Morphological description of Pintomyia (Pifanomyia) veintemillasi n. sp., a new sand fly species from the sub-Andean region of Bolivia.

BACKGROUND: Most sand fly species are located in the Americas; some act as vectors of leishmaniasis and other human diseases. In Bolivia, about 25% of Neotropical species have been identified, and only a few have been implicated as vectors of cutaneous and visceral leishmaniasis. A new species of anthropophilic sand fly from the sub-Andean region of Alto Beni is described herein. METHODS: A large systematic entomological survey was carried out in a subtropical humid forest located in the Marimonos mountain range, at around 900 m altitude, in the municipality of Palos Blancos, Sud Yungas Province, Department of La Paz, Bolivia. Sand flies were captured over a period of 26 months between January 1982 and February 1984, at the ground and canopy level, using both CDC light traps and protected human bait. A total of 24,730 sand flies were collected on the ground, distributed in 16 species, and 3259 in the canopy, with eight species. One of these species was labeled as Pintomia (Pifanomyia) nevesi, although certain morphological features allowed us to doubt that it was that taxon. To define the identity of this sand fly, a re-evaluation (this work) was recently carried out through morphological analyses and measurements of the available specimens mounted on Euparal, previously labeled as Pi. (Pif.) nevesi. RESULTS: Based on the morphological traits and measurements, the re-evaluated specimens were definitively identified as a new sand fly species, Pintomyia (Pifanomyia) veintemillasi, closely related to Pi. (Pif.) nevesi and Pintomyia (Pifanomyia) maranonensis within the Evansi series. This new sand fly was the third most numerous anthropophilic species at the floor (6.2%) and the second most numerous anthropophilic at the canopy (35.1%). CONCLUSIONS: A new anthropophilic sand fly species is described as Pi. (Pif.) veintemillasi n. sp. This sand fly species was caught at about 900 m altitude in the Marimonos mountain range, a highly endemic area for cutaneous and mucosal leishmaniasis due to Leishmania (Viannia) braziliensis. Therefore, this species could be involved in the leishmaniasis transmission in the sub-Andean foothills of Alto Beni, Department of La Paz, Bolivia.

PCR-RFLP of ribosomal internal transcribed spacers highlights inter and intra-species variation among Leishmania strains native to La Paz, Bolivia.

Human leishmaniasis is highly endemic in Bolivia and shows a growing incidence. This report reveals the genetic variability of 35 isolates mainly belonging to Leishmania braziliensis and Leishmania amazonensis species. Among them, 31 were from human patients with different clinical presentations, 3 strains from Lutzomya nuneztovari anglesi (the proven vector of L. amazonensis) and 1 strain of a mammal (Conepatus chinga). The isolates were analyzed by isoenzyme electrophoresis (MLEE) and PCR-RFLP of ITS rRNA genes, a genetic marker highly polymorphic and better adapted to sub-structuring of populations. MLEE and RFLP-ITS were in agreement to discriminate the species, 12 belong to L. (V.) braziliensis, 21 to L. (L.) amazonensis, 1 to Leishmania (V.) lainsoni and 1 to Leishmania (L.) chagasi. Among L. (V.) braziliensis the RFLP-ITS only highlights variability. Ten isolates from either cutaneous or mucocutaneous clinical forms, were grouped together (bootstrap value of 99.8%) apart from two others, one from a mammal (C. chinga), the other from a patient with a cutaneous form. Among L. (L.) amazonensis both markers detect variability but no significant sub-division was identified including isolates from different clinical forms. Moreover, the high frequency of several isolates from cutaneous forms occurred during an outbreak, with putative hybrid character (multiloci heterozygous patterns depicted by MLEE) could be linked to better fitness of these parasites. However, in the absence of observation of hypothetical parents, their hybrid status remains a question.

Morphometrical evidence for speciation within Bolivian Lutzomyia aragaoi (Diptera: Psychodidae).

For Bolivian specimens of Lutzomyia aragaoi (Costa Lima, A., 1932. Sobre os phlebotomos americanos (Diptera, Psychodidae). Mem. Inst. Oswaldo Cruz 26, 15-69), collected in the same light-traps, we show the existence of two distinct morphotypes distinguished by male parameres. These sympatric forms were observed in the Alto Beni, Subandean region of Bolivia, and in the North Beni, Amazonian region of Bolivia, two areas separated by large, sparsely forested, "llanos". Univariate morphometric comparisons between these two forms showed non-overlapping variation of size for external structures of the genitalia (lateral lobe, style and coxite), allowing separation of them on the basis of a single measurement. Multivariate discriminant analysis of head and wing dimensions-excluding genitalia structures-grouped the insects according to their morphotype instead of their geographic origins. The two forms also showed different patterns in number and distribution of low mesepisternal setae. The existence of these two separate forms in close sympatry suggests reproductive isolation, hence a speciation process.

Geographic variation of metric properties within the neotropical sandflies.

Traditional morphometrics remains a useful tool for differentiating sandflies species, particularly closely related taxa. Within a single species, however, size variation among geographic populations might interfere with species distinction. In the past decades, a search for a metric property less prone to individual variations led to the use of ratios, and more recently to the use of size-free variables (after tentative size extraction). While morphometrics is continuously enriched with new, more efficient techniques describing shape, the question remains for the morphologist whether an efficient removing of within-species size variation is sufficient to produce stable, specific characters. Is a single species metrically recognizable in spite of its geographical variation? To address this question the intraspecific variation in 10 neotropical sandflies was examined within and between large South American ecogeographic regions: the Amazonian region, the Sub-Andean and the Chaco regions of Bolivia, and the Atlantic Coast of Brazil. Thus, the geographic stability of metric properties, as derived from measurements between landmarks, was investigated 10 times allowing a total of 29 inter-regional and 13 intra-regional conspecific comparisons. Metric proportions remained stable among conspecific populations of a single ecogeographic region. From one region to another, however, size-independent changes were significant and their amount was correlated with altitude. This could reflect an important role of some environmental changes in shaping the insects, and should be taken into account when using morphometrics to identify sandflies.

Description of Lutzomya (Pifanomyia) robusta n. sp. (Diptera, Psychodidae, Phlebotominae) from Peruvian Equadorean interandean areas

Descreve-se Lutzomyia (Pifanomyia) robusta, sp.n., provável vetora de bartonelose e leishmaniose tegumentar, de ocorrência em vales interandinos no Peru e Equador e que apresenta estreita afinidade com L. serrana (Damasceno e Arouck). A separaçäo de ambas foi possível, por meio de análise de variância de alguns caracteres do macho e apenas um da fêmea. Na análise de variância, foram estudadas populaçöes de L. serrana da regiäo amazônica do Brasil, Peru e Bolívia; costa do Equador, regiäo atlântica e outras áreas do Brasil. Corrobora-se a sinonímia de Phlebotomus guayasi Rodriguez com L. serrana

Leishmaniose en Bolivie. IV. Le chien dans les cycles des leishmanioses en Bolivie / Leishmaniasis in Bolivia. IV. The dog in the cycles of leishmaniasis in Bolivia

Na Bolívia, o cäo participa do ciclo da leishmaniose visceral (Leishmania (Le.) chagasi nas Yungas (alt. 1.000-2.000 m) e também do ciclo da leishmaniose tegumentar (Le. (V.) brasiliensis) no Alto Beni (alt. 400-600m). Entretanto, o animal tem funçöes diferentes nos dois ciclos. Constitui-se no reservatório principal de Le. (Le.) chagasi nas Yungas, podendo ser o único e ser a fonte de contaminacäo para o homem. No caso de Le. (V.) braziliensis no alto Beni, o cäo é como o homem, somente um hospedeiro "vítima"; o reservatório deste parasito é desconhecido, embora se desconfie de mamíferos selvagens