Despite the importance of rubber trees (Hevea brasiliensis Muell. Arg.) to Brazil, little is known about mite population fluctuation on this crop. The aim of this work was to study the fluctuation of the mite population on rubber trees in the state of Mato Grosso and to observe the evolution of the symptoms caused by their attack. This study was conducted in rubber tree fields at Itiquira and Pontes e Lacerda in the state of Mato Grosso with six clones: FX 3864, RRIM 600, IAN 873, IAN 713, PB 260 and PR 255. Samplings were conducted between August 1998 and July 2000. The 1998/1999 samples consisted of 150 leaves of each of the basal, median and apical strata of 10 plants, randomly taken. The 1999/2000 sampling methodology was changed due the results for the previous partial for five leaves of the median stratum of each of 15 plants randomly taken. Calacarus heveae Feres was the most frequent species in Itiquira and Phyllocoptruta serigueirae Feres in Pontes e Lacerda. Early leaf drop was observed only in Itiquira
Calacarus heveae; Tenuipalpus heveae and Eriophyidae
