Population dynamics and the spread of Unaspis yanonensis (Kuwana) in Calabria.

The occurrence of Unaspis yanonensis (Kuwana) (Hemiptera: Diaspididae) in Calabria (southern Italy) poses a serious threat to citrus cultivation. A regional survey was performed to record information about its distribution in local citrus orchards. Field population dynamics were also studied. The arrowhead scale, U. yanonensis, was recorded in the two main citrus cultivation areas of Calabria. In the investigated environments U. yanonensis completed two generations per year; a typical bi-modal oviposition was recorded. The arrowhead scale overwintered as second-instar males and pre-ovipositing females.