Winter and spring application of SPLAT-CLM for control of citrus leafminer (Phyllocnistis citrella)

Citrus leafminer, Phyllocnistis citrella Stainton, is active throughout the year in Florida and reproduces on periodic leaf flush in winter.  We tested mating disruption in mature grapefruit trees during winter and spring using SPLAT-CLM, an emulsified wax with prolonged release of the insect's primary pheromone component, (Z,Z,E)-7,11,13-hexadecatrienal.  SPLAT-CLM was applied in 2-ha blocks in winter and/or spring using a tractor-mounted machine that dispensed 1-g dollops into the tree canopy at a rate of 500 g/ha.  Mating disruption was evaluated using pheromone-baited traps, and leaf mining was evaluated on new leaf flush.  Based on disruption of male catch in pheromone traps and leaf infestation, the winter season treatment did not improve control in spring compared with a spring application alone.  Moth flight preceded widespread leaf mining, suggesting that external sources may be important for colonizing some groves in spring.