{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T09:18:14Z","timestamp":1772615894418,"version":"3.50.1"},"reference-count":89,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2020,9,25]],"date-time":"2020-09-25T00:00:00Z","timestamp":1600992000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010661","name":"Horizon 2020","doi-asserted-by":"publisher","award":["776045"],"award-info":[{"award-number":["776045"]}],"id":[{"id":"10.13039\/100010661","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Eucalyptus Longhorned Borers (ELB) are some of the most destructive pests in regions with Mediterranean climate. Low rainfall and extended dry summers cause stress in eucalyptus trees and facilitate ELB infestation. Due to the difficulty of monitoring the stands by traditional methods, remote sensing arises as an invaluable tool. The main goal of this study was to demonstrate the accuracy of unmanned aerial vehicle (UAV) multispectral imagery for detection and quantification of ELB damages in eucalyptus stands. To detect spatial damage, Otsu thresholding analysis was conducted with five imagery-derived vegetation indices (VIs) and classification accuracy was assessed. Treetops were calculated using the local maxima filter of a sliding window algorithm. Subsequently, large-scale mean-shift segmentation was performed to extract the crowns, and these were classified with random forest (RF). Forest density maps were produced with data obtained from RF classification. The normalized difference vegetation index (NDVI) presented the highest overall accuracy at 98.2% and 0.96 Kappa value. Random forest classification resulted in 98.5% accuracy and 0.94 Kappa value. The Otsu thresholding and random forest classification can be used by forest managers to assess the infestation. The aggregation of data offered by forest density maps can be a simple tool for supporting pest management.<\/jats:p>","DOI":"10.3390\/rs12193153","type":"journal-article","created":{"date-parts":[[2020,9,28]],"date-time":"2020-09-28T08:02:58Z","timestamp":1601280178000},"page":"3153","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":37,"title":["Detection of Longhorned Borer Attack and Assessment in Eucalyptus Plantations Using UAV Imagery"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2852-379X","authenticated-orcid":false,"given":"Andr\u00e9","family":"Duarte","sequence":"first","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"given":"Luis","family":"Acevedo-Mu\u00f1oz","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5042-8190","authenticated-orcid":false,"given":"Catarina I.","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"given":"Lu\u00eds","family":"Mota","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"given":"Alexandre","family":"Sarmento","sequence":"additional","affiliation":[{"name":"Terradrone, Av. E.U.A. N\u00ba 97, 12 Dto. Sala 03, 1700-167 Lisboa, Portugal"}]},{"given":"Margarida","family":"Silva","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"given":"S\u00e9rgio","family":"Fabres","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5606-7878","authenticated-orcid":false,"given":"Nuno","family":"Borralho","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. Francisco, Rua Jos\u00e9 Estev\u00e3o (EN 230-1), 3800-783 Aveiro, Portugal"}]},{"given":"Carlos","family":"Valente","sequence":"additional","affiliation":[{"name":"RAIZ\u2014Forest and Paper Research Institute, Quinta de S. 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