A morphological, isoenzymatic and behavioural study of ten populations of Anopheles(Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 (Diptera: culicidae) including from the type-locality - Baradero, Argentina

Anopheles (Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 shows morphological and behavioural variations which results in it being sometimes considered as a major malaria vector and at other times as playing no important role in epidemiology. With the aim of clarifying the taxonomy of the species, comparative morphological and isoenzymatic studies were made in populations from the type-locality, Baradero, Argentina and from 9 different localities inBrazil. Morphological studies consisted of the observation of eggs in scanning electron microscopy, of complete chaetotaxy of larvae and pupae and of the detailed drawing of male and female adults. Only Guajara-Mirim and Rio Branco populations, described previously as Anopheles deaneorum sp.n., showed morphological differences. Isoenzymes were studied using 4th instar larvae homogenate and agarosegel electrophoresis. Eleven enzymatic loci were analyzed. By calculation of Nei's Genetic Distance (D), the populations could be separated into 5 groups: i)Baradero, ii)Marajo, iii)Boa Vista, iv)Angra, Itaguai and Paraipaba and v)Guajara-Mirim and Rio Branco. These groups belong to 2 major clusters called I and II, separated by D = 0.345. In the I cluster are groups i, ii and iii and in II clusteriv and v. In I, D=0.246 separates i and ii from iii, while i is separated by D =0.181 from ii. In II, D = 0.223 between iv and v. Only the population of group vcould be distinguished morphologically from the others, leading to the description of an independent species An. deaneorum.

Gastromermis cordobensis n. sp. (Nematoda: Mermithidae) parasitizing Simulium lahillei Patterson & Shannon (Diptera: Simuliidae) in Argentina

Gastromermis cordobensis n. sp (Nematoda: Mermithidae) a parasite of larvae of the blackfly Simulium lahillei Paterson & Shannon (Diptera: Simuliidae) in Argentina, is described. Diagnostic characters of this species include a mouth ventrlly shifted; six cephalic papillae; eigh hypodermal chords; small and pear shaped amphids; a long and S-shaped vagina; a singl spicule, which is long, has non-uniform walls, and a tip with sculpture; three rows of genital papillae, the middle one with 18 pre-anal and 10 post-anal papillae, the lateral rows have 36 papillae each; oval eggs; and post-parasitic juveniles with long thin tails. Pre-parasitic and parasitic juveniles are included in the description.

Development of nuclear DNA probes for the typing of Trypanososma cruzi

We have developed and tested a new way of typing Trypanosoma cruzi, mamely the use of cloned nuclear DNA fragments as genetic markers. Restriction fragment length polymorphisms were verified on Soutern blots hybridized to random probes. Fragment patterns were analyzed and dendrograms constructed. Our results on well characterized laboratory strains correlate well to published isoenzyme studies. Some of the probes were also hybridized to chromosomes separated by pulse field gel electrophoresis a higher degree of heterogeneity was observed at this level.

Taxonomic studies of the subgenus Helcocyrtomya: I. Series Oswaldoi (Diptera, Psychodidae, Phlebotominae)

Attempting to review the species of sandflies in the series oswaldoi of the subgenus Helcocyrtomyia, we examined 7650 specimens collected in different Brazilian regions during 35 years and deposited in the collection of the Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, MG. As main results of this study new species of Helcocyrtomyia were described (Lutzomya pusilla and Lutzomya capixaba), in addition to the females of Lutzomyia ferreirana and Lutzomyia peresi; which had been described only by the males. The geographic distribution of the material examined is also presented.

A new filaria of a lizard transmitted by sandflies

A description is given of Madathamugadia wanjii n. sp., a Splendidofilariinae parasite of the gecko Ptyodactylus hasselquistii, on the west bank of the River Jordan and of its life cycle in Phlebotomus duboscqi. The new species is close to M. ivaschkini (Annaev, 1976) n. comb., of Turkmenistan, wich is also transmitted by sandflies (Reznik, 1982). The genus Madathamugadia is now comprised of four species, two from Madagascar and two from the Mediterranean sub-region; it differs from the genus Thamugadia by the presence of a double row of papillae anterior to the cloaca of the male. The larval characters of Splendidofilarinae of lizards confirm the affinity of these parasites to the Splendidofilarinae of birds (Chandlerella and Splendidofilaria); the first group could have arisen from the second by "captures" wich could have occurred in several places.

Análise faunística dos helmintos de pardais (Passer domesticus L., 1758) capturados em Campo Grande, Rio de Janeiro, RJ

Sparrows captured in Campo Grande, Rio de Janeiro, RJ, were examined through necropsy and the helmints found were identified. The prevalence, intensity of infection and the habitat of each helminth species found are showed. An analysis of the helminth fauna using the importance value of the species collected indicated that in the sparrow the dominant species are: Leucochloridium parcum, Tanaisia inopina, Choanotaenia passerina, Dispharynx nasuta and Tetrameres minima; and the co-dominant species are: Echinostoma revolutum, Eumegacetes mediximus and Mediorhynchus papillosus. According to the host specificity were classified as specialist species: L. parcum, T. inopina, C. passerina and T. minima; and as generalist species: E. revolutum, E. medioximus, D. nasuta and M. papillosus. Echinostoma revolutum was found for the first time in P. domesticus. The species E. medioximus , T. minima and D. nasuta were found for the first time in the sparrow in Brazil. The species C. passerina and M. papillosus were found for the first time in Brazil, expanding their distribution to the Neotropical region.

Halipegus dubius Klein, 1905 (Trematoda, Hemiuridae): a redescription, with notes on the working of the ovarian complex

A redescription of Halipegus dubius Klein, 1905, of Brazilian frogs Leptodactylus pentadactylus and L. ocellatus, is presented. The parasite was found exclusively in the buccal cavity, in number varying from 1 (in most instances) to 3, and exceptionally 25 (one instance). Morphological data were based on 40 whole-mounted specimens and 4 serially sectioned ones. Larval development takes place in planorbid snails (Biomphalaria glabrata and B. tenagophila) and in an undetermined species of cyclops. Working of the ovarian complex was followed by microscopical observation of life specimens. Constrating with the similarity of the four American species of Halipegus currently recognized as valid, they can be easily separated by the characters of their cercariae.

Nova espécie de Hyla da Serra da Mantiqueira, Itatiaia, Estado do Rio de Janeiro, (Amphibia, Anura, Hylidae)

Hyla gouveai n. sp. is described and illustrated and it is closest to the bigger individuals of the species in the group "circumdata", not presenting, however, the characteristic pattern of dark transversal bands on the posterior inner coxal surface.

Host tissue destruction by Entamoeba histolytica: molecules mediating adhesion, cytolysis, and proteolysis

Entamoeba histolytica, the protozoan parasite causing human amoebisis, has recently been found to comprise two genetically distinct forms, potentially pathogenic and constitutively nonpathogenic ones. Host tissue destruction by pathogenic forms is belived to result from cell functions mediaed by a lectin-type adherence receptor, a pore-forming peptide involved in host cell lysis, and abundant expression of cysteine proteinase(s). Isolation and molecular cloning of these amoeba products have provided the tools for structural analyses and manipulations of cell functions including comparisons between pathogenic and nonpathogenic forms.

A programme for computer aided identification of Phlebotomine sandflies of the Americas (CIPA): presentation and check-list of American species

The CIPA programme is a collaborative project including two entomologists from France and seven South and Central America countries. Its objective is the development of an expert system for computer aided identification of phlebotomine sandflies from the Americas. It also includes the formation of data bases for bibliographic, taxonomic and biogeographic data. Participant consensus on taxonomic prerequisites, standardization in bibliographic data collections and selection of descriptive variables for the final programme has been established through continous communication among participants and annual meetings. The adopted check-list of American sandflies presented here includes 386 specific taxa, ordered into genera and 28 sub-genera or species groups.

Taxonomic studies of the subgenus Helcocyrtomyia: II. series Vexator (Diptera, Psychodidae, Phlebotominae)

Continuing to review the subgenus Helcocyrtomyia (Diptera, Psychodidae, Phlebotomiane) some specimens of sandflies from the vexator series were examined. Taxonomic remarks, geographic distribution and drawings of those species are presented.

Two new mermithidis (Nematoda: Mermithidae) parasites of Simulium wolffhuegeli Roubaud and S. jujuyense (Paterson & Shannon) (Diptera: Simuliidae) in Argentina

Two new species of mermithids (Nematoda: Mermithidae), Gastromermis doloresi n. sp. a parasite of Simulium wolffhuegeli Roubaud and Hydromermis doloresi n. sp. a parasite of S. jujuyense (Paterson & Shannon) from Córdoba, Argentina, are described and illustrated. G. doloresi n. sp. is characterized by having medium sized, pear-shaped and oval amphids, eight hypodermal chords all around the body, cylindrical S-shaped vagina, single long spicule 528 [mi]m, whith teh sculpture tip, three rows of genital papillae in which the middle row contains 17 pre-anal and 9 post-anal papillae, and lateral rows contain 18 papillae. Hydromermis doloresi n. sp. can be distinghished by the following: medium sized, pear-shaped amphids, eight hypodermal chords, a cylindrical, S-shaped vagina, one short curved spicule with sculpture and genital papillae in three rows. The medium ventral row of papillae has 4 double and 9 single pre-anal papillae and 3 double and 6 single port-anal papillae, lateral rows have 18 single papillae each.

Limnaea peregrina Clessin, 1882, Synonym of Lymnaea columella Say, 1817 (Gastropoda: Lymnaeidae)

A description is given of the shell, radula, renal region, reproductive system and egg capsules of topotypic specimens of limnaea peregrina Clessin, 1882. This investigation intends contributing to define the specific identity of that nominal species. A close anatomical comparison with Lymnaea columella Say, 1817 from Michigan, USA, shows that both forms are indistinguishable, giving support to previous inferences from some authors. Data on egg hatching are presented.

Multilocus enzyme electrophoresis study of Bacillus sphaericus

Multilocus enzyme electrophoresis (MLEE) has been used in the study of some Bacillus species. In this work we applied MLEE and numerical analysis in the study of the Bacillus sphaericus group. B. sphaericus can be distinguished from other entomopathogenic Bacillus by a unique allele (NP-4). Within the species, all insect pathogens were recovered in the same phenetic cluster and all of these strains have the same band position (electrophoresis migration) on the agarose gel (ADH-2). The entomopathogenic group of B. sphaericus seems to be a clonal population, having two widespread frequent genotypes (zymovar 59 and zymovar 119).

The snail hosts of schistosomiasis: some evolutionary and ecological perspectives in relation to control

Despite opportunities for radiation provided by spatio-temporal isolation, the basic morphological plan of pulmonate snails has remained conservative. In consequence of the resulting dearth of morphological characters and their plasticity, there is a case for using biochemical characters such as exogenous chemicals released by the snails (e.g. amino acids) and their chemoreception niche as taxonomic aids to classify snails of medical importance. As these same chemicals are used by snails to distinguish conspecifics they could also be used as "environmental antibodies" in controlled release formulations (CRF's) designed to remove target snails in a specific, cost-effective and ecologically acceptable manner. The snails, surface-living bacteria, algae and macrophytic plants are considered as co-evolved, interactive modular systems with strong mutualistic elements. Recently, anthropogenic perturbations such as deforestation, and damming of flowing waters, have benefited these modules whereas others such as river canalization, acid deposition, accumulation of pesticide residues and eutrophication have harmed them. Research is needed to elucidate the factors which limit the growth of snails in primitive habitats, uninfluenced by man, as well as in those subject to harmful anthropogenic factors. The understanding thus gained could be applied to develop cost-effective primary health care strategies to reduce or prevent transmission of schistosomiasis and other water related diseases.