Seasonal Abundance and within tree Spatial Distribution of Phyllocnistis citrella (Lepidoptera: Gracillariidae).
[Jahreszeitliches Vorkommen und räumliche Verbreitung von Phyllocnistis citrella (Lepidoptera: Gracillariidae)]
Tsagkarakis, A. E.; Perdikis, D. CH.; Lykouressis, D. P.
The citrus leafminer (CLM)Phyllocnistis citrella Stainton 1856 is a widespread pest of citrus. This was a 2-yr study aimed to thoroughly investigate the seasonal population abundance and the within tree distribution of each CLM immature stage in citrus. The seasonal abundance of CLM was monitored by collecting young flush. Each sampled tree was divided into sampling quadrants (north, south, east and west), and two layers (0.5–1.5 m and 1.5–2.5 m) within each quadrant. The population fluctuation pattern indicates that, in the region of the study, CLM completes 4 or 5 overlapping generations annually. The peak population was recorded in October and November. Population densities were much higher in the low than the high strata of the trees, in the second year of the study. Among the different quadrants the CLM population was less frequently recorded in the west part of the trees. Furthermore, seasonality was indicated in the distribution of the pest on the trees. CLM was proved to select less frequently the western part of the trees in autumn, whereas in summer, no preference was recorded. The importance of these results in more effective management programs of this pest is discussed.