Oviposition of Toxorhynchites theobaldi in different types of artificial containers in Mexico.

Toxorhynthites th.eobaldi (Dyar and Knab) is a neotropical mosquito which, as other members of the genus, is carnivorous in its larval stages and is not haematophagous in the adult stage (Steffan and Evenhuis 1981). It is a widely distributed species in tropical America (Clark-Gil and Darsie 1983, Darsie and Mitchell 1985), which offers some potential as a natural enemy of Aedes aegypti (Linn.) because both insects prefer to oviposit in temporary breeding sites. However, little is known of its ecology and relatively few observations on larval habitats and oviposition site preferences have been made under natural conditions. The Iarvae have been found in cut and bored insect damaged bamboo cane (Davis 1944), bromeliads and leaf axils (Forattini 1965) and rock holes (Heinemann and Belkin 1978). With regard to the oviposition site preferences, Tx. theobald.i las Tx. lrypoptes (Knab)l oviposits near ground level as well as in the canopy (Galindo et al. 1951). It also uses artificial containers, where eggs have been collected in graveyard flowerpots in Venezuela where it preferred shaded places as oviposition sites (Rubio et al. 1980, Rubio and Ayesta 1984). In order to determine if this predator can exert natural control upon Ae. aegypti populations, more observations need to be made upon manufactured containers used as habitats. This paper describes the variation in Tx. theobddi egg numbers in different habitat types including artificial containers. Sampling of Tx. thcobaldi eggs was carried out in the graveyards of Mante City, Tamaulipas as well as Valles City, San Luis Potosi in Mexico. Both localities are included in the "Huasteca Region" located in northeastern Mexico. The region has a tropical climate with summer rains. Forest vegetation is minimum and in transition