Nível de dano, plantas invasoras hospedeiras, inimigos naturais e controle do psilídeo da goiabeira (Triozoida sp.) no submédio S?o Francisco

摘要

This study was conducted to increment the integrated management of Triozoida sp. (Hemiptera, Psylliidae) in guava plants at the S?o Francisco River Valley. The damage level, weed hosts, selectivity and effect of the thiamethoxam 10GR and 250WG in the control of psylliidae were evaluated. The experiment was carried out in an irrigated area, at Petrolina, Pernambuco, in a randomized block design with four replications. Treatments consisted of: 1) thiamethoxam 10GR applied on soil; 2) thiamethoxam 250WG sprayed weekly; 3) thiamethoxam 10GR applied on soil + thiamethoxam 250WG sprayed weekly; 4; 5; 6) thiamethoxam 250WG sprayed when 10, 20 and 30% of infested branches were reached, respectively; 7; 8; 9) thiamethoxam 10GR applied on soil + thiamethoxam 250WG sprayed when 10, 20 and 30% of infested branches were reached, respectively; and 10) control (no insecticide). The percentage of infested branches in the control treatment differed significantly from the treatments 2 (2.8%), 3 (4.3%), 4 (19.7%), 7 (13.4%), 8 (14.5%) and 9 (15.0%). When thiamethoxam was used, the population reduction of natural enemies ranged from 12.5 to 39.6%, corresponding, in the selective scale, to grades (1 = non offensive (< 25%), 2 = not very toxic (25-50%). Number and weight of fruits were similar in all the treatments. Fifty one weed species and no host of Triozoida sp. were found.