Attacks of Calacarus heveae Feres and Tenuipalpus heveae Baker can cause intense premature defoliation of plants. It is likely that this leaf fall before the natural senescence period results in decreased photosynthetic capacity and, hence, decreased production. The objective of this work was to evaluate the effect of defoliation caused by mites in rubber tree latex production. The experiment was conducted in Reginópolis, SP, using the clone PB 235, from September 2002 to August 2003, with two treatments: a plot sprayed with pesticides to avoid defoliation and a plot without spraying. The plants were under a 1/2 S d/5 6d/7. 10m/y. ET 3.3 % 4/y tapping system. The production was weighed monthly. Mite samplings were carried out at 7 to 10-day intervals. The defoliation was evaluated by measuring the light intensity under the tree canopy using a luximeter. There was a significant difference on mite occurrence. Mean occurrence of C. heveae, considering all the evaluations, was 0.34 mites/cm² in the sprayed area and 0.93 mites/cm² in the plot without spraying. For T. heveae, mean occurrence was 0.06 and 1.09 mites/cm², respectively. There was significant difference for both defoliation and production in May, June, July and August.
Calacarus heveae Feres; damage; Hevea brasiliensis Müll. Arg.; Tenuipalpus heveae Baker
