Population Dynamics of Telenomus fariai (Hymenoptera: Scelionidae) a Parasite of Chagas' Disease Vectors. IX. Larval Competition and Population Size Regulation under Laboratory Conditions

ESCALANTE, G. AND J. E. RABINOVICH

Population Ecology

Society of Population Ecoloogy

Año: 1979 p. 235 - 246

1438-390X

A series of experiments were carried out with the endophagous egg parasite Telenomus fariai on its host Triatoma phyllosoma pallidipennis to determine the possible role of intraspecific competition by the parasi te progeny in population regulation of the parasite. Eight parasite densities (1, 3, 5, 10, 20, 30, 40, and 50 individuals per vial) were used, and the design of sequentially sacrificed replicates applied. Survivorship curves for each density indicated smaller number of progeny per host at higher densities, and the shapes of the curves suggested a relatively early mortality process. MORRIS´ linear regression technique for determining withingeneration densi ty-dependence was used, and the results showed that only larval mortality could be identified as density dependent. The Sa111e technique applied within the larval stage proved that only mortality of larvae in their second, third, and fourth day of development were responsible for population regulation. The applicability of the technique, as well as the relevance of the results for natural population, is discussed.