Seasonal occurrence of mites (Acari) and presence of resistance factors to Calacarus heveae e Tenuipalpus heveae (Acari: Eriophyidae, Tenuipalpidae) in rubber tree progenies cultivated in Mato Grosso do Sul

Abstract

The mites Calacarus heveae Feres (Eriophyidae) and Tenuipalpus heveae Baker (Tenuipalpidae) are considered to be key pests in rubber tree crops. The selection of more resistant clones can be an important strategy for the control of these pests. Therefore, this research aims at identifying rubber tree progenies which are resistant to these species as the starting point for the selection of clones to be recommended for the establishment in São Paulo state. In order to achieve that, 100 progenies obtained from seeds of the clones RRIM 600, GT 1, PR 255, IAC 15, IAC 35, IAC 40, IAC 41, IAC 44, PB 28/59 and IRCA 111 are being tested on the UNESP farm in the city of Selvíria-MS, in 2009/2010 period. The most promising clones will be evaluated again in 2010/2011 and 2011/2012. For that, monthly, will be collected from each plant, four extremities of branches to count in the laboratory, of the C. heveae and T. heveae mites. The defoliation levels observed will be evaluated with a note scale from 0 to 5, being 0 for no defoliation and 5 for total defoliation. The symptoms will be recorded in photographs. Moreover, this project is also aimed at identifying the species of predators mites present in the area, observe the seasonal occurrence of these species and correlate their populations with the populations of C. heveae and T. heveae. In each sampling, a container with alcohol at 70% will be prepared for each evaluated clone. A leaflet from each clone will be placed in these containers, which will be shaken briefly. Afterwards, the leaflets will be removed and the found mites will be mounted on microscope slides and examined under the phase contrast microscope for the identification of the species. (AU)