Resumen

URIAS-LOPEZ, Mario Alfonso  y  SALAZAR-GARCIA, Samuel. Avocado leafroller and avocado stem weevil populations in "Hass" avocado orchards in Nayarit, Mexico. Agric. Téc. Méx [online]. 2008, vol.34, n.4, pp.431-441. ISSN 0568-2517.

Since there is scarce information on avocado insects pests in Nayarit, Mexico, the objectives of this study were: a) to collect field information of the life history and behavior of the avocado leafroller (Amorbia cuneana) and the stem weevil (Copturus aguacatae), b) to determine their population dynamics, and c) their incidence on avocado trees managed with site specific fertilization. The study was conducted from 2004 to 2006 in La Yerba (Tepic county) and Emiliano Zapata (Xalisco county), Nayarit, Mexico. Four generations of the avocado leafroller were detected from june to November. The development from egg to adult lasted 35 to 43 days. Avocado leafroller populations were higher in La Yerba than in E. Zapata, but no differences on fruit damage were detected. Avocado leafroller populations were present from June to November, but the highest populations were detected during the last generation (October-November). The highest leafroller populations occurred in the second year; in La Yerba this occurred on November 20 and in E. Zapata on October 13 (1.5 and 1.2 larvae branch, respectively). Only one generation of the avocado stem borer was recorded, which lasted 292 days from egg to adult. Populations of this pest were also higher in La Yerba than in E. Zapata. With the exception of the rainy season, larvae of the avocado stem borer were present almost the whole year, During the first year, the population peak was observed in January-February and in the second year during April (11.15 and 18.1 stem borers per tree, respectively). Higher populations were recorded in avocado trees with low fertilizer rates, compared to site specific balanced fertilization.

Palabras llave : Amorbia cuneana; Copturus aguacatae; fertilization; population dynamics.