Objective: To assess the chemical components and toxicity of Artemisia herba-alba (A. herba- alba) essential oil against two major stored cereal pests, Tribolium castaneum (T. castaneum) and Trogoderma granarium (T. granarium). Methods: Two bioassay actions were tasted: repellent and fumigant actions against adult and larvae, respectively, to assess the effect of A. herba-alba essential oil. Results: Gas chromatography-mass spectrometer analyses of the essential oil contained β-thujone (12.50%), α-thujone (8.78%), sabinyl acetate (8.56%), terpinene-4-ol (8.51%), α-terpineol (3.35%), 1,8-cineol (5.45%), γ-terpene (4.82%), camphor (4.52%), dimethyl- ethylbenzene (3.93%) and α-terpinene (3.35%) as the major components. Fumigant toxicity tests showed that A. herba-alba oil was more toxic than T. granarium (LC50 = 2.09 mg/mL, LC90 = 4.12 mg/mL) and T. castaneum (LC50 = 6.39 mg/mL, LC90 = 10.10 mg/mL). Conclusions: This study has highlighted a bioinsecticide activity of A. herba-alba against two insect pests of stored foodstuffs (T. castaneum and T. granarium). The Artemisia essential oil offers an interesting potential insecticide that could be studied more deeply to isolate and identify the active substances, to study their physiological impact on other insects

Objective:To evaluate toxic activities of essential oils obtained from Rosmarinus officinalis and Lavandula stoechas against the fourth larval instars of Orgyia trigotephras.Methods:A total of 1 200 larvae were divided into three groups Ⅰ,Ⅱ,Ⅲ.Group Ⅰ was to investigate the effect of extracted essential oils from these aromatic plants as gastric disturbance.Bacillus thuringiensis and ethanol were used as control group.Group Ⅱ was used as contact action and Group Ⅲ was used as fumigant action.Oecis and ethanol were used as control group.During the three experiments,the effect of essential oils on larvae was assessed.Results:The chemical composition of essential oils from two medicinal plants was determined and,their insecticidal effects on the fourth larval slate of Orgyia trigotephras were assessed.The two simples presented an insecticidal activity,nevertheless Rosmarinus officinalis essential oil was less efficient compared to Lavandula stoechas one are discussed.Conclusions:The relationship between the chemical composition and the biologieal activities is confirmed by the present findings.Therefore the potential uses of these essential oils as bioinsecticides can he considered as an alternative to the use of synthetic products.

Helminthosis is a very important disease affecting the poultry industry, especially the traditionally reared free ranging chickens. In Tunisia, the poultry production is considered as the most important source of protein in as much as chickens provide 53 % of animal protein production. The traditionally reared poultry farming system exposes chickens to many types of parasites, however, very little work has been done to establish the extend of helminth infection in Tunisia. The aim of this work is to investigate various aspects of helminth infections. A significant difference (p < 0.01) was found between the prevalence rates of helminth parasites in the different agro-ecological zones. The highest prevalence was observed in lowland areas of northern Tunisia (Siliana district). This suggests that agro-ecology has a major influence on the distribution of helminth parasites. Recovered nematodes included Heterakis spp. (100 %), Ascaridia galli (53.33 %) and Acuaria hamulosa (37 %). The principal cestode species encountered were Hymenolepis spp. (73.33 %) and Raillietina spp. (33.33 %).

Background Essential oils extracted from aromatic and medicinal plants have many biological properties and are therefore an alternative to the use of synthetic products. The chemical composition of essential oils from two medicinal plants ( Eucalyptus globulus and E. lehmannii ) was determined and, their insecticidal effects on the third and fourth larval stages of Orgyia trigotephras were assessed. Results Larvae were collected from Jebel Abderrahmane (North-East of Tunisia), conserved in groups of 50/box (21 × 10 × 10 cm) at a temperature of 25°C. Larvae were tested for larvicidal activities of essential oils . Each oil was diluted in ethanol (96%) to prepare 3 test solutions (S1 = 0.05%, S2 = 0.10% and S3 = 0.50%). Essential oils were used for contact, ingestion and Olfactory actions and compared to reference products ( Bacillus thuringiensis and Decis). Olfactory action of essential oils shows that larvae mortality is higher than contact action, lower than ingestion action. MTM and FTM of S3 of E. lehmannii were respectively 1 h 32 min and 1 h 39 min are higher than those of E. globulus (MTM = 51 min and FTM = 1 h 22 min 34 sec). Contact action of E. lehmannii oil shows low insecticidal activity compared to E. globulus . MTM are respectively (1 min 52 sec and 1 min 7 sec), FTM are (2 min 38 sec, 1 min 39 sec), are the shortest recorded for S3, on the third stage of larvae. The fourth stage of larvae, MTM are (2 min 20 sec and 2 min 9 sec), FTM are (3 min 25 sec, 3 min 19 sec). Ingestion action of essential oils is longer than the contact action, since the time of death exceeds 60 minutes for all species. Conclusion Results shows that essential oils have a toxic action on nerves leading to a disruption of vital system of insects. High toxic properties make these plant-derived compounds suitable for incorporation in integrated pest management programs.

The aim of the present study is to investigate for the first time the genetic diversity of samples identified morphologically as Fasciola hepatica (Platyhelminthes: Trematoda: Digenea) (n=66) from sheep and cattle from two localities of Sardinia and to compare them with available data from other localities by partial sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes, the mitochondrial cytochrome c oxidase subunit I (COI), and nicotinamide adenine dinucleotide dehydrogenase subunit I (ND1) genes. Comparison of the sequences from Sardinia with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. hepatica. The nucleotide sequencing of ITS rDNA showed no nucleotide variation in the ITS-1, 5.8S and ITS-2 rDNA sequences among all Sardinian samples, comparing with two ITS-2 haplotypes in standard F. hepatica, showing a substitution C/T in 20 position 859, reported previously from Tunisia, Algeria, Australia, Uruguay and Spain. The present study shows that in Sardinian sheep and cattle there is the most frequent haplotype (FhITS-H1) of F. hepatica species from South Europe. Considering NDI sequences, the phylogenetic trees showed reliable grouping among the haplotypes of F. hepatica from Sardinia and the mitochondrial lineage I, including the main N1 haplotype, observed previously from Europe (Russia, Belarus, Ukraine and Bulgaria), Armenia, West Africa (Nigeria), America (Uruguay and USA), Asia (Turkey, Japan, and China), Georgia, Turkmenistan, Azerbaijan and Australia. Furthermore, common haplotypes FhCOI-H1 and FhCOI-H2 of F. hepatica from Sardinia also corresponded mostly to the first lineage including the main C1 haplotype reported previously from Eastern European and Western Asian populations, they belonged just to a phylogenically distinguishable clade, as F. hepatica from Australia, France, Turkey, Uruguay, Russia, Armenia, Ukraine, Belarus, Turkmenistan, USA, Tunisia and Algeria, indicating that this is the main haplotype involved in the spread of F. hepatica throughout all continents.

Fasciolosis caused by Fasciola hepatica and Fasciola gigantica (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. From Africa, F. gigantica has been previously characterized from Burkina Faso, Senegal, Kenya, Zambia and Mali, while F. hepatica has been reported from Morocco and Tunisia, and both species have been observed from Ethiopia and Egypt on the basis of morphometric differences, while the use of molecular markers is necessary to distinguish exactly between species. Samples identified morphologically as F. gigantica (n=60) from sheep and cattle from different geographical localities of Mauritania were genetically characterized by sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes and the mitochondrial Cytochrome c Oxidase I (COI) gene. Comparison of the sequences of the Mauritanian samples with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. gigantica. The nucleotide sequencing of ITS rDNA of F. gigantica showed no nucleotide variation in the ITS-1, 5.8S, and ITS-2 rDNA sequences among all samples examined and those from Burkina Faso, Kenya, Egypt and Iran. The phylogenetic trees based on the ITS-1 and ITS-2 sequences showed a close relationship of the Mauritanian samples with isolates of F. gigantica from different localities of Africa and Asia. The COI genotypes of the Mauritanian specimens of F. gigantica had a high level of diversity, and they belonged to the F. gigantica phylogenically distinguishable clade. The present study is the first molecular characterization of F. gigantica in sheep and cattle from Mauritania, allowing a reliable approach for the genetic differentiation of Fasciola spp. and providing basis for further studies on liver flukes in the African countries.

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. Samples identified morphologically as Fasciola sp. in Equus caballus host species from the city of Tunis (north of Tunisia) were genetically characterized, for the first time, by sequences of the 1st (ITS-1), the 5.8S and 2nd (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the Tunisian samples with sequences of Fasciola spp. from GenBank showed that the specimens examined had sequences identical to those of F. hepatica sequences selected as reference. The nucleotide sequencing of ITS rDNA showed no nucleotide variation in the ITS-1, 5.8S, or ITS-2 rDNA sequences among all F. hepatica samples parasitizing horses from Tunis, versus 2 ITS-2 haplotypes in standard F. hepatica, showing a substitution C/T in position 859, reported previously from Tunisia, Algeria, and Spain. The present study is the first demonstration of the existence of the most frequent haplotype (FhITS-H1) of F. hepatica species in horses from Tunis (north of Tunisia) by the genetic approach using ITS rDNA as genetic marker, providing a foundation for further studies on Fasciola sp. in North African countries.

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and F. gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples identified morphologically as Fasciola sp. in buffaloes and goats from Tonekabon city (northern Iran) were genetically characterised by sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the North Iranian samples with sequences of Fasciola spp. from GenBank showed that the specimens examined had sequences identical to those of F. hepatica (n=22, 45.83%) and F. gigantica (n=17, 35.42%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n=9, 18.75%), which had nucleotides overlapped between the two Fasciola species in all the positions. The nucleotide sequencing of ITS rDNA of F. hepatica and F. gigantica from Tonekabon city showed no nucleotide variation in the ITS-1 and ITS-2 rDNA sequences, versus two ITS-2 haplotypes in standard F. hepatica reported in GenBank. The intergenic transcribed spacers ITS-1 and ITS-2 showed to allow a reliable approach for the genetic differentiation of Fasciola spp., providing foundation for further studies on F. hepatica, F. gigantica and their intermediate forms in the endemic areas.

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered as the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and Fasciola gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples from buffaloes and goats from different localities of northern Iran were identified morphologically and then genetically characterized by sequences of the first (ITS-1) and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the northern Iranian samples with sequences of Fasciola spp. from GenBank showed that the examined specimens had sequences identical to those of the most frequent haplotypes of F. hepatica (n=25, 48.1%) and F. gigantica (n=20, 38.45%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n=7, 13.45%), which had nucleotides overlapped between the two Fasciola species in all the positions. The ITS sequences from populations of Fasciola isolates in buffaloes and goats had experienced introgression/hybridization as previously reported in isolates from other ruminants and humans. Based on ITS-1 and ITS-2 sequences, flukes are scattered in pure F. hepatica, F. gigantica and intermediate Fasciola clades, revealing that multiple genotypes of Fasciola are able to infect goats and buffaloes in North of Iran. Furthermore, the phylogenetic trees based upon the ITS-1 and ITS-2 sequences showed a close relationship of the Iranian samples with isolates of F. hepatica and F. gigantica from different localities of Africa and Asia. In the present study, the intergenic transcribed spacers ITS-1 and ITS-2 showed to be reliable approaches for the genetic differentiation of Fasciola spp., providing bases for further studies on F. hepatica, F. gigantica and their intermediate forms in the endemic areas in Asia.

Larval forms of the genus Hysterothylacium have been previously reported in teleost fish from the North African coasts of central Mediterranean Sea by morphological analysis. In the present study, samples identified morphologically as Hysterothylacium aduncum (n = 62), from Merluccius merluccius, Trachurus mediterraneus and Pagellus erythrinus from different geographical locations of the Tunisian coasts, were genetically characterised by sequences of the first (ITS-1), the 5.8S and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the sequences obtained with those available in public gene databases confirmed that all the samples from the Tunisian coasts belong to a single species, namely H. aduncum. All specimens from the Tunisian coasts showed one indel in position 787 in ITS-2 sequences not reported by any of the previously published sequences from the Atlantic and Pacific Oceans, Adriatic Sea (Mediterranean Sea) and the East Greenland Sea, suggesting the existence of a population-specific pattern exhibiting a low differentiation of this parasite in this area. This is the first molecular characterization of H. aduncum from the Tunisian coasts using ITS rDNA sequences which allows the definition of genetic markers for their unequivocal identification, and provides further biological data on these nematodes in marine fish off the Tunisian coasts, improving the picture of the occurrence of these taxa in the North African coasts of central Mediterranean Sea.

On a analyse la biodiversite et la variabilite genetique du parasite Cysticercus tenuicollis en Tunisie, par etude du polymorphisme genetique du gene mitochondrial ribosomal (rrnS) de l'ADN mitochondrial. L'alignement des sequences obtenues avec les sequences disponibles en GenBank a permis de caracteriser genetiquement les larves morphologiquement identifiees. L'analyse de la variabilite du gene rrnS chez C. tenuicollis a montre une differenciation genique nulle de l'ensemble des specimens etudies.

Specimens of Contracaecum rudolphii Hartwich, 1964 (Nematoda: Anisakidae) from Phalacrocorax aristotelis (Linnaeus) from the Archipelago of La Maddalena (Sardinia, western Mediterranean Sea) were characterised genetically and compared with C. rudolphii A sensu D'Amelio et al. 1990 and C. rudolphii B sensu D'Amelio et al. 1990 from Phalacrocorax carbo sinensis (Blumenbach) from north-eastern Italy, and with C. rudolphii C sensu D'Amelio et al. 2007 from Phalacrocorax auritus (Lesson) from west-central Florida, USA. The sequencing of the small subunit of the mitochondrial ribosomal RNA gene (rrnS) and by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the same gene and of the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) allowed the identification of all specimens of C. rudolphii from P. aristotelis as C. rudolphii A. The results confirmed that the definition of genetic markers, following the analysis of nuclear ribosomal and mitochondrial DNA, provides quick and practical diagnostic tools for the detection of the 3 sibling species of C. rudolphii. The occurrence of C. rudolphii in P. aristotelis is reported for the first time from the Mediterranean area, improving the picture of the dispersal patterns of the populations of these piscivorous birds, and confirming the existence of different and isolated populations between the North and South European waters.

A total of 242 larval forms of Anisakis collected from marine fishes at different sites off the Moroccan and Mauritanian coasts, recognised as belonging to Type I and Type II larvae, were identified by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphisms) of the ITS (Internal Transcribed Spacers) region (ITS-1, 5.8 subunit rRNA gene and ITS-2), using a previously established molecular key. The Type I larvae were found with a frequency of 98.34% and were identified as belonging to the following species: A. simplex s.str., A. pegreffii, A. simplex s.str/A. pegreffii heterozygote genotypes, A. typica, A. ziphidarum and Anisakis sp. A. The Type II larvae were found to belong to A. physeteris, with the frequency of 1.65%. The results reported in the present study provide further epizootiological and biological data on the Anisakis spp. in marine fishes off the Moroccan and Mauritanian coasts, improving the picture of the occurrence of these species in the central Atlantic coasts.

Larval forms of the genus Anisakis were reported infecting several fish species from the North African coasts of central Mediterranean Sea. Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis was used to investigate the occurrence of larval forms of different Anisakis species in teleost fishes and squid from North African coasts of the Mediterranean Sea and to establish the geographical and host range of these parasites in this area. A total of 282 Anisakis larvae were identified by PCR-RFLP from 13 teleost fish species and one cephalopod species captured at different sites off the Algerian, Tunisian and Libyan coasts. The type I larvae were found with a frequency of 93.62% and were identified as belonging to the following species: Anisakis simplex s.str., Anisakis pegreffii, A. simplex s.str/A. pegreffii hybrids and Anisakis typica. The type II larvae were found to belong to Anisakis physeteris, with the frequency of 6.38%. The record of A. simplex s.str/A. pegreffii hybrids, previously recorded from the Spanish and Portuguese Atlantic coasts and the Alboran Sea, extends their geographic distribution to the Tunisian coasts. The occurrence of A. simplex s.str. and hybrids away from their known area of distribution may predict the successful use of Anisakis larvae for tagging Scomber scombrus fish stocks for fisheries management purposes. Moreover, the results reported provide valuable information regarding the diversity of Anisakis species in the study area, indicating that several Anisakis sibling and morphospecies coexist in the North African coasts of the Mediterranean Sea.

Two gadiform species with a successive bathymetric and an ecological and economical importance in the Mediterranean fishing industry, Phycis blennoides and Phycis phycis, were selected for the present study. A total of 592 fresh specimens belonging to the Gadiformes genus were obtained from local commercial fisheries. The investigation was centred on anisakid parasites of 272 specimens of the greater forkbeard (P. blennoides) and 320 of the forkbeard (P. phycis) captured off the Mediterranean coasts of Tunisia (eastern Mediterranean Sea). Four species of nematodes were identified: Anisakis simplex s.1., Anisakis physeteris, Hysterothylacium aduncum and Hysterothylacium fabri. The total prevalence was 53.75% in the forkbeard and 51.47% in the greater forkbeard. The highest values of prevalence (38.75%, 2–14), mean intensity (6.74±3.4) and mean abundance (2.61) were all obtained for H. fabri L4 in the forkbeard. The most frequent parasite in the greater forkbeard was H. aduncum L3 with 32.35% (1–3) prevalence and values of 1.21±0.58 and 0.39 for mean intensity and mean abundance, respectively. The infestation parameters were also analysed according to the host length, and prevalence was highest in P. blennoides longer than 35 cm in respect of all anisakid species. Whilst in P. phycis, the highest prevalence, conditioned by H. fabri parasitisation, was found in fish with length reaching a maximum of more than 40 cm. When the data were grouped seasonally, clear patterns were observed for P. blennoides and P. phycis species, with prevalence and mean intensity of all the anisakid species peaking in spring and summer.

Les especes de la zone nearctique sont caracterisees par des spicules a trois branches principales: lame, fourche et sabot, mais la division de la fourche au-dela du tiers distal de la hauteur du spicule est egalement caracteristique des especes palearctiques. Les especes sont tres proches morphologiquement les unes des autres. Elles se differencient principalement par la structure du synlophe dans la region oesophagienne, la disposition relative des cotes 6, 8 et 9 de la bourse caudale et par la forme des pointes spiculaires. L'etude est faite a partir d'un nouveau materiel canadien. Redescription d'Oswaldocruzia pipiens Walton, 1929, parasite de Rana sylvatica. Description de cinq nouvelles especes : (1) Oswaldocruzia audebertae n.sp., parasite de Bufo americanus. (2) O. canadensis n.sp., parasite de Bufo americanus. (3) O. andersoni n.sp., parasite de Bufo americanus. (4) O. priceae n.sp., parasite de Rana pipiens. (5) O. stevensi n.sp., parasite de Bufo americanus. O. leidyi Travassos, 1917 est consideree comme un nomen nudum. O. leidyi Steiner, 1924, para; site de Hyla carolinensis, est caracterisee par une bourse caudale de type I et l'absence d'ailes cervicales. O. collaris Walton, 1929, O. subauricularis (Rudolphi, 1819) sensu Walton, 1929, O. minuta Walton, 1941 et O. waltoni Ingles, 1936 sont classees en species inquirendae. Une cle dichotomique des Oswaldocruzia nearctiques est proposee.

Like all the other Ethiopian Oswaldocruzia already known, the 2 new species are characterized by uncomplicated spicules, without clear differentiation between the handle and the lamina, the latter being distally divided into 4 or 5 tips.Oswaldocruzia ohlerae n. sp., a parasite of Bufo camerounensis, is characterized (1) by a caudal bursa of type II like O. polycercus Baker, 1982, a parasite of B. polycercus but O. polycercus has no cervical alae; (2) by cervical alae composed of 2 triangular crests like O. johnstoni, a parasite of Petropedetes johnstoni Durette-Desset and Vaucher, 1979 but O. johnstoni has a caudal bursa of type I.Oswaldocruzia ineichi n. sp. known only through a sole male has cervical alae composed of 2 triangular crests like O. ohlerae n. sp but it differs by a caudal bursa of type I and by cuticular crests well developed at midbody. The closely related species is O. johnstoni which has a caudal bursa of type I and cervical alae conposed of 2 triangular crests. But in O. ineichi, rays 8 arise on the dorsal ray and not at its base; in the oesophagal region, the dorsal crests spread on the whole dorsal side and the shape of the spicular tips is different.

A'Oswaldocruzia peruensis n. sp., parasite de Stenocercus roseiventris du Pérou.L'espèce appartient aux Oswaldocruzia néotropicaux caractérisés : (1) par des spicules à trois branches principales (lame, fourche et sabot) avec division de la fourche en deçà de son tiers distal et division de la lame en «peigne» à son extrémité distale ; (2) par une disposition relative des côtes 6, 8 et dorsale de type II.La seule espèce proche, Oswaldocruzia vaucheri Ben Slimane & Durette-Desset, 1993, parasite d'un Leptodactylidae d'Équateur, s'en distingue par l'existence de crêtes et non d'ondulations cuticulaires et par la forme des ailes cervicales.

L'examen d'Oswaldocruzia de Cuba et de Porto Rico montre l'existence de quatre espèces différentes.O. lenteixeirai Vigueras, 1938, dépourvue d'ailes cervicales, possède des côtes bursales 8 chevauchées par les côtes 6 dans leurs deux tiers proximaux et des côtes bursales 5-6 jointives ; mâle avec 32-38 crêtes cuticulaires au milieu du corps ; vestibule pourvu de formations distales.O. moraveci n. sp.(= O. lenteixeirai sensu Barus et Moravec, 1967, nec Vigueras, 1938) se différencie de la précédente par des côtes bursales 8 chevauchées par les côtes 6 dans leur partie médiane et des côtes bursales 5-6 divergentes à leur extrémité ; vestibule dépourvu de formations distales.O. anolisi Barus et Coy Otero, 1968, pourvue de grandes ailes cervi¬ cales, possède des côtes bursales 8 chevauchées par les côtes 6 dans leur partie médiane et des côtes bursales 5-6 jointives ; mâle avec 50 crêtes cuticulaires au milieu du corps ; vestibule dépourvu de formations distales.O. barusi n. sp., pourvue d'ailes cervicales peu développées, possède des côtes bursales 8 chevauchées par les côtes 6 dans leur partie médiane et des côtes bursales 5-6 jointives ; mâle avec 38 crêtes cuticulaires au milieu du corps; vestibule dépourvu de formations distales.

1 14 BADREDDINE BEN SLIMANE & MARIE-CLAUDE DURETTE-DESSET avec un vaste spectre d'hôtes qui couvre aussi bien les Amphibiens que les Reptiles, sa répartition est cosmopolite et le nombre d'espèces élevé (plus de 40).Par ailleurs, il est situé à la base des Molineinae parasites de Mammifères (cf.Durette-Desset et Chabaud, 1981).Cependant, s'il est bien défini au niveau générique, il pose un grand nombre de problèmes au niveau spécifique aussi bien d'ordre systématique que taxonomique.Nous nous proposons de faire l'étude de ce grand genre d'une part en nous basant sur l'étude du synlophe peu ou mal connu, d'autre part en utilisant de nouveaux critères morphologiques dans le but de découvrir s'il existe des types morphologiques propres à telle ou telle grande région biogéographique.Grâce à la générosité de nos collègues du Museum de Genève, nous avons un matériel très abondant d'Amérique du Sud.L'objet de cette première note concerne la description de 4 nouvelles espèces chez des Amphibiens d'Equateur.MATERIEL ET METHODES Le matériel a été récolté en Equateur chez 40 Amphibiens appartenant à 3 familles et 4 genres: 9 Bufo typhonius (Bufonidae), 10 Bolitoglossa equatoriana (Plethodontidae), 10 Eleutherodactylus variabilis (Leptodactylidae) et 10 Ischnocnema quixensis (Leptodactylidae).Les Amphibiens ont été capturés dans la province de Napo à deux endroits différents: San Pablo de Kantesiya sur le Rio Aquarico et Hacienda Primavera, à environ 30 kms en amont de Puerto Fransises de Orellana.Les Nematodes parasitent l'intestin grêle des Amphibiens à l'exception d'unBufo typhonius dans l'estomac duquel ils ont été récoltés.