Pietro Luciano

Cork quality estimation by using Compton tomography

The quality control of cork stoppers is mandatory in order to guarantee the perfect conservation of the wine. Several techniques have been developed but until now the quality control was essentially related to the status of the external surface. Thus possible cracks or holes inside the stopper will be hidden. In this paper a new technique based on X-ray Compton tomography is described. It is a non-destructive technique that allows one to reconstruct and visualize the cross-section of the cork stopper analyzed, and so to put in evidence the presence of internal imperfections. Some results are reported and compared with visual classification.

Spatial analysis of gypsy moth populations in Sardinia using geostatistical and climate models

1 Spatial fluctuations of the Sardinian population of the gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae) were characterized using geostatistical and climate models. Data on gypsy moth egg mass abundance recorded at 282 permanent monitoring sites from 1980 to 2004 were incorporated in a geographic information system with the vegetational, geomorphological and pedological features of the sites. 2 Statistical analyses revealed that the relative outbreak frequency was related to the predominant host tree, slope and elevation of the monitoring sites, whereas there was no correlation between outbreak frequency and exposure and soil type. 3 By using bioclimatic modelling, probability maps of gypsy moth outbreaks were generated. The model identified a probability surface with climatic conditions favourable to gypsy moth outbreaks and thus potentially subject to defoliation. The maps included 92 sites where outbreaks never occurred, suggesting that the Sardinian climate may not be a determinant factor for gypsy moth outbreaks. 4 The geostatistical method cokriging with outbreak frequency as a covariate was found to be the most suitable technique to estimate gypsy moth egg mass abundance. Semivariograms showed spatial correlation of egg mass abundance within the range 18.5–53 km. The results obtained were used to create regional gypsy moth distribution maps by cokriging, which demonstrated the outbreak foci and different infestation levels at each monitoring area. These results can help to delimit the treatment areas and develop rational gypsy moth management programmes.

Different susceptibility of indigenous populations of Lymantria dispar to the exotic entomopathogen Entomophaga maimaiga

The recovery of the host‐specific entomopathogen Entomophaga maimaiga is still limited to certain world areas, although it is recently spreading to Eastern Europe. This study evaluated the effectiveness and fitness of an E. maimaiga isolate from Balkans against Lymantria dispar populations collected along the Italian peninsula and main islands, where the fungus has never been reported. As a result of different bioassays, the pathogenicity against gypsy moth larvae was generally confirmed, although significant differences among insects feeding upon diverse forest plant species were observed. The lack of significant susceptibility of other lepidopteran species from the same areas is also reported.

Occupancy of the territory by Lymantria dispar (L.) (Lepidoptera Erebidae) egg masses as a predictive index of damage

(*) Sezione di Patologia Vegetale ed Entomologia, Università degli Studi di Sassari, Viale Italia 39, 07100 Sassari, Italy (**) Istituto per lo Studio degli Ecosistemi, Consiglio Nazionale delle Ricerche, Traversa la Crucca 3, 07100 Sassari, Italy (***) Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy (°) Corresponding author: Roberto Mannu, e-mail: roberto.mannu@ise.cnr.it