Prospettive di lotta integrata nell'agrumicoltura sarda

Preliminary integrated control trials were performed in two fruit growing areas of Sardinia (Simaxis, Siniscola) in 1979. On the orange groves of SimaxisPlanococcus citri(Risso) is the most important phytophage, followed byPanonychus citriMc Gr. andDialeurodes citri(Ashm.). The indigenous natural enemies ofPlanococcus {Anagyrus pseudococciGrlt.,Leptomastidea abnormisGrlt.,Chrysopasp.,Chilocorus bipustulatus(L.)) andPanonychus(Stethorus punctillumWeiss,Amblyseius stipulatusA.H.) do not occur in sufficient number to limit infestation and it is therefore necessary to use chemical control with 2 treatments of white oil + methidathion and an acaricide (chlorfenson + propargil). This treatment has also contained infestation ofDialeurocleswhich is also actively preyed byClitostethus arcuatus(Rossi).Cryptolaemus montrouzieriMuls.,Leptomastix dactylopii(How.) andProspaltella lahorensis(How.) were introduced to improve the biological control ofPlalnococcusandDialeurodes.Ceratitis capitatais the most important phytophage or the clementine crop in Siniscola. Populations are monitoring with withe traps baited with trimedlure and reached a maximum of 150 males/trap/weck at the end or October. Three treatments with hait-spray (protein hydrolysate + Fenthion) proved insufficient to contain the infestation due to rain in September and October. In November, although 40% or fruits were punctured, only 2% contained live larvae. Heavy aphid infestations (particularlyAplzis citricolaV.d.G.) were recorded in June on around 50% of the shoots. One treatment with sclective aphicides stopped the infestation without influencing beneficial predators (mainly Coccinellids). For the orange cultures in Siniscola, bait-spray applications limited damage byCeratitisand no action was necessary against aphids, since infestations were small and the plants had low susceptibility. On the basis or these observations, for the different phytophages are proposed some sample methodologics and the relative intervention thresholds .