic analyses along with a comprehensive and more detailed description of the genera will help resolve the relationships within this group.

The nematicidal activity of buckwheat (Fagopyrum esculentum Moench) on the root-knot nematode Meloidogyne incognita was tested. Dried plant methanol extract presented higher nematicidal activity than fresh plant extracts with an EC50 = 62.6 ± 26.0 and 40.8 ± 26.1 μg/ml after 48 and 72 hours of immersion, respectively. GC-MS analysis showed the presence of 17 aldehydes, with salicylaldehyde (o-hydroxybenzaldehyde) being the most abundant at 16%. Nematicidal activity of the latter and other aldehydes with chemical similarities was then assessed. The most active aldehyde was o-hydroxybenzaldehyde followed by m-hydroxybenzaldehyde, p-hydroxybenzaldehyde and benzeneacetaldehyde with an EC50 of about 11.0 ± 1.0, 31.0 ± 22.0, 75.0 ± 23.0 and 168.1 ± 52.3 μg/ml after 1 day of immersion, respectively. Position 2 of the hydroxyl group in the benzene ring seems to be very important for the nematicidal activity, followed by positions 3 and 4. As a complementary experiment, synergistic activity was observed when we added o-hydroxybenzaldehyde to m-hydroxybenzaldehyde and to p-hydroxybenzaldehyde with an EC50 after 24 hours of immersion of 8.0 ± 2.5 and 6.1 ± 2.3 μg/ml, respectively. Antioxidant activity assessment showed that this latter is inversely proportional to nematicidal activity. Our results showed that F. esculentum and its major compound salicylaldehyde could be integrated into the pest management system.