Effect of buprofezin on Icerya purchasi and Planococcus citri.
Icerya purchasi and Planococcus citri nymphs were exposed to aqueous suspensions of 25% wettable buprofezin powder [an insect growth regulator] (0.0008-0.05% a.i.) in the laboratory. Dipping lemons in 0.002, 0.01 and 0.05% a.i. resulted in 91-99% nymphal mortality of P. citri, while 100% mortality was recorded when I. purchasi crawlers or 2nd-instar nymphs were exposed to 0.05% sprays; 3rd-instar I. purchasi nymphs were less susceptible (51% mortality). Death of the early stages occurred mainly during moulting to the 2nd instar. At 0.05%, sprays applied to adults slightly reduced fecundity and decreased egg hatch to 31% for I. purchasi and to 7-49% for P. citri, depending on the exposure period of the females. At 0.05%, buprofezin showed strong ovicidal activity on P. citri, resulting in over 80% inhibition of egg hatch.