[Reproduction of the larvivorous fish Poecilia reticulata (Poeciliidae) in natural conditions]. / Aspectos de la reproduccion del pez larvivoro Poecilia reticulata (Poeciliidae) en condiciones naturales.

The main reproduction characteristics of the larvivorous fish Poecilia reticulata, were determined under natural conditions. The study was carried out in a ditch of dirty water sink at the Lenin Park (Havana City) in the period comprised between November 1986 and May 1987. The samplings were performed monthly, and the presence of gravid females was demonstrated during the whole period, while the average of embryo/female increased remarkably during April. Such results contribute to the knowledge of the biology of this fish for its better use in the biologic control of mosquito larvae.

[Aspects of larval density of Culex nigripalpus Theobald, 1901 (Diptera: Culicidae) in natural conditions]. / Aspectos de la densidad larval de Culex nigripalpus Theobald, 1901 (Diptera: Culicidae) en condiciones naturales.

A study was carried out in order to determined the larval population density of Culex nigripalpus, vector of different parasitic and viral diseases in the neotropical region. Two population from Havana and Havana City Provinces were studied during the period comprised between November 1986 and November 1987. The higher densities of this species appeared during December 1986 (838.2 larvae/m2) and November 1987 (495 larvae/m2) in Santa Cruz del Norte (Havana) and in November 1986 (343.2 larvae/m2), January 1987 (232.65 larvae/m2), February 1987 (580.8 larvae/m2) in the Lenin Park (Havana City).