Osservazioni sulla dinamica di popolazione di due cicaline ampelofaghe nella Sicilia occidentale

Observations on population dynamics of leafhoppers in Western Sicily vineyardsFrom 2007 to 2009 field observations were carried out in two vineyards (organically and conventionally managed) inMenfi (Agrigento province, Sicily). Population dynamics of two leafhoppers, Jacobiasca lybica (cotton leafhopper) andZygina rhamni were followed by chromotropic traps and leaf observation in field. Both species were constantly presentin vineyards. Z. rhamni did not register statistical differences between the two fields, while J. lybica was mostly presentin the conventionally managed field. In this vineyard for two consecutive years (2007 and 2008) J. lybica population exceededthe intervention threshold. On the other hand, in the organically managed vineyard the cotton leafhopper populationremained below the intervention threshold for all the observation period.