Effects of Insecticides on Asian Citrus Psyllid (Hemiptera: Psyllidae) Populations in a Florida Citrus Grove

Asian citrus psyllid, Diaphorina citri Kuwayama, populations were monitored in a ‘Valencia’ sweet orange on sour orange rootstock plot planted in 1997. The plot was scouted weekly and the number of psyllids, percent trees infested, and the percentage of flush infested per tree were recorded over a 3-year period. The plot was treated with 7 insect control treatments: Admire (imidacloprid) applied at 12-, 6-, 3-, or 2-month intervals; Temik applied annually; Meta-Systox R applied annually; or no insecticide control using a randomized complete block design. Psyllid infestations persisted throughout the year. The lowest populations occurred during the winter (NovemberJanuary) with peaks in the spring and fall. Annual applications of Temik, Meta-Systox R, or Admire did not reduce psyllid populations. Biannual or more frequent applications of Admire significantly reduced psyllid numbers, percentage of trees with psyllid infestations, and the percentage of flushes infested with psyllids.