The initial pattern of oogenesis after a feed is similar for mated and unmated A. persicus. The peak number of mature oocytes within the females occurred on the seventh day at 30 °C. Both groups ovulated but only mated females oviposited.At the end of the first week the mature eggs of unmated females began to undergo dissociation and resorption. The early onset of this process seems to exclude the presence of unlaid eggs as a factor inhibiting ovarian maturation.Many more eggs matured within the mated than the unmated female. After oviposition, the ovaries appear as in the unfed virgin except oocytes are fewer.When the male was mated consecutively to the 7–8th virgin female, there was a decrease in the number of eggs laid. This indicates that the male factor(s) effecting oogenesis and oviposition act on a quantitative rather than an ‘all or none’ basis.To determine whether a female was effectively mated, the ampulla must be checked for sperm. The reason for this is that the spermiophore capsules may be resorbed or may lack sperm.Spermless spermiophores enhanced fecundity but did not effect oviposition.There was evidence of mechanical influence on oocyte maturation when beads were introduced into the vagina of A. persicus. An increase in the number of beads increased the number of mature oocytes.Chemical influence on oogenesis was demonstrated by injection of male gland complex into the body cavity of unmated females.

An official control programme against Echinococcus granulosus and Taenia hydatigena has been in operation in New Zealand for more than 28 years and against Taenia ovis for more than 18 years. This unique effort to control three metazoan parasites at the same time has led to a change from endemic to extinction status for E. granulosus but only a change from hyperendemic to endemic status for T. hydatigena and T. ovis. This has presented problems in determining the most cost-effective future control strategies. To facilitate this, a benefit/cost analysis of 20 options for the combined control of E. granulosus, T. hydatigena and T. ovis in New Zealand was undertaken. This showed that for E. granulosus a future change from the current non-targeted to a targeted approach is strongly indicated. For T. ovis 6 options were cost-effective using a discount rate of 10%. These were (1) a targeted control package using a vaccine in the non-targeted attack phase; (2) a targeted control package using a larvicide in the attack phase; (3) the transfer of all losses due to and responsibility for the control of T. ovis to the producer who administers a larvicide to sheep to be killed for dog food; (4) the transfer of all losses due to and responsibility for the control of T. ovis to the producer who administers praziquantel every 6 weeks to dogs; (5) and (6) two options involving the discontinuation of control. Control of T. hydatigena was assumed to be an incidental outcome of the policies for the other two parasites.

Most epidemiological models assume that disease is the inevitable outcome of infection (see Bailey, 1957). Yet as Dubos (1965) has said; ‘Throughout nature, infection without disease is the rule rather than the exception’. There are, in fact, many diseases whose distribution cannot be explained solely by a consideration of the probabilities of host parasite encounters. In these cases, a diseased state is only one possible outcome of an interaction between parasite phenotypes, host phenotypes and the external environment. Haemonchosis is an example of such a disease and has been studied extensively in quantitative terms (see Whitlock & Georgi, 1968).

Existing algorithms for predicting species' distributions sit on a continuum between purely statistical and purely biological approaches. Most of the existing algorithms are aspatial because they do not consider the spatial context, the occurrence of the species or conditions conducive to the species' existence, in neighbouring areas. The geostatistical techniques of kriging and cokriging are presented in an attempt to encourage biologists more frequently to consider them. Unlike deterministic spatial techniques they provide estimates of prediction errors. The assumptions and applications of common geostatistical techniques are presented with worked examples drawn from a dataset of the bluetongue outbreak in northwest Europe in 2006. Emphasis is placed on the importance and interpretation of weights in geostatistical calculations. Covarying environmental data may be used to improve predictions of species’ distributions, but only if their sampling frequency is greater than that of the species’ or disease data. Cokriging techniques are unable to determine the biological significance or importance of such environmental data, because they are not designed to do so.

Angiostrongylus cantonensis is a parasitic nematode of rodents and a leading aetiological agent of eosinophilic meningitis in humans. Definitive diagnosis is difficult, often relying on immunodiagnostic methods which utilize crude antigens. New immunodiagnostic methods based on recombinant proteins are being developed, and ideally these methods would be made available worldwide. Identification of diagnostic targets, as well as studies on the biology of the parasite, are limited by a lack of molecular information on Angiostrongylus spp. available in databases. In this study we present data collected from DNA random high-throughput sequencing together with proteomic analyses and a cDNA walking methodology to identify and obtain the nucleotide or amino acid sequences of unknown immunoreactive proteins. 28 080 putative ORFs were obtained, of which 3371 had homology to other deposited protein sequences. Using the A. cantonensis genomic sequences, 156 putative ORFs, matching peptide sequences obtained from previous proteomic studies, were considered novel, with no homology to existing sequences. Full-length coding sequences of eight antigenic target proteins were obtained. In this study we generated not only the complete nucleotide sequences of the antigenic protein targets but also a large amount of genomic data which may help facilitate future genomic, proteomic, transcriptomic or metabolomic studies on Angiostrongylus.

Parasites manipulate their hosts’ phenotype to increase their own fitness. Like any evolutionary adaptation, parasitic manipulations should be costly. Though it is difficult to measure costs of the manipulation directly, they can be evaluated using an indirect approach. For instance, theory suggests that as the parasite infrapopulation grows, the investment of individual parasites in host manipulation decreases, because of cost sharing. Another assumption is that in environments where manipulation does not pay off for the parasite, it can decrease its investment in the manipulation to save resources. We experimentally infected rainbow trout Oncorhynchus mykiss with the immature larvae of the trematode Diplostomum pseudospathaceum, to test these assumptions. Immature D. pseudospathaceum metacercariae are known for their ability to manipulate the behaviour of their host enhancing its anti-predator defenses to avoid concomitant predation. We found that the growth rate of individual parasites in rainbow trout increased with the infrapopulation size (positive density-dependence) suggesting cost sharing. Moreover, parasites adjusted their growth to the intensity of infection within the eye lens where they were localized suggesting population density sensing. Results of this study support the hypothesis that macroparasites can adjust their growth rate and manipulation investment according to cost sharing level and infrapopulation size.

The drug-metabolizing enzymes of some helminths can deactivate anthelmintics and therefore partially protect helminths against these drugs' toxic effect. The aim of our study was to assess the activity of the main drug-metabolizing enzymes and evaluate the metabolism of selected anthelmintics (albendazole, flubendazole, mebendazole) in the rat tapeworm Hymenolepis diminuta, a species often used as a model tapeworm. In vitro and ex vivo experiments were performed. Metabolites of the anthelmintics were detected and identified by HPLC with spectrofluorometric or mass–spectrometric detection. The enzymes of H. diminuta are able to reduce the carbonyl group of flubendazole, mebendazole and several other xenobiotics. Although the activity of a number of oxidation enzymes was determined, no oxidative metabolites of albendazole were detected. Regarding conjugation enzymes, a high activity of glutathione S-transferase was observed. A methyl derivative of reduced flubendazole was the only conjugation metabolite identified in ex vivo incubations of H. diminuta with anthelmintics. The results revealed that H. diminuta metabolized flubendazole and mebendazole, but not albendazole. The biotransformation pathways found in H. diminuta differ from those described in Moniezia expanza and suggest the interspecies differences in drug metabolism not only among classes of helminths, but even among tapeworms.

Thirty Holstein Friesian heifer calves, 3 months of age, were used to evaluate whether a low primary infection with Dictyocaulus viviparus would result in immunity against challenge infection 5 or 12 weeks later. Fifteen calves were experimentally infected with 30 larvae at day 0, while the other calves remained as uninfected controls. On day thirty-five 6 primary infected (G1) and 6 non-infected calves (G2) were challenged with 2000 larvae. These groups were necropsied on day 70. On day 84 the remaining 9 primary infected (G3) and 9 non-infected (G4) calves were similarly challenged and necropsied on day 119. Respiratory signs developed in most calves from approximately 2 weeks after challenge, but signs were more severe in G2 and G4 than in G1 and G3. The low primary infection resulted in significantly reduced faecal larval excretion (>80%) and worm burdens (>70%). In the primary infected groups the proportion of female worms in the worm burden was increased, suggesting that part of the developed immunity affected survival of the worms after their establishment in the host. Worm lengths and worm fecundity were also significantly reduced. All observed effects were stronger following challenge on day 84 than on day 35, but the effect of the duration of a primary infection (contrast between G1 and G3) was only statistically significant in the case of mean faecal larval excretion on the day of necropsy (P<0.05) and fecundity (P<0.05).

Immunophilins comprise two protein families, cyclophilins (CYPs) and FK506-binding proteins (FKBPs), and are the major receptors for the immunosuppressive drugs cyclosporin A (CsA) and FK506 (tacrolimus), respectively. Most eukaryotic species have at least one immunophilin and some of them have been associated with pathogenesis of infectious or parasitic diseases or the action of antiparasitic drugs. The human malarial parasite Plasmodium falciparum has 13 immunophilin or immunophilin-like genes but the functions of their products are unknown. We set out to identify the parasite proteins that interact with the major CYPs, PfCYP19A and PfCYP19B, and the FKBP, PfFKBP35, using a combination of co-immunoprecipitation and yeast two-hybrid screening. We identified a cohort of putative interacting partners and further investigation of some of these revealed potentially novel roles in parasite biology. We demonstrated that (i) P. falciparum CYPs interacted with the heat shock protein 70, (ii) treatment of parasites with CYP ligands disrupted transport of the rhoptry-associated protein 1, and (iii) PfFKBP35 interacted with parasite histones in a way that might modulate gene expression. These findings begin to elucidate the functions of immunophilins in malaria. Furthermore, the known antimalarial effects of CsA, FK506 and non-immunosuppressive derivatives of these immunophilin ligands could be mediated through these partner proteins.

A model simulating Dictyocaulus viviparus infection in calves is described. The present paper only deals with the parasitic phase of the life-cycle. Descriptions are given for establishment, development rate of juvenile stages, mortality rates of both juvenile and adult stages, and fecundity. Literature data were used to to develop parameter functions and to estimate initial values for constants. Development of acquired immunity, defined as the proportional ability of the host to reduce the number of parasite individuals in some stage or about to move into a next stage, against establishment (protection) or affecting mortality rates of juvenile or adult parasite stages has been included. The effect of immunity on one parameter or process is viewed as distinctly separate from the effect on another. Preliminary comparisons between model prediction and observations gives encouraging results, indicating that the model simulates experimental D. viviparus infection in calves reasonably well. Some quantitative discrepancies between prediction and observation make clear however, that not all parts of the model are accurate. Further experimentation is needed to re-evaluate current model description and to improve model simulation.

The cat flea, Ctenocephalides felis, is a major pest species on companion animals thus of significant importance to the animal health industry. The aim of this study was to develop sampling and storage protocols and identify stable reference genes for gene expression studies to fully utilize the growing body of molecular knowledge of C. felis. RNA integrity was assessed in adult and larvae samples, which were either pierced or not pierced and stored in RNAlater at ambient temperature. RNA quality was maintained best in pierced samples, with negligible degradation evident after 10 days. RNA quality from non-pierced samples was poor within 3 days. Ten candidate reference genes were evaluated for their stability across four group comparisons (developmental stages, genders, feeding statuses and insecticide-treatment statuses). Glyceraldehyde 3 phosphate dehydrogenase (GAPDH), 60S ribosomal protein L19 (RPL19) and elongation factor-1α (Ef) were ranked highly in all stability comparisons, thus are recommended as reference genes under similar conditions. Employing just two of these three stable reference genes was sufficient for accurate normalization. Our results make a significant contribution to the future of gene expression studies in C. felis, describing validated sample preparation procedures and reference genes for use in this common pest.

The principal aim of this study was to optimize the diagnosis of canine neuroangiostrongyliasis (NA). In total, 92 cases were seen between 2010 and 2020. Dogs were aged from 7 weeks to 14 years (median 5 months), with 73/90 (81%) less than 6 months and 1.7 times as many males as females. The disease became more common over the study period. Most cases (86%) were seen between March and July. Cerebrospinal fluid (CSF) was obtained from the cisterna magna in 77 dogs, the lumbar cistern in f5, and both sites in 3. Nucleated cell counts for 84 specimens ranged from 1 to 146 150 cells μL−1 (median 4500). Percentage eosinophils varied from 0 to 98% (median 83%). When both cisternal and lumbar CSF were collected, inflammation was more severe caudally. Seventy-three CSF specimens were subjected to enzyme-linked immunosorbent assay (ELISA) testing for antibodies against A. cantonensis; 61 (84%) tested positive, titres ranging from <100 to ⩾12 800 (median 1600). Sixty-one CSF specimens were subjected to real-time quantitative polymerase chain reaction (qPCR) testing using a new protocol targeting a bioinformatically-informed repetitive genetic target; 53/61 samples (87%) tested positive, CT values ranging from 23.4 to 39.5 (median 30.0). For 57 dogs, it was possible to compare CSF ELISA serology and qPCR. ELISA and qPCR were both positive in 40 dogs, in 5 dogs the ELISA was positive while the qPCR was negative, in 9 dogs the qPCR was positive but the ELISA was negative, while in 3 dogs both the ELISA and qPCR were negative. NA is an emerging infectious disease of dogs in Sydney, Australia.

Interest in the long-term low temperature preservation of malaria parasites was initiated by Coggeshall's (1939) demonstration that the intra-erythrocytic stages could survive storage at −76°C for 70 days. Numerous studies have subsequently been published in which a variety of techniques have been used. In addition, several reviews have included sections on the cryopreservation of malaria, the most recent being by James (1980), Leef, Hollingdale, & Beaudoin (1981), Nguyen-Dinh, Chemangey-Masaba, Spencer, Campbell, Chin & Collins (1981) and a WHO memorandum (1981). Most of these reports and reviews have dealt with the problems of cryopreserving malaria parasites from a parasitological viewpoint. In an attempt to provide a cryobiologically orientated review of value both to cryobiologists and practicing parasitologists the published technical reports have been summarized in chronological order in Tables 1 and 2, and the important cryobiological parameters are discussed.

The effects of plerocercoids of the cestode Triaenophorus nodulosus infecting the livers of native Eurasian perch Perca fluviatilis and non-native pumpkinseed Lepomis gibbosus was investigated in 17 sites along the Moselle watershed. With a single exception, infected individuals were not observed in the main channel whether or not northern pike Esox lucius, a final host, was present. In ponds where the pike was present, the prevalence of T. nodulosus averaged 86% in Eurasian perch and 15% in pumpkinseed. The parasite was not present at all in ponds when pike were absent. Parasite load, hepatosomatic index (HSI), gonadosomatic index (GSI) and body condition index (CI) were compared between hosts in one site where parasite prevalence and fish abundance was highest. HSI in infected perch was significantly higher than in uninfected perch, whereas no differences in HSI were detected between infected and uninfected pumpkinseed. While perch were more frequently infected and had a greater average parasite load than pumpkinseed, there were no significant differences in either indicator between the two species. Furthermore, no significant differences in GSI or CI were observed between infected and uninfected fish in either species, by either gender or maturity stage. We hypothesize that pumpkinseed is more resistant to the parasite or less likely to feed upon infected copepods than perch.

1. While investigating the parasites of the holly leaf-miner (Phytomyza ilicis Curt.) with a view to utilizing them in the control of this troublesome pest of holly in western Canada, a species of Opius, which on examination proved to be new to science, was reared from the fly puparia.

2. A fairly complete account of the general systematics, distribution, biology, and morphology of the various developmental stages of this parasite is set down in the preceding pages. The primary larva is particularly interesting because of its unusual orientation. After the anatomical details had been worked out it was discovered that the concave side of the larva, which would normally be regarded as the ventral surface, is actually the dorsal one.

3. The genus Opius, whose distribution is world-wide, contains a very large number of species which parasitize important economic pests. In temperate regions the insects which suffer most from their attacks are species of Pegomyia, Agromyza, Rhagoletis, Phytomyza and Cerodonta, whilst in tropical and subtropical areas the most favoured hosts belong to one or other of the two genera Dacus and Anastrepha.

4. The host relationship of the genus, because of its importance from both economic and taxonomic standpoints, is discussed at some length.

5. In the first stadium Opius ilicis is a larval parasite, but the three succeeding instars live in the host pupa, and the imago emerges from the puparium. A very interesting phase in the life history of this parasite occurs towards the end of the first stage. At this point the development of the larva is arrested and further growth cannot take place until the host has pupated.

6. Very little work has so far been carried out on the larval morphology of the Opiinae, but that done up to the present, including the foregoing descriptions, would seem to indicate that the larvae of this tribe form a fairly homogeneous group. The main distinguishing characters of these larvae are listed in section VII of this paper.

7. It is pointed out that O. ilicis, in spite of being intrinsically inferior to Chrysocharis gemma, is responsible for the destruction of a certain number of hosts which escape the attentions of the latter parasite, and although the percentage accounted for is small (maximum parasitism in 1939 4%), it nevertheless fills a particular niche of its own, and so must be of some definite value in the scheme of control.

8. The chief method employed by the first instar of Chrysocharis gemma in the destruction of rival Opius larvae would appear to be direct mandibular attack. Several reasons have been put forward to account for the decided inferiority which is exhibited by the Braconid when it comes into conflict with this Chalcid.

9. In section X, a number of interesting points which have a general bearing on the study of parasite larvae are discussed. These include the cephalic skeleton and its probable function in successive instars, the taxonomic value of this structure in the parasitic Hymenoptera, the apparent absence of a tracheal system in the second and third instar larvae of O. ilicis, and arrested development in the Opiinae and some related forms.

1. A key to the laelaptid paraphages of Myriapoda is given.

2. Hypoaspis (Hypoaspis) spirostrepti Oudms is transferred to the subgenus Jululadaps. J. rotundatus Berl. is regarded as a synonym of this species.

3. Hypoaspis (Hypoaspis) indicus Vitzth. is regarded as a synonym of Julolaelaps luctator Berl.

4. Hypoaspis (Coleolaelaps) amazon is figured.

5. The subgenus Julolaelaps is defined and a key given to the species. The type species is figured.

6. Three new species are described, namely Hypoaspis (Julolaelaps) peritremalis, H. (J.) myriapodalis and H. (J.) pararotundatus.

7. A list of all the known species of Laelaptidae occurring on millipedes is given.

Anopheles elutus females are attracted by human beings. The human body eliminates certain substances which exert an attraction. The expired air alone is sufficient to attract the mosquitoes. Mild air currents may play an important part in carrying and directing these attracting factors towards the mosquitoes.

Hsp90 is a widely distributed and highly conserved molecular chaperone that is ubiquitously expressed throughout nature, being one of the most abundant proteins within non-stressed cells. This chaperone is up-regulated following stressful events and has been involved in many cellular processes. In Toxoplasma gondii, Hsp90 could be linked with many essential processes of the parasite such as host cell invasion, replication and tachyzoite-bradyzoite interconversion. A Protein-Protein Interaction (PPI) network approach of TgHsp90 has allowed inferring how these processes may be altered. In addition, data mining of T. gondii phosphoproteome and acetylome has allowed the generation of the phosphorylation and acetylation map of TgHsp90. This review focuses on the potential roles of TgHsp90 in parasite biology and the analysis of experimental data in comparison with its counterparts in yeast and humans.

The life-cycle of S. gallinarum may be briefly summarised as follows:

Commencing with the ordinary parasite in the blood of the fowl, the spirochaete grows until it reaches a certain length (16 μ–19 μ) and then divides by the peculiar mode of transverse division described above. This process is repeated and is probably the only method of multiplication of the parasite within the blood. When the spirochaetes disappear from the circulation some of them break up into coccoid bodies which, however, do not usually redevelop in the fowl. When the spirochaetes are ingested by Argas persicus, some of them pass through the gut wall into the coelomic fluid. From this medium they bore their way into the cells of the various organs of the tick and there break up into a number of coccoid bodies. These intracellular forms multiply by ordinary fission in the cells of the Malpighian tubules and gonads. Some of the coccoid bodies are formed in the lumen of the gut and Malpighian tubules. The result is that some of the coccoid bodies may be present in the Malpighian secretion and excrement of an infected tick and when mixed with the coxal fluid may gain entry into another fowl by the open wound caused by the tick's bite. They then elongate and redevelop into ordinary spirochaetes in the blood of the fowl, and the cycle may be repeated.