Evaluation of a lure efficiency towards green lacewings in organic apricot orchard.

摘要

Apricot is one of the least sensitive stone fruit to aphids, but infestations of the mealy plum aphid may commercially damage fruits ready to harvest. Management of aphid infestations in organic orchard should also consider enhancing beneficial insects and limiting aphid species hard to control (wax-protected aphids). Green lacewings management through lures should represent a potential way to enhance the efficiency of this generalist predator against aphids. To evaluate this strategy, tests were performed in the frame of the P.O.N. BRIMET project (cod. MIUR 12929), between 2005 and 2007, in organic orchards in Southern Italy, near Nova Siri Marina (MT). Experimental design was used to assess attractiveness of a mixture of phenylacetaldehyde, methylsalicylate and acetic acid, and to evaluate the influence on oviposition of green lacewings. The experimental field was parcelled out into two similar lots, one of which with the lure in the central area. Trials on apricot were compared to the results obtained in peach orchards of the Centro di Ricerca per la Frutticoltura, near Rome. Results prove the attractiveness of this chemical lure towards Chrysoperla carnea (Stephens), but with a slight increase of oviposition in the apricot parcel with tested substances through the years. Only in 2007 we could measure an evident increase of oviposition on apricot trees. Better results were achieved on peach orchard where we could notice a more complex entomofauna. On apricot, the aphid presence can be assumed as a key factor for lacewings oviposition, and the presence of this lure as a secondary factor for a higher oviposition rate. Further basic research on lacewings oviposition strategies are evidenced; moreover, an on-time application of lures upon the early symptoms of aphid infestations could represent the best application strategies to enhance natural population of lacewings on field.