The guava-psyllid, Triozoida limbata (Enderlein), is a severe pest of guava orchards, reducing fruit production. This communication shows the results of an experiment aimed to test nicotinoid insecticides for controlling the guava-psyllid at a high-density level of infestation. Unsatisfactory control of this pest was achieved with imidacloprid AL 100 g/L, at 5, 10 or 20 mL sprayed once onto the guava stem; with imidacloprid SC 200 g/L, at 0.6 mL in 2 L of water/tree and with thiacloprid SC 480 g/L, at 0.2 mL in 2 L of water/tree, both sprayed twice (15 day interval) on the guava foliage. Possible causes of the failure are discussed in relation to several factors, since previous research showed satisfactory control of the guava-psyllid with these insecticides.
Guava; nicotinoid insecticides; stem application; foliage spraying
