POPULATION FLUCTUATION OF Tetranychus sp. IN Ipomoea purpurea (L.) Roth AND ESTABLISHMENT OF Euseius stipulatus (Athias-Henriot) IN MIRAFLORES / LIMA / PERU

Abstract

This research was conducted in two fields of Ipomoea purpurea (L.) Roth on the cliffs of Miraflores-Lima: “San Martín” and “Armendáriz”, with the objectives to determine the population fluctuation of Tetranychus sp. and Euseius stipulates (Athias-Henriot) on the leaves of I. purpurea, and to determine the effect of the release of E. stipulatus into the Tetranychus sp. population. The evaluation lasted one year, from October 2013 to October 2014. The methodology consisted in dividing each sector into five areas and evaluating weekly and randomly, 20 leaves (upper and lower side), for a total of 100 leaves per sector. The higher infestation occurred in San Martin, with a density of 74.9 mites per leaf at 24.1 °C and 76.4% of relative humidity. In the Armendáriz sector, Tetranychus sp. presence was lower, with a density of 11.2 individuals / leaf at 23.7 °C and at 76.3% of relative humidity. In general, the higher peaks of Tetranychus sp. occur in summer when temperatures are higher and their cycles are shorter. Nevertheless, it was demonstrated that it has a damaging affect all year. Through the liberations, the predator action of E. stipulatus over the different stadiums of Tetranychus sp. was successfully demonstrated..