Vectors of cutaneous leishmaniasis in north-central Venezuela

Abstract. An entomological survey was undertaken from January 1991 to February 1992 in El Ingenio, Miranda State, Venezuela, an endemic area of cutaneous leishmaniasis: prevalence of 10.7 cases per 100,000 inhabitants.
A total of 4863 female sandflies (Phlebotominae) of fourteen species were collected in Shannon traps, then dissected and examined for leishmanial infections.
Lutzomyia ovallesi (85.4%) and Lu. gomezl (11.2%) were the predominant anthropophilic species of sandfly. Fifty-one (1.19%) Lu. ovallesi and two(0.47%) Lu. gomezi had natural infection with Leishmania promastigotes. Identification of the parasites was done by using the polymerase chain reaction (PCR) and DNA hybridization. Two isolates from Lu. gomezi and forty-nine from Lu. ovallesi were typed as Leishmania braziliensis and three of the latter reacted with Le. mexicana also. This is the first report of Lu. gomezi with parasites typed as Le. braziliensis.
We concluded that Lu. ovallesi is the primary vector of cutaneous leishmaniasis in the north-central area of Venezuela and Lu. gomezi should be regarded as an additional vector.     

Vector competence of some Neotropical sandflies for the Leishmania (Viannia) braziliensis complex

Abstract. To evaluate the vector competence of some Lutzomyia spp. (Diptera: Psychodidae) for Leishmania (Viannia) spp. (Kinetoplastida: Trypanosoma-tidae), experimental infections of anthropophilic sandflies from the Colombian Pacific coast were performed, through membrane feeding and xenodiagnosis on hamsters infected with Le.(V.)braziliensis or Le.(V.)panamensis. Wild-caught or F, generation females of Lutzomyia gomezi, Lu.hartmanni, Lu.panamensis and Lu. trapidoi were allowed to feed on hamster lesions and then maintained at 26^oC and >80% r.h. on a sugar-water diet until dissection on the fifth day post-infection (p.i.).
Despite similar infection rates (range 37–44%) in both Lu.gomezi and Lu.trapidoi , infections were heavier (>100 parasites) in the latter species. Infections of Lu.trapidoi with Le.braziliensis ( n = 21) and Le.panamensis (n = 27) showed parasite migration toward the foregut, with promastigote colonization of the stomodeal valve and appearance of infective forms. In contrast, infections of Lu.gomezi with Le. braziliensis (n = 10) and Le.panamensis (n = 5) were light (<50 parasites) and usually restricted to the pylorus. In Lu.hartmanni , only a few promastigotes were found in the pylorus and midgut of 3/8 specimens infected with Le.braziliensis , and no Le.panamensis developed (n = 19). By day 5 p.i., promastigote colonization of the hind- and midgut by Le.panamensis was observed in 2/4 Lu.panamensis but not Le.braziliensis (n = 3).
It was concluded that Lu.trapidoi is a more efficient vector than Lu.gomezi for both Le.braziliensis and Le.panamensis , and that Lu.hartmanni and Lu.panamensis are of minor importance for Leishmania transmission in this endemic area.     

Three new species of the genus Leucon Kröyer, 1846 (Crustacea: Cumacea) from the continental slope off Surinam

Three new, and apparently closely related, species of cumacean are described from the continental slope off Surinam: Leucon turgidulus sp.nov. from about 500 m depth, L. medius sp.nov. from about 1000m and about 1500m, and L.jonesi sp.nov from about 1500m and about 2000m. The species have not been found in extensive collections from other parts of the deep Atlantic. Leucon pallidus G.O. Sars, 1865 is the most closely comparable of the previously known members of the genus.