Population Dynamics of Citrus Leafminer (Lepidoptera: Gracillariidae) as Measured by Interception Traps and Egg and Larva Sampling in Lime

Apical leaf sampling and interception sticky traps were used to assess seasonal density for the citrus leafminer, Phyllocnistis citrella Stainton, adults and eggs plus early-instar larvae, respectively, in lime orchards. Traps intercepted greater numbers of adults when placed in the middle or top of the tree canopy than in the lower canopy. Citrus leafminer was most abundant in the spring, summer and fall, and numbers were reduced between November 1994 and January 1995. In 1994, adult capture and egg and larval density were higher than in 1995. The development of an efficient means to estimate citrus leafminer egg density or, alternatively, develop techniques to aid in prioritizing egg sampling was attempted. The probability of finding eggs in the vicinity of a passive interception trap was determined. A linear relationship was found between cumulative number of moths captured and citrus leafminer egg density (r² = 0.52). A lower variability was recorded for adult traps than for egg densities.