Paysandisia archon or Barrenadota Caterpillar is a plague coming from the American South Cone that attacks the palms. The first references of their presence in Europe, in the Mediterranean coasts of Italy and France, date back from 4 or 5 years. The introduction had to imports of palms of rustic the Butia species yatay and Trithrinax coming from Argentina that contained this plague. With his gradual expansion of north to the south it arrived at Catalonia, where it was declared officially in May of 2002 and, later, in June of the same year, it was detected for the first time in the Valencian Community.

Main species of affected palms

In the Spanish Mediterranean coast, the most sensible species to this plague are Trachycarpus fortunei, Chamaerops humilis and Phoenix canariensis. However, also other species affected have been observed like: Romanzoffiana Syagrus, filifera Washingtonia, robust Washingtonia, reclinata Phoenix, Phoenix roebelenii, Livistona spp. or armata Brahea.

Therefore, given the cultural and economic importance of the palms in our community, this plague supposes an authentic threat, reason why we must eradicate it with all means to our reach.

Description of the insect

Paysandisia archon is a lepidóptero of the Castniidae family. Its biological cycle is annual, although in certain conditions it could be biennial. The adult is a butterfly (8-10 cm of spread) that makes the putting in the crown of the palm. The eggs are resembled a rice grain, of about 4-5 mm in length and of color ivory. When eclosionar, the larva looks for the most tender zones and begins to feed on the eye of the palm, being drilled a gallery by the interior of the trunk or estipe.

The larvaria phase can last between 11 and 21 months, after which the larva forms the cocoon with fibers of the own palm and crisálida to transform themselves into adult and to reinitiate the cycle.

Sintomatología and damages

The symptoms vary according to the affected species, being more easily reconocibles by the presence of orifices ready in form of fan in the leaves (produced by the larvae when the leaves still are inside the palm). Also, another appreciable symptom, sometimes at first, is the presence of rest of fiber compressed and hardened plugging the galleries made by the caterpillar.

Sometimes the trunk is narrowed and inclined slightly in the affected zone acquiring one more a darker tonality sometimes. However, the palms can not present/display the described sintomatología and have the plague, since as much the putting as the first larvarios stages can happen unnoticed.

Depending as large as the palm and on the number of caterpillars in their interior, these can get to cause the death of the plant.

Chemical fight

The good operation of the treatments with clorpirifos+dimetoato has been verified (although he is not authorized in dactylifera Phoenix destined to the production of dates). The treatments must be made to spurt on the crown of the palm and its trunk, dunking well so that the products can filter by the galleries and arrive until the larvae, that are the most vulnerable state of Paysandisia archon. The recommended periocidad is weekly for curativos treatments, and biweekly for preventive treatments.

Other means of fight

· Revision and exhaustive control of plants coming from countries or zones affected by the plague
· Immobilization of the games affected, enmallando them from May to October with the purpose of avoiding the flight of the adults and the programming of the plague.
· Destruction of the palms very affected by means of burns of the same ones.