versión impresa ISSN 0120-9965
HILARION, Alejandra et al. Criteria for the release of Phytoseiulus persimilis Athias Henriot (Parasitiformes: Phytoseiidae) in rose culture. Agron. colomb. [online]. 2008, vol.26, n.1, pp. 68-77. ISSN 0120-9965.
Phytoseiulus persimilis has been used in IPM programs as alternative to the use of acaricides in order to control the phytophagous mite Tetranychus urticae. The damages caused by T. urticae generate the cost of management about 4,500 dollars per hectare, which corresponds approximately to 30% of pesticide cost (Ceniflores, 2008). The implementation of this management strategy must consider the release criteria based upon the population levels of T. urticae in the crop estimated by means of appropriate sampling methods. In this research, a methodology for estimating the population density of T. urticae is proposed, in order to assess the quantity of P. persimilis to be released in the rose crop, and the effectiveness of control exerted by P. persimilis was evaluated. In the experimental area, 81 squares were taken, at each of them three rose plants were randomly selected and the number of individuals were counted were counted taken three leaves on the stratum on the plant. The optimum number of sampling units for a bietapic sampling was assessed. The functional response was assumed as a criterion to set the release of P. persimilis. The population density of T. urticae after each release was divided by the population prior to the release, in order to obtain an index control, which was compared between the management strategies. By means of the biological control a greater reduction in the population density and its lesser variation in time were obtained.
Palabras llave : mites; biological control; sampling.