Four cytotypes of Simulium exiguum occur in Ecuador, where this morphospecies is the primary vector of onchocerciasis. In this paper, we give the first full description of the banding pattern of the larval polytene chromosomes of the Quevedo cytotypes differ from the chromosomal standard sequence (of the Cayapa cytotype) by the fixed inversions IIL-5 and IIL-6. The Quevedo cytotype additionally differs from the standard and Bucay cytotypes by processing a differentiated X chromosome, wich is indicated by the inversion IIS-A. As the degree of reproductive isolation between the Bucay and Quevedo cytotypes has not yet been estabilished, they must be regarded as intraspecific variants of the same species. In fact, isoenzyme characterizations showed that the Bucay and Quevedo cytotypes are differentiated only to the extent expected of incipient species or geographical populations. Moreover, the sibiling species status previously given to the Bucay cytotype needs be reassessed, there being inadequate analysis from areas in Ecuador where Bucay occurs in sympatry with the standard Cayapa cytotype. No isoenzyme electromorphs were discovered that identified all or mostadult females of any one (cytotype-pure) collection.

Genomic DNA fragments from males of Psychodopygus wellcomei were isolated and shown to be useful as sensitive diagnostic probles for positively separting individuals of this species from those of Ps. complexus. These two members of the Ps. squamiventris series are found sympatrically in foci of cutaneous leishmaniasis in the hill forests of southern Pará State. Of the two species, only Ps. welcomei is thought to be an important vector of Leishmania braziliensis sensu stricto, buth this is based on circumstantial evidence because of the difficulties of identifying female sandflies wothin the series. The diagnostic probes were isolated from a library of Ps. wellcomei built by ligationg short fragments of Sau 3A-resistricted, genomic DNA into the plasmid vector PUC 18. Differential screening of 1316 library clones with total genomic DNA of Ps. Wellcomei and Ps. complexus identified 5 recombinants, with cross-hybridizing inserts of repetitive DNA, that showed strong specificity for Ps. wellcomei. As little as 0.4% of the DNA extracted from an individual sandfly (=ca. 0.5 namograms) was specifically detected. The diagnostic probes were used to identify as Ps. wellcomei a wild-caught female sandfly found infected with L. braziliensis s.s., providing only the second positive association between these two species.

No segundo semestre de 1980, 112 (ou aproximadamente 16%) dos habitantes do recém estabelecido bairro de São José, cidade de Manaus, contraíram leishmaniose, durante o desmatamento que realizavam em seus lotes localizados na floresta tipo "terra firme". Com a ajuda da SUCAM, os AA. realizaram um estudo piloto para investigar a viabilidade de redução das populações de Lutzomyia umbratilis, o vetor silvático de Leishmania braziliensis guyanensis, borrifando inseticidas na base das árvores grandes da floresta que são os lugares preferidos de repouso diurno destes insetos. A maioria do contato homem-vetor ocorre nestes lugares de repouso diurno (o vetor sendo mais ativo à noite nas copas das árvores) e, assim sendo, foi animador constatar uma nítida redução das populações de L. umbratilis nas bases das árvores por um período de 21 dias após uma única aplicação de emulsão de D.D.T. numa área de 200m quadrados. Quantidade apreciável de D.D.T. permaneceu na base das árvores por pelo menos oito meses, o que proporcionou a não ocupação das mesmas por L. umbratilis durante pelo menos onze meses. Os resultados mostram que a emulsão de D.D.T. teve efeito repelente e letal(L. umbratilis foi altamente suscetível ao D.D.T. em "kits" da O.M.S.). Em contraste com as populações das bases das árvores, as populações noturnas de L. umbratilis (capturadas em armadilhas de luz tipo CDC, ou atacando ao homem não foram significantemente reduzidas pelo tratamento com D.D.T., o que sugere a possível existência de apreciável imigração noturna em áreas experimentais e/ou que lugares de repouso alternativo tenham sido procurados pelos flebótomos. São apresentadas sugestões para ampliar o estudo piloto e a necessidade de colaboração com uma equipe clínica é enfatizada. A leishmania b. guyanensis é o agente etiológico de uma forma de leishmaniose tegumentar humana ("pian bos") hiperendêmica numa vasta extensão geográfica que se estende da Guiana Francesa à Amzônia Central, ao Norte do Rio...

In the second half of 1980, 112 (or ca. 16%) of the inhabitants of the new settlement of São José, city of Manaus, contracted cutaneous leishmaniasis whilst clearing their properties of terra firme rainforest. With the aid of SUCAM, the authors carried out a pilot study to investigate the feasibility of reducing populations of Lutzomyia umbratilis, the local silvatic vector of Leishmania braziliensis guyanensis, by spraying insecticide on its favoured diurnal resting sites, the bases of the larger forest trees. Most manvector contact is at these resting sites and, therefore, it was encouraging to record a marked reduction of the tree-base populations of L. umbratilis for 21 days following just one application of D.D.T. emulsion in an area 200m square. Most of the treated trunks were not occupied by L. umbratilis for at least eleven months. Suggestions for extending the pilot study are made, and the need for collaboration with a clinical team is emphasized. Leishmania b. guyanensis is the aetiological agent of [quot ]pain bois[quot ], which is hyperendemic from French Guiana to central Amazônia. In the absence of proven vaccines or methods of vector control, some simple methods for limiting transmission of Le. b. guyanensis to man are listed.

Psychodopygus wellcomei, um vetor comprovado de leishmaniose (muco) cutânea, foi pela primeira vez encontrado fora da Bacia Amazõnica, no Estado do Ceará. Evidência parasitológica e entomológica sugere que a Leishmania braziliensis braziliensis transmitida pelo Ps. wellcomei encontra-se largamente espalhada no "Maciço montanhoso do Brasil".

Psychodopygus wellcomei, a proven vector of (muco-)cutaneous leishmaniasis, has been found for the first time outside of the Amazon Basin, in Ceará State. Parasitological and entomological evidence suggests that the Leishmania braziliensis braziliensis/Ps. wellcomei zoonosis is widespread on the Brazilian Shield.