The red palm weevil threatens flora in Greece

So far only gardens and nurseries affected

By Nikos Thymakis (1)

An incursion that presumably began with the palm trees of doubtful quality and origins that were imported as part of projects for the 2004 Olympic Games in Athens first became apparent in November 2005.

That was when horticulturalist Dimitris Economou located the first unfamiliar insect in a palm tree in his garden at Hersonissos, Crete.

The intruder was identified as Rhynchophorus ferrugineus, or red palm weevil, by this writer in cooperation with Dimitris Kontodivas, entomologist at the Benaki Phytopathology Institute and secretary of the Greek Entomology Association.

The problem has since spread throughout Greece, affecting both palms in gardens and those produced in local nurseries.

The gravest threat posed by the insect is to the unique palm forest of Vai, which is listed in the Natura 2000 network and contains the last significant population of the Cretan date palm, Phoenix theophrasti, a native of Crete.

The red palm weevil comes from Central Asia and is considered to be the worst enemy of palms.

Of the palms found in the Mediterranean basin, those worst affected are the date palm (Phoenix dactylifera) and the Canary palm (Phoenix canariensis).

Experiments conducted at the Benaki Phytopathology Institute have shown that the beetle also destroys the Cretan date palm.

The red palm weevil larva, which is grayish-cream with a brownish head, infests the plant. The beetle, which bears marks that are deep orange to black, appears in the warm season.

Its life cycle is about three to four months, and in Greece the beetles have been observed flying from March to December.

In 2006, the red palm weevil was found in many places including Crete, Rhodes, Attica (Oropos and Hellenikon) and has very likely infested palms in other parts of the country.

The damage it has caused has worried not only producers and importers but also private businesses (mainly hoteliers who have planted lots of palms). The insect was also found on Cyprus last year.

The red palm weevil is not easy to find. In some countries people use sensitive microphones and earphones to track it down from the noise made by the caterpillar inside the tree trunk.

Scientists abroad are conducting research into ways of combating the insect by means of microorganisms that kill insects (nematodes, fungus and viruses as biological enemies). Such research is still in its infancy in Greece.

(1) Nikos Thymakis is a consultant agriculturalist and founding member of the Greek Society of Friends of Palms who has published widely on the subject of palms in Greece and the conservation of the Cretan palm (thymakis@-agroartistioco.com). This article first appeared in the July issue of Kathimerini's monthly supplement, Eco.