Lutzomyia reducta Feliciangeli et al., 1988, a host of Leishmania amazonensis, sympatric with two other members of the Flaviscutellata complex in southern Amazonas and Rondônia, Brazil (Diptera: Psychodidae)

A member of the Lutzomyia flaviscutellata complex from Rondônia and southern Amazonas States, Brazil, is so close to the Venezuelan Lutzomyia olmeca recuta Feliciangeli et al., 1988, that it is regarded as belonging to the same species. Since this phlebotomine co-extis with L. olmeca nociva in Brazil, the subspecific status of the former is untenable and is rased to specific rank, as Lutzomyia reducta. The Brazilian material is described and illustrated, and compared with specimens of L. o. nociva and L. flaviscutellata from the same area. Keys to the known taxa of the flaviscutellata complex are presented. Leishmania amazonensis was isolated from one heavily infected specimen of L. reducta, making this the third species of the flaviscutellata complex to be implicated as a vector of this parasite in Brazil. The relative abundance of the three sympatric flaviscutellata complex species varies locally and appears to be related to soil drainage. L. reducta constituted about 25% if all phlebotomines captured in Disney traps at poorly drained and well drained site, but appears not to coloniza areas subject to periodic flooding. L. olmeca nociva was restricted to poorly drained areas not subject to flooding, whereas L. flaviscutellata was ubiquitous L. reducta has never been detected north of the Amazon river in Brazil, but absence of recosrds from western and northwestern Amazonas State may reflect lack of collecting in these areas.

A new species of Amphisbaena from the state of Amazonas, Brasil (Reptilia, Amphisbaenia, Amphisbaenidae)

Amphisbaena hugoi, sp. n., from the site of the Balbina hydroelectric dam, in the state of Amazonas (01º53'S, 59º28'W), is sufficiently characterized by having (one specimen known): 4 preanal pores; 225 body annuli; 36 tail annuli, with autotomy constriction on the 13th annulus, 16 dorsal and 18 ventral segments to a midbody annulus; body color patter a brown back and a white belly, clearly demarcated, anteriorly at the level of the lateral sulcus, posteriorly one and then two scales below it, with a thin light line on the lateral sulcus, a white cap on the head, dorsally extending onto the neck; autotomy annulus ventrally brown-colored.

Ecology of phlebotomine sand flies (Diptera: Psychodidae)in a focus of Leishmania (Viannia) brasiliensis in northeastern Colombia

The phlebotomine sand fly fauna of two coffee plantations in a Leishmania-endemic area of Norte de Santander, Colombia was studied. Regular insect collections using a variety of methods were made for three and a half years. Information was obtained on diurnal resting sites, host range and seasonal abundance for 17 species, of wich five (Lutzomyia spinicrassa, Lu. serrana,Lu. shannoni, Lu. ovallesi and Lu. gomezi) were far more numerous than the others, anthropophilic and present throughout the year. The behaviour of these and the remaining 12 species is discussed in relation to their potential role in transmission of Leishmania (Viannia) brasiliensis in the area.

Naturally acquired antibodies against the major merozoite surface coat protein (MSP-1) of Plasmodium falciparum acquired by residents in an endemic area of Colombia

A preliminary baseline epidemiological malaria survey was conducted in the village of Punta Soldado, Colombia. Parasite prevalence and density as well as serological data were obtained from 151 asymptomatic children and adults. Fifty individuals were infected with Plasmodium falciparum. The mean parasite density was 184 parasites/mm3. Greater than 90 of the sample population were P. falciparum antibody positive as detected by the indirect immunofluorescent antibody test (IFAT). The enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against the major merozoite surface protein (MSP-1) of P. falciparum. In this population, anti-MSP-1 antibody concentration is acquired in an age dependent manner with equal immunogenicity to both the N- and C-terminal regions of the molecule. Infection at the time of sampling was associated with a higher anti-MSP-1 antibody concentration than that found in non-infected individuals. Further studies are planned to assess the role of immune and non-immune factors in limiting the number of cases of severe malaria seen in this population.

Genetic variability and differentiation between populations of Rhodnius prolixus and R. pallescens, vectors of Chagas' Disease in Colombia

Enzyme polymorphism in Rhodnius prolixus and R. pallescens (Hemiptera, Reduviidae), principal vectors of Chagas' disease in Colombia, was analyzed using starch gel electrophoresis. Three geographic locations were sampled in order to determine gene flow between populations and to characterize intra- and interspecific differences. Of 25 enzymes assayed 10 were successfully resolved and then used to score the genetic variation. The enzymes PEPD, GPI, PGM and ICD were useful to differentiate these species and PGD, PGM and MDH distinguished between sylvatic and domiciliary populations of R. prolixus. Both polymorphism and heterozygosity indicated greater genetic variability in sylvatic habitats (H = 0.021) compared to domiciliary habitats (H = 0.006) in both species. Gene flow between sylvatic and domiciliary populations in R. prolixus was found to be minimal. This fact and the genetic distance between them suggest a process of genetic isolation in the domiciliary population.

Two new species of the subgenus Peytonulus of Sabethes (Diptera: Culicidae) from Colombia

The adults and male genitalia of two new species of Sabethes subgenus Peytonulus are described from Colombia. The male genitalia are illustrated and the species are distinguished from one another and other members of the subgenus.

Report on a collection of Lutzomyia sand flies (Diptera: Psychodidae) from the middle Solimões (Amazonas, Brazil)

Fifty-two species of Lutzomyia sand flies were identified in contemporaneous samples totalling only 1875 individuals, collected at the same site in tall primary terra-firme rainforest, near the south bank of the Solimões River. The most abundant species belonged to the subgenera Trichophoromyia and Nyssomyia. The subgenera Psathyromyia, Nyssomyia and Psychodopygus represented the greatest number of species. A new, aberrant species of the subgenus Psathyromyia (L. cultellata) and the female of Lu. souzacastroi are described. The Phlebotominae are proposed as a suitable indicator group for biogeographic and diversity studies.

Man-biting activity of Anopheles (Nyssorhynchus) albimanus and An. (Kerteszia) neivai (Diptera: Culicidae) in the Pacific Lowlands of Colombia

The daily man-biting activity of Anopheles (Nyssorhynchus) albimanus and An. (Kerteszia) neivai was determined in four ecologically distinct settlements of the Naya River, Department of Valle, Colombia. Differences were found among the settlements with respect to the mosquito species present, intradomiciliary and extradomiciliary biting activity and population densities.

Sandfly Lutzomyia longipalpis in a cutaneous leishmaniasis focus in central Colombia

Lutzomyia longipalpis, 15 other species of the genus Lutzomyia, and one species of Brumptomyia were collected in an endemic focus of cutaneous leishmaniasis in a river canyon 450 m above sea-level, in Rio Claro, Antioquia, Colombia. The presence of Lu. longipalpis is associated with the destruction of the primary forest and the development of new farmland and rural settlement in this region. The composition of species identified a different habitat for Lu. longipalpis in Colombia. Lu. yuilli and Lu. longipalpis were predominant (68.26%) followed by Lu. trapidoi, Lu. hartmani, Lu. triramula, Lu. panamensis, Lu. gomezi.

Onchocerciasis in Ecuador: Prevalence of Infection on the Ecuador-Colombia Border in the Province of Esmeraldas

The prevalence of onchocerciasis infection was determined in communities on 7 rivers located in the northern area of the cantón San Lorenzo, province of Esmeraldas. Diagnosis of the infection was obtained by skin biopsies and recombinant-antigen based-serology. No evidence of infection was detected in 9 communities studied along the Río Mataje, which forms the frontier between Ecuador and Colombia, nor in 10 adjacent communities located on 5 interior rivers. Evidence for Onchocerca volvulus infection was found in 4 communities on the Río Tululví with the following prevalence: La Boca (3.5% by biopsy and 3.9% by serology), Guayabal (9.1% by both biopsy and serology), La Ceiva (51.5% by biopsy and 53% by serology), and Salidero (4% by biopsy and 7.7% by serology). A few individuals in these communities were seropositive for O. volvulus in the absence of detectable dermal microfilariae: these might harbor very light or prepatent infections. No clinical disease attributable to onchocerciasis was found. The infected communities will be included in the ivermectin-based National Control Program for the disease, with no evidence of the infection having extended north of the Ecuadorian-colombian border