The palms are considered as the unofficial second flag of Dubrovnik, but the arrival of the palm weevil disease took a toll on a number of the palms in the whole Mediterranean area. The palm weevil known as Rhynchophorus ferrugineus has become the most hazardous pest of the date palm in the world leaving many infected palms almost impossible to cure. Damage to these palms is produced mainly by the larvae after the adult females lay eggs at the base of young leaves or in wounds to the leaves and trunks: the grubs feed on the soft fibers and terminal bud tissues. They move towards the interior of the palm making tunnels and large cavities. The infection of the palms is visible only after a long period from the first arrival of the larvae.
Recently the scientists from the Arboretum Trsteno have managed to cure one palm, but the pest still presents a problem since it is not sure if the cured palm can be easily infected again. A vast amount of research has been dedicated to it, but unfortunately no safe techniques for early detection of the pest have been devised.
Not all the palms placed next to the famed staircase designed by one of the greatest Croatian sculptors, Ivan Meštrović, are to be cut since the alpinists are still taking care of a few palms in the hope they will flourish again.
