Our knowledge of the Indian Rhynchobdellid leeches is still in its infancy, and the little that we have, we owe to the researches of Harding, Kaburaki, and Moore. After the publication of the Hirudinea volume by Harding & Moore (1927) in the Fauna of British India Series, Bhatia (1930a, b, 1934, 1939), Chelladurai (1934) and Raj (1951, 1954a, b) have contributed to the systematics of this group. The present work has been undertaken with a view to advancing further our knowledge of Indian Rhynchobdellid leeches. In this work, the neurosomic theory of somite limits launched independently by Castle (1900) and Moore (1900) has been followed in counting the annular composition of somites. This paper, the first of the series, deals with the description of four Glossiphonid leeches, of which three are new to science, while the fourth one is of zoogeographical importance.

The genus Paradilepis Hsü, 1935 syn. Meggittiella Lopez-Neyra, 1942, is defined as follows (Hsü, 1935, p. 536): ‘Dilepididae. Rostellum armed with a double crown of hooks. External segmentation little marked. Genital pores unilateral. Genital ducts pass dorsal to excretory vessels and to nerve. Testes few in number, situated to either side of the female glands. Uterus sacciform, little lobed. Parasites of birds.’

Factors that drive parasite specificity and differences in infection dynamics among alternative host species are important for ecology and evolution of host–parasite interactions, but still often poorly known in natural systems. Here, we investigated spatiotemporal dynamics of infection, host susceptibility and parasite-induced changes in host phenotype in a rarely explored host–parasite system, the Australapatemon sp. trematode infecting two sympatric species of freshwater leeches, Erpobdella octoculata and Helobdella stagnalis. We show significant variation in infection abundance between the host species in both space and time. Using experimental infections, we also show that most of this variation likely comes from interspecific differences in exposure rather than susceptibility. Moreover, we demonstrate that the hiding behaviour of E. octoculata, but not that of H. stagnalis, was impaired by the infection irrespective of the parasite abundance. This may increase susceptibility of E. octoculata to predation by the final avian host. We conclude that differences in patterns of infection and in behavioural alterations among alternative sympatric host species may arise in narrow spatial scales, which emphasises the importance of local infection and transmission dynamics for parasite life cycles.

Experimental infections of mallards (Anas platyrhynchos L.) with Typhlocoelum cucumerinum sisowi (Skrjabin, 1913) and of canvasbacks (Aythya valisineria (Wilson)) with Typhlocoelum cucumerinum cucumerinum (Rudolphi, 1809) revealed significant differences in various parameters of the life-cycle in the definitive host. Both T. c. sisowi and T. c. cucumerinum migrate to the trachea via the abdominal cavity, air sacs and lungs, although T. c. cucumerinum migrate more quickly and more synchronously than T. c. sisowi. Typhlocoelum c. sisowi has a shorter expected life-span than T. c. cucumerinum but grows and reaches maturity more quickly than T. c. cucumerinum. Evidence suggests that T. c. cucumerinum has a higher fecundity than T. c. sisowi. These differences in the patterns of migration, growth and development are related not only to differences between the two host species but also to differences intrinsic to the parasites, and serve to provide biological support for considering them as separate sub-species.

Paedogenesis, or the multiplication of an animal in its immature stages of life, is a very rare phenomenon and is known to occur only in a few species of holometabolic insects.

1. Rearing. Larvae of Trombicula autumnalis were fed on young mice (about 8 days old); after 48 hr. at 25° C. they began dropping off fully engorged.

The post-larval stages were reared individually in separate filter-paper cells. At room temperature, 100% R. H., the engorged larvae were actively mobile for about 6–12 days, and for 12–20 days at 30° C., 100% R.H., before entering a quiescent stage (the developing nymphal stage). The nymphs emerged after about 33 days at room temperature, and 25 days at 30° C., from the time the engorged larvae dropped off the host.

Of the nymphs which developed to adults, four fed on a mixture of yeast, molasses, and agar plus chicken faeces; one fed upon the exuded contents of the eggs of Aëdes aegypti; and another fed upon a mixture of all the ingredients mentioned. Young and old nymphs of Trombicula autumnalis appeared to be incapable of feeding upon intact insects' eggs; neither did they show any particular predilection for the exuded contents of insects' eggs offered as a soft mass, and only with some difficulty were they made to introduce this food into the gut. When chicken faeces were offered as food the nymphs did not feed upon it.

A method of ‘forced feeding’ was adopted, that is to say, nymphs were placed upon or guided on to the periphery of the food mass provided. When a nymph moved away it was replaced upon the food, and the process was repeated until the nymph showed signs of introducing the food into the gut. Occasionally a nymph after being placed upon the food remained in situ and fed continuously for about 6–8 hr. until completely engorged.

2. The post-embryonic forms. The features of the stages (the larva nymph and adult), are described with respect to their development and growth.

The transition, or developing stages (the pre-nymph and pre-adult), are closed systems which resemble the pupal stage of a holometabolous insect. The developing mite is enclosed by the cuticular remains of the preceding mobile stage, and a second inner or intermediate cuticle. Large flattened cells of epidermal origin are present, usually lying against the inner surface of the intermediate cuticle. Emergence of the nymph and adult depends upon the combined effects of an active secretion, which causes a disintegration of the intermediate cuticle, and muscular exertion.

3.Dimorphism. Two kinds of dimorphism are shown during the growth of T. autumnalis; sexual dimorphism associated with size, and nymphal dimorphism depending on marked differences in body shape and in the length of the posterior setae.

Both kinds of dimorphism are initiated at the beginning of post-larval life (beginning of nymphal development).

The time which the engorged larva takes to settle is inversely proportional to the size of the post-larval stages; in other words, the amount of activity and accompanying usage of acquired food reserves before the engorged larva settles appear to govern the absolute size of the individual during post-larval life. There is an indication of small forms becoming male and larger ones female.

Two types of nymph (referred to in this paper as α-type and β-type nymphs) were bred from out-wardly identical larvae. The differences in the growth of the body as a whole and the posterior setae, which distinguish the two types of nymph, appear to be of developmental origin.

4. The life cycle in the natural environment. Laboratory findings confirm the view that only one generation is produced each year, but that successive broods are produced throughout the season of incidence.

Isometric tension recordings and the single sucrose-gap technique were used to record mechanical and electrical activity of somatic muscle from G. erinaceus metacestodes in vitro. Praziquantel (≥ 10−6 M) raised baseline tension and largely abolished spontaneous fluctuations in tension. The effect of the drug was critically dependent on the presence and availability of calcium in the bathing medium. In calcium-free solution or in the presence of manganese or lanthanum (10 mm) praziquantel failed to induce a rise in baseline tension. Electrical recordings of somatic muscle activity showed the action of praziquantel to be accompanied by membrane depolarization and loss of slow depolarizations and spikes. Tegumental membrane potential, as measured by microelectrodes, was not affected by the drug. These results suggest that in vitro praziquantel causes contraction of the somatic muscle of G. erinaceus by membrane depolarization and influx of extracellular calcium.

Twelve rabbits were dosed with infective larvae of a sheep parasite Nematodirus battus and killed in a serial manner over a period of 32 days. The percentage of worms which became established was 10–36% over the first 24 days after infection. The minimum period of development of the parasitic stages was similar to that in sheep, although adult worms recovered from rabbits were on average smaller than worms normally found in sheep. The course of migration followed by the parasitic larvae was the same as in sheep. The distribution of fourth-stage larvae and fifth-stage worms along the small intestine was that of a normal frequency distribution. N. battus was still infective for lambs and rabbits after one passage through the rabbit.

I would like to express my appreciation for the advice and encouragement given in the course of this work by Mr M. G. Christie.

That ducks are subject to infestation by sarcosporidia has long been known. It seems to have been emphasised particularly because ducks afforded one of the first-known instances of the occurrence of these puzzling protozoa in birds. Very few new records have been published until now and no adequate illustrations of the gross features of the infestation have appeared. A general review of the subject and presentation of additional cases, with illustrations, therefore seems desirable.

The family Fellodistomidae Nicoll 1913 comprises two subfamilies, Fellodistominae Nicoll 1909 and Haplocladinae Odhner 1911, which are composed of a large number of genera of small flukes, all parasitic in fishes. The type genus of the family was described by Stafford in 1904 from the gall bladder of a Canadian wolf-fish, Anarrhichas lupus. Subsequently several new genera have been added from European and American fishes, but until now no representative of the family has been reported from India.

The glycolipids of Ascaris suum represent either neutral, zwitterionic or acidic structures. The acidic fraction comprises a sulphatide and an unusual phosphoinositolglycosphingolipid (Lochnit et al. 1998b). The sulphatide was previously localized to the hypodermis, contractile zone of somatic muscle cells and the external musculature of the female uterus, whereas the presence of the phosphoinositolglycosphingolipid species was restricted to the intestine. The neutral and zwitterionic components belong to the arthro-carbohydrate series, which are substituted in their zwitterionic structures by phosphocholine (PC) and in one glycolipid by an additional phosphoethanolamine residue. In previous immunohistochemical localization studies, however, the chemical nature of the PC-substituted biomolecules has not been investigated in detail. Here, we report on the immunohistochemical localization and differentiation of phosphocholine-containing structures into lipid- and protein-bound species in adult A. suum. The patterns of immunostaining, obtained with a PC-specific monoclonal antibody and anti-zwitterionic glycolipid hyperimmune serum in the female worm, indicated a parallel organ distribution for glycolipid- and protein-bound PC-epitopes. Immunoreactivity was localized to specific tissues of the body wall, intestine and reproductive tract. This is the first report of surface-located PC-epitopes for ascarids. The patterns of immunolabelling obtained with antibodies directed against the unsubstituted arthro-carbohydrate series backbone suggested that the glycolipid-bound epitope was restricted to the hypodermis, whilst the protein-bound antigenic determinant resembled that for PC.

The spontaneous free-swimming behaviour of the cercaria of Transversotrema patialense was recorded using a high-speed micro-cinematographic technique. The sequential change in configuration of the cercaria was analysed quantitatively and the angular relationships of the cercarial components determined with respect to the trajectory of the organism. The cercaria swims tail-first while the tail stem oscillates through an arc of 100–120° with a frequency of 30 Hz at 24°C. The body region oscillates, almost exactly out of phase, through an arc of 180°C at the same frequency. The two furcae execute alternate effective and recovery strokes so that two symmetrical effective strokes are performed during each propulsive cycle. The Reynolds number of the swimming cercaria was approximately 2. The relative importance of viscous and inertial forces in cercarial propulsion is discussed.

Social wasps can face many challenges during their colony cycle, including the presence of parasites. The order Strepsiptera is among the main parasites of the wasp genus Polistes. The aim of this study was to evaluate the effect of an endoparasite species on the host Polistes ferreri, with the hypothesis that females of this social wasp would undergo morphophysiological alterations as well as changes in their cuticular chemical profile caused by the obligate endoparasite. On average, parasitism was found in 10% of the colonies studied. All the parasitized females showed filamentous ovarioles without developing oocytes, which indicates a physiological castration. Moreover, the endoparasites present in the gaster of females caused its volume to increase, and the presence of endoparasites changed the cuticular chemical profiles of females, confirming our hypothesis. It is likely that this parasitism effect could hamper the maintenance of wasp colonies.

Ribonucleic acid which was normally present in Toxoplasma gondii was found to disappear or become undemonstrable during the action of the dye-test antibodies using cytochemical techniques. A possible explanation for the mechanism of the dye test has been put forward based on this evidence.

The purpose of this workshop was to collect together colleagues investigating the intermediary metabolism of protozoa, with a view to discussing those pathways involved in energy metabolism and the production of ATP and other high-energy compounds, together with the factors affecting energy balance. The aspects of energy metabolism chosen for discussion comprised the metabolic pathways ranging from the strictly anaerobic to highly oxidative; subcellular compartmentation of these pathways within the protozoa; the functional role of these pathways including a consideration of aero-tolerance; and the use of inhibitors as biochemical probes and potential chemotherapeuticagents. Hopefully this approach has produced a broad 'over-view' of important areas of protozoan energy metabolism which will enable both the specialist and non-specialist to appreciate the similarities and differences between the metabolic behaviour of a range of protozoa.

(1) An account is given of a serious infestation in sheep and lambs by Ixodes ricinus in the uplands of Denbighshire, North Wales.

(2) This infestation was accompanied by serious disturbance of health resulting in the general deterioration of the flock and the death of lambs.

(3) Experimental dippings were commenced in 1924, using a special “short-interval” arsenical dip supplied by the Cooper Technical Bureau, London. Serial dippings were made each spring at five-day intervals. When possible an early autumn series was conducted.

(4) The objects were (a) to control the infestation, (b) to control the diseased condition, and (c) to attempt to eradicate ticks from the land.

(5) The control of both the ticks and the disease were easily effected. A few sporadic cases of disease did occur during the course of the experiment.

(6) Eradication has not yet been accomplished, but the average number of ticks was reduced from 121 per animal in May 1924 to 0-96 per animal in July 1926.

(7) It is therefore suggested that short-interval dipping for serious tick infestation in sheep is practicable on British hill farms, and that resultant mortality from disease can thereby be reduced.

Lernaeenicus radiatus, a mesoparasitic pennellid copepod, has long been known in the northwest Atlantic with metamorphosed females infecting the muscle of marine fish. The study herein is the first to identify a definitive first host, black sea bass Centropristis striata, for L. radiatus supporting larval development to adults and sexual reproduction in the gills. This finding suggests a two-host life cycle for L. radiatus, with black sea bass as the first host. Heavy infections in the gill were associated with considerable pathology related to a unique and invasive attachment process that penetrated the gill and selectively attached to the gill filament cartilage. The morphology of the developing copepod was highly conserved with that of a related pennellid copepod, Lernaeocera branchialis, though was distinguished by the attachment process, unique pigmentation and other morphologic features described herein. Sequencing the small and large subunits of the ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes demonstrated L. radiatus to share closer identities with Lernaeocera and Haemobaphes spp. pennellid copepods rather than other Lernaeenicus spp. available in GenBank to date. Taxonomy of L. radiatus is discussed in relation to life cycles, tissue tropism, morphology and genetics of other closely related pennellid copepods.

Previously we have characterized the complete gene encoding a pyruvate decarboxylase (PDC)/indolepyruvate decarboxylase (IPDC) of Phytomonas serpens, a trypanosomatid highly abundant in tomato fruits. Phylogenetic analyses indicated that the clade that contains the trypanosomatid protein behaves as a sister group of IPDCs of γ-proteobacteria. Since IPDCs are key enzymes in the biosynthesis of the plant hormone indole-3-acetic acid (IAA), the ability for IAA production by P. serpens was investigated. Similar to many microorganisms, the production of IAA and related indolic compounds, quantified by high performance liquid chromatography, increased in P. serpens media in response to amounts of tryptophan. The auxin functionality was confirmed in the hypocotyl elongation assay. In tomato fruits inoculated with P. serpens the concentration of free IAA had no significant variation, whereas increased levels of IAA-amide and IAA-ester conjugates were observed. The data suggest that the auxin produced by the flagellate is converted to IAA conjugates, keeping unaltered the concentration of free IAA. Ethanol also accumulated in P. serpens-conditioned media, as the result of a PDC activity. In the article we discuss the hypothesis of the bifunctionality of P. serpens PDC/IPDC and provide a three-dimensional model of the enzyme.

The intestinal parasitic nematode, Baylisascaris transfuga, was recorded in wild rodents for the first time. Representatives of four murid species (15 Myodes rufocanus, 10 M. rutilus, 3 M. glareolus and 27 Microtus oeconomus) were collected in the White Sea coastal habitats in the south of the Kola Peninsula, Russia in July 2015 and examined for parasites. Encapsulated nematode larvae were detected in the mesentery and the large intestine wall of one grey-sided vole (M. rufocanus) and one tundra vole (M. oeconomus). Based on morphology, the larvae were identified as belonging to the genus Baylisascaris Sprent 1968. The partial 18S rDNA sequence of the larvae from the voles was obtained and fully corresponded to the sequence of Baylisascaris transfuga in the NCBI GenBank. The ITS rDNA and CoxI mtDNA sequences these larvae were also similar to the respective B. transfuga sequences in GenBank. The presence of B. transfuga in wild rodents suggests that rodents can participate in the B. transfuga life cycle.