Within the Citrus Surveillance Plan for this campaign and as in previous years, we are sending you the data on the monitoring of the California Red Scale that we have obtained.

The maximum number of sensitive forms (N1+N2) is the optimum time for carrying out a phytosanitary treatment. This time can be predicted by monitoring three variables: the evolution of the California red scale life stages in a given plot, the number of male California red scales captured in that same plot, and the average thermal integral for this species in the nearest municipalities. The evolution of the percentages of California red scale life stages helps determine the optimum treatment time (N1+N2). The number of male captures helps detect the peak flight period, and the time elapsed between this flight and the next generation will depend on the temperature, and therefore, on the evolution of the thermal integral. The Thermal Integral indicates the number of degrees accumulated since January 1st of the current year that exceed the threshold temperature for development (for    Aonidiella aurantii = 11.7 ºC); it is expressed as degree-days, which are obtained as the difference between the average temperature and the threshold temperature, provided that the latter is exceeded, and being the value zero when the average temperature is less than the threshold.

The following shows the current situation of the California red scale in various representative locations within the citrus-growing area of the Valencian Community. For this purpose, the following has been represented in each of the locations:

1. The  evolution of stadium percentages of the California red louse.

2. The   Thermal integral for A. aurantii as an average of those obtained in the Agroclimatic Stations closest to the monitoring plot of stages provided by the Irrigation Technology Service of the Conselleria.

For more information: http://gipcitricos.ivia.es/seguimiento-piojo-rojo-de-california-2016.html