Articles

A Gis-based cost distance approach to analyse the spread of Matsucoccus feytaudi in Tuscany, Italy (Coccoidea Matsucoccidae)


Abstract


The Maritime pine bast scale Matsucoccus feytaudi Ducasse was introduced into south-eastern France from the Atlantic regions and since then has moved eastward to reach Tuscany, Italy, causing decay and death of thousands of hectares of pine stands. Monitoring of the pine bast scale by pheromone traps in Tuscany since 2000 has allowed us to obtain yearly data on the pest’s diffusion. The data were processed by means of the Thiessen polygons algorithm to obtain the distribution of the insect. A GIS cost distance model was adopted to simulate the spread of M. feytaudi infestation: dominant winds were used in the least accumulative distance calculation, together with Pinus pinaster presence as secondary factor. The overall accuracy of the model calculated for the years 2003 to 2008 ranged between 70.0% and 81.8%; user’s and producer’s accuracy showed greater variability, but with good performances in the majority of cases. The use of pheromone traps and spatial analysis enabled to produce annual maps for the Tuscany, with the identification of the Maritime pine forests more susceptible to M. feytaudi colonization. This cartography was an important tool for regional offices in the identification of areas requiring direct forestry management.

Keywords

Pinus pinaster Aiton; non-indigenous insects; monitoring; spatial analysis; spread management

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